检索结果-南通市图书馆

Environment and COVID-19 incidence: A critical review

Journal of Environmental Sciences 2023年第2期124卷 933-951页

作者： Jiatong Han Jie Yin xiaoxu wu Danyang Wang Chenlu Li State Key Laboratory of Remote Sensing Science College of Global Change and Earth System ScienceBeijing Normal UniversityBeijing 100875China

The coronavirus disease 2019(COVID-19)pandemic is an unprecedented worldwide health crisis.Many previous research studies have found and investigated its links with one or some natural or human environmental factors.However,a review on the relationship between COVID-19 incidence and both the natural and human environment is still lacking.This review summarizes the inter-correlation between COVID-19 incidence and environmental factors.Based on keyword searching,we reviewed 100 relevant peer-reviewed articles and other research literature published since January 2020.This review is focused on three main findings.One,we found that individual environmental factors have impacts on COVID-19 incidence,but with spatial heterogeneity and uncertainty.Two,environmental factors exert interactive effects on COVID-19 incidence.In particular,the interactions of natural factors can affect COVID-19 transmission in micro-and macro-ways by impacting SARS-CoV-2 survival,as well as human mobility and behaviors.Three,the impact of COVID-19 incidence on the environment lies in the fact that COVID-19-induced lockdowns caused air quality improvement,wildlife shifts and socio-economic depression.The additional value of this review is that we recommend future research perspectives and adaptation strategies regarding the interactions of the environment and COVID-19.Future research should be extended to cover both the effects of the environment on the COVID-19 pandemic and COVID-19-induced impacts on the environment.Future adaptation strategies should focus on sustainable environmental and public policy responses.

关键词： COVID-19 Natural environment Human environment Interaction

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

High-static-low-dynamic stiffness isolator based on an electromagnetic negative stiffness spring with long linear stroke

引用

Science China(Technological Sciences) 2024年第3期67卷 740-752页

作者： YUAN ShuJin wu YaJun SONG DaiPing PU HuaYan MOU LiSheng HOU Lei ZHAO JingLei LI XuePing LUO Jun wu Jie HUANG xiaoxu State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China China Aerodynamics Research and Development Center Mianyang 621000China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Negative stiffness mechanisms can improve low-frequency vibration isolation performance and have been widely used in the vibration isolation of precision equipment. However, the negative stiffness mechanism usually introduces a nonlinear stiffness,resulting in a nonlinear response and worsening the vibration isolation performance, especially under large amplitude vibration.In this paper, an electromagnetic spring with linear negative stiffness(ESLNS) is proposed, in which the antagonistic ampere forces of the energized coils are used to generate negative stiffness within a long linear stroke. The magnetic field distribution is improved through the design of the magnetic circuit, thereby increasing the stiffness generation efficiency. The stiffness can be adjusted bidirectionally by current within the range of positive and negative stiffness. An electromagnetic stiffness model was established based on the equivalent magnetic circuit method. Experimental measurements verified the accuracy of the model and proved the linearity of the electromagnetic spring. A vibration isolator with high static and low dynamic stiffness(HSLDS) based on the ESLNS is designed and tested. The experimental results prove that the introduction of the ESLNS can effectively expand the isolation frequency band without changing the equilibrium position. Moreover, the vibration isolator with ESLNS does not produce nonlinear response. The proposed electromagnetic spring with linear negative stiffness extends the application range of HSLDS isolators to a large amplitude vibration environment.

关键词： linear negative stiffness mechanism low-frequency vibration isolation electromagnetic spring vibration control

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

Texture and Geochemistry of Multi-stage Hydrothermal Scheelite in the Mamupu Cu-Au-Mo(-W)Deposit,Eastern Tibet:Implications for Tungsten Mineralization in the Yulong Belt

引用

Acta Geologica Sinica(English Edition) 2024年第3期98卷 701-716页

作者： ZHANG xiaoxu TANG Juxing LIN Bin WANG Qin HE Liang YAN Gang SHAO Rui wu Qiang DU Qiu ZHAXI Pingcuo Chengdu Center China Geological Survey(Geosciences Innovation Center of Southwest China)Chengdu 610081China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China Earth Sciences College Chengdu University of TechnologyChengdu 610059China No.6 Geological Party Tibetan Bureau of Geology and Mineral Exploration and DevelopmentLhasa 851400China Tibet Shengyuan Mining Group Co. Ltd.Lhasa 851400China

