Objective To study the current situation of China’s pharmacovigilance system,and to provide some suggestions for the improvement of related policies.Methods A policy modeling consistency(PMC)index model of pharmacovi...Objective To study the current situation of China’s pharmacovigilance system,and to provide some suggestions for the improvement of related policies.Methods A policy modeling consistency(PMC)index model of pharmacovigilance policy was constructed to quantitatively assess the samples of policies combining text mining.Then,the PMC surface was established to obtain the visualization results of China’s pharmacovigilance policy samples,and their shortcomings were clearly analyzed by comparison.Results and Conclusion Forty-one percent of China’s pharmacovigilance policies were rated as excellent,54%as acceptable,and the overall evaluation was acceptable.But there is still some room for improvement.On the whole,there are problems of insufficient policy synergy,lack of policy incentives and constraints,and incomplete coverage of policy functions.It is recommended that China’s pharmacovigilance policy system should be optimized by strengthening policy coordination,increasing policy incentives and constraints,and guiding multi-subjects to participate in coordination.These findings and recommendations can provide operational ideas for the system of China’s pharmacovigilance policy.展开更多
Weighting values for different habitat variables used in multi-factor habitat suitability index (HSI) modeling reflect the relative influences of different variables on distribution of fish species. Using the winter-s...Weighting values for different habitat variables used in multi-factor habitat suitability index (HSI) modeling reflect the relative influences of different variables on distribution of fish species. Using the winter-spring cohort of neon flying squid (Ommastrephes bartramii) in the Northwestern Pacific Ocean as an example, we evaluated the impact of different weighting schemes on the HSI models based on sea surface temperature, gradient of sea surface temperature and sea surface height. We compared differences in predicted fishing effort and HSI values resulting from different weighting. The weighting for different habitat variables could greatly influence HSI modeling and should be carefully done based on their relative importance in influencing the resource spatial distribution. Weighting in a multi-factor HSI model should be further studied and optimization methods should be developed to improve forecasting squid spatial distributions.展开更多
In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and i...In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different.展开更多
The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)fr...The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.展开更多
Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative e...Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative expression of the characteristics of planation surface plays a key role in reconstructing and describing the evolutionary process of landforms. In this study, Landform Planation Index(LPI), a new terrain derivative, was proposed to quantify the characteristics of planation surface. The LPIs were calculated based on the summit surfaces formed according to the clustering results of peaks. Ten typical areas in the Ordos Platform located in the central part of the Loess Plateau of China are chosen as the test areas for investigating their planation characteristics with the LPI. The experimental results indicate that the LPI can be effectively used to quantify the characteristics of planation surfaces. In addition, the LPI can be further used to depict the patterns of spatial differentiation in the Ordos Platform. Although the present Ordos Platform area is full of the high-density gullies, its planation characteristics is found to be well preserved. Furthermore, the characteristics of the planation surfaces can also reflect the original morphology of the Ordos Platform before the loess dusts deposition process evolved in this area. The statistical results of the LPI show that there is a gradually increasing tendency along with the increasing of slope gradient of summit surface. It indicates that the characteristics of planation surfaces vary among test areas with different landforms. These findings help to deepen the understanding of planation characteristics of the loess landform and its underlying paleotopography. Results of this study can be also served as an important theoretical reference value for revealing the evolutionary process of loess landform.展开更多
Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal a...Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers （op-amps）. The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup.展开更多
The limitations of several existing classical rock damage models were critically appraised. Thereafter, a description of a new model to estimate the response of rock was provided. The results of an investigation lead ...The limitations of several existing classical rock damage models were critically appraised. Thereafter, a description of a new model to estimate the response of rock was provided. The results of an investigation lead to the development and confirmation of a new index parabola damage model. The new model is divided into two parts, fictitious damage and real damage and bordered by the critical damage point. In fictitious damage, the damage variable follows the index distribution, while in the real damage a parabolic distribution is used. Thus, the so called index parabola damage model is derived. The proposed damage model is applied to simulate the damage procedure of marble under uni axial loading. The results of the tests show that the proposed model is in excellent agreement with experimental data, in particular the nonlinear characteristic of rock deformation is adequately represented. [展开更多
This paper presents a method for structured scene modeling using micro stereo vision system with large field of view. The proposed algorithm includes edge detection with Canny detector, line fitting with principle axi...This paper presents a method for structured scene modeling using micro stereo vision system with large field of view. The proposed algorithm includes edge detection with Canny detector, line fitting with principle axis based approach, finding corresponding lines using feature based matching method, and 3D line depth computation.展开更多
