Reasonable development and utilization of spatial resources in the coastal zone not only affects the development quality of the marine economy but also impacts the utilization efficiency of spatial resources,playing a...Reasonable development and utilization of spatial resources in the coastal zone not only affects the development quality of the marine economy but also impacts the utilization efficiency of spatial resources,playing an important role in regional sustainable development.Depending on the natural,economic,and societal characteristics of a region,research topics such as using relevant methods to divide the coastline,proper spatial development of the coast,protecting coastal zones,and achieving higher spatial resource distribution efficiency have recently become hot topics in geographic research.Most of the scholars construct the evaluation index system from the perspective of economic and ecological factors and undertake some exploration of the division methods.However,the selection of indicators for a coastal zone needs a different and more scientific approach.There is a need for emphasizing the overall strategy of land-ocean integration in developing spatial resources in a coastal zone.Taking the coastal zone in Ningbo as an example,this paper develops a new evaluation framework and spatial function regionalization method that is used to divide the coastline and coastal zone.Based on the perspective of overall strategy for the land and ocean,we evaluate the suitability of coastline development.We then propose the spatial function regionalization of the coastal zone.Finally,based on the status quo of spatial development in Ningbo,we divide the coastal zone into ecological space,production space and living space,and propose adjustment directions and control requirements for the different types of spatial layouts.展开更多
Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divide...Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.展开更多
As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundw...As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundwork for the regulation of land use and protection. This paper probes the system of evaluation indices and applies the methods of spatial analysis and classification clustering to the calculation of the ecologically significant value and economically significant value in each evaluation unit. After use of a classification matrix integrated by the two significant values, city space can be divided into four functional types, namely, feasible development area, moderate development area, moderate conservation area and prohibited exploiting area, and these are the basis for spatial development and control.展开更多
The recent publication by Mollaoglu et al.1 in Cell reveals an unexpected role for tumor derived IL4 in driving immunotherapy resistance in ovarian cancer(OvCa).This finding nominates the combination of immunotherapy ...The recent publication by Mollaoglu et al.1 in Cell reveals an unexpected role for tumor derived IL4 in driving immunotherapy resistance in ovarian cancer(OvCa).This finding nominates the combination of immunotherapy and IL4-signaling targeting strategies as a promising new approach for the treatment of advanced OvCa.Ovarian Cancer(OvCa)is the third most common gynecological malignant disease affecting women.2 It is often diagnosed at late stages and is characterized by heterogenous features with limited treatment options.Initial response to standard of care platinumbased chemotherapy combined with surgery is often followed by disease relapse and subsequent death of patients.Despite the recent success of immune checkpoint inhibition in different cancer entities,most OvCa patients do not benefit from immunotherapy-based treatment approaches.The responsiveness of ovarian tumors to immune checkpoint blockade(ICB)is thereby hindered by weak immunogenicity due to low mutational burden and an immune suppressive tumor microenvironment(TME)characterized by heterogenous immune cell infiltration.3 Still,functional evidence for key factors that govern cancer cellimmune cell interaction and drive immunotherapy resistance in OvCa remains limited.展开更多
