In order to explore the influence of wet nitrogen(N)deposition on N output in watersheds,this study selected a typical small watershed(Chenjiagou,CJG)in the Three Gorges Reservoir(TGR)area based on one-year observatio...In order to explore the influence of wet nitrogen(N)deposition on N output in watersheds,this study selected a typical small watershed(Chenjiagou,CJG)in the Three Gorges Reservoir(TGR)area based on one-year observation of rainfallrunoff N forms.Characteristics and sources of N output were clarified by chemical statistics and isotopic abundance,and the contribution of N deposition to the N output was quantified by the output coefficient method.The N flux of wet deposition was estimated at 18.53 kg N ha^(-1) yr^(-1),and originated mostly from agricultural activities.Watershed N was significantly accumulated from upper to lower reaches due to frequent human activities.Seasonal changes of riverine N were strongly affected by chemical fertilizer,with the highest concentration in spring and the lowest in winter.Nitrate was mainly derived from chemical fertilizer,accounting for 38.83% of all sources.N concentration in processes of different rainfall events had a hysteresis effect corresponding to the flow rate.Three rainfall events greatly changed DTN(Dissolved total N)outputs:rainstorm caused 91.26 kg DTN output,which was 11 times that of moderate rain(8.46 kg)and 4 times that of heavy rain(20.80 kg).N deposition contributed 19.89% of riverine N output in the watershed.The results can provide theoretical support for the control of N pollution in the TGR area.展开更多
The thesis gives a brief account of the status of the labor economy in Three Gorges Reservoir area,which indicates that the labor economy in this area has made certain development and is characterized by fragile ecolo...The thesis gives a brief account of the status of the labor economy in Three Gorges Reservoir area,which indicates that the labor economy in this area has made certain development and is characterized by fragile ecology,backward economic development and weak capacity to absorb employment,the Three Gorges Reservoir area is densely populated and has lots of rural surplus labors which need to be transferred.Then the thesis analyzes the problems in the labor export of this region,which can be manifested in the following aspects:the exported labors are with low quality and single skill;they are narrow-minded and have strong intention for their employment regions;they have low income but high risk to get employed;the government does not provide strong supporting services for exported labors.In order to solve these problems,the thesis proposes the suggestions and measures to develop the labor economy in Three Gorges Reservoir area,say,to perfect and ameliorate the training mechanism and improve the quality and skills of labors;to build the platform of employment network and solve the problems of the asymmetric employment information;to actively develop the intermediary organizations and promote the a proper movement of labor forces;to fully exert the function of government in logistic services and resolve the difficulties of the exported workers.展开更多
Abiotic stress,including flooding,seriously affects the normal growth and development of plants.Mulberry(Morus alba),a species known for its flood resistance,is cultivated worldwide for economic purposes.The transcrip...Abiotic stress,including flooding,seriously affects the normal growth and development of plants.Mulberry(Morus alba),a species known for its flood resistance,is cultivated worldwide for economic purposes.The transcriptomic analysis has identified numerous differentially expressed genes(DEGs)involved in submergence tolerance in mulberry plants.However,a comprehensive analyses of metabolite types and changes under flooding stress in mulberry remain unreported.A non-targeted metabolomic analysis utilizing liquid chromatographytandem mass spectrometry(LC-MS/MS)was conducted to further investigate the effects of flooding stress on mulberry.A total of 1,169 metabolites were identified,with 331 differentially accumulated metabolites(DAMs)exhibiting up-regulation in response to flooding stress and 314 displaying down-regulation.Pathway enrichment analysis identified significant modifications in many metabolic pathways due to flooding stress,including amino acid biosynthesis and metabolism and flavonoid biosynthesis.DAMs and DEGs are significantly enriched in the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways for amino acid,phenylpropanoid and flavonoid synthesis.Furthermore,metabolites such as methyl jasmonate,sucrose,and D-mannose 6-phosphate accumulated in mulberry leaves post-flooding stress.Therefore,genes and metabolites associated with these KEGG pathways are likely to exert a significant influence on mulberry flood tolerance.This study makes a substantial contribution to the comprehension of the underlying mechanisms implicated in the adaptation of mulberry plants to submergence.展开更多
This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthes...This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiologicaland biochemical characteristics. At present, some studies have only studied the rhizosphere microbialcommunity characteristics of F. taipaiensis and have not discussed the effects of different microbial species on thegrowth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria toconduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compoundinoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilizedsoil functioning as the control group. The results reveal that intercellular CO_(2) concentration (Ci), stomatal conductance(Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited anincrease in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase(SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD,and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. Theinoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. taipaiensis.The composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis,manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuableinsights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.展开更多
Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly...Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly increased.This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F.taipaiensis P.Y.Li to the cultivation process of F.taipaiensis P.Y.Li.The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F.taipaiensis P.Y.Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis,physiological and biochemical properties,and gene expression related to the protective enzyme system in F.taipaiensis P.Y.Li.The experiment,conducted in pots at room temperature,included a control group(CK)and groups inoculated with inorganic phosphorussolubilizing bacteria:W1(Bacillus cereus),W2(Serratia plymuthica),W12(Bacillus cereus and Serratia plymuthica),and groups inoculated with organophosphorus-solubilizing bacteria:Y1(Bacillus cereus),Y2(Bacillus cereus),Y12(Bacillus cereus and Bacillus cereus),totaling seven groups.Compared to CK,most growth indices in the bacterial addition groups showed significant differences,with W12 achieving the highest values in all indices except the leaf area index.The content of photosynthetic pigments,photosynthetic parameters,and osmoregulatory substances increased variably in each bacterial treatment group.W12 exhibited the highest content of chlorophyll a and soluble protein,while W1 had the highest free proline content.The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT)in all inoculated groups were higher than in CK,with significant changes in SOD and CAT activities.The malondialdehyde(MDA)content in all inoculated groups was lower than in CK,with Y12 being the lowest,at approximately 30%of CK.Gene expression corresponding to these three enzymes also increased variably,with POD expression in Y2 being the highest at 2.73 times that of CK.SOD and CAT expression in Y12 were the highest,at 1.84 and 4.39 times that of CK,respectively.These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F.taipaiensis P.Y.Li,with the mixed inoculation groups W12 and Y12 demonstrating superior effects.This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F.taipaiensis P.Y.Li.展开更多
Zirconia ceramics have become increasingly widely used in recent years and are favored by relevant enterprises. From the traditional dental field to aerospace, parts manufacturing has been used, but there is limited r...Zirconia ceramics have become increasingly widely used in recent years and are favored by relevant enterprises. From the traditional dental field to aerospace, parts manufacturing has been used, but there is limited research on the deformation and damage process of zirconia ceramics. This article analyzes the acoustic emission characteristics of each stage of ceramic damage from the perspective of acoustic emission, and explores its deformation process characteristics from multiple perspectives such as time domain, frequency, and EWT modal analysis. It is concluded that zirconia ceramics exhibit higher brittleness and acoustic emission strength than alumina ceramics, and when approaching the fracture, it tends to generate lower frequency acoustic emission signals.展开更多
To understand heavy metal content in soil of rural landfill in Chongqing,samples were collected at 10 sampling sites of different counties.Zn,Cr,Cu,Cd and Pb contents were analyzed,and their pollution degrees were eva...To understand heavy metal content in soil of rural landfill in Chongqing,samples were collected at 10 sampling sites of different counties.Zn,Cr,Cu,Cd and Pb contents were analyzed,and their pollution degrees were evaluated by single-factor evaluation and index of geoaccumulation. Results displayed that there was no Cr pollution in soil of rural landfill in Chongqing,but Cd pollution was very serious. Pb,Zn and Cu showed spatial difference in different counties. Dispersion degrees of Zn and Pb pollution were lower,and their pollution degrees were also relatively lower.Dispersion degree of Cu pollution was higher,and its pollution degree was also relatively higher.展开更多
As rapid development of economy and acceleration of urbanization process,air pollution problem in Chongqing was more and more prominent. By referring to statistical yearbook and investigating energy usage and economy ...As rapid development of economy and acceleration of urbanization process,air pollution problem in Chongqing was more and more prominent. By referring to statistical yearbook and investigating energy usage and economy activity levels of various industrial sectors of Chongqing,basic data( activity level,energy production and consumption situation) of various economic sectors of Chongqing during 2007-2012 were obtained. Using emission coefficient method,soot emission inventory in Chongqing during 2007-2012 was established. Meanwhile,input-output model containing environmental factor was established to study relationship between economy development and environmental protection and number relationship between economy development and pollutant emission. According to the results,countermeasures of emission reduction in Chongqing were put forward.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 are...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
When multiple ground-based radars(GB-rads)are utilized together to resolve three-dimensional(3-D)deformations,the resolving accuracy is related with the measurement geometry constructed by these radars.This paper focu...When multiple ground-based radars(GB-rads)are utilized together to resolve three-dimensional(3-D)deformations,the resolving accuracy is related with the measurement geometry constructed by these radars.This paper focuses on constrained geometry analysis to resolve 3-D deformations from three GB-rads.The geometric dilution of precision(GDOP)is utilized to evaluate 3-D deformation accuracy of a single target,and its theoretical equation is derived by building a simplified 3-D coordinate system.Then for a 3-D scene,its optimal accuracy problem is converted into determining the minimum value of an objective function with a boundary constraint.The genetic algorithm is utilized to solve this constrained optimization problem.Numerical simulations are made to validate the correctness of the theoretical analysis results.展开更多
To address the restriction of fiber-optic surface plasmon resonance(SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-typ...To address the restriction of fiber-optic surface plasmon resonance(SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-type structure and microsphere structure is proposed in this paper. The fiber sidepolishing technique converts the coaxial dual-waveguide fiber into a D-type one, and the evanescent wave in the ring core leaks, generating a D-type sensing region;the fiber optic fused ball push technology converts the coaxial dual waveguides into microspheres, and the stimulated cladding mode evanescent wave leaks, producing the microsphere sensing region. By injecting light into the coaxial dual-waveguide middle core alone, the sensor can realize single-stage sensing in the microsphere sensing area;it can also realize dual-channel sensing in the D-type sensing area and microsphere sensing area by injecting light into the ring core. The refractive index measurement ranges for the two channels are 1.333–1.365 and 1.375–1.405, respectively, with detection sensitivities of 981.56 nm/RIU and 4138 nm/RIU. The sensor combines wavelength division multiplexing and space division multiplexing technologies, presenting a novel research concept for multi-channel fiber SPR sensors.展开更多