BACKGROUND： At present, suppurative meningitis is mainly treated through anti-infection with antibiotics, depressing encephalic pressure with mannitol , lowering body temperature with drugs , supporting treatment, et...BACKGROUND： At present, suppurative meningitis is mainly treated through anti-infection with antibiotics, depressing encephalic pressure with mannitol , lowering body temperature with drugs , supporting treatment, etc. However, Jt takes a long course of treatment and has poor therapeutic effect. Successive irrigation of subarachnoid cavity maybe have better effect on suppurative meningitis.OBJECTIVE： We compared the successive irrigation of subbarachnoid cavity with routine therapeutic methods to observe the effect of successive irrigation of subarachnoid cavity on the body temperature, cerebrospinal fluid pressure, the number of white blood cell and the level of protein of suppurative meningitis dogs. DESIGN： A randomized and controlled animal experiment SETTING： Institute of Neuroscience, Taihe Hospital Affiliated to Yunyang Medical College MATERIALS： Totally 17 healthy adult male Beagle dogs, of common grade, weighing 9 to 10 kg, were involved in the experiment, and raised in the 20 ℃ temperature with relative humidity of 50% for 1 week. They were randomized into 3 groups： normal group （n=5）, control group （n=5） and irrigation group （n=6）. Artificial cerebrospinal fluid was prepared according to the level of glucose and chloride of cerebrospinal fluid of normal dogs, and then it was sterilized with high pressure. METHODS ： This experiment was carried out in the experimental animal center of Yunyang Medical College from April to August 2001. ① After the dogs were anesthetized,1 mL fresh staphylococcus aureus liquid [（1.5-1.6）× 10^9 L 1] was injected into medullary cistern to establish suppurative meningitis models. ② After models were successfully established, intravenous drip infusion of 1.2 ×10^6 U/（kg.d）, muscular injection of sulfadiazine sodium of 100 mg/（kg.d ）and intravenous injection of 200 g/L mannitol of 5 g/（kg .time） for 3 times a day were performed in the control group. The irrigation of subarachnoid meningitis was conducted in the irrigation group besides the routine treatments in the control group： Artificial cerebrospinal fluid was successively injected into the epidural catheter in the waist part. The mixtures of artificial cerebrospinal fluid and inflammatory cerebrospinal fluid flowed out incessantly from epidural catheter of medullary cistern. Irrigation was ended 48 hours later. Dogs were routinely raised in the control group. ③ From the first day after being modeled to the 14^th day after treatment, the rectal temperatures were daily measured in the morning, at noon and in the evening respectively, then the mean temperatures were calculated. From the 2^nd day after being modeled to the 14^th day after treatment, puncture at waist was given once, and the cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured. MAIN OUTCOME MEASURES ： The body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured on suppurative meningitis model dogs. RESULTS＂ Totally 17 Beagle dogs were involved in this study.①The body temperatures of dogs were significantly reduced in the control group and in irrigation group on the 1^st day after treatment and lower than suppurative meningitis model dogs on the 2^nd day after being modeled （P 〈 0.05）. The body temperatures were gradually decreased in control group from the 2^nd day after being modeled to the 14^th day after treatment （P 〈 0.01）, but were significantly higher than those of dogs in normal group on the 14^th day after treatment （P 〈 0.05）. The body temperatures of dogs were gradually decreased in irrigation group on the 2^nd day or 3^rd day after treatment （P 〈 0.01） and then were close to the normal body temperature on the 14^th day after treatment. ②There was the same cerebrospinal fluid pressure in control group as in irrigation group on the 2^nd day after being modeled （P 〉 0.05）, but significantly decreased in two groups from the 1s＇ day or 2^nd day after treatment （P 〈 0.01）, and cerebrospinal fluid pressure was close to the normal level in irrigation group. Although the cerebrospinal fluid pressure raised a little on the 3^rd day or 4^th day after treatment in the irrigation group （P〈 0.05）, but recovered to the normal level on the 9^th day after treatment again. It decreased slowly in the control group and still was sig- nificantly higher than normal group on the 14^hd day after treatment （P〈 0.01 ）. ③No significant difference existed in number of white blood cell and the level of protein between control group and irrigation group on the 2^nd day following modeled. Both of them began to significantly decrease on the 1^st and 2^nd day after treatment （P 〈 0.01 ）. Although the number of white blood cell and the level of protein rebounded a little in irrigation group 3 or 4 days after treatment （P〈 0.05）, they were gradually decreased and recovered to normal levels on the 13^th day after treatment. The number of white blood cell and the level of protein slowly decreased in the control group compared with irrigation group and were still significantly higher than normal group on the 14^th day （P〈 0.01 ）. EONELUSEON ： Irrigation of subarachnoid cavity can decrease the body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein at early stage of suppurative meningitis, and the therapeutic effect is better than that of routine treatment.展开更多
Soil loss tolerance （/） is the maximum rate of annual soil erosion that is tolerated and still allows a high level of crop productivity to be sustained economically and indefinitely. In the black soil region of Nort...Soil loss tolerance （/） is the maximum rate of annual soil erosion that is tolerated and still allows a high level of crop productivity to be sustained economically and indefinitely. In the black soil region of Northeast China, an empirically determined, default Tvalue of 200 （t/km2.a） is used for designing land restoration strategies for different types of soils. The ob- jective of this study was to provide a methodology to calculate a quantitative T for different black soil species. A field investigation was conducted to determine the typical soil profiles of 21 black soil species in the study area and a quantitative methodology based on a modified soil productivity index model was established to calculate the Tvalues. These values, which varied from 68 t/km2.a to 358 t/km2-a, yielded an average Tvalue of 141 t/km2.a for the 21 soil species. This is 29.5% lower than the current national standard T value. Two significant factors that influenced the T value were soil thickness and vulnerability to erosion. An acceptable reduction rate of soil productivity over a planned time period of 1% is recommended as necessary for maintaining long-term sustainable soil productivity. Compared with the cur- rently used of regional unified standard T value, the proposed method, which determines T using specific soil profile indices, has more practical implications for effective, sustainable management of soil and water conservation.展开更多
The metropolitan resources comprehensive efficiencies （also called comprehensive technical efficiency, short for CTE, thereafter）, change trends and causes are investigated using DEA and Malmquist index models, resp...The metropolitan resources comprehensive efficiencies （also called comprehensive technical efficiency, short for CTE, thereafter）, change trends and causes are investigated using DEA and Malmquist index models, respectively, in China during the period 1990–2006. Firstly, the DEA model results show that the metropolitan CTE was just fair to middling with the characteristics of almost declining from the Eastern Coastal to Western China, and only few metropolises were DEA efficient. Secondly, the results also show that the PTE was correlated with the urban population sizes of metropolises negatively, and the SE correlated positively with the urban population sizes of metropolises in 1990, 2000 and 2006, that is, with urban population sizes getting larger the corresponding PTE was decreasing accordingly, and the SE was increasing consequently and the increasing rate was smaller with the scale increase. Thirdly, the influencing factors of metropolitan efficiency were SE and PTE in 1990 and 2000, respectively. But the PTE became the predominant influencing factor with the rapid expansions of built-up areas and population scales of metropolises in 2006. Fourthly, the Malmquist index results show that the CTE change trends were increasing weakly, the technological change trends were declining, and the TFP change trends were declining obviously during 1990–2006, in which they were all increasing during the sub-period 1990–2000, and all decreasing during the sub-period 2000–2006. Fifthly, the Malmquist index results also demonstrate that the CTE change trend was increasing weakly in the Eastern Coastal China, declining in Central China, and declining evidently in Western China. And with the urban population size increasing the increasing trends of SE became weaker and weaker. And the main causes for the CTE being not too high and its change trends and TFP change trends being increasing weakly lie mainly in the technological degeneracy and PTE change trends declining significantly during 2000–2006. Finally, the analyses show that the China’s metropolitan population boom and the rapid spread of built-up area had really caused their resources efficiency losses.展开更多
