Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In parti...Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In particular,the causes of how male-male competition promotes the increased cognitive abilities to increase brains are as yet unexplored in anurans.To evaluate the effect of male-male competition on variation in brain size in B.andrewsi,we compared the differences in relative brain size between mated males and unpaired males under natural and experimental conditions.We found that mated males had relatively larger brains than unpaired males in a natural population when controlling the effect of body size.Likewise,we also found that there were larger brains in mated males than in unpaired males in both experiment 1 where two males competed for a female and experiment 2 where three males competed for a female,suggesting that males with mating success during male-male competition possess increased brain size and cognitive abilities.When we compared difference in relative brain size in mated males between experiment2 and experiment 1 we found that males experiencing more intense competition did not display larger brains than males experiencing relatively weak competition,suggesting that low intensity competition is already enough to trigger the increase in relative brain size in B.andrewsi.展开更多
The giant Jiama deposit is a post-collisional porphyry Cu-polymetallic system located in the Gangdese metallogenic belt of Xizang.It consists of three deposits:The Main deposit,the Zegulangbei deposit,and the South Pi...The giant Jiama deposit is a post-collisional porphyry Cu-polymetallic system located in the Gangdese metallogenic belt of Xizang.It consists of three deposits:The Main deposit,the Zegulangbei deposit,and the South Pit deposit according to exploration and research.The South Pit deposit is a high-grade Cu-Pb-Zn deposit,but its genesis is unclear.To investigate its genesis,a detailed study was conducted on the deposit geology,geochronology and amphibole geochemistry.The results indicate that the weighted average 206Pb/238U age of the zircons from the granite porphyry in the South Pit is 15.38±0.45 Ma,and the molybdenite from the mineralized skarn yield a ReOs isochron age of 15.23±0.22 Ma,in line with the age of the Main deposit(15.7-14.3 Ma).The amphiboles in the granite porphyry of the South Pit,magnesiohornblende and actinolite,are high in Mg and Ca and low in K.They crystallized at temperatures of 705-7490C,pressures of 0.44-0.67 kbar,oxygen fugacity of-14.31--13.69(NNO),and depths of 1.7-2.5 km.Mapping of structure and alteration indicates that the South Pit skarn developed due to the metasomatism of marble of hornfels or carbonate in fold hinge dilation and an interlayer detachment zone by magmatic hydrothermal fluids.According to the age of magmatism and geological features,the South Pit deposit and the Main deposit have originated from the same Miocene magmatism,but the South Pit deposit was affected by the gliding nappe tectonic system.The amphibole geochemistry indicates that the ore-related magma of the South Pit has a high oxygen fugacity and is rich in water.展开更多
With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry o...With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.展开更多
This paper introduces the method of data envelopment analysis （DEA） for evaluation of the degree of harmony between water resources and economic development of the water conservancy area of China＇s South-to-North W...This paper introduces the method of data envelopment analysis （DEA） for evaluation of the degree of harmony between water resources and economic development of the water conservancy area of China＇s South-to-North Water Diversion Project （SNWDP）. For this evaluation, a super-efficiency DEA （SEDEA） model was developed based on the super-efficiency method. To verify the applicability of the SEDEA model, both the SEDEA model and a normal-efficiency DEA （NEDEA） model were used to evaluate the degree of harmony between water resources and economic development of typical cities in the SNWDP water conservancy area. The results show that the SEDEA model ranks the degree of harmony of typical cities more efficiently than the NEDEA model, and thus can better evaluate the degree of harmony between water resources and economic development of different cities than the NEDEA model. Furthermore, the SEDEA model can be applied as an operational research tool in regional water resources management.展开更多