Numerous studies have focused on modern hydroclimate and the modulated mechanisms in the Tianshan Mountains(TMs),arid central Asia.However,the detailed information of hydroclimatic processes beyond the instrumental pe...Numerous studies have focused on modern hydroclimate and the modulated mechanisms in the Tianshan Mountains(TMs),arid central Asia.However,the detailed information of hydroclimatic processes beyond the instrumental period is still scarce.This paper reconstructed a hydrology history from core sediments of the Dalongchi Lake in the Tianshan Mountains.The comparability between endmembers(EMs)of grain size and ICP-AES based geochemical elements in the lake sediments highlighted their availability for hydrological reconstructions.Hydrodynamic forces(EM1,EM4,Ti/Al and Li/Al),chemical weathering intensity[(Mg+Ca+K)/Al],salinity proxy(Mg/Ca)and redoxsensitive proxy(Fe/Mn)highly correlated with the first principal component(P<0.01),whereas paleoproductivity proxies(TN,TOC,Ba/Al,Zn/Al and Cu/Al)and C/N showed high loadings on the second principal component(P<0.05).The inferred hydrology progress was nonlinearly responded to temperature,precipitation and climate-dictated glaciers.Specifically,the water level didn’t always covary with the humidity because of glaciers.The maximum water level was the comprehensive result of glaciers melting and high humidity around 1830 CE.Thereafter,water level continually decreased with declining moisture at high temperature,implying a limited buffering capacity of glaciers in the Dalongchi Lake basin.EM3-indicated eolian activity intensity was caused by the behaviors of Siberian High because the latter intensified surface wind and the dust transportation.The hydrothermal patterns were characterized by warm/dry and cold/wet alternations in a long run although warm/wet pattern was identified from a short-term view.展开更多
Fiber cladding surface plasmon resonance(SPR)sensors have few structures,and a clad SPR sensor based on S-type fiber is proposed in this paper.This new type of fiber cladding SPR sensor was formed by electrofusing an ...Fiber cladding surface plasmon resonance(SPR)sensors have few structures,and a clad SPR sensor based on S-type fiber is proposed in this paper.This new type of fiber cladding SPR sensor was formed by electrofusing an S-shaped structure on the fiber to couple the light in the fiber core to the cladding.In this paper,the effects of fiber parameters on the performance of the sensor were studied by simulation and experiment.Based on the conclusion that the smaller the core diameter is,the closer the working band of the SPR resonance is to long wavelengths,and that the geometric characteristics mean that a multimode fiber can receive the fiber cladding light from a small core diameter few-mode fiber,a dual channel SPR sensor with a double S-type fiber cascade was proposed.In the refractive index detection range of 1.333–1.385refractive index units(RIU),the resonant working band of channel I is 627.66 nm–759.78 nm,with an average sensitivity of 2540.77 nm/RIU,and the resonant working band of channel II is 518.24 nm–658.2 nm,with an average sensitivity of2691.54 nm/RIU.The processing method for the S-type fiber cladding SPR sensor is simple,effectively solving the problem of this type of SPR sensor structure and the difficult realization of a dual channel.The sensor is expected to be used in the fields of medical treatment and biological analysis.展开更多
Meituan Waimai,which was officially launched in November 2013,has created a huge market for food delivery in China.After years of development,China’s online food delivery market reached RMB 664.62 billion in 2020.In ...Meituan Waimai,which was officially launched in November 2013,has created a huge market for food delivery in China.After years of development,China’s online food delivery market reached RMB 664.62 billion in 2020.In 2022,Meituan Waimai and Ele.me,two food delivery platforms,have created a duopoly in China’s food delivery industry.Due to the success of the food delivery industry,a significant amount of food delivery packaging waste has caused far-reaching harm.This literature review primarily organizes the research on the impact of online food delivery packaging from the perspective of environmental protection.It uses the criterion layer index of online food delivery waste management ecosystem to analyze the impact of the government,environmental non-governmental organizations(NGOs),garbage recycling processors,consumers,online food delivery platforms,takeaway merchants,and takeaway packaging manufacturers.The review shows that scholars generally believe that takeaway waste management is a complex process involving multiple factors.The implementation of policies at the government level is inadequate,and studies at the environmental NGO level are scant.At the consumer level,more environmental awareness education is required.Online food delivery platforms and takeaway merchants should assume greater corporate social responsibility,and manufacturers of takeaway packaging need prioritize the substitution of environmentally friendly materials.There is a consensus that paper-made and recyclable packaging boxes are more environmentally friendly than degradable packaging,which is not as environmentally friendly as is commonly believed.The academia and the industry have conducted various studies and pilot projects on recyclable packaging.If all levels cooperate well,this will be an effective way to manage takeaway packaging garbage.At last,we propose the following assumptions for future research:Besides environmental hazards,takeaway garbage has caused direct or indirect physical harm to humans and animals.Increasing consumer awareness may increase their propensity to participate in governance.Additionally,existing food delivery platforms may need to improve their corporate social responsibility awareness to provide environmentally conscious consumers with sufficient and effective plastic reduction guidance measures during the ordering process.Moreover,will biodegradable plastic products face the same ironic situation as biofuels?That is,the initial intention of technology development is to improve the environment,but the actual process of production or processing may controversially aggravate the environment.展开更多
Logic gates are fundamental structural components in all modern digital electronic devices. Here, nonequilibrium Green's functions are incorporated with the density functional theory to verify the thermal spin tra...Logic gates are fundamental structural components in all modern digital electronic devices. Here, nonequilibrium Green's functions are incorporated with the density functional theory to verify the thermal spin transport features of the single-molecule spintronic devices constructed by a single molecule in series or parallel connected with graphene nanoribbons electrodes. Our calculations demonstrate that the electric field can manipulate the spin-polarized current. Then, a complete set of thermal spin molecular logic gates are proposed, including AND, OR, and NOT gates. The mentioned logic gates enable different designs of complex thermal spin molecular logic functions and facilitate the electric field control of thermal spin molecular devices.展开更多