To determine whether ultrasound features can improve the diagnostic performance of tumor markers in distinguishing ovarian tumors,we enrolled 719 patients diagnosed as having ovarian tumors at Nanfang Hospital from Se...To determine whether ultrasound features can improve the diagnostic performance of tumor markers in distinguishing ovarian tumors,we enrolled 719 patients diagnosed as having ovarian tumors at Nanfang Hospital from September 2014 to November 2016.Age,menopausal status,histopathology,the International Federation of Gynecology and Obstetrics(FIGO)stages,tumor biomarker levels,and detailed ultrasound reports of patients were collected.The area under the curve(AUC),sensitivity,and specificity of the bellow-mentioned predictors were analyzed using the receiver operating characteristic curve.Of the 719 patients,531 had benign lesions,119 had epithelial ovarian cancers(EOC),44 had borderline ovarian tumors(BOT),and 25 had non-EOC.AUCs and the sensitivity of cancer antigen 125(CAI25),human epididymis-specific protein 4(HE4),Risk of Ovarian Malignancy Algorithm(ROMA),Risk of Malignancy Index(RMI1),HE4 model,and Rajavithi-Ovarian Cancer Predictive Score(R-OPS)in the overall population were 0.792,0.854,0.856,0.872,0.893,0.852,and 70.2%,56.9%,69.1%,60.6%,77.1%,71.3%,respectively.For distinguishing EOC from benign tumors,the AUCs and sensitivity of the above mentioned predictors were 0.888,0.946,0.947,0.949,0.967,0.966,and 84.0%,79.8%,87.4%,84.9%,90.8%,89.1%,respectively.Their specificity in predicting benign diseases was 72.9%,94.4%,87.6%,95.9%,86.3%,90.8%,respectively.Therefore,we consider biomarkers in combination with ultrasound features may improve the diagnostic performance in distinguishing malignant from benign ovarian tumors.展开更多
Perfluorinated or polyfluorinated compounds(PFCs)continue entering to the environmental as individuals or mixtures,but their toxicological information remains largely unknown.Here,we investigated the toxic effects and...Perfluorinated or polyfluorinated compounds(PFCs)continue entering to the environmental as individuals or mixtures,but their toxicological information remains largely unknown.Here,we investigated the toxic effects and ecological risks of Perfluorooctane sulfonic acid(PFOS)and its substitutes on prokaryotes(Chlorella vulgaris)and eukaryotes(Microcystis aeruginosa).Based on the calculated EC50 values,the results showed that PFOS was significantly more toxic to both algae than its alternatives including Perfluorobutane sulfonic acid(PFBS)and 6:2 Fluoromodulated sulfonates(6:2 FTS),and the PFOS-PFBS mixture was more toxic to both algae than the other two PFC mixtures.The action mode of binary PFC mixtures on Chlorella vulgaris was mainly shown as antagonistic and on Microcystis aeruginosa as synergistic,by using Combination index(CI)model coupled with Monte Carlo simulation.The mean risk quotient(RQ)value of three individual PFCs and their mixtures were all below the threshold of 10^(−1),but the risk of those binary mixtures were higher than that of PFCs individually because of their synergistic effect.Our findings contribute to enhance the understanding of the toxicological information and ecological risks of emerging PFCs and provide a scientific basis for their pollution control.展开更多
Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low tim...Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low time efficiency. This paper presents two new methods with high efficiency to build a Content-based 3D model retrieval system. First, an improvement is made on the ＂Shape Distribution （D2）＂ algorithm, and a new algorithm named ＂Quick D2＂ is proposed. Four sample 3D mechanical models are used in an experiment to compare the time cost of the two algorithms. The result indicates that the time cost of Quick D2 is much lower than that of D2, while the descriptors extracted by the two algorithms are almost the same. Second, an expandable 3D model repository index method with high performance, namely, RBK index, is presented. On the basis of RBK index, the search space is pruned effectively during the search process, leading to a speed up of the whole system. The factors that influence the values of the key parameters of RBK index are discussed and an experimental method to find the optimal values of the key parameters is given. Finally, ＂3D Searcher＂, a content-based 3D model retrieval system is developed. By using the methods proposed, the time cost for the system to respond one query online is reduced by 75% on average. The system has been implemented in a manufacturing enterprise, and practical query examples during a case of the automobile rear axle design are also shown. The research method presented shows a new research perspective and can effectively improve the content-based 3D model retrieval efficiency.展开更多
As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China betw...As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China between 2003 and 2017,this paper considers the dynamic spatio-temporal characteristics of industrial SO_(2) emissions in the"2+26"in North China and extended cities in North China and decomposes the determinants of industrial SO_(2) emissions into eight effects using the Generalized Divisia Index Model(GDIM).The contributions of each effect on changes in emissions are assessed on regional,provincial,and prefectural levels,as well as according to various stages.The results indicate the following.First,industrial SO2 emissions in the"2+26"cities in North China and extended cities in North China exhibit spatial autocorrelation and agglomeration effects.Cities with high-high(HH)and low-low(LL)agglomeration patterns were concentrated in Shanxi and Henan provinces,respectively.Second,industrialization,energy consumption,and economic development were the main factors that increased industrial SO2 emissions,while technology,energy sulfur intensity,and economic sulfur intensity were the key factors that reduced them.Third,13 cities,induding Tangshan,were the most important regions where further emissions regulations need to be implemented.These cities were divided into three types and different corresponding measures for reducing their emissions are suggested.Based on the conclusions of this study,this paper puts forward some targeted policy recommendations for reducing industrial SO_(2) emissions according to different categories of cities.展开更多