Traditional risk factors fall into four categories： natural disasters, public health, accidents during production and social security. The four types of risks are called as public safety issues by the government of C...Traditional risk factors fall into four categories： natural disasters, public health, accidents during production and social security. The four types of risks are called as public safety issues by the government of China. New risk factors are the ones that are connected to human discoveries and more attention to them, which is called locking risk. What is more, such risk factors will continue to emerge with the development of human society. Currently, traditional risk factors have not been eliminated, while new risks have emerged gradually. There are countless relations between new risks and global climatic changes. Therefore, figuring out the relationship between new risks, global climatic changes as well as natural disasters is of great importance. This study takes China as an example. The population data at county level in China in 1991, 2000 and 2009 （including rural population, urban population and total population of three） were selected. By calculating the urbanization rate of the population, the rate of urbanization at county level in China in three years was drawn. And it is superimposed with the disaster zoning in China to analyze the correlation between population changes and natural disasters and reveal the magnitude of disaster effects caused by population urbanization. It can provide the basis for the disaster chain risk assessment under the gnidanee of the regional law of China＇s natural disaster chain and lay the foundation for the study of the relationship between new risk factors and traditional risk factors. So, risks governance can be perfectly combined with developing the green economy during the development of human society, and ultimately, the goal of harmony between human and nature can be achieved.展开更多
It is well established that Cretaceous magmatism in the South China Block(SCB)is related to the Paleo-Pacific subduction.However,the starting time and the associated deep crust-mantle processes are still debatable.Maf...It is well established that Cretaceous magmatism in the South China Block(SCB)is related to the Paleo-Pacific subduction.However,the starting time and the associated deep crust-mantle processes are still debatable.Mafic dike swarms carry important information on the deep earth(including mantle)geodynamics and geochemical evolution.In the Jiangnan Orogen(South China).there is no information on whether the Mesozoic magmatic activities in this region are also directly related to the Pacific subduction or not.In this study,we present detailed zircon U-Pb geochronological,wholerock element and Sr-Nd isotope data for Early Cretaceous Tuanshanbei dolerite dikes,and provide new constraints on the condition of the lithospheric mantle and mantle dynamics of the SCB during that time.LA-ICP-MS zircon U-Pb dating suggests that this dolerite erupted in the Early Cretaceous(~145 Ma).All samples have alkaline geochemical affinities with K_(2)O+Na_(2)O=3.11-4.04 wt%,K_(2)O/Na_(2)O=0.50-0.72,and Mg^(#)=62.24-65.13.They are enriched in LILE but depleted in HFSE with higher initial^(87)Sr/^(86)Sr ratio(0.706896-0.714743)and lower ε_(Nd)(t)(-2.61 to-1.67).They have high Nb/U,Nb/La,La/Sm and Rb/Sr,and low La/Nb,La/Ta,Ce/Pb,Ba/Rb,Tb/Yb and Gd/Yb ratios.Such geochemical signatures suggest that the fractional crystallization is obvious but crustal contamination play a negligible role during magmatic evolution.Tuanshanbei dolerite were most likely derived from low-degree(2%-5%)partial melting of a phlogopite-bearing mantle material consisted of~85% spinel peridotite and~15% garnet peridotite previously metasomatized by asthenospherederived fluids/melts with minor subduction-derived fluids/melts.Slab-rollback generally lead to the upwelling of the hot asthenosphere.The upwelling of asthenosphere consuming the lithospheric mantle by thermo-mechanical-chemical erosion.The lithospheric mantle may have partially melted due to the heating by the upwelling asthenosphere and lithospheric extension.It is inferred that the Tuanshanbei dolerite might be associated with the initial slab rollback and corresponding lithospheric extension occurred potentially at ca.145 Ma.展开更多
In recent years,China has made remarkable technological progress in a number of areas.Given this progress,it is crucial to rapidly transform technological results into productivity gains.