By taking Batang Township in Gangnan District,Guigang City,Guangxi Zhuang Autonomous Region for an example,Principal Component Analysis(PCA),GIS technique and SPSS13.0 were applied to comprehensively evaluate 3 princi...By taking Batang Township in Gangnan District,Guigang City,Guangxi Zhuang Autonomous Region for an example,Principal Component Analysis(PCA),GIS technique and SPSS13.0 were applied to comprehensively evaluate 3 principal factors:value of ecological environment,foundation of economic development,value of natural resources;three-dimensional coordinates of economy-ecology-resource combinations were obtained;and finally,functional zoning for the spatial development was realized,22 administrative villages in this town were classified into 6 categories.Among these 6 types of functional zoning,regions of key development and moderate development are Batang Village,Xinlu Village,Suwan Village,Xinmeng Village,Bancun Village,Daxin Village and Gaoxin Village,which are endowed with excellent traffic conditions,solid economic foundation and low sensitivity of ecological environment,thus are suitable to be developed as major spatial carriers of town and industrial development;regions of controlled development are mainly Gaobei Village,Gaoling Village,Sugang Village,Mulong Village and Zhenxin Village,which have moderate economic foundation,dominant crop farming and moderate sensitivity of ecological environment,and also are close to the key developed areas,thus they should be developed with proper control;grey elastic regions mainly include Hengling Village,Sanban Village,Xueshan Village,Shanquan Village and Xinhua Village,which have poor economic foundation and low sensitivity of ecological environment,but excellent natural resources and traffic conditions,thus can be developed as backup land for towns and industrial development;regions of moderate and key protection include Gaolang Village,Cenxi Village,Xin'an Village and Xin'he Village,which have fragile ecological environment and poor economic foundation,thus should be developed according to the principle of "protection first,intensive exploration".展开更多
BACKGROUND： Tetramethylpyrazine （TMP） presents the effect of anti-platelet aggregation, reduces arteria resistance, increases cerebral blood flow, and improves microcirculation. OBJECTIVE： To observe the effects o...BACKGROUND： Tetramethylpyrazine （TMP） presents the effect of anti-platelet aggregation, reduces arteria resistance, increases cerebral blood flow, and improves microcirculation. OBJECTIVE： To observe the effects of TMP on the learning and memory abilities and the number of neurons in cortex and hippocampus after focal cerebral ischemia in rats DESIGN： A randomized controlled tria SETTING： Department of Human Anatomy and Histological Embryology, School of Medicine, Xi＇an Jiaotong University. MATERIALS： Fifty adult male Sprague-Dawley rats, weighing 250-300 g were supplied by the Experimental Animal Center, School of Medicine, Xi＇an Jiaotong University. TMP was purchased from Wuxi Seventh Pharmaceutical Co.Ltd （Lot Number： 2004051106, Specification： 2 mL/piece）. METHODS ： The experiments were carried out in School of Medicine of Xi＇an Jiaotong University from June 2004 to May 2005. The 50 rats were randomly divided into five groups according to the random number table method： sham-operated group, cerebral ischemia control group, low-dose TMP group, middle-dose TMP group and high-dose TMP group, 10 rats in each group. Rats in the TMP groups were immediately treated with intraperitoneal injection of TMP of 40, 80 and 120 mg/kg respectively, and those in the sham-operated group and cerebral ischemia control group were injected intraperitoneally by isovolume saline, once a day for 14 days successively. On the 15^th day, the spatial learning and memory abilities of the rats were assessed with the Morris water maze test, and then the changes of neuron numbers in cortex and hippocampus were observed by Nissl staining of brain sections. MAIN OUTCOME MEASURES ： The results of Morris water maze test and the changes of neuron numbers in cortex and hippocampus by Nissl staining of brain sections were observed. RESULTS： Finally 39 rats were involved in the analysis of results, and the other 11 died of excessive anesthesia or failure in model establishment. ① The rats in the cerebral ischemia control group manifested obvious spatial cognitive deficits in the place navigation trial and spatial probe trial. The mean values of escape latency in the sham-operated group, low, middle and high-dose TMP groups were obviously shorter than that in the cerebral ischemia control group [（23.92±2.21）, （41.84±3.74）, （39.50 ±3.80）, （31.38_±3.72）, （61.60±3.61） s, P 〈 0.05-0.01]. In the spatial probe trial, significant differences in the percentage of time spending in the former platform quadrant and frequency of crossing the former platform site in the sham-operated group, lose, middle and high-dose TMP groups were obviously higher or more than those in the cerebral ischemia control group [（36.27±3.42） %, （35.84±2.54）%, （38.43±3.08）%, （36.51±1.96）%, （22.24±3.46）%; （11 ±1 ）, （10±1）, （8_±1）, （8±1）, （4±1） times, P 〈 0.01]. ② In the morphological observation, the numbers of neurons in ipsilateral （left） parietal cortex in the sham-operated group, low, middle and high-dose TMP groups were obviously more than that in the cerebral ischemia control group [（98±8）, （65±5）, （53±6）, （57±6）, （37±6）/0.625 mm^2, P 〈 0.01], but the number of neurons in left hippocampus had no obvious differences among the groups （P 〉 0.05）. CONCLUSION ： TMP can improve obviously the spatial learning and memory function after permanent focal cerebral ischemia in rats, and the neuroprotective role of the drug in cortex may be involved in its mechanism.展开更多