We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of imp...We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of importance,are Secchi depth,sediment composition,water temperature,salinity,current velocity,water depth and nutrient quality. Specific factor piecewise functions have been used to transform parameter values into normalized quality indexes. The weight of each factor was defined using expert knowledge and the analytic hierarchy process(AHP) method. All of the data thus obtained were interpolated using the inverse distance weighted(IDW) interpolation method to create maps for the entire region. In this study,the analysis of habitat suitability in the subtidal zone of Xiaoheishan Island was conducted for four seasons. According to the GIS-based HSI model,the optimal habitat of Z ostera marina L. appears in spring,although habitat remains suitable all year round. On the whole,the optimum site for eelgrass restoration is located in the eastern region,followed by the western and southern regions. We believe that the GIS-based HSI model could be a promising tool to select sites for Z ostera marina L. restoration and could also be applicable in other types of habitat evaluation.展开更多
This paper gives a detailed introduction to the biotic resources in Panxi Area and lists the most typical biotic resources in this area. The authors of this paper adopt the biotic resource abundance evaluation index m...This paper gives a detailed introduction to the biotic resources in Panxi Area and lists the most typical biotic resources in this area. The authors of this paper adopt the biotic resource abundance evaluation index model R1= （S0t -- S1t ） × S1i-1 （i= 1,2,3, …n） to make a quantitative calculation of the biotic resource abundance in this area, and the calculation results show that this area abounds in biotic resources. Through the analysis of the causes of abundant biotic resources in this area, the luxuriant biotic resources in Panxi Area are largely attributed to the complex and varied environment, atrocious climate in history and the introduction of alien species. The purpose of this paper is to point out that biotic resource exploitation is one of the driving forces of economic development in this area, and to emphasize the necessity of biotic resource preservation and its harmonious development with the environment.展开更多
Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carb...Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index（LMDI） model. The main conclusions are as follows： 1） Total anthropogenic carbon emission of Nanjing increased from 1.22928 ×10^7 t in 2000 to 3.06939 × 10^7 t in 2009, in which the carbon emission of Inhabitation, mining ＆ manufacturing land accounted for 93% of the total. 2） The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining ＆ manufacturing land was the highest（200.52 t/ha）, which was much higher than that of other land use types. 3） The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity（2.83 t/ha） in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4） Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5） Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development.展开更多
To evaluate urban human settlement, we propose a human settlement environment development index(HSEDI) model by choosing vegetation coverage, land surface temperature, impervious surfaces, slope, wetness, and water co...To evaluate urban human settlement, we propose a human settlement environment development index(HSEDI) model by choosing vegetation coverage, land surface temperature, impervious surfaces, slope, wetness, and water condition as the evaluation factors. We applied the proposed model to Xuzhou City, Jiangsu Province, China. Landsat-5 Thematic Mapper(TM) images from 1998 to 2010 and digital elevation model(DEM) data with a 30-m resolution were used to calculate the values of the six evaluation factors. The HSEDI value in Xuzhou City was found to be between 2.24 and 8.10 from 1998 to 2010, and it was further divided into five levels, uninhabitable, moderately uninhabitable, generally inhabitable, moderately inhabitable, and inhabitable. The best HSEDI value was in 2007. The generally inhabitable region was about 100.98 km^2, covering 30.87% of the total area in 2007; the moderately inhabitable region was about 170.58 km2 covering 52.15% of the total area; the inhabitable region was about 32.03 km^2, covering 9.79% of the total area; the percentage of the uninhabitable region was zero; and that of the moderately uninhabitable region was very small, less than 1.00%. Moreover, we analyzed the habitability in the respect of spatial patterns and change detection. Results show that the degraded regions of habitability quality are mainly located in the urban fringe and the improved regions are mainly located in the main urban and rural areas. Reason for the degraded habitability quality is the rapid progress of urbanization. However, the increase in urban green spaces and the construction of the main urban area promoted the improved habitability quality. Besides, we further analyzed socio-economic and socio-demographic data to confirm the results of the habitability analysis. The results indicate that the human settlement in Xuzhou City is in a satisfactory condition, but some efforts should be made to control the possible uninhabitable and moderately uninhabitable regions, and to improve the quality of the generally inhabitable regions.展开更多
Surface plasmon resonance of noble metal nanoparticles leads to the optical absorption enhancement effects,which have great potential applications in solar cell.By using the general numerical method of discrete dipole...Surface plasmon resonance of noble metal nanoparticles leads to the optical absorption enhancement effects,which have great potential applications in solar cell.By using the general numerical method of discrete dipole approximation （DDA）,we study the absorption and scattering properties of two-dimensional square silver nanodisks （2D SSN） arrays on the single crystal silicon solar cell.Based on the effective reflective index model of the single crystal silicon solar cell,we investigate the optical enhancement absorption of light energy by varying the light incident direction,particle size,aspect ratio,and interparticle spacing of the silver nanodisks.The peak values and position of the optical extinction spectra of the 2D square arrays of noble metal nanodisks are obtained with the different array structures.展开更多
文摘Objective To study the current situation of China’s pharmacovigilance system,and to provide some suggestions for the improvement of related policies.Methods A policy modeling consistency(PMC)index model of pharmacovigilance policy was constructed to quantitatively assess the samples of policies combining text mining.Then,the PMC surface was established to obtain the visualization results of China’s pharmacovigilance policy samples,and their shortcomings were clearly analyzed by comparison.Results and Conclusion Forty-one percent of China’s pharmacovigilance policies were rated as excellent,54%as acceptable,and the overall evaluation was acceptable.But there is still some room for improvement.On the whole,there are problems of insufficient policy synergy,lack of policy incentives and constraints,and incomplete coverage of policy functions.It is recommended that China’s pharmacovigilance policy system should be optimized by strengthening policy coordination,increasing policy incentives and constraints,and guiding multi-subjects to participate in coordination.These findings and recommendations can provide operational ideas for the system of China’s pharmacovigilance policy.