Multistage tungsten mineralization was recently discovered in the Mamupu copper-polymetallic deposit in the southern Yulong porphyry copper belt(YPCB),Tibet.This study reports the results of cathodoluminescence,trace element and Sr isotope analyses of Mamupu scheelite samples,undertaken in order to better constrain the mechanism of W mineralization and the sources of the ore-forming fluids.Three different types of scheelite are identified in the Mamupu deposit:scheelite A(Sch A)mainly occurs in breccias during the prograde stage,scheelite B(Sch B)forms in the chlorite-epidote alteration zone in the retrograde stage,while scheelite C(Sch C)occurs in distal quartz sulfide veins.The extremely high Mo content and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde stage.Compared with ore-related porphyries,Sch A has a similar REE pattern,but with higher ΣREE,more depleted HREE and slightly lower(^(87)Sr/^(86)Sr)i ratios.These features suggest that Sch A is genetically related to ore-related porphyries,but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic composition.Sch B shows dark(Sch B-I)and light(Sch B-II)domains under CL imaging.From Sch B-I to Sch B-II,LREEs are gradually depleted,with MREEs being gradually enriched.Sch C has the highest LREE/HREE ratio,which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE-rich minerals,such as diopside and garnet,in the early prograde stage.The Mo content in Sch B and Sch C gradually decreased,indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later,the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely controlled by oxygen fugacity.The extensive interaction of magmatic-hydrothermal fluids and carbonate provides the necessary Ca^(2+)for the precipitation of scheelite in the Mamupu deposit.

关键词： scheelite geochemistry Mamupu Cu deposit Yulong porphyry copper belt eastern Tibet

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

Review on piezoelectric actuators:materials,classifications,applications,and recent trends

引用

Frontiers of Mechanical Engineering 2024年第1期19卷 5-33页

作者： Xuyang ZHOU Shuang wu xiaoxu WANG Zhenshan WANG Qixuan ZHU Jinshuai SUN Panfeng HUANG Xuewen WANG Wei HUANG Qianbo LU Institute of Flexible Electronics(IFE) Northwestern Polytechnical UniversityXi’an 710072China School of Automation Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China

Piezoelectric actuators are a class of actuators that precisely transfer input electric energy into displacement,force,or movement outputs efficiently via inverse piezoelectric effect-based electromechanical coupling.Various types of piezoelectric actuators have sprung up and gained widespread use in various applications in terms of compelling attributes,such as high precision,flexibility of stoke,immunity to electromagnetic interference,and structural scalability.This paper systematically reviews the piezoelectric materials,operating principles,representative schemes,characteristics,and potential applications of each mainstream type of piezoelectric actuator.Herein,we intend to provide a more scientific and nuanced perspective to classify piezoelectric actuators into direct and indirect categories with several subcategories.In addition,this review outlines the pros and cons and the future development trends for all kinds of piezoelectric actuators by exploring the relations and mechanisms behind them.The rich content and detailed comparison can help build an in-depth and holistic understanding of piezoelectric actuators and pave the way for future research and the selection of practical applications.

关键词： piezoelectric actuator piezoelectric effect amplified piezoelectric actuator ultrasonic actuator stepping actuator piezoelectric polymer

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

Impact of environmental factors on gastric cancer:A review of the scientific evidence,human prevention and adaptation

引用

Journal of Environmental Sciences 2020年第3期32卷 65-79页

作者： Jie Yin xiaoxu wu Suping Li Chenlu Li Zhiyi Guo State Key Laboratory of Remote Sensing Science College of Global Change and Earth System ScienceBeijing Normal UniversityBeijing 100875China The Second People’s Hospital of Lanzhou City Lanzhou 730046China