The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of ur...The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning.展开更多
Applying 3-dimension finite difference method, the distribution characteristics of horizontal field transfer functions for rectangular conductor have been computed, and the law of distribution for Re-part and Im-part ...Applying 3-dimension finite difference method, the distribution characteristics of horizontal field transfer functions for rectangular conductor have been computed, and the law of distribution for Re-part and Im-part has been given. The influences of source field period, the conductivity, the buried depth and the length of the conductor on the transfer functions were studied. The extrema of transfer functions appear at the center, the four corners and around the edges of conductor, and move with the edges. This feature demonstrates that around the edges are best places for transfer functions' observation.展开更多
BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known ...BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE： To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING： A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS： Eight right-handed, male, college students in their 20s （mean age 21.5 years） and six right-handed, male, adults in their 40s （mean age 45.7 years）, who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS： A spatial task was presented while brain images were acquired using a 3T fMRI system （ISOL Technology, Korea）. The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES： The accuracy rate （number of correct answers/total number of items x 100%） of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups （20s versus 40s）. RESULTS： The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance （P = 0.012）. CONCLUSION： Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe.展开更多
To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional a...To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional areas over the years and appearance month of the maximum rainfall were conducted statistics. Results showed that frequency distribution of heavy rain in whole year in different functional areas was different,but it was similar in the same functional zone. Temporal-spatial distribution of rainstorm was more independent,and there were different performances in various districts of each functional area. In urban functional core area and urban functional expansion area,rainstorm times was more,and the maximum precipitation was larger. In urban development new district,rainstorm times and the maximum precipitation were relatively smaller in whole Chongqing. In ecological conservation development area of northeast Chongqing,rainstorm duration was longer,and we needed prevention and control during June- September. In ecological protection area of southeast Chongqing,although rainstorm occurrence times was the most in Chongqing,the heavy rainstorm was less.展开更多
Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of...Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of the half-space.By using the obtained half-space Green's function,an integral rep- resentation of the scattered waves by a cylindrical obstacle is then derived.Finally,by analyzing the far-zone behavior of the integrands of the integral representation.the far-field pattern of the scattered waves in a half-space obtained.展开更多
Functional brain network (FBN) measures based on functional magnetic resonance imaging (fMRI) data, has become important biomarkers for early diagnosis and prediction of clinical outcomes in neurological diseases, suc...Functional brain network (FBN) measures based on functional magnetic resonance imaging (fMRI) data, has become important biomarkers for early diagnosis and prediction of clinical outcomes in neurological diseases, such as Alzheimer’s diseases (AD) and its prodromal state (<em>i</em>.