基金supported by the National 863 project (2007AA092201 2007AA092202)+4 种基金National Development and Reform Commission Project (2060403)"Shu Guang" Project (08GG14) from Shanghai Municipal Education CommissionShanghai Leading Academic Discipline Project (Project S30702)supported by the National Distantwater Fisheries Engineering Research Center, and Scientific Observing and Experimental Station of Oceanic Fishery Resources, Ministry of Agriculture, ChinaYong Chen’s involvement in the project was supported by the Shanghai Dongfang Scholar Program
文摘Weighting values for different habitat variables used in multi-factor habitat suitability index (HSI) modeling reflect the relative influences of different variables on distribution of fish species. Using the winter-spring cohort of neon flying squid (Ommastrephes bartramii) in the Northwestern Pacific Ocean as an example, we evaluated the impact of different weighting schemes on the HSI models based on sea surface temperature, gradient of sea surface temperature and sea surface height. We compared differences in predicted fishing effort and HSI values resulting from different weighting. The weighting for different habitat variables could greatly influence HSI modeling and should be carefully done based on their relative importance in influencing the resource spatial distribution. Weighting in a multi-factor HSI model should be further studied and optimization methods should be developed to improve forecasting squid spatial distributions.
文摘In order to compare the aviation network of mid-south,northwest and southwest of China to reveal the structure similarity and difference for providing quantitative evidence to construct regional aviation network and improve its structure,hierarchical index model of regional aviation network was established through dividing the aviation network into layers to research its structure characters.Data matrixes were defined to record the basic state of regional aviation network.Index matrixes were constructed to describe the quantitative features of regional aviation network.On the basis of these indexes,several structure indexes of all layers of aviation network were calculated to show the structure features of aviation network,such as ratio of passenger volume within the region with across the region,share rate of passenger volume among layers,ratio of average number of airline for each airport,ratio of average passenger volume for each airline and ratio of airline rate.According to the statistical data,similar structure of share rate of passenger volume among layers and average passenger volume for each airline in their regional aviation network was found after calculating.But on the side of ratio of passenger volume within the region with across the region,ratio of average number of airlines for each airport and ratio of airline rate were different.
基金The National Key R&D Program of China under contract Nos 2019YFD0901401 and 2019YFD0901404the National Natural Science Foundation of China under contract No.NSFC41876141+1 种基金the Shanghai Science and Technology Innovation Program under contract No.19DZ1207502the Construction and Application of Natural Resources Satellite Remote Sensing Technology System under contract No.202101004。
文摘The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.
基金Under the auspices of National Natural Science Foundation of China(No.41201464,41471316)Priority Academic Program Development of Jiangsu Higher Education Institutions(No.164320H101)
文摘Planation surface, a surface that is almost flat, is a kind of low-relief landforms. Planation surface is the consequence of the denudation and planation processes under a tectonic stable condition. The quantitative expression of the characteristics of planation surface plays a key role in reconstructing and describing the evolutionary process of landforms. In this study, Landform Planation Index(LPI), a new terrain derivative, was proposed to quantify the characteristics of planation surface. The LPIs were calculated based on the summit surfaces formed according to the clustering results of peaks. Ten typical areas in the Ordos Platform located in the central part of the Loess Plateau of China are chosen as the test areas for investigating their planation characteristics with the LPI. The experimental results indicate that the LPI can be effectively used to quantify the characteristics of planation surfaces. In addition, the LPI can be further used to depict the patterns of spatial differentiation in the Ordos Platform. Although the present Ordos Platform area is full of the high-density gullies, its planation characteristics is found to be well preserved. Furthermore, the characteristics of the planation surfaces can also reflect the original morphology of the Ordos Platform before the loess dusts deposition process evolved in this area. The statistical results of the LPI show that there is a gradually increasing tendency along with the increasing of slope gradient of summit surface. It indicates that the characteristics of planation surfaces vary among test areas with different landforms. These findings help to deepen the understanding of planation characteristics of the loess landform and its underlying paleotopography. Results of this study can be also served as an important theoretical reference value for revealing the evolutionary process of loess landform.
文摘Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers （op-amps）. The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup.
文摘The limitations of several existing classical rock damage models were critically appraised. Thereafter, a description of a new model to estimate the response of rock was provided. The results of an investigation lead to the development and confirmation of a new index parabola damage model. The new model is divided into two parts, fictitious damage and real damage and bordered by the critical damage point. In fictitious damage, the damage variable follows the index distribution, while in the real damage a parabolic distribution is used. Thus, the so called index parabola damage model is derived. The proposed damage model is applied to simulate the damage procedure of marble under uni axial loading. The results of the tests show that the proposed model is in excellent agreement with experimental data, in particular the nonlinear characteristic of rock deformation is adequately represented. [
文摘This paper presents a method for structured scene modeling using micro stereo vision system with large field of view. The proposed algorithm includes edge detection with Canny detector, line fitting with principle axis based approach, finding corresponding lines using feature based matching method, and 3D line depth computation.
