检索结果-南通市图书馆

Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China

引用

Chinese Geographical Science 2023年第4期33卷 616-633页

作者： LI Dongmei WEN qing qi Yue ZHANG Pingyu Northeast Regional Development Research Center Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China School of Public Administration and Law Northeast Agricultural UniversityHarbin 150038China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions.

关键词： rural function depopulation trade-off and synergy typical black soil region Northeast China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis and Reactivity of Trifluoromethylthiophosphonium Salts

引用

Chinese Journal of Chemistry 2023年第21期41卷 2779-2787页

作者： Wen-qi Xu Xiu-Hua Xu Feng-Ling qing Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academyof Sciences345 LinglingLuShanghai 200032China

This article described an unprecedented synthesis of trifluoromethylthiophosphonium salts from allyl trifluoromethyl sulfoxide and phosphines in the presence of trimethylsilyl trifluoromethanesulfonate(TMSOTf)through Mislow-Evans-type rearrangement.The resulting trifluoromethylthiophosphonium salts were firstly isolated and fully characterized.These fluoroalkylphosphonium salts,as exemplified by trifluoromethylthio triphenylphosphonium salt(6a),exhibited unique and versatile reaction with nucleophiles and deoxygenative trifluoromethylthiolation reaction of carboxylic acids.Furthermore,the photoredox catalytic tunable radical hydrotrifluoromethylation and hydrotrifluoromethythiolation of unactivated alkenes with 6a was successfully.

关键词： Phosphonium salts Fluorine Rearrangement Trifluoromethylthiolation Synthetic methods

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Well logging evaluation of fine-grained hydrate-bearing sediment reservoirs: Considering the effect of clay content

引用

Petroleum Science 2023年第2期20卷 879-892页

作者： Lin-qi Zhu Jin Sun Xue-qing Zhou qing-Ping Li qi Fan Song-Lin Wu Shi-Guo Wu Laboratory of Marine Geophysics and Georesources of Hainan Province Institute of Deep-sea Science and EngineeringChinese Academy of SciencesSanya572000HainanChina Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao266061ShandongChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiGuangdong519000China State Key Laboratory of Natural Gas Hydrates Beijing100028China China National Offshore Oil Corporation Research Institute Co.Ltd. Beijing100028China

Hydrate reservoirs are different from the host reservoirs of all other fossil energy sources because the characteristics of hydrate reservoirs are generally controlled by deep-sea fine-grained sedimentation. In such reservoirs, the reliability of the classical logging evaluation models established for diagenetic reservoirs is questionable. This study used well W8 in the qiongdongnan Basin to explore the clay content, porosity, saturation, and hydrate-enriched layer identification of a logging-based hydrate reservoir, and it was found that considering the effect of the clay content on the log response is necessary in the logging evaluation of hydrate reservoirs. In the evaluation of clay content, a method based on the optimization inversion method can obtain a more reliable clay content than other methods. Fine-grained sediment reservoirs have a high clay content, and the effect of clay on log responses must be considered when calculating porosity. In addition, combining density logging and neutron porosity logging data can obtain the best porosity calculation results, and the porosity calculation method based on sonic logging predicted that the porosity of the studied reservoir was low. It was very effective to identify hydrate layers based on resistivity, but the clay distribution and pore structure will also affect the relationship between resistivity, porosity and saturation, and it was suggested that the factors effecting the resistivity of different layers should be considered in the saturation evaluation and that a suitable model should be selected. This study also considered the lack of clarity of the relationships among the lithology, physical properties, hydrate-bearing occurrence properties, and log response properties of hydrate reservoirs and the lack of specialized petrophysical models. This research can directly help to improve hydrate logging evaluation.

关键词： Gas hydrate Well logging Porosity Saturation Shale distribution form

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Non-contact gaseous microplasma electrode as anode for electrodeposition of metal and metal alloy in molten salt

引用

Chinese Chemical Letters 2024年第4期35卷 166-169页

作者： Junhan Luo Qi Qing Liqin Huang Zhe Wang Shuang Liu Jing Chen Yuexiang Lu Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China The MOE Key Laboratory of Resources and Environmental System Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China Nuclear Research Institute for Future Technology and Policy Seoul National UniversitySeoul 08826Republic of Korea

Microplasma based on glow discharge could act as a non-contact gaseous electrode and has attracted much attention in both fundamental research and application. Herein, with microplasma as the anode,the electrodeposition process of a series of metal and metal alloys in molten salt has been systemically studied. Four metal cations with different valence states, silver(Ag~+), nickel(Ni^(2+)), copper(Cu^(2+)), and iron(Fe^(3+)), could all be reduced on the solid cathode with high current efficiency and the corresponding metal products were of high purity. The electrodeposition of aluminum-lanthanum(Al-Ln) alloy on the aluminum cathode was also successfully carried out with microplasma as the anode, and the same alloy was obtained by using the conventional anode electrode. These results indicated that microplasma anode based on non-contact direct-current(DC) glow discharge is a promising electrode to be applied in molten salt electrolysis.