Globally,gastric cancer(GC) ranks fifth in prevalence and third in fatalities,and shows a distinct geographical distribution in morbidity and mortality.Such a spatial pattern indicates that environmental factors could be an important contributor to GC.We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936-2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide.Environmental factors affect GC from the aspects of water,soil,air,radiation,and geology.Risk factors identified include water type,water pollution,water hardness,soil type,soil pollution,soil element content,climate change,air pollution,radiation,altitude,latitude,topography,and lithology;and most of them have an adverse impact on GC.Furthermore,we found that their effects followed five common rules:(1) the leading environmental factors that affect GC incidence and mortality vary by region,(2) the same environmental factors may have different effects on GC in different regions,(3) some different environmental factors have similar effects on GC in essence,(4) different environmental factors often interact to have combined or synergistic effects on GC,and(5)environmental factors can affect human factors to have an impact on GC.Environmental factors have a great impact on GC.Human beings may prevent GC by controlling carcinogenic factors,screening high-risk populations and providing symptomatic and rehabilitative treatments.Furthermore,adaptation measures are recommended to reduce GC risk on private and public levels.Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.

关键词： Gastric cancer Environmental factor Review Impact Human prevention Human adaptation

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

沥青混合料节能减排及温拌再生技术研究

引用

交通节能与环保 2024年第1期20卷 117-120,127页

作者：吴晓旭舒航中国市政工程西南设计研究总院有限公司四川成都610000

为减小再生沥青路面的能耗和碳排放,推动道路工程向经济绿色集约型发展,文章分析了沥青路面能耗和碳排放量化的计算方法,从温拌技术、改变能源类型、更换新型施工机械设备、优化管理等方面探讨了沥青混合料路面节能减排的实现途径,基于... 详细信息

为减小再生沥青路面的能耗和碳排放,推动道路工程向经济绿色集约型发展,文章分析了沥青路面能耗和碳排放量化的计算方法,从温拌技术、改变能源类型、更换新型施工机械设备、优化管理等方面探讨了沥青混合料路面节能减排的实现途径,基于工程实例,研究了温拌技术对再生混合料的路用性能及节能减排的影响规律,结果表明再生沥青混合料在生产环节的能耗和碳排放远高于其他施工环节,且容易受RAP掺量、集料含水量的影响。

关键词：温拌再生能耗碳排放实现途径节能减排

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

基于灰狼优化的混频支持向量机在股指预测与投资决策中的应用研究

引用

中国管理科学 2024年第5期32卷 73-80页

作者：蔡毅唐振鹏吴俊传杜晓旭陈凯杰福建农林大学经济与管理学院福建福州350002 南昌大学经济管理学院江西南昌330031 福州大学经济与管理学院福建福州350108

股市的剧烈波动会影响金融市场的平稳运行进而影响经济增长,如何对股市的走势进行精准预测一直是学术界关注的焦点问题。由于股指收益率具有非平稳、非线性特征,仅利用历史序列作为影响因素将导致预测精度不佳。考虑到基金仓位变化对股... 详细信息

股市的剧烈波动会影响金融市场的平稳运行进而影响经济增长,如何对股市的走势进行精准预测一直是学术界关注的焦点问题。由于股指收益率具有非平稳、非线性特征,仅利用历史序列作为影响因素将导致预测精度不佳。考虑到基金仓位变化对股市的信息增益作用及二者数据间存在混频关系,提出一种反向混频数据抽样模型(R-MIDAS)与机器学习算法结合的新模型,应用于27个行业股指收益率的预测及投资决策的研究中。实证结果表明:R-MIDAS-GWO-SVR模型在多数行业的预测效果优于基准模型;基于预测结果开展单一行业与多行业组合的投资策略,R-MIDAS-GWO-SVR模型的表现也更好,其风险调节的绩效指标显著优于其余模型。

关键词：股指收益率时间序列预测反向混频数据公募基金仓位投资决策

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

低压氧舱处置时间对高海拔大鼠心搏骤停模型制备的影响

引用

中华危重病急救医学 2024年第1期36卷 82-85页

作者：刘洁马增文石晓旭吴妍南措吉宋凤卿张斌青海大学附属人民医院(青海省人民医院)急诊科中山大学心肺脑复苏研究所高原分所西宁810000 中山大学孙逸仙纪念医院急诊科中山大学心肺脑复苏研究所广东广州510006

目的建立高海拔低压低氧环境大鼠心搏骤停模型,探讨低压氧舱处置时间对建立高海拔大鼠心搏骤停模型的影响。方法以SPF级健康雄性SD大鼠作为研究对象,实验分别在2个不同海拔地区开展。将中山大学心肺脑复苏研究所高原分所(青海西宁)的实... 详细信息