文摘BACKGROUND： At present, suppurative meningitis is mainly treated through anti-infection with antibiotics, depressing encephalic pressure with mannitol , lowering body temperature with drugs , supporting treatment, etc. However, Jt takes a long course of treatment and has poor therapeutic effect. Successive irrigation of subarachnoid cavity maybe have better effect on suppurative meningitis.OBJECTIVE： We compared the successive irrigation of subbarachnoid cavity with routine therapeutic methods to observe the effect of successive irrigation of subarachnoid cavity on the body temperature, cerebrospinal fluid pressure, the number of white blood cell and the level of protein of suppurative meningitis dogs. DESIGN： A randomized and controlled animal experiment SETTING： Institute of Neuroscience, Taihe Hospital Affiliated to Yunyang Medical College MATERIALS： Totally 17 healthy adult male Beagle dogs, of common grade, weighing 9 to 10 kg, were involved in the experiment, and raised in the 20 ℃ temperature with relative humidity of 50% for 1 week. They were randomized into 3 groups： normal group （n=5）, control group （n=5） and irrigation group （n=6）. Artificial cerebrospinal fluid was prepared according to the level of glucose and chloride of cerebrospinal fluid of normal dogs, and then it was sterilized with high pressure. METHODS ： This experiment was carried out in the experimental animal center of Yunyang Medical College from April to August 2001. ① After the dogs were anesthetized,1 mL fresh staphylococcus aureus liquid [（1.5-1.6）× 10^9 L 1] was injected into medullary cistern to establish suppurative meningitis models. ② After models were successfully established, intravenous drip infusion of 1.2 ×10^6 U/（kg.d）, muscular injection of sulfadiazine sodium of 100 mg/（kg.d ）and intravenous injection of 200 g/L mannitol of 5 g/（kg .time） for 3 times a day were performed in the control group. The irrigation of subarachnoid meningitis was conducted in the irrigation group besides the routine treatments in the control group： Artificial cerebrospinal fluid was successively injected into the epidural catheter in the waist part. The mixtures of artificial cerebrospinal fluid and inflammatory cerebrospinal fluid flowed out incessantly from epidural catheter of medullary cistern. Irrigation was ended 48 hours later. Dogs were routinely raised in the control group. ③ From the first day after being modeled to the 14^th day after treatment, the rectal temperatures were daily measured in the morning, at noon and in the evening respectively, then the mean temperatures were calculated. From the 2^nd day after being modeled to the 14^th day after treatment, puncture at waist was given once, and the cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured. MAIN OUTCOME MEASURES ： The body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured on suppurative meningitis model dogs. RESULTS＂ Totally 17 Beagle dogs were involved in this study.①The body temperatures of dogs were significantly reduced in the control group and in irrigation group on the 1^st day after treatment and lower than suppurative meningitis model dogs on the 2^nd day after being modeled （P 〈 0.05）. The body temperatures were gradually decreased in control group from the 2^nd day after being modeled to the 14^th day after treatment （P 〈 0.01）, but were significantly higher than those of dogs in normal group on the 14^th day after treatment （P 〈 0.05）. The body temperatures of dogs were gradually decreased in irrigation group on the 2^nd day or 3^rd day after treatment （P 〈 0.01） and then were close to the normal body temperature on the 14^th day after treatment. ②There was the same cerebrospinal fluid pressure in control group as in irrigation group on the 2^nd day after being modeled （P 〉 0.05）, but significantly decreased in two groups from the 1s＇ day or 2^nd day after treatment （P 〈 0.01）, and cerebrospinal fluid pressure was close to the normal level in irrigation group. Although the cerebrospinal fluid pressure raised a little on the 3^rd day or 4^th day after treatment in the irrigation group （P〈 0.05）, but recovered to the normal level on the 9^th day after treatment again. It decreased slowly in the control group and still was sig- nificantly higher than normal group on the 14^hd day after treatment （P〈 0.01 ）. ③No significant difference existed in number of white blood cell and the level of protein between control group and irrigation group on the 2^nd day following modeled. Both of them began to significantly decrease on the 1^st and 2^nd day after treatment （P 〈 0.01 ）. Although the number of white blood cell and the level of protein rebounded a little in irrigation group 3 or 4 days after treatment （P〈 0.05）, they were gradually decreased and recovered to normal levels on the 13^th day after treatment. The number of white blood cell and the level of protein slowly decreased in the control group compared with irrigation group and were still significantly higher than normal group on the 14^th day （P〈 0.01 ）. EONELUSEON ： Irrigation of subarachnoid cavity can decrease the body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein at early stage of suppurative meningitis, and the therapeutic effect is better than that of routine treatment.
基金Foundation： National Natural Science Foundation of China, No.40671111 No.41101267 Nonprofit Sector Special Funds of the Ministry of Water Resources of China, No.2010332030
文摘Soil loss tolerance （/） is the maximum rate of annual soil erosion that is tolerated and still allows a high level of crop productivity to be sustained economically and indefinitely. In the black soil region of Northeast China, an empirically determined, default Tvalue of 200 （t/km2.a） is used for designing land restoration strategies for different types of soils. The ob- jective of this study was to provide a methodology to calculate a quantitative T for different black soil species. A field investigation was conducted to determine the typical soil profiles of 21 black soil species in the study area and a quantitative methodology based on a modified soil productivity index model was established to calculate the Tvalues. These values, which varied from 68 t/km2.a to 358 t/km2-a, yielded an average Tvalue of 141 t/km2.a for the 21 soil species. This is 29.5% lower than the current national standard T value. Two significant factors that influenced the T value were soil thickness and vulnerability to erosion. An acceptable reduction rate of soil productivity over a planned time period of 1% is recommended as necessary for maintaining long-term sustainable soil productivity. Compared with the cur- rently used of regional unified standard T value, the proposed method, which determines T using specific soil profile indices, has more practical implications for effective, sustainable management of soil and water conservation.
基金National Natural Science Foundation of China No.40671054 No.40635026
文摘The metropolitan resources comprehensive efficiencies （also called comprehensive technical efficiency, short for CTE, thereafter）, change trends and causes are investigated using DEA and Malmquist index models, respectively, in China during the period 1990–2006. Firstly, the DEA model results show that the metropolitan CTE was just fair to middling with the characteristics of almost declining from the Eastern Coastal to Western China, and only few metropolises were DEA efficient. Secondly, the results also show that the PTE was correlated with the urban population sizes of metropolises negatively, and the SE correlated positively with the urban population sizes of metropolises in 1990, 2000 and 2006, that is, with urban population sizes getting larger the corresponding PTE was decreasing accordingly, and the SE was increasing consequently and the increasing rate was smaller with the scale increase. Thirdly, the influencing factors of metropolitan efficiency were SE and PTE in 1990 and 2000, respectively. But the PTE became the predominant influencing factor with the rapid expansions of built-up areas and population scales of metropolises in 2006. Fourthly, the Malmquist index results show that the CTE change trends were increasing weakly, the technological change trends were declining, and the TFP change trends were declining obviously during 1990–2006, in which they were all increasing during the sub-period 1990–2000, and all decreasing during the sub-period 2000–2006. Fifthly, the Malmquist index results also demonstrate that the CTE change trend was increasing weakly in the Eastern Coastal China, declining in Central China, and declining evidently in Western China. And with the urban population size increasing the increasing trends of SE became weaker and weaker. And the main causes for the CTE being not too high and its change trends and TFP change trends being increasing weakly lie mainly in the technological degeneracy and PTE change trends declining significantly during 2000–2006. Finally, the analyses show that the China’s metropolitan population boom and the rapid spread of built-up area had really caused their resources efficiency losses.