It is important to understand the research trends and hotspots of global soil nutrient migration and control. Based on the core collection of WOS (Web of Science), citespace knowledge map analysis tool was used to ana...It is important to understand the research trends and hotspots of global soil nutrient migration and control. Based on the core collection of WOS (Web of Science), citespace knowledge map analysis tool was used to analyze the number of publications, cooperation networks, disciplines, research hotspots and frontier trends on nutrient migration in soil. The results showed that: the number of publications on the study of soil nutrient migration showed a good growth from 1990 to 2021. 173 countries had cooperative relationships. The number of articles published in the United States and China was significantly higher than that in other countries, while Chinese Academy of Sciences was the institution with the largest number of publications. It was a comprehensive system that permeates with agriculture, environmental science, botany and other disciplines. The research of nutrient migration in soil mainly focused on the measures of microbial community in different land types to promote nutrient transformation, improve soil fertility and reduce nutrient loss. In the future, the research trends will be the management measures of soil nutrient loss, the relationship between the change of soil nutrient and plant community diversity, and the remediation of agricultural contaminated soil. Through the above analysis, there was an overall understanding of soil nutrient migration. The research on nutrient migration may continue to increase in the future. It is suggested that Chinese research institutions, teams and universities need to strengthen international cooperation, and speed up their integration with the international community.展开更多
In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local ...In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local optimum of the standard fruit fly optimization algorithm. By using the information of the iteration number and the maximum iteration number, the proposed algorithm uses the floor function to ensure that the fruit fly swarms adopt the large step search during the olfactory search stage which improves the search speed;in the visual search stage, the small step is used to effectively avoid local optimum. Finally, using commonly used benchmark testing functions, the proposed algorithm is compared with the standard fruit fly optimization algorithm with some fixed steps. The simulation experiment results show that the proposed algorithm can quickly approach the optimal solution in the olfactory search stage and accurately search in the visual search stage, demonstrating more effective performance.展开更多
Based on the “Healthy China 2030 Planning Outline”, the literature method and logical analysis method are used to review and analyze the implementation process of China’s school football policy from three dimension...Based on the “Healthy China 2030 Planning Outline”, the literature method and logical analysis method are used to review and analyze the implementation process of China’s school football policy from three dimensions: value, interest appeal and institutional background. The study believes that in order to break through the bottleneck of policy implementation and improve the effect of policy implementation, it is necessary to establish correct values and form broad recognition of policies;meet the reasonable interests of all parties and form a synergy for policy implementation;optimize the institutional environment for policy implementation and form effective incentives.展开更多
Electromagnetic acoustic emission technology is one of nondestructive testing, which can be used for defect detection of metal specimens. In this study, round and cracked metal specimens, round metal specimens, and in...Electromagnetic acoustic emission technology is one of nondestructive testing, which can be used for defect detection of metal specimens. In this study, round and cracked metal specimens, round metal specimens, and intact metal specimens were prepared. And the electromagnetic acoustic emission signals of the three specimens were collected. In addition, the local mean decomposition(LMD), Autoregressive model(AR model) and least squares support vector machine (LSSVM) algorithms were combined to identify the eletromagnetic acoustic emission signals of round and cracked, round, and intact specimens. According to the algorithm recognition results, the recognition accuracy of can reach above 97.5%, which has a higher recognition rate compared with SVM and BP neural network. The results of the study show that the algorithm is able to identify quickly and accurately crack defect in metal specimens.展开更多
This paper analyzes the current situation of college teachers’teaching organization ability based on teaching implementation by using the literature method and inductive deduction method,and summarizes the factors af...This paper analyzes the current situation of college teachers’teaching organization ability based on teaching implementation by using the literature method and inductive deduction method,and summarizes the factors affecting the teaching ability of college public physical education teachers,in order to provide references for the improvement of the teaching effect of college physical education,and help the implementation of the national strategy of healthy China and sports power.The teaching implementation of physical education teachers in colleges and universities is mainly affected by the drafting of teaching objectives,teaching design,teaching evaluation,and other factors.The teaching workload makes teachers tired of teaching preparation,teaching design fails to think deeply about the major and learning situation,teaching evaluation method is single,and other phenomena.In view of the problems in the implementation of the curriculum,it is proposed to participate in education and teaching training to update the educational concept,regularly carry out teaching and research activities to improve the teaching organization ability,and write teaching logs to improve the ability of sustainable development.展开更多
基金supported by Youth Project of Science and Technology Research Program of Chongqing Education Commission of China(No.KJQN202101201)。
文摘In order to explore the influence of wet nitrogen(N)deposition on N output in watersheds,this study selected a typical small watershed(Chenjiagou,CJG)in the Three Gorges Reservoir(TGR)area based on one-year observation of rainfallrunoff N forms.Characteristics and sources of N output were clarified by chemical statistics and isotopic abundance,and the contribution of N deposition to the N output was quantified by the output coefficient method.The N flux of wet deposition was estimated at 18.53 kg N ha^(-1) yr^(-1),and originated mostly from agricultural activities.Watershed N was significantly accumulated from upper to lower reaches due to frequent human activities.Seasonal changes of riverine N were strongly affected by chemical fertilizer,with the highest concentration in spring and the lowest in winter.Nitrate was mainly derived from chemical fertilizer,accounting for 38.83% of all sources.N concentration in processes of different rainfall events had a hysteresis effect corresponding to the flow rate.Three rainfall events greatly changed DTN(Dissolved total N)outputs:rainstorm caused 91.26 kg DTN output,which was 11 times that of moderate rain(8.46 kg)and 4 times that of heavy rain(20.80 kg).N deposition contributed 19.89% of riverine N output in the watershed.The results can provide theoretical support for the control of N pollution in the TGR area.