<em>e</em>., Mild cognitive impairment, MCI). In the past decades, researchers have developed numbers of approaches for FBN estimation, including Pearson’s correction (PC), sparse representation (SR), and so on. Despite their popularity and wide applications in current studies, most of the approaches for FBN estimation only consider the dependency between the measured blood oxygen level dependent (BOLD) time series, but ignore the spatial relationships between pairs of brain regions. In practice, the strength of functional connection between brain regions will decrease as their distance increases. Inspired by this, we proposed a new approach for FBN estimation based on the assumption that the closer brain regions tend to share stronger relationships or similarities. To verify the effectiveness of the proposed method, we conduct experiments on a public dataset to identify the patients with MCIs from health controls (HCs) using the estimated FBNs. Experimental results demonstrate that the proposed approach yields statistically significant improvement in seven performance metrics over using the baseline methods.展开更多
This article analyzes The Kite Runner with the help of spactial narrative. The novel will be analyzed from three angles—the function of spatial narrative, the basic unit of spatial narrative, the periphery of spatial...This article analyzes The Kite Runner with the help of spactial narrative. The novel will be analyzed from three angles—the function of spatial narrative, the basic unit of spatial narrative, the periphery of spatial narrative and the overall effect presented in the novel by using these narrative techniques.展开更多
Vegetation biomass is an important component of terrestrial ecosystem carbon stocks. Grasslands are one of the most widespread biomes worldwideplaying an important role in global carbon cycling. Thereforestudying spat...Vegetation biomass is an important component of terrestrial ecosystem carbon stocks. Grasslands are one of the most widespread biomes worldwideplaying an important role in global carbon cycling. Thereforestudying spatial patterns of biomass and their correlations to environment in grasslands is fundamental to quantifying terrestrial carbon budgets. The Eurasian steppean important part of global grasslandsis the largest and relatively well preserved grassland in the world. In this studywe analyzed the spatial pattern of aboveground biomass（AGB）and correlations of AGB to its environment in the Eurasian steppe by meta-analysis. AGB data used in this study were derived from the harvesting method and were obtained from three data sources（literatureglobal NPP database at the Oak Ridge National Laboratory Distributed Active Archive Center（ORNL）some data provided by other researchers）. Our results demonstrated that：（1） as for the Eurasian steppe overallthe spatial variation in AGB exhibited significant horizontal and vertical zonality. In detailAGB showed an inverted parabola curve with the latitude and with the elevationwhile a parabola curve with the longitude. In additionthe spatial pattern of AGB had marked horizontal zonality in the Black Sea-Kazakhstan steppe subregion and the Mongolian Plateau steppe subregionwhile horizontal and vertical zonality in the Tibetan Plateau alpine steppe subregion.（2） Of the examined environmental variablesthe spatial variation of AGB was related to mean annual precipitation（MAP）mean annual temperature（MAT）mean annual solar radiation（MAR）soil Gravel contentsoil p H and soil organic content（SOC） at the depth of 0–30 cm. NeverthelessMAP dominated spatial patterns of AGB in the Eurasian steppe and its three subregions.（3） A Gaussian function was found between AGB and MAP in the Eurasian steppe overallwhich was primarily determined by unique patterns of grasslands and environment in the Tibetan Plateau. AGB was significantly positively related to MAP in the Black Sea-Kazakhstan steppe subregion（elevation 〈 3000 m）the Mongolian Plateau steppe subregion（elevation 〈 3000 m） and the surface（elevation ≥ 4800 m） of the Tibetan Plateau. Neverthelessthe spatial variation in AGB exhibited a Gaussian function curve with the increasing MAP in the east and southeast margins（elevation 〈 4800 m） of the Tibetan Plateau. This study provided more knowledge of spatial patterns of AGB and their environmental controls in grasslands than previous studies only conducted in local regions like the Inner Mongolian temperate grasslandthe Tibetan Plateau alpine grasslandetc.展开更多
The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the fo...The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers, this paper calculates the trajectories of photoelectrons in a photocathode. Thus the distribution of photoelectron spots on the emit-face is obtained, which is namely the point spread function. The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function. The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length, and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration. Furthermore, the resolution is enhanced considerably by increasing the active-layer thickness, especially at high spatial frequencies. The best spatial resolution is 860 lp/mm, for the GaAs photocathode of doping concentration 1 ×10^19 cm 3 electron diffusion length 3.6 μm and the active-layer thickness 2 μm, under the 633-nm light irradiated. This research will contribute to the future improvement of the cathode＇s resolution for preparing a high performance GaAs photocathode, and improve the resolution of a low light level image intensifier.展开更多