基金grants from Guangdong Science and Technology Department of China(No.2016A020215115)Science and Technology Bureau of Tianhe District,Guangzhou,Guangdong(No.201604KW010)Science and Technology Bureau of Huadu District,Guangzhou,Guangdong(No.HD15CXY006).
文摘To determine whether ultrasound features can improve the diagnostic performance of tumor markers in distinguishing ovarian tumors,we enrolled 719 patients diagnosed as having ovarian tumors at Nanfang Hospital from September 2014 to November 2016.Age,menopausal status,histopathology,the International Federation of Gynecology and Obstetrics(FIGO)stages,tumor biomarker levels,and detailed ultrasound reports of patients were collected.The area under the curve(AUC),sensitivity,and specificity of the bellow-mentioned predictors were analyzed using the receiver operating characteristic curve.Of the 719 patients,531 had benign lesions,119 had epithelial ovarian cancers(EOC),44 had borderline ovarian tumors(BOT),and 25 had non-EOC.AUCs and the sensitivity of cancer antigen 125(CAI25),human epididymis-specific protein 4(HE4),Risk of Ovarian Malignancy Algorithm(ROMA),Risk of Malignancy Index(RMI1),HE4 model,and Rajavithi-Ovarian Cancer Predictive Score(R-OPS)in the overall population were 0.792,0.854,0.856,0.872,0.893,0.852,and 70.2%,56.9%,69.1%,60.6%,77.1%,71.3%,respectively.For distinguishing EOC from benign tumors,the AUCs and sensitivity of the above mentioned predictors were 0.888,0.946,0.947,0.949,0.967,0.966,and 84.0%,79.8%,87.4%,84.9%,90.8%,89.1%,respectively.Their specificity in predicting benign diseases was 72.9%,94.4%,87.6%,95.9%,86.3%,90.8%,respectively.Therefore,we consider biomarkers in combination with ultrasound features may improve the diagnostic performance in distinguishing malignant from benign ovarian tumors.
基金supported by the National Key Research and Development Program of China(No.2018YFC1407501)the Key Laboratory Open Fund of Fishery Ecology Environment,Ministry of Agriculture,China.
文摘Perfluorinated or polyfluorinated compounds(PFCs)continue entering to the environmental as individuals or mixtures,but their toxicological information remains largely unknown.Here,we investigated the toxic effects and ecological risks of Perfluorooctane sulfonic acid(PFOS)and its substitutes on prokaryotes(Chlorella vulgaris)and eukaryotes(Microcystis aeruginosa).Based on the calculated EC50 values,the results showed that PFOS was significantly more toxic to both algae than its alternatives including Perfluorobutane sulfonic acid(PFBS)and 6:2 Fluoromodulated sulfonates(6:2 FTS),and the PFOS-PFBS mixture was more toxic to both algae than the other two PFC mixtures.The action mode of binary PFC mixtures on Chlorella vulgaris was mainly shown as antagonistic and on Microcystis aeruginosa as synergistic,by using Combination index(CI)model coupled with Monte Carlo simulation.The mean risk quotient(RQ)value of three individual PFCs and their mixtures were all below the threshold of 10^(−1),but the risk of those binary mixtures were higher than that of PFCs individually because of their synergistic effect.Our findings contribute to enhance the understanding of the toxicological information and ecological risks of emerging PFCs and provide a scientific basis for their pollution control.
基金supported by National Natural Science Foundation of China(Grant No. 51175287)National Science and Technology Major Project(Grant No. 2011ZX02403)
文摘Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low time efficiency. This paper presents two new methods with high efficiency to build a Content-based 3D model retrieval system. First, an improvement is made on the ＂Shape Distribution （D2）＂ algorithm, and a new algorithm named ＂Quick D2＂ is proposed. Four sample 3D mechanical models are used in an experiment to compare the time cost of the two algorithms. The result indicates that the time cost of Quick D2 is much lower than that of D2, while the descriptors extracted by the two algorithms are almost the same. Second, an expandable 3D model repository index method with high performance, namely, RBK index, is presented. On the basis of RBK index, the search space is pruned effectively during the search process, leading to a speed up of the whole system. The factors that influence the values of the key parameters of RBK index are discussed and an experimental method to find the optimal values of the key parameters is given. Finally, ＂3D Searcher＂, a content-based 3D model retrieval system is developed. By using the methods proposed, the time cost for the system to respond one query online is reduced by 75% on average. The system has been implemented in a manufacturing enterprise, and practical query examples during a case of the automobile rear axle design are also shown. The research method presented shows a new research perspective and can effectively improve the content-based 3D model retrieval efficiency.
基金the financial support from the National Natural Science Foundation of China[Grant number.72074183,Grant number.71403120]the Humanities and Social Science Foundation of Chinese Ministry of Education[Grant number.20YJC630104]+1 种基金the National Social Science Foundation of China[Grant number.18ZDA052]the Fundamental Research Funds for the Central Universities[Grant number.JBK2007186].
