检索结果-南通市图书馆

changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

Advances in climate change Research 2024年第2期15卷 265-274页

作者： Yong YANG ren-sheng c.en Yong-Jian DING Hong-Yuan LI Zhang-Wen LIU Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of cryospheric Sc.ences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil conservation and environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different ***,the changes in land surface freeze-thaw processes under climate change on a global scale are still *** on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to *** results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,*** FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to *** annual FG areas in the NH,SH,and globe all show significant decreasing trends(pcade,*** FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD *** prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming

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

Microstructure and texture evolution of cu–cr–co–Ti alloys during the two-stage cryorolling

引用

Rare Metals 2024年第9期43卷 4535-4547页

作者： Jia-Jun Zhang Long-Jian Li Zhi-Feng Liu Zong-Ning c.en en-Yu Guo Hui-Jun Kang ren-Geng Li Tong-Min Wang Key Laboratory of Solidification control and Digital Preparation Technology (Liaoning Province) School of Materials Science and EngineeringDalian University of Technology center of Hyper-Gravity Experimental and Interdisciplinary Research Zhejiang University Ningbo Institute of Dalian University of Technology！Ningbo315000 China Key Laboratory for Light-Weight Materials Nanjing Tech University

This study entailed an investigation of the mechanical properties, microstructural and texture orientation evolutions of cuDcrDcoDTi alloys prepared via twostage cryorolling and intermediate aging treatment. To this end, X-ray diffraction and electron backscatter diffraction were employed. The results indicate that the two-stage cryorolling and intermediate aging treatments led to the development of profuse twin bundles and significantly enhanced the mechanical properties. The initial cryorolling led to coplanar slip and developed a strong Y({111} ) orientation, accelerating the formation of Goss({011} ) orientation and a Brass-type *** intermediate aging treatment relieved the restriction on dislocation slip and reoriented the grains toward the copper({112} ) and Z({111} ) *** Z orientation, with a relatively high volume fraction,dominated the macrotexture. Secondary cryorolling intensified twinning and shear banding, transforming the copper-type shear bands into Brass-type shear bands with rhomboidal prism morphology. The areas inside the Brasstype shear bands exhibited a Y orientation, and the areas outside the shear bands exhibited a stable Brass-type texture. The evident decrease in the weighted Schmid factors demonstrated that the two-stage cryorolling and intermediate aging treatment can modify the texture evolution and aid the design of high-performance cu alloys.

关键词： copper alloys Electron backscatter diffraction Macrotexture evolution Schmid factor Two-stage cryorolling

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Multifunctional role of oral bacteria in the progression of nonalcoholic fatty liver disease

引用

World Journal of Hepatology 2024年第5期16卷 688-702页

作者： en-Hua Mei chao Yao Yi-Nan c.en Shun-Xue Nan sheng-cai Qi Shanghai Medical college Fudan UniversityShanghai 200000China Department of Prothodontics Shanghai Stomatological HospitalFudan UniversityShanghai 200000China Shanghai Key Laboratory of craniomaxiofacial Development and Diseases Fudan UniversityShanghai 200000China

Non-alcoholic fatty liver disease(NAFLD)encompasses a spectrum of liver disorders of varying severity,ultimately leading to *** spectrum primarily consists of NAFL and non-alcoholic *** pathogenesis of NAFLD is closely associated with disturbances in the gut micr-obiota and impairment of the intestinal ***-gut commensal flora,particularly bacteria,play a pivotal role in the progression of ***,Porphyromonas gingivalis,a principal bacterium involved in periodontitis,is known to facilitate lipid accumulation,augment immune responses,and induce insulin resistance,thereby exacerbating fibrosis in cases of periodontitis-associated *** influence of oral microbiota on NAFLD via the“oral-gut-liver”axis is gaining recognition,offering a novel perspective for NAFLD management through microbial imbalance *** review endeavors to encapsulate the intricate roles of oral bacteria in NAFLD and explore underlying mechanisms,emphasizing microbial control strategies as a viable therapeutic avenue for NAFLD.