关键词： Microplasma Anode Molten salt Electrodeposition Al-Ln alloy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Danshensu Ameliorates Cardiac Ischaemia Reperfusion Injury through Activating Sirt1/Fox01/Rab7 Signal Pathway

引用

Chinese Journal of Integrative Medicine 2020年第4期26卷 283-291页

作者： SUN Da-wei GAO qing qi Xin Department of Neurology Tianjin Academy of Traditional Chinese Medicine Affiliated HospitalTianjin(300120)China School of Integrative Medicine Tianjin University of Traditional Chinese MedicineTianjin(301617)China Department of Cardiology Tianjin Union Medical CenterTianjin(300121)China

Objective:To explore the specific molecular mechanisms of Danshensu(DSS)in the treatment of ischemia reperfusion injury(IRI).Methods:IRI model was established with isolated rat hearts by performing global ischaemia for 30 min,and then followed by 60 min reperfusion.Also,H9C2 cells were subjected to 4-h hypoxia followed by 3-h reoxygenation.Then 10|i mol/L DSS were added in the reperfusion/reoxygenation step to intervene IRI.Cardiac function,structural change and apoptosis were respectively tested by Langendorff System,hematoxylin and eosin(HE)and terminal-deoxynucleotidyl transferase mediated nick endabeling(TUNEL)stainings.Then lactate dehydrogenase(LDH),cardiac troponin T(cTnT),reactive oxygen species(ROS),superoxide dismutase(SOD)and glutathione peroxidase(GSH-PX)were detected by enzyme-linked immunosorbent assay(ELISA).Sirt1/FoxO1/Rab7 Signal Pathway was monitored at both protein and mRNA levels.Results:The results showed that IRI not only greatly attenuated cardiac function(LVDP and±dp/dtmax,P<0.01,P<0.05)and increased the level of the marker enzymes(cTnT,LDH,P<0.01)from the coronary effluents,but also markedly induced changes in the structure of cardiomyocytes and contributed to apoptosis,which were mediated by boosted en doge nous ROS.However,after treatment with DSS all above indexes were improved,which was related to activating Sirt1/FoxO1/Rab7 signal pathway accompanied with the enhancement of antioxidant defense system,such as SOD and GSH-PX.Conclusion:DSS is able to protect hearts from IRI,which may be attributable to inhibiting excessive ROS through Sirt1/FoxO1/Rab7 signaling.

关键词： Chinese medicine Danshensu ischemia reperfusion injury Sirt1/FoxO1/Rab7 signal pathway reactive oxygen species apoptosis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Glutamine supplementation attenuates intestinal apoptosis by inducing heat shock protein 70 in heatstroke rats

引用

世界急诊医学杂志(英文) 2023年第1期14卷 37-43页

作者： Li-wen Du Bao-qing Xu Kai Xun Fang-qi Zhang Department of Emergency Ningbo No.2 HospitalNingbo 315000China Department of Pathology the 900th Hospital of Joint Logistics Support Force of Chinese PLAFuzhou 350025China Department of Pulmonary and Critical Care Medicine the 987th Hospital of Joint Logistics Support Force of Chinese PLABaoji 721000China

BACKGROUND:Heatstroke is the most hazardous heat-related illness and has a high fatality rate.We investigated whether glutamine supplementation could have a protective effect on heatstroke rats.METHODS:Twenty-five 12-week-old male Wistar rats(weight 305±16 g)were randomly divided into a control group(n=5),heatstroke(HS)group(n=10),and heatstroke+glutamine(HSG)group(n=10).Seven days before heat exposure,glutamine(0.4 g/[kg·d])was administered to the rats in the HSG group by gavage every day.Three hours after heat exposure,serum samples were collected to detect white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines in the rats.The small intestine tissue was stained to analyze pathological structural changes and apoptosis.Finally,immunohistochemistry and Western blotting were used to analyze the expression levels of heat shock protein 70(HSP70).Multiple comparisons were analyzed by using one-way analysis of variance,and the Bonferroni test was conducted for the post hoc comparisons.RESULTS:After heat exposure,the core temperature of the HS group(40.65±0.31°C)was higher than the criterion of heatstroke,whereas the core temperature of the HSG group(39.45±0.14°C)was lower than the criterion.Glutamine supplementation restored the increased white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines that were induced by heatstroke to normal levels.The intestinal mucosa was injured,and the structure of tight junctions was damaged in the HS group;however,the structure of intestinal mucosal epithelial cells was stable in the HSG group.Glutamine supplementation alleviated intestinal apoptosis and up-regulated HSP70 expression.CONCLUSION:Glutamine supplementation may alleviate intestinal apoptosis by inducing the expression of HSP70 and have a protective effect on heatstroke rats.

关键词： Heatstroke Glutamine Core temperature Intestinal apoptosis Heat shock protein 70

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Techniques for increasing the yield of stem cell-derived exosomes:what factors may be involved?