The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the...The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the basins as the rifting process cannot be accurately described by a simple (one episode) stretching model. The study shows that the multiphase stretching model, combined with the back-stripping technique, can be used to reconstruct the subsidence history and the stretching process of the lithosphere, and to evaluate the depth to the top of the asthenosphere and the deep thermal evolution of the basins. The calculated results obtained by applying the quantitative model to the episodic rifting process of the Tertiary Qiongdongnan and Yinggehai basins in the South China Sea are in agreement with geophysical data and geological observations. This provides a new method for quantitative evaluation of the geodynamic process of multiphase rifting occurring during the Tertiary in eastern China.展开更多
This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy ...This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy issues concerning the building of a new socialist countryside, especially from the perspective of balancing urban and rural development. The underlying viewpoint of this article is that to promote the building of a new countryside, a system and mechanism of balancing urban and rural development must be gradually established and improved. The policies should focus on improving the social mobility mechanism to remove the institutional barriers to the social mobility of farmers; establishing public finances to cover both urban and rural areas to narrow the gap in basic public service provision between cities and the countryside; expediting the establishment of a social security network to protect the interests of rural disadvantaged groups; improving the mechanism of protecting land-use rights and interests of farmers; effectively organizing the mechanism of ensuring allocations for the building of a new countryside; improving the organizational structure of rural society to support self-organized farmers' groups; and changing the concept of rural governance and the operation of social governance.展开更多
This study aims to investigate the influence of rapid economic development on pollution at the municipal level in China.It constructs a Stochastic Impacts by Regression on Population,Affluence and Technology model(STI...This study aims to investigate the influence of rapid economic development on pollution at the municipal level in China.It constructs a Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT model) and uses comprehensive municipal data on industrial pollution and economic performance.The dataset contains 290 cities from2003 to 2016 as a sample for the panel data analysis.The study further separates the cities into two groups by their levels of economic development for heterogeneity analysis.It reveals that a low level of economic development would aggravate environmental pollution,and when the economy reaches a high level,this economic development will improve environmental quality.We also find that the relationships between foreign direct investment and industrial dust and sulfur dioxide(SO_2) discharge are significant,while the relationship between economic growth and effluent emission is not.The more developed subsample cities present an inverted U-shaped curve between industrial pollutant emission,GDP per capita,and foreign direct investment,while the less developed subsamples show no such relationship.Since the shape of these curves differs among regions,their turning points vary accordingly.Based on this finding,this study suggests that the governments of more developed cities should balance environmental pollution and economic development by enhancing environmental regulations and adjusting industrial structure.展开更多
Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillat...Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction （HDE） and solvent-free microwave extraction （SME） oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME （56.7%） and HDIE （60.0%） oils were significantly different （P〈0.05） from those of sea water （63.3%） and chloramphenicol （15.0%）. Larva lethality was different significantly （P〈0.05） between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration （LC50） of the oils was 〉 1000 mg/ml recommended as an index for non-toxicity which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.展开更多
Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000...Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000 and 5000 mg/kg） and subacute （200, 400 and 600 mg/kg） toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. Results： In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degen- eration. Conclusion： These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.展开更多
Phosphite (Phi)-based fungicides are used to control the oomycete Phytophthora infestans which causes late blight disease, the most devastating disease in potatoes. In order to examine the effects of Phi-based fungici...Phosphite (Phi)-based fungicides are used to control the oomycete Phytophthora infestans which causes late blight disease, the most devastating disease in potatoes. In order to examine the effects of Phi-based fungicides on potato tubers through foliar or post-harvest application, a metabolite profiling approach based on gas chromatography coupled to mass spectrometry (GC-MS) has been established. A total of 132 metabolites were detected using the GC-MS approach. Among these, 34 metabolites were identified after normalization and annotated with a compound name with standard mass spectral library. Metabolomic analysis of Phi-treated plants showed significant differences in the levels of many metabolites especially amino acids. Multivariate statistical approaches, such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), were employed to explore the relationships between metabolites to detect group differences. A good discrimination between the control and the Phi-treated plants was observed, which demonstrated that significant changes in the metabolite profile have been caused by the two different Phi applications (foliar or post-harvest). This finding suggests that the alteration of specific metabolite levels by accumulation of Phi can lead to resistance against the pathogen.展开更多