During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition e...During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta(PRD) during 1991–2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do.展开更多
文摘Reasonable development and utilization of spatial resources in the coastal zone not only affects the development quality of the marine economy but also impacts the utilization efficiency of spatial resources,playing an important role in regional sustainable development.Depending on the natural,economic,and societal characteristics of a region,research topics such as using relevant methods to divide the coastline,proper spatial development of the coast,protecting coastal zones,and achieving higher spatial resource distribution efficiency have recently become hot topics in geographic research.Most of the scholars construct the evaluation index system from the perspective of economic and ecological factors and undertake some exploration of the division methods.However,the selection of indicators for a coastal zone needs a different and more scientific approach.There is a need for emphasizing the overall strategy of land-ocean integration in developing spatial resources in a coastal zone.Taking the coastal zone in Ningbo as an example,this paper develops a new evaluation framework and spatial function regionalization method that is used to divide the coastline and coastal zone.Based on the perspective of overall strategy for the land and ocean,we evaluate the suitability of coastline development.We then propose the spatial function regionalization of the coastal zone.Finally,based on the status quo of spatial development in Ningbo,we divide the coastal zone into ecological space,production space and living space,and propose adjustment directions and control requirements for the different types of spatial layouts.
基金Under the auspices of Grant Program of Clean Development Mechanism Fund of China(CDMF)(No.2014092)Task 2 of Key Service Project 5 for the Characteristic Institute of Chinese Academy of Sciences(No.TSS-2015-014-FW-5-2)+2 种基金National Natural Science Foundation of China(No.41571159)The Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA20010301)Jiangsu Natural Science Foundation(No.BK20181105)
文摘Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.
基金Under the auspices of the National Science Foundation of China(No.41871119,41871209)
文摘As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundwork for the regulation of land use and protection. This paper probes the system of evaluation indices and applies the methods of spatial analysis and classification clustering to the calculation of the ecologically significant value and economically significant value in each evaluation unit. After use of a classification matrix integrated by the two significant values, city space can be divided into four functional types, namely, feasible development area, moderate development area, moderate conservation area and prohibited exploiting area, and these are the basis for spatial development and control.
基金funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation,LE 3613/3-1).
文摘The recent publication by Mollaoglu et al.1 in Cell reveals an unexpected role for tumor derived IL4 in driving immunotherapy resistance in ovarian cancer(OvCa).This finding nominates the combination of immunotherapy and IL4-signaling targeting strategies as a promising new approach for the treatment of advanced OvCa.Ovarian Cancer(OvCa)is the third most common gynecological malignant disease affecting women.2 It is often diagnosed at late stages and is characterized by heterogenous features with limited treatment options.Initial response to standard of care platinumbased chemotherapy combined with surgery is often followed by disease relapse and subsequent death of patients.Despite the recent success of immune checkpoint inhibition in different cancer entities,most OvCa patients do not benefit from immunotherapy-based treatment approaches.The responsiveness of ovarian tumors to immune checkpoint blockade(ICB)is thereby hindered by weak immunogenicity due to low mutational burden and an immune suppressive tumor microenvironment(TME)characterized by heterogenous immune cell infiltration.3 Still,functional evidence for key factors that govern cancer cellimmune cell interaction and drive immunotherapy resistance in OvCa remains limited.