文摘The thesis gives a brief account of the status of the labor economy in Three Gorges Reservoir area,which indicates that the labor economy in this area has made certain development and is characterized by fragile ecology,backward economic development and weak capacity to absorb employment,the Three Gorges Reservoir area is densely populated and has lots of rural surplus labors which need to be transferred.Then the thesis analyzes the problems in the labor export of this region,which can be manifested in the following aspects:the exported labors are with low quality and single skill;they are narrow-minded and have strong intention for their employment regions;they have low income but high risk to get employed;the government does not provide strong supporting services for exported labors.In order to solve these problems,the thesis proposes the suggestions and measures to develop the labor economy in Three Gorges Reservoir area,say,to perfect and ameliorate the training mechanism and improve the quality and skills of labors;to build the platform of employment network and solve the problems of the asymmetric employment information;to actively develop the intermediary organizations and promote the a proper movement of labor forces;to fully exert the function of government in logistic services and resolve the difficulties of the exported workers.
基金The funding for this research was provided by the General Program of Chongqing Natural Science Foundation(No.cstc2020jcyj-msxmX0073)Scientific and Technological Research Program of Chongqing Municipal Education Commission(Nos.KJQN202001209,KJZD-K202301206)Chongqing Graduate Research Innovation Project(CYS22698).
文摘Abiotic stress,including flooding,seriously affects the normal growth and development of plants.Mulberry(Morus alba),a species known for its flood resistance,is cultivated worldwide for economic purposes.The transcriptomic analysis has identified numerous differentially expressed genes(DEGs)involved in submergence tolerance in mulberry plants.However,a comprehensive analyses of metabolite types and changes under flooding stress in mulberry remain unreported.A non-targeted metabolomic analysis utilizing liquid chromatographytandem mass spectrometry(LC-MS/MS)was conducted to further investigate the effects of flooding stress on mulberry.A total of 1,169 metabolites were identified,with 331 differentially accumulated metabolites(DAMs)exhibiting up-regulation in response to flooding stress and 314 displaying down-regulation.Pathway enrichment analysis identified significant modifications in many metabolic pathways due to flooding stress,including amino acid biosynthesis and metabolism and flavonoid biosynthesis.DAMs and DEGs are significantly enriched in the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways for amino acid,phenylpropanoid and flavonoid synthesis.Furthermore,metabolites such as methyl jasmonate,sucrose,and D-mannose 6-phosphate accumulated in mulberry leaves post-flooding stress.Therefore,genes and metabolites associated with these KEGG pathways are likely to exert a significant influence on mulberry flood tolerance.This study makes a substantial contribution to the comprehension of the underlying mechanisms implicated in the adaptation of mulberry plants to submergence.
基金a Key Project of the Natural Science Foundation of Chongqing Education Committee(KJZD-K202101201).
文摘This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiologicaland biochemical characteristics. At present, some studies have only studied the rhizosphere microbialcommunity characteristics of F. taipaiensis and have not discussed the effects of different microbial species on thegrowth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria toconduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compoundinoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilizedsoil functioning as the control group. The results reveal that intercellular CO_(2) concentration (Ci), stomatal conductance(Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited anincrease in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase(SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD,and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. Theinoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. taipaiensis.The composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis,manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuableinsights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.
基金This work was funded by Chongqing Municipal Technology Innovation and Application Development Program(cstc2020jscx-gksb0001)Yunnan Academician(Expert)Workstation Project(202105AF150073).