文摘As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China between 2003 and 2017,this paper considers the dynamic spatio-temporal characteristics of industrial SO_(2) emissions in the"2+26"in North China and extended cities in North China and decomposes the determinants of industrial SO_(2) emissions into eight effects using the Generalized Divisia Index Model(GDIM).The contributions of each effect on changes in emissions are assessed on regional,provincial,and prefectural levels,as well as according to various stages.The results indicate the following.First,industrial SO2 emissions in the"2+26"cities in North China and extended cities in North China exhibit spatial autocorrelation and agglomeration effects.Cities with high-high(HH)and low-low(LL)agglomeration patterns were concentrated in Shanxi and Henan provinces,respectively.Second,industrialization,energy consumption,and economic development were the main factors that increased industrial SO2 emissions,while technology,energy sulfur intensity,and economic sulfur intensity were the key factors that reduced them.Third,13 cities,induding Tangshan,were the most important regions where further emissions regulations need to be implemented.These cities were divided into three types and different corresponding measures for reducing their emissions are suggested.Based on the conclusions of this study,this paper puts forward some targeted policy recommendations for reducing industrial SO_(2) emissions according to different categories of cities.
基金Supported by the Key Laboratory of Marine Ecology and Environmental Science and Engineering,SOA(No.MESE-2013-01)the National Natural Science Foundation of China(No.41206102)the National Marine Public Welfare Research Project(No.201305009)
文摘We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of importance,are Secchi depth,sediment composition,water temperature,salinity,current velocity,water depth and nutrient quality. Specific factor piecewise functions have been used to transform parameter values into normalized quality indexes. The weight of each factor was defined using expert knowledge and the analytic hierarchy process(AHP) method. All of the data thus obtained were interpolated using the inverse distance weighted(IDW) interpolation method to create maps for the entire region. In this study,the analysis of habitat suitability in the subtidal zone of Xiaoheishan Island was conducted for four seasons. According to the GIS-based HSI model,the optimal habitat of Z ostera marina L. appears in spring,although habitat remains suitable all year round. On the whole,the optimum site for eelgrass restoration is located in the eastern region,followed by the western and southern regions. We believe that the GIS-based HSI model could be a promising tool to select sites for Z ostera marina L. restoration and could also be applicable in other types of habitat evaluation.
文摘This paper gives a detailed introduction to the biotic resources in Panxi Area and lists the most typical biotic resources in this area. The authors of this paper adopt the biotic resource abundance evaluation index model R1= （S0t -- S1t ） × S1i-1 （i= 1,2,3, …n） to make a quantitative calculation of the biotic resource abundance in this area, and the calculation results show that this area abounds in biotic resources. Through the analysis of the causes of abundant biotic resources in this area, the luxuriant biotic resources in Panxi Area are largely attributed to the complex and varied environment, atrocious climate in history and the introduction of alien species. The purpose of this paper is to point out that biotic resource exploitation is one of the driving forces of economic development in this area, and to emphasize the necessity of biotic resource preservation and its harmonious development with the environment.
基金Under the auspices of National Natural Science Foundation of China(No.41301633)National Social Science Foundation of China(No.10ZD&030)+1 种基金Postdoctoral Science Foundation of China(No.2012M511243,2013T60518)Clean Development Mechanism Foundation of China(No.1214073,2012065)
文摘Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index（LMDI） model. The main conclusions are as follows： 1） Total anthropogenic carbon emission of Nanjing increased from 1.22928 ×10^7 t in 2000 to 3.06939 × 10^7 t in 2009, in which the carbon emission of Inhabitation, mining ＆ manufacturing land accounted for 93% of the total. 2） The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining ＆ manufacturing land was the highest（200.52 t/ha）, which was much higher than that of other land use types. 3） The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity（2.83 t/ha） in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4） Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5） Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development.
基金Under the auspices of National Natural Science Foundation of China(No.41471356)Fundamental Research Funds for the Central Universities(No.2014ZDPY14)Priority Academic Program Development of Jiangsu Higher Education Institutions(No.SZBF2011-6-B35)
文摘To evaluate urban human settlement, we propose a human settlement environment development index(HSEDI) model by choosing vegetation coverage, land surface temperature, impervious surfaces, slope, wetness, and water condition as the evaluation factors. We applied the proposed model to Xuzhou City, Jiangsu Province, China. Landsat-5 Thematic Mapper(TM) images from 1998 to 2010 and digital elevation model(DEM) data with a 30-m resolution were used to calculate the values of the six evaluation factors. The HSEDI value in Xuzhou City was found to be between 2.24 and 8.10 from 1998 to 2010, and it was further divided into five levels, uninhabitable, moderately uninhabitable, generally inhabitable, moderately inhabitable, and inhabitable. The best HSEDI value was in 2007. The generally inhabitable region was about 100.98 km^2, covering 30.87% of the total area in 2007; the moderately inhabitable region was about 170.58 km2 covering 52.15% of the total area; the inhabitable region was about 32.03 km^2, covering 9.79% of the total area; the percentage of the uninhabitable region was zero; and that of the moderately uninhabitable region was very small, less than 1.00%. Moreover, we analyzed the habitability in the respect of spatial patterns and change detection. Results show that the degraded regions of habitability quality are mainly located in the urban fringe and the improved regions are mainly located in the main urban and rural areas. Reason for the degraded habitability quality is the rapid progress of urbanization. However, the increase in urban green spaces and the construction of the main urban area promoted the improved habitability quality. Besides, we further analyzed socio-economic and socio-demographic data to confirm the results of the habitability analysis. The results indicate that the human settlement in Xuzhou City is in a satisfactory condition, but some efforts should be made to control the possible uninhabitable and moderately uninhabitable regions, and to improve the quality of the generally inhabitable regions.
基金supported by the National Natural Science Foundation of China under Grant No. G050104011004024the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. A0901040110018512026
文摘Surface plasmon resonance of noble metal nanoparticles leads to the optical absorption enhancement effects,which have great potential applications in solar cell.By using the general numerical method of discrete dipole approximation （DDA）,we study the absorption and scattering properties of two-dimensional square silver nanodisks （2D SSN） arrays on the single crystal silicon solar cell.Based on the effective reflective index model of the single crystal silicon solar cell,we investigate the optical enhancement absorption of light energy by varying the light incident direction,particle size,aspect ratio,and interparticle spacing of the silver nanodisks.The peak values and position of the optical extinction spectra of the 2D square arrays of noble metal nanodisks are obtained with the different array structures.