文摘By taking Batang Township in Gangnan District,Guigang City,Guangxi Zhuang Autonomous Region for an example,Principal Component Analysis(PCA),GIS technique and SPSS13.0 were applied to comprehensively evaluate 3 principal factors:value of ecological environment,foundation of economic development,value of natural resources;three-dimensional coordinates of economy-ecology-resource combinations were obtained;and finally,functional zoning for the spatial development was realized,22 administrative villages in this town were classified into 6 categories.Among these 6 types of functional zoning,regions of key development and moderate development are Batang Village,Xinlu Village,Suwan Village,Xinmeng Village,Bancun Village,Daxin Village and Gaoxin Village,which are endowed with excellent traffic conditions,solid economic foundation and low sensitivity of ecological environment,thus are suitable to be developed as major spatial carriers of town and industrial development;regions of controlled development are mainly Gaobei Village,Gaoling Village,Sugang Village,Mulong Village and Zhenxin Village,which have moderate economic foundation,dominant crop farming and moderate sensitivity of ecological environment,and also are close to the key developed areas,thus they should be developed with proper control;grey elastic regions mainly include Hengling Village,Sanban Village,Xueshan Village,Shanquan Village and Xinhua Village,which have poor economic foundation and low sensitivity of ecological environment,but excellent natural resources and traffic conditions,thus can be developed as backup land for towns and industrial development;regions of moderate and key protection include Gaolang Village,Cenxi Village,Xin'an Village and Xin'he Village,which have fragile ecological environment and poor economic foundation,thus should be developed according to the principle of "protection first,intensive exploration".
基金the National Natural Science Foundation of China, No. 30170300 30300109
文摘BACKGROUND： Tetramethylpyrazine （TMP） presents the effect of anti-platelet aggregation, reduces arteria resistance, increases cerebral blood flow, and improves microcirculation. OBJECTIVE： To observe the effects of TMP on the learning and memory abilities and the number of neurons in cortex and hippocampus after focal cerebral ischemia in rats DESIGN： A randomized controlled tria SETTING： Department of Human Anatomy and Histological Embryology, School of Medicine, Xi＇an Jiaotong University. MATERIALS： Fifty adult male Sprague-Dawley rats, weighing 250-300 g were supplied by the Experimental Animal Center, School of Medicine, Xi＇an Jiaotong University. TMP was purchased from Wuxi Seventh Pharmaceutical Co.Ltd （Lot Number： 2004051106, Specification： 2 mL/piece）. METHODS ： The experiments were carried out in School of Medicine of Xi＇an Jiaotong University from June 2004 to May 2005. The 50 rats were randomly divided into five groups according to the random number table method： sham-operated group, cerebral ischemia control group, low-dose TMP group, middle-dose TMP group and high-dose TMP group, 10 rats in each group. Rats in the TMP groups were immediately treated with intraperitoneal injection of TMP of 40, 80 and 120 mg/kg respectively, and those in the sham-operated group and cerebral ischemia control group were injected intraperitoneally by isovolume saline, once a day for 14 days successively. On the 15^th day, the spatial learning and memory abilities of the rats were assessed with the Morris water maze test, and then the changes of neuron numbers in cortex and hippocampus were observed by Nissl staining of brain sections. MAIN OUTCOME MEASURES ： The results of Morris water maze test and the changes of neuron numbers in cortex and hippocampus by Nissl staining of brain sections were observed. RESULTS： Finally 39 rats were involved in the analysis of results, and the other 11 died of excessive anesthesia or failure in model establishment. ① The rats in the cerebral ischemia control group manifested obvious spatial cognitive deficits in the place navigation trial and spatial probe trial. The mean values of escape latency in the sham-operated group, low, middle and high-dose TMP groups were obviously shorter than that in the cerebral ischemia control group [（23.92±2.21）, （41.84±3.74）, （39.50 ±3.80）, （31.38_±3.72）, （61.60±3.61） s, P 〈 0.05-0.01]. In the spatial probe trial, significant differences in the percentage of time spending in the former platform quadrant and frequency of crossing the former platform site in the sham-operated group, lose, middle and high-dose TMP groups were obviously higher or more than those in the cerebral ischemia control group [（36.27±3.42） %, （35.84±2.54）%, （38.43±3.08）%, （36.51±1.96）%, （22.24±3.46）%; （11 ±1 ）, （10±1）, （8_±1）, （8±1）, （4±1） times, P 〈 0.01]. ② In the morphological observation, the numbers of neurons in ipsilateral （left） parietal cortex in the sham-operated group, low, middle and high-dose TMP groups were obviously more than that in the cerebral ischemia control group [（98±8）, （65±5）, （53±6）, （57±6）, （37±6）/0.625 mm^2, P 〈 0.01], but the number of neurons in left hippocampus had no obvious differences among the groups （P 〉 0.05）. CONCLUSION ： TMP can improve obviously the spatial learning and memory function after permanent focal cerebral ischemia in rats, and the neuroprotective role of the drug in cortex may be involved in its mechanism.