文摘Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly increased.This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F.taipaiensis P.Y.Li to the cultivation process of F.taipaiensis P.Y.Li.The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F.taipaiensis P.Y.Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis,physiological and biochemical properties,and gene expression related to the protective enzyme system in F.taipaiensis P.Y.Li.The experiment,conducted in pots at room temperature,included a control group(CK)and groups inoculated with inorganic phosphorussolubilizing bacteria:W1(Bacillus cereus),W2(Serratia plymuthica),W12(Bacillus cereus and Serratia plymuthica),and groups inoculated with organophosphorus-solubilizing bacteria:Y1(Bacillus cereus),Y2(Bacillus cereus),Y12(Bacillus cereus and Bacillus cereus),totaling seven groups.Compared to CK,most growth indices in the bacterial addition groups showed significant differences,with W12 achieving the highest values in all indices except the leaf area index.The content of photosynthetic pigments,photosynthetic parameters,and osmoregulatory substances increased variably in each bacterial treatment group.W12 exhibited the highest content of chlorophyll a and soluble protein,while W1 had the highest free proline content.The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT)in all inoculated groups were higher than in CK,with significant changes in SOD and CAT activities.The malondialdehyde(MDA)content in all inoculated groups was lower than in CK,with Y12 being the lowest,at approximately 30%of CK.Gene expression corresponding to these three enzymes also increased variably,with POD expression in Y2 being the highest at 2.73 times that of CK.SOD and CAT expression in Y12 were the highest,at 1.84 and 4.39 times that of CK,respectively.These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F.taipaiensis P.Y.Li,with the mixed inoculation groups W12 and Y12 demonstrating superior effects.This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F.taipaiensis P.Y.Li.
文摘Zirconia ceramics have become increasingly widely used in recent years and are favored by relevant enterprises. From the traditional dental field to aerospace, parts manufacturing has been used, but there is limited research on the deformation and damage process of zirconia ceramics. This article analyzes the acoustic emission characteristics of each stage of ceramic damage from the perspective of acoustic emission, and explores its deformation process characteristics from multiple perspectives such as time domain, frequency, and EWT modal analysis. It is concluded that zirconia ceramics exhibit higher brittleness and acoustic emission strength than alumina ceramics, and when approaching the fracture, it tends to generate lower frequency acoustic emission signals.
基金Supported by Municipal Key Laboratory Project of Chongqing HigherSchool,China(WEPKL2013QN-02)Municipal Innovation and Entre-preneurship Training Program of University Student in Chongqing in2013,China(201310643003)
文摘To understand heavy metal content in soil of rural landfill in Chongqing,samples were collected at 10 sampling sites of different counties.Zn,Cr,Cu,Cd and Pb contents were analyzed,and their pollution degrees were evaluated by single-factor evaluation and index of geoaccumulation. Results displayed that there was no Cr pollution in soil of rural landfill in Chongqing,but Cd pollution was very serious. Pb,Zn and Cu showed spatial difference in different counties. Dispersion degrees of Zn and Pb pollution were lower,and their pollution degrees were also relatively lower.Dispersion degree of Cu pollution was higher,and its pollution degree was also relatively higher.
基金Supported by Municipal Key Laboratory Project of Chongqing HigherSchool,China(WEPKL2013MS-10)National Innovation and Entre-preneurship Training Program of University Student in 2013,China(201310643003)
文摘As rapid development of economy and acceleration of urbanization process,air pollution problem in Chongqing was more and more prominent. By referring to statistical yearbook and investigating energy usage and economy activity levels of various industrial sectors of Chongqing,basic data( activity level,energy production and consumption situation) of various economic sectors of Chongqing during 2007-2012 were obtained. Using emission coefficient method,soot emission inventory in Chongqing during 2007-2012 was established. Meanwhile,input-output model containing environmental factor was established to study relationship between economy development and environmental protection and number relationship between economy development and pollutant emission. According to the results,countermeasures of emission reduction in Chongqing were put forward.
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.
基金supported by the National Natural Science Foundation of China(61960206009,61971037,31727901)the Natural Science Foundation of Chongqing+1 种基金China(2020jcyj-jq X0008)Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-warning in Three Gorges Reservoir Area(ZD2020A0101)。
文摘When multiple ground-based radars(GB-rads)are utilized together to resolve three-dimensional(3-D)deformations,the resolving accuracy is related with the measurement geometry constructed by these radars.This paper focuses on constrained geometry analysis to resolve 3-D deformations from three GB-rads.The geometric dilution of precision(GDOP)is utilized to evaluate 3-D deformation accuracy of a single target,and its theoretical equation is derived by building a simplified 3-D coordinate system.Then for a 3-D scene,its optimal accuracy problem is converted into determining the minimum value of an objective function with a boundary constraint.The genetic algorithm is utilized to solve this constrained optimization problem.Numerical simulations are made to validate the correctness of the theoretical analysis results.
基金supported by the National Natural Science Foundation of China (Grant No. 61705025)the Natural Science Foundation of Chongqing (Grant Nos. cstc2019jcyjmsxm X043 and cstc2018jcyj AX0817)+2 种基金the Fund from the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality (Grant Nos. KJQN201801217, KJQN202001214, KJQN201901226, and KJ1710247)the Fund from Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-Warning in Three Gorges Reservoir Area (Grant Nos. ZD2020A0103 and ZD2020A0102)the Fundamental Research Funds for Chongqing Three Gorges University of China (Grant No. 19ZDPY08)。
文摘To address the restriction of fiber-optic surface plasmon resonance(SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-type structure and microsphere structure is proposed in this paper. The fiber sidepolishing technique converts the coaxial dual-waveguide fiber into a D-type one, and the evanescent wave in the ring core leaks, generating a D-type sensing region;the fiber optic fused ball push technology converts the coaxial dual waveguides into microspheres, and the stimulated cladding mode evanescent wave leaks, producing the microsphere sensing region. By injecting light into the coaxial dual-waveguide middle core alone, the sensor can realize single-stage sensing in the microsphere sensing area;it can also realize dual-channel sensing in the D-type sensing area and microsphere sensing area by injecting light into the ring core. The refractive index measurement ranges for the two channels are 1.333–1.365 and 1.375–1.405, respectively, with detection sensitivities of 981.56 nm/RIU and 4138 nm/RIU. The sensor combines wavelength division multiplexing and space division multiplexing technologies, presenting a novel research concept for multi-channel fiber SPR sensors.