关键词： Non-alcoholic fatty liver disease Oral bacteria Gut bacteria Periodontitis Non-alcoholic steatohepatitis

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

Reducing Operation Emissions and Improving Work Effic.ency Using a Pure Electric Wheel Drive Tractor

引用

engineering 2024年第6期37卷 230-245页

作者： chang-Kai Wen Wen ren Qing-Zhen Zhu chun-Jiang Zhao Zhen-Hao Luo sheng-Li Zhang Bin Xie Zhi-Jun Meng Research center of Intelligent Equipment Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China State Key Laboratory of Intelligent Agricultural Power Equipment Beijing 100097China BYD company Limited Shenzhen 518118China college of Agricultural engineering Jiangsu UniversityZhenjiang 212013China college of engineering China Agricultural UniversityBeijing 100083China

In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction effic.ency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,including an electric motor drive system,a battery ballast system,and an electro–hydraulic suspension *** paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions,leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front-and rear-axle loads of a ***,the tractor is prototyped and assembled,and ploughing tests are carried *** ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83%and increases the traction effic.ency by 10.28%compared with the average torquedistribution *** with the conventional traction control mode,the joint control method for traction and ballast proposed in this paper results in a 3.7%increase in traction effic.ency,a 15.05%decrease in slip,and a 4.9%reduction in total drive motor energy *** study will help to improve the operation quality and traction effic.ency of electric tractors in complex soil conditions.

关键词： Electric tractor Ploughing unit Torque distribution Active ballast Traction performance

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

High-performance sodium storage for cobalt phosphide composite array electrodes

引用

Rare Metals 2024年第8期43卷 3724-3734页

作者： Man Zhang Xiao-Xu Liu Tian-Yi Ji Yang Li Da-Wei sheng Shao-Dong Li Pei-Pei ren Ze-Xiang Shen School of Material Sc.ence and engineering Shaanxi University of Science and TechnologyXi'an 710021China School of Physical and Mathematical Sc.ences Nanyang Technological UniversitySingapore 637371Singapore

Transition metal phosphides hold great potential as sodium-ion batteries anode materials owing to their high theoretical capacity and modest ***,volume changes and low intrinsic conductivity seriously largely hinder the further development of metal phosphide *** design of phosphide anode materials with reasonable structure is conducive to solving the problems of volume expansion and slow reaction kinetics during the *** this work,a composite material integrating zeolite imidazolate backbone(ZIF) and carbon materials was synthesized by the original growth ***,by the oxidation-phosphating process,coP nanoarray composites riveted to carbon fiber(coP@cF) were *** the coP@cF,coP nanoparticles are uniformly distributed on ZIF-derived carbon,reducing agglomeration and volume change during *** also provides a highly conductive network for the active material,improving the electrode ***,when evaluated as an anode for sodium-ion batteries,coP@cF electrode displays enhanced reversible capacity(262 mAh·g^(-1) at 0.1 A·g^(-1)after 100 cycles),which is much better than that of pure cF electrode(57 mAh·g^(-1) at 0.1 A·g^(-1) after 100 cycles)prepared without the addition of *** rate performance of coP@cF electrode is also superior to that of pure cF electrode at various current densities from 0.05 to1 A·g^(-1).The sodium storage behavior of coP@cF was revealed by ex-situ X-ray photoelectron spectroscopy,X-ray diffraction,and synchrotron radiation absorption *** method provides a reference for the design and synthesis of anode materials in sodium-ion batteries.

关键词： cobalt phosphide Array structure Freestanding anodes Sodium-ion batteries

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

Structure Regulation of Electric Double Layer via Hydrogen Bonding Effect to Realize High-Stability Lithium-Metal Batteries

引用

energy & environmental Materials 2024年第3期7卷 72-83页

作者： sheng Liu chaozhu Shu Yu Yan Dayue Du Longfei ren Ting Zeng Xiaojuan Wen Haoyang Xu Xinxiang Wang Guilei Tian Ying Zeng college of Materials and chemistry&chemical engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China Institute of Fundamental and Frontier Sc.ences University of Electronic Science and Technology of ChinaChengdu 611731China State Key Laboratory of Polymer Materials engineering Polymer Research InstituteSichuan UniversityChengdu 610065China

The interfacial chemistry of solid electrolyte interphases(SEI)on lithium(Li)electrode is directly determined by the structural chemistry of the electric double layer(EDL)at the ***,a strategy for regulating the structural chemistry of EDL via the introduction of intermolecular hydrogen bonds has been proposed(p-hydroxybenzoic acid(pHA)is selected as proof-of-concept).According to the molecular dynamics(MD)simulation and density functional theory(DFT)calculation results,the existence of hydrogen bonds realizes the anion structural rearrangement in the EDL,reduces the lowest unoccupied molecular orbital(LUMO)energy level of anions in the EDL,and the number of free solvent molecules,which promotes the formation of inorganic species-enriched SEI and eventually achieves the dendrite-free Li *** on this strategy,Li‖cu cells can stably run over 185 cycles with an accumulated active Li loss of only 2.27 mAh cm^(-2),and the long-term cycle stability of Li‖Li cells is increased to 1200 *** addition,the full cell pairing with the commercial LiFePO_(4)(LFP)cathodes exhibits stable cycling performance at 1c,with a capacity retention close to 90%after 200 cycles.