目的建立高海拔低压低氧环境大鼠心搏骤停模型,探讨低压氧舱处置时间对建立高海拔大鼠心搏骤停模型的影响。方法以SPF级健康雄性SD大鼠作为研究对象,实验分别在2个不同海拔地区开展。将中山大学心肺脑复苏研究所高原分所(青海西宁)的实验大鼠称重、编号,放入低压氧舱中饲养(模拟海拔高度3000 m,升降速15 m/min,温度20℃,舱内压力69.5 kPa,舱内氧气压力14.5 kPa),饲养30 d后按照随机数字表法选取30只大鼠,采用窒息法制备心搏骤停模型,作为低压低氧30 d组;饲养60 d后再次随机选取40只大鼠制备心搏骤停模型,作为低压低氧60 d组。中山大学心肺脑复苏研究所(广东广州)采用相同方法随机选取30只大鼠制备心搏骤停模型,作为平原对照组。比较各组大鼠制模前体质量及制模过程中窒息诱导时间的差异。结果最终低压低氧30 d组有16只大鼠完成心搏骤停模型制备,低压低氧60 d组有22只大鼠完成心搏骤停模型制备。平原对照组、低压低氧30 d组与低压低氧60 d组大鼠制模前体质量差异无统计学意义〔g:429.00(389.25,440.75)、440.00(415.50,486.25)、440.00(400.00,452.50),均P>0.05〕。低压低氧60 d组大鼠窒息诱导时间较低压低氧30 d组明显延长(s:294.59±75.39比234.31±93.86,P0.05)。结论低压氧舱处置60 d的大鼠更适用于制备高海拔心搏骤停模型,也符合高海拔大鼠氧储备和耐缺氧的机体特点。

关键词：高海拔地区心搏骤停大鼠模型低压氧舱

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

肺腺癌脑转移的诊疗进展

引用

河北医药 2024年第5期46卷 759-763页

作者：武晓旭张俊萍山西医科大学第三医院(山西白求恩医院山西医学科学院同济山西医院) 太原市030032

肺癌是目前已知发病率和病死率最高的恶性肿瘤,而肺癌脑转移是晚期肺腺癌患者中常见的致死性并发症,包括脑实质转移及脑膜转移两种方式。相对于脑实质转移,肺腺癌出现脑膜转移的发生率和临床诊断率都比较低,治疗手段相对受限,效果不佳,... 详细信息

肺癌是目前已知发病率和病死率最高的恶性肿瘤,而肺癌脑转移是晚期肺腺癌患者中常见的致死性并发症,包括脑实质转移及脑膜转移两种方式。相对于脑实质转移,肺腺癌出现脑膜转移的发生率和临床诊断率都比较低,治疗手段相对受限,效果不佳,自然生存时间较短。单纯依据临床症状、影像学检查及脑脊液细胞学检查诊断,存在漏诊和误诊等情况,可延误患者治疗,而液体活检的出现可大幅提高其早期诊断率。外科手术、化疗、放疗、靶向治疗、抗血管生成治疗及免疫治疗等都可作为肺腺癌脑转移的治疗手段,但对于不同患者,如何选用适合且有效的治疗方案,至今尚无定论。因此,本文就肺腺癌脑转移的诊疗相关研究进展进行综述,以期为肺腺癌脑转移患者寻找最优治疗方案提供理论基础。

关键词：肺腺癌脑转移早期诊断治疗液体活检

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

Research on Calculation Method of Aerodynamic Parameters of Supersonic Probe Based on Gas Compressibility Factor

引用

Journal of Thermal Science 2022年第1期31卷 111-119页

作者： ZHONG Jingjun HUANG Gangfeng wu Wanyang KAN xiaoxu Merchant Marine College Shanghai Maritime University1550 Haigang AvenuePudong DistrictShanghai 201306

The supersonic multi-hole probe is an essential test tool for wind tunnel experiments, which is necessary to develop the basic research of improving the measurement accuracy and expanding the application of the probes.

关键词： supersonic flow probe gas compressible factor aerodynamic parameter error analyses

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

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：