Objective: To evaluate the antioxidant activities and phytochemical content of the leaf and root extracts of Rumex crispus using the solvents extraction; methanol extract,ethanol extract, acetone extract(ACE), and wat...Objective: To evaluate the antioxidant activities and phytochemical content of the leaf and root extracts of Rumex crispus using the solvents extraction; methanol extract,ethanol extract, acetone extract(ACE), and water extract.Methods: Total flavonoids content, total phenolic content, and total proanthocyanidin were evaluated using spectrophotometric equivalents of the standards, quercetin, gallic acid and catechin respectively. The antioxidant activities of the plant extracts were determined using ABTS, DPPH, ferric reducing antioxidant power, total antioxidant capacity and nitric oxide scavenging assays.Results: The flavonoids and phenols contents of the extracts were in the range of(19.39 ± 4.08) to(526.23 ± 17.52) mg QE/g and(16.95 ± 12.03) to(240.68 ± 3.50) mg GAE/g, respectively. ACE of the leaf has the highest value of total flavonoids content(526.23 ± 17.52) mg QE/g while ACE of the root has the highest value of total phenolic content(240.68 ± 3.50) mg GAE/g. The highest content of total proanthocyanidin(645.38 ± 1.33) mg CE/g was in ACE of the root. Significant amounts of saponin and alkaloid were also present in the root and leaf extracts. All solvent fractions showed significant antioxidant activities(P < 0.05) with ACE of the root having the highest scavenging value as shown in DPPH, ABTS, total antioxidant capacity, nitric oxide and ferric reducing antioxidant power(IC50= 0.014 mg/m L, <0.005 mg/m L, 0.048 mg/m L,0.067 mg/m L, and 0.075 mg/m L, respectively).Conclusions: In this study, the mean phytochemical content of the root of Rumex crispus is higher than that of the leaf and this may have contributed to its high antioxidant activities. This may also justify the frequent use of the root more than the leaves in traditional medicine for the cure of helminthic infections.展开更多
1 Introduction The conflict between resources and the environment has been increasingly outstanding as the population,economy and society around the globe have developed rapidly since the 21st century.An important cha...1 Introduction The conflict between resources and the environment has been increasingly outstanding as the population,economy and society around the globe have developed rapidly since the 21st century.An important challenge that the human展开更多
The Linjiasandaogou gold deposit is located in the Qingchengzi Orefield,North China Craton,China,and has not attracted many studies.We present geochronological,whole-rock geochemical,and Sr–Nd–Hf isotopic data to co...The Linjiasandaogou gold deposit is located in the Qingchengzi Orefield,North China Craton,China,and has not attracted many studies.We present geochronological,whole-rock geochemical,and Sr–Nd–Hf isotopic data to constrain the age and tectonic setting of the mineralization.U–Pb dating of zircon from pre-and post-ore dikes indicates the Linjiasandaogou Au deposit formed at ca.227–226 Ma.The granite porphyry(ca.227 Ma)and quartz diorite porphyry(ca.228 Ma),which are slightly older than the mineralization,have(;Sr/;Sr)i-=0.7127–0.7162,εNd(t)=–13.7 to–17.0,andεHf(t)=–14.6 to–16.9,and display enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements.Two lamprophyres(226 and225 Ma),which are slightly younger than the mineralization,have higher(;Sr/;Sr)i(0.7165–0.7216),negativeεNd(t)(–11.2 to–14.3)andεHf(t)(–15.6 to–18.6)values,and are enriched in light rare earth elements but depleted in high field strength elements(Nb and Ta).The geochemical characteristics of the granitoid and lamprophyres indicate a lower crustal and enriched mantle source,respectively.We infer that the Linjiasandaogou Au deposit formed in a postcollisional tectonic setting,following the collision between the North China,Yangtze craton,and Central Asian Orogeny in Triassic.展开更多
Hydroxycitric acid （HCA） is derived primarily from the Garcinia plant and is widely used for its anti-in- flammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this stu...Hydroxycitric acid （HCA） is derived primarily from the Garcinia plant and is widely used for its anti-in- flammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund＇s Adjuvant （CFA） emulsion containing myelin oligodendrocyte glycoprotein （35-55）. Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reduc- tase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress.展开更多
Geochemical maps are of great value in mineral exploration.Integrated geochemical anomaly maps provide comprehensive information about mapping assemblages of element concentrations to possible types of mineralization/...Geochemical maps are of great value in mineral exploration.Integrated geochemical anomaly maps provide comprehensive information about mapping assemblages of element concentrations to possible types of mineralization/ore,but vary depending on expert's knowledge and experience.This paper aims to test the capability of deep neural networks to delineate integrated anomaly based on a case study of the Zhaojikou Pb-Zn deposit,Southeast China.Three hundred fifty two samples were collected,and each sample consisted of 26 variables covering elemental composition,geological,and tectonic information.At first,generative adversarial networks were adopted for data augmentation.Then,DNN was trained on sets of synthetic and real data to identify an integrated anomaly.Finally,the results of DNN analyses were visualized in probability maps and compared with traditional anomaly maps to check its performance.Results showed that the average accuracy of the validation set was 94.76%.The probability maps showed that newly-identified integrated anomalous areas had a probability of above 75%in the northeast zones.It also showed that DNN models that used big data not only successfully recognized the anomalous areas identified on traditional geochemical element maps,but also discovered new anomalous areas,not picked up by the elemental anomaly maps previously.展开更多
基金funded by the National Natural Science Foundation of China (32370456)the Key Project of Natural Sciences Foundation of Sichuan Province (22NSFSC0011)。
文摘Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In particular,the causes of how male-male competition promotes the increased cognitive abilities to increase brains are as yet unexplored in anurans.To evaluate the effect of male-male competition on variation in brain size in B.andrewsi,we compared the differences in relative brain size between mated males and unpaired males under natural and experimental conditions.We found that mated males had relatively larger brains than unpaired males in a natural population when controlling the effect of body size.Likewise,we also found that there were larger brains in mated males than in unpaired males in both experiment 1 where two males competed for a female and experiment 2 where three males competed for a female,suggesting that males with mating success during male-male competition possess increased brain size and cognitive abilities.When we compared difference in relative brain size in mated males between experiment2 and experiment 1 we found that males experiencing more intense competition did not display larger brains than males experiencing relatively weak competition,suggesting that low intensity competition is already enough to trigger the increase in relative brain size in B.andrewsi.