关键词： electric double layer electrolyte additives intermolecular hydrogen bonds Li metal batteries p-Hydroxybenzoic acid

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

Prognostic significance and relationship of SMAD3 phosphoisoforms and VEGFR-1 in gastric cancer:A clinicopathological study

引用

World Journal of Gastrointestinal Oncology 2024年第1期16卷 118-132页

作者： Shi-Lin Lv Pei Guo Jun-Rong Zou ren-sheng c.en Ling-Yu Luo De-Qiang Huang Hospital of Gastroenterology Institute of Digestive DiseasesThe First Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina Department of Pathology Shenzhen Hospital of Southern Medical UniversityShenzhen 518000Guangdong ProvinceChina Institute of Urology The First Affiliated Hospital of Gannan Medical UniversityGanzhou 341000Jiangxi ProvinceChina Department of Pathology The First Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina

BAcKGROUND The TGF-β/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer ***3 phosphorylation is a crucial prognostic marker in gastric *** To determine the prognostic value and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric *** This was a single-center observational study which enrolled 98 gastric cancer patients and 82 adjacent normal gastric tissues from patients aged 32-84 years(median age 65)between July 2006 and April *** were followed up until death or the study ended(median follow-up duration of 28.5 mo).The samples were used to generate tissue microarrays(TMAs)for immunohistochemical(IHc)*** expressions of TGF-β1,pSMAD3c(S423/425),pSMAD3L(S204),and VEGFR-1 in gastric cancer(Gc)tumor tissue and normal tissue were measured by IHc staining using TMAs obtained from 98 Gc *** and survival information of the patients was recorded by Outdo Biotech from May 2007 to July *** relationship between TGF-β1,pSMAD3c(S423/425),pSMAD3L(S204),and VEGFR-1 protein expression levels was analyzed using Pearson's correlation *** relationship between protein expression levels and clinicopathological parameters was analyzed using the chi-squared test.A survival curve was generated using the Kaplan-Meier survival *** TGFβ-1 and VEGFR-1 expression was significantly upregulated in gastric cancer tissue compared to adjacent noncancerous *** positive expression of phosphorylated isoforms of Smad3 varied depending on the phosphorylation site[pSMAD3c(S423/425):51.0%and pSMAD3L(S204):31.6%].High expression of pSMAD-3L(S204)was significantly correlated with larger tumors(P=0.038)and later N stages(P=0.035).Additionally,high expression of VEGFR-1 was closely correlated with tumor size(P=0.015)and pathological grading(P=0.013).High expression of both pSMAD3L(S204)and VEGFR-1 was associated with unfavorable outcomes in terms of overall survival(OS).Multiva

关键词： Gastric cancer pSMAD3L(S204) pSMAD3c(S423/425) Survival Transforming growth factor-β1 VEGFR-1

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

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging parameters and serum tumor markers in rectal carcinoma prognosis

引用

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1796-1807页

作者： ren-Qi Mu Jun-Wei Lv cai-Yun Ma Xiao-Hui Ma Dong Xing Hou-sheng Ma Department of Radiology Yantai Mountain HospitalYantai 264001Shandong ProvinceChina Department of Radiology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina Department of Gynaecology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina The First clinical Medical college Xinjiang Medical UniversityUrumqi 830011Xinjiang Uygur Autonomous RegionChina