基金National Natural Science Foundation of China,No.41630644Innovative Think-tank Foundation for Young Scientists of China Association for Science and Technology,No.DXB-ZKQN-2017-048。
文摘The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning.
文摘Applying 3-dimension finite difference method, the distribution characteristics of horizontal field transfer functions for rectangular conductor have been computed, and the law of distribution for Re-part and Im-part has been given. The influences of source field period, the conductivity, the buried depth and the length of the conductor on the transfer functions were studied. The extrema of transfer functions appear at the center, the four corners and around the edges of conductor, and move with the edges. This feature demonstrates that around the edges are best places for transfer functions' observation.
文摘BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE： To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING： A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS： Eight right-handed, male, college students in their 20s （mean age 21.5 years） and six right-handed, male, adults in their 40s （mean age 45.7 years）, who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS： A spatial task was presented while brain images were acquired using a 3T fMRI system （ISOL Technology, Korea）. The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES： The accuracy rate （number of correct answers/total number of items x 100%） of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups （20s versus 40s）. RESULTS： The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance （P = 0.012）. CONCLUSION： Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe.
基金Supported by Chongqing Municipal Frontiers and Application Base Research Program,China(cstc2014jcyjA 20002)Chongqing Municipal Key Laboratory of Institutions of Higher Education,China(WEPKL2013MS-10)+1 种基金Wanzhou District Soft Science Project,China(201404009)Innovation Planning Project for University Students of Chongqing Three Gorges University,China(2014-55)
文摘To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional areas over the years and appearance month of the maximum rainfall were conducted statistics. Results showed that frequency distribution of heavy rain in whole year in different functional areas was different,but it was similar in the same functional zone. Temporal-spatial distribution of rainstorm was more independent,and there were different performances in various districts of each functional area. In urban functional core area and urban functional expansion area,rainstorm times was more,and the maximum precipitation was larger. In urban development new district,rainstorm times and the maximum precipitation were relatively smaller in whole Chongqing. In ecological conservation development area of northeast Chongqing,rainstorm duration was longer,and we needed prevention and control during June- September. In ecological protection area of southeast Chongqing,although rainstorm occurrence times was the most in Chongqing,the heavy rainstorm was less.
文摘Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of the half-space.By using the obtained half-space Green's function,an integral rep- resentation of the scattered waves by a cylindrical obstacle is then derived.Finally,by analyzing the far-zone behavior of the integrands of the integral representation.the far-field pattern of the scattered waves in a half-space obtained.
文摘Functional brain network (FBN) measures based on functional magnetic resonance imaging (fMRI) data, has become important biomarkers for early diagnosis and prediction of clinical outcomes in neurological diseases, such as Alzheimer’s diseases (AD) and its prodromal state (<em>i</em>.<em>e</em>., Mild cognitive impairment, MCI). In the past decades, researchers have developed numbers of approaches for FBN estimation, including Pearson’s correction (PC), sparse representation (SR), and so on. Despite their popularity and wide applications in current studies, most of the approaches for FBN estimation only consider the dependency between the measured blood oxygen level dependent (BOLD) time series, but ignore the spatial relationships between pairs of brain regions. In practice, the strength of functional connection between brain regions will decrease as their distance increases. Inspired by this, we proposed a new approach for FBN estimation based on the assumption that the closer brain regions tend to share stronger relationships or similarities. To verify the effectiveness of the proposed method, we conduct experiments on a public dataset to identify the patients with MCIs from health controls (HCs) using the estimated FBNs. Experimental results demonstrate that the proposed approach yields statistically significant improvement in seven performance metrics over using the baseline methods.