基金supported by the National Key Research and Development Program of China(No.2022YFC2905004)Open Fund from Sino Probe Laboratory(No.SL202405)+4 种基金the Basic Research Fund of Institute of mineral Resource,Chinese Academy of Geological Sciences(No.JKYZD202316)the National Natural Science Foundation of China(Nos.42272093,42230813)China Scholarship Council Project,and the Geological Survey Project(No.DD20230054)Science and Technology Support Project in a new round of prospecting breakthrough strategic action(No.ZKKJ202429)the Central Government Guided Local Scientific and Technological Development Funding Project(No.XZ202401YD0006)。
文摘The giant Jiama deposit is a post-collisional porphyry Cu-polymetallic system located in the Gangdese metallogenic belt of Xizang.It consists of three deposits:The Main deposit,the Zegulangbei deposit,and the South Pit deposit according to exploration and research.The South Pit deposit is a high-grade Cu-Pb-Zn deposit,but its genesis is unclear.To investigate its genesis,a detailed study was conducted on the deposit geology,geochronology and amphibole geochemistry.The results indicate that the weighted average 206Pb/238U age of the zircons from the granite porphyry in the South Pit is 15.38±0.45 Ma,and the molybdenite from the mineralized skarn yield a ReOs isochron age of 15.23±0.22 Ma,in line with the age of the Main deposit(15.7-14.3 Ma).The amphiboles in the granite porphyry of the South Pit,magnesiohornblende and actinolite,are high in Mg and Ca and low in K.They crystallized at temperatures of 705-7490C,pressures of 0.44-0.67 kbar,oxygen fugacity of-14.31--13.69(NNO),and depths of 1.7-2.5 km.Mapping of structure and alteration indicates that the South Pit skarn developed due to the metasomatism of marble of hornfels or carbonate in fold hinge dilation and an interlayer detachment zone by magmatic hydrothermal fluids.According to the age of magmatism and geological features,the South Pit deposit and the Main deposit have originated from the same Miocene magmatism,but the South Pit deposit was affected by the gliding nappe tectonic system.The amphibole geochemistry indicates that the ore-related magma of the South Pit has a high oxygen fugacity and is rich in water.
基金supported by the Major Program of National Social Science Foundation,China(19ZDA083)National Natural Science Foundation,China(71603193 and 71974151)Teaching&Research Project of Wuhan University,China(1201-413200127)。
文摘With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. 2010B25814)the Philosophy and Social Science Foundation of Hohai University (Grant No. 2007402011)+1 种基金the Philosophy and Social Science Foundation of Jiangsu Province (Grant No. 07EYC059)a special project of the Ministry of Water Resources of the People's Republic of China (Grant No. 5006518023)
文摘This paper introduces the method of data envelopment analysis （DEA） for evaluation of the degree of harmony between water resources and economic development of the water conservancy area of China＇s South-to-North Water Diversion Project （SNWDP）. For this evaluation, a super-efficiency DEA （SEDEA） model was developed based on the super-efficiency method. To verify the applicability of the SEDEA model, both the SEDEA model and a normal-efficiency DEA （NEDEA） model were used to evaluate the degree of harmony between water resources and economic development of typical cities in the SNWDP water conservancy area. The results show that the SEDEA model ranks the degree of harmony of typical cities more efficiently than the NEDEA model, and thus can better evaluate the degree of harmony between water resources and economic development of different cities than the NEDEA model. Furthermore, the SEDEA model can be applied as an operational research tool in regional water resources management.