BAcKGROUND Rectal carcinoma(Rc),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality of life of *** present,dynamic contrast-enhanced magnetic resonance imaging(DcE-MRI)parameters and serum carbohydrate antigen 19-9(cA19-9)and cA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of ***,the accuracy of these evaluation modalities still needs further *** study explores the application and value of these methods in evaluating the T stage and differentiation degree of *** To analyze the diagnostic performance of DcE-MRI parameters combined with serum tumor markers(TMs)in assessing pathological processes and prognosis of Rc *** A retrospective analysis was performed on 104 Rc patients treated at Yantai Yuhuangding Hospital from May 2018 to January *** were categorized into stages T1,T2,T3,and T4,depending on their T stage and differentiation *** addition,they were assigned to low(L group)and moderate-high differentiation(M+H group)groups based on their differentiation *** levels of DcE-MRI parameters and serum cA19-9 and cA125 in different groups of patients were *** addition,the value of DcE-MRI parameters[volume transfer constant(Ktrans),rate constant(Kep),and extravascular extracellular volume fraction(Ve)in assessing the differentiation and T staging of Rc patients was ***,the usefulness of DcE-MRI parameters combined with serum cA19-9 and cA125 Levels in the evaluation of Rc differentiation and T staging was *** Ktrans,Ve,cA19-9 and cA125 were higher in the high-stage group and L group than in the low-stage group and M+H Group,respectively(Pcurve(AUcs)of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages,respectively,and 0.672 and 0

关键词： Rectal carcinoma Volume transfer constant Rate constant Extravascular extracellular volume fraction Serum carbohydrate antigen 19-9 Serum carbohydrate antigen 125

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

Federated Offline Reinforcement Learning with Proximal Policy Evaluation

引用

chinese Journal of Electronics 2024年

作者： sheng YUE Yongheng DenG Guanbo WANG Ju ren Yaoxue ZHANG Department of computer Sc.ence and Technology BNRist Tsinghua University Zhongguancun Laboratory

Offline reinforcement learning (RL) has gathered increasing attention in recent years, which seeks to learn policies from static datasets without active online exploration. However, the existing offline RL approaches often require a large amount of pre-collected data and hence are hardly implemented by a single agent in practice. Inspired by the advancement of federated learning (FL), this paper studies federated offline reinforcement learning(FORL), whereby multiple agents collaboratively carry out offline policy learning with no need to share their raw trajectories. clearly, a straightforward solution is to simply retrofit the off-the-shelf offline RL methods for FL, whereas such an approach easily overfits individual datasets during local updating, leading to instability and subpar performance. To overcome this challenge, we propose a new FORL algorithm, named model-free (MF)-FORL, thatexploits novel “proximal local policy evaluation” to judiciously push up action values beyond local data support, enabling agents to capture the individual information without forgetting the aggregated knowledge. Further, we introduce a model-based variant, MB-FORL, capable of improving the generalization ability and computational effic.ency via utilizing a learned dynamics model. We evaluate the proposed algorithms on a suite of complex and high-dimensional offline RL benchmarks, and the results demonstrate significant performance gains over the baselines.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mechanism, prevention, and control of mining-induced dynamic disasters in underground metal mines in china: challenges and solutions

引用

Journal of central South University 2024年第8期31卷 2549-2606页

作者： Li, Peng cai, Mei-feng Miao, sheng-jun ren, Fen-hua Gorjian, Mostafa Peng, chao Key Laboratory of Ministry of Education for Effic.ent Mining and Safety of Metal Mines University of Science and Technology Beijing Beijing China Department of Earth Ocean and Atmospheric Sciences University of British Columbia Vancouver Canada Deep Mining Laboratory of Shandong Gold Group co. Ltd. Laizhou China

Metal mineral resources play an indispensable role in the development of the national economy. Dynamic disasters in underground metal mines seriously threaten mining safety, which are major sc.entific and technological problems to be solved urgently. In this article, the occurrence status and grand challenges of some typical dynamic disasters involving roof falling, spalling, collapse, large deformation, rockburst, surface subsidence, and water inrush in metal mines in china are systematically presented, the characteristics of mining-induced dynamic disasters are analyzed, the examples of dynamic disasters occurring in some metal mines in china are summarized, the occurrence mechanism, monitoring and early warning methods, and prevention and control techniques of these disasters are highlighted, and some new opinions, suggestions, and solutions are proposed simultaneously. Moreover, some shortcomings in current disaster research are pointed out, and the direction of efforts to improve the prevention and control level of dynamic disasters in china’s metal mines in the future is prospected. The integration of forward-looking key innovative theories and technologies in the abovementioned aspects will greatly enhance the cognitive level of disaster prevention and mitigation in china’s metal mining industry and achieve a significant shift from passive disaster relief to active disaster prevention.

关键词： dynamic disasters mechanism monitoring and early warning prevention and control underground metal mines

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：