文摘This article analyzes The Kite Runner with the help of spactial narrative. The novel will be analyzed from three angles—the function of spatial narrative, the basic unit of spatial narrative, the periphery of spatial narrative and the overall effect presented in the novel by using these narrative techniques.
基金The Chinese Academy of Sciences Strategic Priority Research Program,No.XDA05050602The Key Program of National Natural Science Foundation of China,No.31290221
文摘Vegetation biomass is an important component of terrestrial ecosystem carbon stocks. Grasslands are one of the most widespread biomes worldwideplaying an important role in global carbon cycling. Thereforestudying spatial patterns of biomass and their correlations to environment in grasslands is fundamental to quantifying terrestrial carbon budgets. The Eurasian steppean important part of global grasslandsis the largest and relatively well preserved grassland in the world. In this studywe analyzed the spatial pattern of aboveground biomass（AGB）and correlations of AGB to its environment in the Eurasian steppe by meta-analysis. AGB data used in this study were derived from the harvesting method and were obtained from three data sources（literatureglobal NPP database at the Oak Ridge National Laboratory Distributed Active Archive Center（ORNL）some data provided by other researchers）. Our results demonstrated that：（1） as for the Eurasian steppe overallthe spatial variation in AGB exhibited significant horizontal and vertical zonality. In detailAGB showed an inverted parabola curve with the latitude and with the elevationwhile a parabola curve with the longitude. In additionthe spatial pattern of AGB had marked horizontal zonality in the Black Sea-Kazakhstan steppe subregion and the Mongolian Plateau steppe subregionwhile horizontal and vertical zonality in the Tibetan Plateau alpine steppe subregion.（2） Of the examined environmental variablesthe spatial variation of AGB was related to mean annual precipitation（MAP）mean annual temperature（MAT）mean annual solar radiation（MAR）soil Gravel contentsoil p H and soil organic content（SOC） at the depth of 0–30 cm. NeverthelessMAP dominated spatial patterns of AGB in the Eurasian steppe and its three subregions.（3） A Gaussian function was found between AGB and MAP in the Eurasian steppe overallwhich was primarily determined by unique patterns of grasslands and environment in the Tibetan Plateau. AGB was significantly positively related to MAP in the Black Sea-Kazakhstan steppe subregion（elevation 〈 3000 m）the Mongolian Plateau steppe subregion（elevation 〈 3000 m） and the surface（elevation ≥ 4800 m） of the Tibetan Plateau. Neverthelessthe spatial variation in AGB exhibited a Gaussian function curve with the increasing MAP in the east and southeast margins（elevation 〈 4800 m） of the Tibetan Plateau. This study provided more knowledge of spatial patterns of AGB and their environmental controls in grasslands than previous studies only conducted in local regions like the Inner Mongolian temperate grasslandthe Tibetan Plateau alpine grasslandetc.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60678043)the Research and Innovation Plan for Graduate Students of Jiangsu Higher Education Institutions,China (Grant No. CX09B 096Z)
文摘The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers, this paper calculates the trajectories of photoelectrons in a photocathode. Thus the distribution of photoelectron spots on the emit-face is obtained, which is namely the point spread function. The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function. The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length, and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration. Furthermore, the resolution is enhanced considerably by increasing the active-layer thickness, especially at high spatial frequencies. The best spatial resolution is 860 lp/mm, for the GaAs photocathode of doping concentration 1 ×10^19 cm 3 electron diffusion length 3.6 μm and the active-layer thickness 2 μm, under the 633-nm light irradiated. This research will contribute to the future improvement of the cathode＇s resolution for preparing a high performance GaAs photocathode, and improve the resolution of a low light level image intensifier.
基金Under the auspices of Humanities and Social Science Foundation of Ministry of Education of China(No.10YJA790047)Funding Project for Academic Human Resources Development in Beijing Union University
文摘During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta(PRD) during 1991–2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do.