基金financially supported by the National Natural Science Foundation of China(No.41902024U1203821L08)+3 种基金the Chongqing Science and Technology Commission(cstc2019jcyjmsxmX0656)the Talent Introduction Program of Chongqing Three Gorges University(17RC08)the Research Center for Sustainable Development of the Three Gorges Reservoir Area(18sxxyjd12)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022447)。
文摘Numerous studies have focused on modern hydroclimate and the modulated mechanisms in the Tianshan Mountains(TMs),arid central Asia.However,the detailed information of hydroclimatic processes beyond the instrumental period is still scarce.This paper reconstructed a hydrology history from core sediments of the Dalongchi Lake in the Tianshan Mountains.The comparability between endmembers(EMs)of grain size and ICP-AES based geochemical elements in the lake sediments highlighted their availability for hydrological reconstructions.Hydrodynamic forces(EM1,EM4,Ti/Al and Li/Al),chemical weathering intensity[(Mg+Ca+K)/Al],salinity proxy(Mg/Ca)and redoxsensitive proxy(Fe/Mn)highly correlated with the first principal component(P<0.01),whereas paleoproductivity proxies(TN,TOC,Ba/Al,Zn/Al and Cu/Al)and C/N showed high loadings on the second principal component(P<0.05).The inferred hydrology progress was nonlinearly responded to temperature,precipitation and climate-dictated glaciers.Specifically,the water level didn’t always covary with the humidity because of glaciers.The maximum water level was the comprehensive result of glaciers melting and high humidity around 1830 CE.Thereafter,water level continually decreased with declining moisture at high temperature,implying a limited buffering capacity of glaciers in the Dalongchi Lake basin.EM3-indicated eolian activity intensity was caused by the behaviors of Siberian High because the latter intensified surface wind and the dust transportation.The hydrothermal patterns were characterized by warm/dry and cold/wet alternations in a long run although warm/wet pattern was identified from a short-term view.
基金the National Natural Science Foundation of China(Grant No.61705025)Chongqing Natural Science Foundation(Grant Nos.cstc2019jcyjmsxmX0431 and cstc2018jcyjAX0817)+2 种基金the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality(Grant Nos.KJQN201801217,KJQN201901226,KJQN202001214,and KJ1710247)Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-Warning in Three Gorges Reservoir Area(Grant Nos.ZD2020A0103 and ZD2020A0102)Fundamental Research Funds for Chongqing Three Gorges University of China(Grant No.19ZDPY08).
文摘Fiber cladding surface plasmon resonance(SPR)sensors have few structures,and a clad SPR sensor based on S-type fiber is proposed in this paper.This new type of fiber cladding SPR sensor was formed by electrofusing an S-shaped structure on the fiber to couple the light in the fiber core to the cladding.In this paper,the effects of fiber parameters on the performance of the sensor were studied by simulation and experiment.Based on the conclusion that the smaller the core diameter is,the closer the working band of the SPR resonance is to long wavelengths,and that the geometric characteristics mean that a multimode fiber can receive the fiber cladding light from a small core diameter few-mode fiber,a dual channel SPR sensor with a double S-type fiber cascade was proposed.In the refractive index detection range of 1.333–1.385refractive index units(RIU),the resonant working band of channel I is 627.66 nm–759.78 nm,with an average sensitivity of 2540.77 nm/RIU,and the resonant working band of channel II is 518.24 nm–658.2 nm,with an average sensitivity of2691.54 nm/RIU.The processing method for the S-type fiber cladding SPR sensor is simple,effectively solving the problem of this type of SPR sensor structure and the difficult realization of a dual channel.The sensor is expected to be used in the fields of medical treatment and biological analysis.
文摘Meituan Waimai,which was officially launched in November 2013,has created a huge market for food delivery in China.After years of development,China’s online food delivery market reached RMB 664.62 billion in 2020.In 2022,Meituan Waimai and Ele.me,two food delivery platforms,have created a duopoly in China’s food delivery industry.Due to the success of the food delivery industry,a significant amount of food delivery packaging waste has caused far-reaching harm.This literature review primarily organizes the research on the impact of online food delivery packaging from the perspective of environmental protection.It uses the criterion layer index of online food delivery waste management ecosystem to analyze the impact of the government,environmental non-governmental organizations(NGOs),garbage recycling processors,consumers,online food delivery platforms,takeaway merchants,and takeaway packaging manufacturers.The review shows that scholars generally believe that takeaway waste management is a complex process involving multiple factors.The implementation of policies at the government level is inadequate,and studies at the environmental NGO level are scant.At the consumer level,more environmental awareness education is required.Online food delivery platforms and takeaway merchants should assume greater corporate social responsibility,and manufacturers of takeaway packaging need prioritize the substitution of environmentally friendly materials.There is a consensus that paper-made and recyclable packaging boxes are more environmentally friendly than degradable packaging,which is not as environmentally friendly as is commonly believed.The academia and the industry have conducted various studies and pilot projects on recyclable packaging.If all levels cooperate well,this will be an effective way to manage takeaway packaging garbage.At last,we propose the following assumptions for future research:Besides environmental hazards,takeaway garbage has caused direct or indirect physical harm to humans and animals.Increasing consumer awareness may increase their propensity to participate in governance.Additionally,existing food delivery platforms may need to improve their corporate social responsibility awareness to provide environmentally conscious consumers with sufficient and effective plastic reduction guidance measures during the ordering process.Moreover,will biodegradable plastic products face the same ironic situation as biofuels?That is,the initial intention of technology development is to improve the environment,but the actual process of production or processing may controversially aggravate the environment.