文摘Traditional risk factors fall into four categories： natural disasters, public health, accidents during production and social security. The four types of risks are called as public safety issues by the government of China. New risk factors are the ones that are connected to human discoveries and more attention to them, which is called locking risk. What is more, such risk factors will continue to emerge with the development of human society. Currently, traditional risk factors have not been eliminated, while new risks have emerged gradually. There are countless relations between new risks and global climatic changes. Therefore, figuring out the relationship between new risks, global climatic changes as well as natural disasters is of great importance. This study takes China as an example. The population data at county level in China in 1991, 2000 and 2009 （including rural population, urban population and total population of three） were selected. By calculating the urbanization rate of the population, the rate of urbanization at county level in China in three years was drawn. And it is superimposed with the disaster zoning in China to analyze the correlation between population changes and natural disasters and reveal the magnitude of disaster effects caused by population urbanization. It can provide the basis for the disaster chain risk assessment under the gnidanee of the regional law of China＇s natural disaster chain and lay the foundation for the study of the relationship between new risk factors and traditional risk factors. So, risks governance can be perfectly combined with developing the green economy during the development of human society, and ultimately, the goal of harmony between human and nature can be achieved.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.42302235,41830211,42272100)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(Grant No.23ptpy143)。
文摘It is well established that Cretaceous magmatism in the South China Block(SCB)is related to the Paleo-Pacific subduction.However,the starting time and the associated deep crust-mantle processes are still debatable.Mafic dike swarms carry important information on the deep earth(including mantle)geodynamics and geochemical evolution.In the Jiangnan Orogen(South China).there is no information on whether the Mesozoic magmatic activities in this region are also directly related to the Pacific subduction or not.In this study,we present detailed zircon U-Pb geochronological,wholerock element and Sr-Nd isotope data for Early Cretaceous Tuanshanbei dolerite dikes,and provide new constraints on the condition of the lithospheric mantle and mantle dynamics of the SCB during that time.LA-ICP-MS zircon U-Pb dating suggests that this dolerite erupted in the Early Cretaceous(~145 Ma).All samples have alkaline geochemical affinities with K_(2)O+Na_(2)O=3.11-4.04 wt%,K_(2)O/Na_(2)O=0.50-0.72,and Mg^(#)=62.24-65.13.They are enriched in LILE but depleted in HFSE with higher initial^(87)Sr/^(86)Sr ratio(0.706896-0.714743)and lower ε_(Nd)(t)(-2.61 to-1.67).They have high Nb/U,Nb/La,La/Sm and Rb/Sr,and low La/Nb,La/Ta,Ce/Pb,Ba/Rb,Tb/Yb and Gd/Yb ratios.Such geochemical signatures suggest that the fractional crystallization is obvious but crustal contamination play a negligible role during magmatic evolution.Tuanshanbei dolerite were most likely derived from low-degree(2%-5%)partial melting of a phlogopite-bearing mantle material consisted of~85% spinel peridotite and~15% garnet peridotite previously metasomatized by asthenospherederived fluids/melts with minor subduction-derived fluids/melts.Slab-rollback generally lead to the upwelling of the hot asthenosphere.The upwelling of asthenosphere consuming the lithospheric mantle by thermo-mechanical-chemical erosion.The lithospheric mantle may have partially melted due to the heating by the upwelling asthenosphere and lithospheric extension.It is inferred that the Tuanshanbei dolerite might be associated with the initial slab rollback and corresponding lithospheric extension occurred potentially at ca.145 Ma.
文摘In recent years,China has made remarkable technological progress in a number of areas.Given this progress,it is crucial to rapidly transform technological results into productivity gains.
文摘The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the basins as the rifting process cannot be accurately described by a simple (one episode) stretching model. The study shows that the multiphase stretching model, combined with the back-stripping technique, can be used to reconstruct the subsidence history and the stretching process of the lithosphere, and to evaluate the depth to the top of the asthenosphere and the deep thermal evolution of the basins. The calculated results obtained by applying the quantitative model to the episodic rifting process of the Tertiary Qiongdongnan and Yinggehai basins in the South China Sea are in agreement with geophysical data and geological observations. This provides a new method for quantitative evaluation of the geodynamic process of multiphase rifting occurring during the Tertiary in eastern China.