引用

Science China(Life Sciences) 2022年第7期65卷 1325-1341页

作者： Zi-Yuan Feng qing-Yi Zhang Jie Tan Hui-qi Xie Laboratory of Stem Cell and Tissue Engineering Orthopedic Research InstituteMed-X Center for MaterialsState Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China

Exosomes are nano-scale extracellular vesicles secreted by cells and constitute an important part in the cell-cell communication.The main contents of the exosomes include proteins,micro RNAs,and lipids.The mechanism and safety of stem cell-derived exosomes have rendered them a promising therapeutic strategy for regenerative medicine.Nevertheless,limited yield has restrained full explication of their functions and clinical applications.To address this,various attempts have been made to explore the up-and down-stream manipulations in a bid to increase the production of exosomes.This review has recapitulated factors which may influence the yield of stem cell-derived exosomes,including selection and culture of stem cells,isolation and preservation of the exosomes,and development of artificial exosomes.

关键词： exosome stem cell yield therapy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Genome-wide identification and characterization of the abiotic-stress-responsive lipoxygenase gene family in diploid woodland strawberry(Fragaria vesca)

引用

Journal of Integrative Agriculture 2022年第7期21卷 1982-1996页

作者： LI Zhi-qi XIE qian YAN Jia-hui CHEN Jian-qing CHEN qing-xi College of Horticulture Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China Horticultural Plant Biology and Metabolomics Center of Haixia Institute of Science and Technology Fujian Agriculture and Forestry UniversityFuzhou 350002P.R.China

Lipoxygenase(LOXs)is a kind of dioxygenase without heme and iron,which plays an important role in the development and adaptation of many plants to the environment.However,the study of strawberry LOX gene family has not been reported.In this study,14 LOX genes were identified from the diploid woodland strawberry genome.The phylogenetic tree divides the FvLOX gene into two subfamilies:9-LOX and 13-LOX.Gene duplication event analysis showed that whole-genome duplication(WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family.QRT-PCR analysis showed that FvLOX genes were expressed in different tissues.Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress,FvLOX3 and FvLOX7 were up-regulated under drought stress,FvLOX6 and FvLOX9 were up-regulated under salt stress,FvLOX2,FvLOX3 and FvLOX6 were up-regulated under salicylic acid(SA)treatment,FvLOX3,FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate(MeJA)treatment,FvLOX4 and FvLOX14 were up-regulated under abscisic acid(ABA)treatment.Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response.We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response.This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.

关键词： lipoxygenase gene family strawberry abiotic stress expression pattern cis-acting element

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flame behavior, shock wave, and instantaneous thermal field generated by unconfined vapor-liquid propylene oxide/air cloud detonation

引用

Defence Technology（防务技术） 2023年第7期25卷 18-32页

作者： Cong-liang Ye qing-lei Du Li-juan Liu qi Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Safety Science and Emergency Management Wuhan University of TechnologyWuhanHubei430070China

Energy output and heating effects are essential for vapor-liquid fuel/air cloud detonation in the fuel-air explosive(FAE) applications or explosion accidents. The purpose of this study is to examine the dynamic large-size flame behavior, shock wave propagation law, and instantaneous thermal field generated by unconfined vapor-liquid propylene oxide(PO)/air cloud detonation. Based on computational fluid dynamics(CFD) and combustion theory, a numerical simulation is used to study the detonation process of a PO/air cloud produced by a double-event fuel-air explosive(DEFAE) of 2.16 kg. The large-scale flame behavior is characterized. The flame initially spreads radially and laterally in a wing shape. Subsequently,the developed flame increases with a larger aspect ratio. Moreover, the propagation laws of shock waves at different heights are discussed. The peak pressure of 1.3 m height level with a stepwise decline is obviously different from that of the ground with an amplitude of reversed ’N’ shape. In the vast majority of the first 6.9 m, the destructive effect of the shock wave near the ground is greater than that of the shock wave at 1.3 m height. Furthermore, the dynamic instantaneous isothermal field is demonstrated.The scaling relationship of various isotherms in the instantaneous thermal field with the flame and initial cloud is summarized. The comprehensive numerical model used in this study can be applied to determine the overpressure and temperature distribution in the entire fuel/air cloud detonation field,providing guidance for assessing the extent of damage caused by DEFAE detonation.

关键词： Numerical simulation Fuel-air explosive Fuel/air cloud Flame Shock wave Thermal field

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Transient Angle Stability of Inverters Equipped with Robust Droop Control

引用

CSEE Journal of Power and Energy Systems 2023年第2期9卷 659-670页

作者： Chen qi Keyou Wang qing-Chang Zhong Jin Xu Guojie Li Key Laboratory of Control of Power Transmission and Conversion Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIllinois60616USA

Transient angle stability of inverters equipped with the robust droop controller is investigated in this work.At first,the conditions on the control references to guarantee the existence of a feasible post-disturbance operating point are derived.Then,the post-disturbance equilibrium points are found and their stability properties are characterized.Furthermore,the attraction regions of the stable equilibrium points are accurately depicted by calculating the stable and unstable manifolds of the surrounding unstable equilibrium points,which presents an explanation to system transient stability.Finally,the transient control considerations are provided to help the inverter ridethrough the disturbance and maintain its stability characteristics.It is shown that the transient angle stability is not a serious problem for droop controlled inverters with proper control settings.

关键词： Droop controlled inverter equilibrium point transient angle stability (un)stable manifold

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：