基金the Natioanl Natural Science Foundation of China (Grant No. 11864011)in part by Youth Project of Scientific and technological Research Program of Chongqing Education Commission (Grant No. KJQN202101204)。
文摘Logic gates are fundamental structural components in all modern digital electronic devices. Here, nonequilibrium Green's functions are incorporated with the density functional theory to verify the thermal spin transport features of the single-molecule spintronic devices constructed by a single molecule in series or parallel connected with graphene nanoribbons electrodes. Our calculations demonstrate that the electric field can manipulate the spin-polarized current. Then, a complete set of thermal spin molecular logic gates are proposed, including AND, OR, and NOT gates. The mentioned logic gates enable different designs of complex thermal spin molecular logic functions and facilitate the electric field control of thermal spin molecular devices.
文摘It is important to understand the research trends and hotspots of global soil nutrient migration and control. Based on the core collection of WOS (Web of Science), citespace knowledge map analysis tool was used to analyze the number of publications, cooperation networks, disciplines, research hotspots and frontier trends on nutrient migration in soil. The results showed that: the number of publications on the study of soil nutrient migration showed a good growth from 1990 to 2021. 173 countries had cooperative relationships. The number of articles published in the United States and China was significantly higher than that in other countries, while Chinese Academy of Sciences was the institution with the largest number of publications. It was a comprehensive system that permeates with agriculture, environmental science, botany and other disciplines. The research of nutrient migration in soil mainly focused on the measures of microbial community in different land types to promote nutrient transformation, improve soil fertility and reduce nutrient loss. In the future, the research trends will be the management measures of soil nutrient loss, the relationship between the change of soil nutrient and plant community diversity, and the remediation of agricultural contaminated soil. Through the above analysis, there was an overall understanding of soil nutrient migration. The research on nutrient migration may continue to increase in the future. It is suggested that Chinese research institutions, teams and universities need to strengthen international cooperation, and speed up their integration with the international community.
文摘In this paper, we present a new fruit fly optimization algorithm with the adaptive step for solving unconstrained optimization problems, which is able to avoid the slow convergence and the tendency to fall into local optimum of the standard fruit fly optimization algorithm. By using the information of the iteration number and the maximum iteration number, the proposed algorithm uses the floor function to ensure that the fruit fly swarms adopt the large step search during the olfactory search stage which improves the search speed;in the visual search stage, the small step is used to effectively avoid local optimum. Finally, using commonly used benchmark testing functions, the proposed algorithm is compared with the standard fruit fly optimization algorithm with some fixed steps. The simulation experiment results show that the proposed algorithm can quickly approach the optimal solution in the olfactory search stage and accurately search in the visual search stage, demonstrating more effective performance.
文摘Based on the “Healthy China 2030 Planning Outline”, the literature method and logical analysis method are used to review and analyze the implementation process of China’s school football policy from three dimensions: value, interest appeal and institutional background. The study believes that in order to break through the bottleneck of policy implementation and improve the effect of policy implementation, it is necessary to establish correct values and form broad recognition of policies;meet the reasonable interests of all parties and form a synergy for policy implementation;optimize the institutional environment for policy implementation and form effective incentives.
文摘Electromagnetic acoustic emission technology is one of nondestructive testing, which can be used for defect detection of metal specimens. In this study, round and cracked metal specimens, round metal specimens, and intact metal specimens were prepared. And the electromagnetic acoustic emission signals of the three specimens were collected. In addition, the local mean decomposition(LMD), Autoregressive model(AR model) and least squares support vector machine (LSSVM) algorithms were combined to identify the eletromagnetic acoustic emission signals of round and cracked, round, and intact specimens. According to the algorithm recognition results, the recognition accuracy of can reach above 97.5%, which has a higher recognition rate compared with SVM and BP neural network. The results of the study show that the algorithm is able to identify quickly and accurately crack defect in metal specimens.
基金Teaching reform project of Chongqing Three Gorges University(Project number:JGZC2111).
文摘This paper analyzes the current situation of college teachers’teaching organization ability based on teaching implementation by using the literature method and inductive deduction method,and summarizes the factors affecting the teaching ability of college public physical education teachers,in order to provide references for the improvement of the teaching effect of college physical education,and help the implementation of the national strategy of healthy China and sports power.The teaching implementation of physical education teachers in colleges and universities is mainly affected by the drafting of teaching objectives,teaching design,teaching evaluation,and other factors.The teaching workload makes teachers tired of teaching preparation,teaching design fails to think deeply about the major and learning situation,teaching evaluation method is single,and other phenomena.In view of the problems in the implementation of the curriculum,it is proposed to participate in education and teaching training to update the educational concept,regularly carry out teaching and research activities to improve the teaching organization ability,and write teaching logs to improve the ability of sustainable development.