文摘This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy issues concerning the building of a new socialist countryside, especially from the perspective of balancing urban and rural development. The underlying viewpoint of this article is that to promote the building of a new countryside, a system and mechanism of balancing urban and rural development must be gradually established and improved. The policies should focus on improving the social mobility mechanism to remove the institutional barriers to the social mobility of farmers; establishing public finances to cover both urban and rural areas to narrow the gap in basic public service provision between cities and the countryside; expediting the establishment of a social security network to protect the interests of rural disadvantaged groups; improving the mechanism of protecting land-use rights and interests of farmers; effectively organizing the mechanism of ensuring allocations for the building of a new countryside; improving the organizational structure of rural society to support self-organized farmers' groups; and changing the concept of rural governance and the operation of social governance.
基金financially supported by the Major Program of National Social Science Foundation (No.16ZDA006)National Natural Science Foundation of China (Nos.71603193 and 71974151)Teaching and Research Project of Wuhan University (No.1201-413200127)。
文摘This study aims to investigate the influence of rapid economic development on pollution at the municipal level in China.It constructs a Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT model) and uses comprehensive municipal data on industrial pollution and economic performance.The dataset contains 290 cities from2003 to 2016 as a sample for the panel data analysis.The study further separates the cities into two groups by their levels of economic development for heterogeneity analysis.It reveals that a low level of economic development would aggravate environmental pollution,and when the economy reaches a high level,this economic development will improve environmental quality.We also find that the relationships between foreign direct investment and industrial dust and sulfur dioxide(SO_2) discharge are significant,while the relationship between economic growth and effluent emission is not.The more developed subsample cities present an inverted U-shaped curve between industrial pollutant emission,GDP per capita,and foreign direct investment,while the less developed subsamples show no such relationship.Since the shape of these curves differs among regions,their turning points vary accordingly.Based on this finding,this study suggests that the governments of more developed cities should balance environmental pollution and economic development by enhancing environmental regulations and adjusting industrial structure.
文摘Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction （HDE） and solvent-free microwave extraction （SME） oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME （56.7%） and HDIE （60.0%） oils were significantly different （P〈0.05） from those of sea water （63.3%） and chloramphenicol （15.0%）. Larva lethality was different significantly （P〈0.05） between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration （LC50） of the oils was 〉 1000 mg/ml recommended as an index for non-toxicity which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.
基金the financial support of Govan Mbeki Research Development Centre, University of Fort Hare, South Africa.Grant number C127
文摘Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000 and 5000 mg/kg） and subacute （200, 400 and 600 mg/kg） toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. Results： In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degen- eration. Conclusion： These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.
文摘Phosphite (Phi)-based fungicides are used to control the oomycete Phytophthora infestans which causes late blight disease, the most devastating disease in potatoes. In order to examine the effects of Phi-based fungicides on potato tubers through foliar or post-harvest application, a metabolite profiling approach based on gas chromatography coupled to mass spectrometry (GC-MS) has been established. A total of 132 metabolites were detected using the GC-MS approach. Among these, 34 metabolites were identified after normalization and annotated with a compound name with standard mass spectral library. Metabolomic analysis of Phi-treated plants showed significant differences in the levels of many metabolites especially amino acids. Multivariate statistical approaches, such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), were employed to explore the relationships between metabolites to detect group differences. A good discrimination between the control and the Phi-treated plants was observed, which demonstrated that significant changes in the metabolite profile have been caused by the two different Phi applications (foliar or post-harvest). This finding suggests that the alteration of specific metabolite levels by accumulation of Phi can lead to resistance against the pathogen.
文摘Objective: To evaluate the antioxidant activities and phytochemical content of the leaf and root extracts of Rumex crispus using the solvents extraction; methanol extract,ethanol extract, acetone extract(ACE), and water extract.Methods: Total flavonoids content, total phenolic content, and total proanthocyanidin were evaluated using spectrophotometric equivalents of the standards, quercetin, gallic acid and catechin respectively. The antioxidant activities of the plant extracts were determined using ABTS, DPPH, ferric reducing antioxidant power, total antioxidant capacity and nitric oxide scavenging assays.Results: The flavonoids and phenols contents of the extracts were in the range of(19.39 ± 4.08) to(526.23 ± 17.52) mg QE/g and(16.95 ± 12.03) to(240.68 ± 3.50) mg GAE/g, respectively. ACE of the leaf has the highest value of total flavonoids content(526.23 ± 17.52) mg QE/g while ACE of the root has the highest value of total phenolic content(240.68 ± 3.50) mg GAE/g. The highest content of total proanthocyanidin(645.38 ± 1.33) mg CE/g was in ACE of the root. Significant amounts of saponin and alkaloid were also present in the root and leaf extracts. All solvent fractions showed significant antioxidant activities(P < 0.05) with ACE of the root having the highest scavenging value as shown in DPPH, ABTS, total antioxidant capacity, nitric oxide and ferric reducing antioxidant power(IC50= 0.014 mg/m L, <0.005 mg/m L, 0.048 mg/m L,0.067 mg/m L, and 0.075 mg/m L, respectively).Conclusions: In this study, the mean phytochemical content of the root of Rumex crispus is higher than that of the leaf and this may have contributed to its high antioxidant activities. This may also justify the frequent use of the root more than the leaves in traditional medicine for the cure of helminthic infections.
文摘1 Introduction The conflict between resources and the environment has been increasingly outstanding as the population,economy and society around the globe have developed rapidly since the 21st century.An important challenge that the human
基金jointly the National Key Research and Development Program of China(Grant Nos.2018YFC0603806 and 2017YFC0601506)the National Natural Science Foundation of China(Grant No.41902101)the Geological Survey Program of China(Grant No.DD20190166)。
文摘The Linjiasandaogou gold deposit is located in the Qingchengzi Orefield,North China Craton,China,and has not attracted many studies.We present geochronological,whole-rock geochemical,and Sr–Nd–Hf isotopic data to constrain the age and tectonic setting of the mineralization.U–Pb dating of zircon from pre-and post-ore dikes indicates the Linjiasandaogou Au deposit formed at ca.227–226 Ma.The granite porphyry(ca.227 Ma)and quartz diorite porphyry(ca.228 Ma),which are slightly older than the mineralization,have(;Sr/;Sr)i-=0.7127–0.7162,εNd(t)=–13.7 to–17.0,andεHf(t)=–14.6 to–16.9,and display enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements.Two lamprophyres(226 and225 Ma),which are slightly younger than the mineralization,have higher(;Sr/;Sr)i(0.7165–0.7216),negativeεNd(t)(–11.2 to–14.3)andεHf(t)(–15.6 to–18.6)values,and are enriched in light rare earth elements but depleted in high field strength elements(Nb and Ta).The geochemical characteristics of the granitoid and lamprophyres indicate a lower crustal and enriched mantle source,respectively.We infer that the Linjiasandaogou Au deposit formed in a postcollisional tectonic setting,following the collision between the North China,Yangtze craton,and Central Asian Orogeny in Triassic.
基金supported by Vice Chancellor for Research,Alborz University of Medical Sciences,No.1394-01-01-1050
文摘Hydroxycitric acid （HCA） is derived primarily from the Garcinia plant and is widely used for its anti-in- flammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund＇s Adjuvant （CFA） emulsion containing myelin oligodendrocyte glycoprotein （35-55）. Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reduc- tase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress.
基金supported by NFSC Funds(Grant Nos.41902071 and 42011530173)the Doctoral Research Start-up Fund,East China University of Technology(DHBK2019313)。
文摘Geochemical maps are of great value in mineral exploration.Integrated geochemical anomaly maps provide comprehensive information about mapping assemblages of element concentrations to possible types of mineralization/ore,but vary depending on expert's knowledge and experience.This paper aims to test the capability of deep neural networks to delineate integrated anomaly based on a case study of the Zhaojikou Pb-Zn deposit,Southeast China.Three hundred fifty two samples were collected,and each sample consisted of 26 variables covering elemental composition,geological,and tectonic information.At first,generative adversarial networks were adopted for data augmentation.Then,DNN was trained on sets of synthetic and real data to identify an integrated anomaly.Finally,the results of DNN analyses were visualized in probability maps and compared with traditional anomaly maps to check its performance.Results showed that the average accuracy of the validation set was 94.76%.The probability maps showed that newly-identified integrated anomalous areas had a probability of above 75%in the northeast zones.It also showed that DNN models that used big data not only successfully recognized the anomalous areas identified on traditional geochemical element maps,but also discovered new anomalous areas,not picked up by the elemental anomaly maps previously.
