检索结果-南通市图书馆

Charge Accumulation Characteristics of SF6-Epoxy Interface Under Negative Repetitive Nanosecond Pulses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1808-1815页

作者： Shaocong wu Geng Chen Yuming Shao Hao Xu Xuanning Zhang Yanyu liang Youping Tu State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

Repetitve nanosecond impulses in gas-insulated metal-enclosed switchgear (GIS) are likely to trigger inside flashover. Interface charges on the spacer in GIS are considered one of the main factors damaging insulation performance and may be induced by overvoltage. For good understanding of insulation failures, accumulation characteristics of charges between SF6 and epoxy spacers under repetitive nanosecond impulses are investigated. It can be found under nanosecond impulses, the charge source in gas volume contributes to interface charge accumulation predominantly. Interface charges will be promoted by impulse number and amplitude. Accumulation processes are analyzed based on runaway electrons mechanism. When impulse amplitude exceeds a threshold value, discharge in the gas volume turns to a runaway mode. A runaway electron leads to the interface charge accumulation. Affected by motion of the runaway electrons, the potential peak gradually moves close to the grounded electrode when impulse amplitude is raised. Meanwhile, increasing impulse number can enhance surface potential. Surface potential will reach saturation eventually. However, memory effect of the repetitive impulse discharge makes the half-peak width of the surface potential at the interface change little. Design of GIS gas-solid insulations can refer to this research.

关键词： GIS interface charge repetitive nano-second pulse SF6

Observation of therapeutic effect of lamp irradiation combined with purple gromwell oil gauze on alleviating intestinal colic in patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第6期16卷 1749-1755页

作者： bi-Zhi Cen Yin-Song Chen Li-Ping Li Jing-Wen wu Yan-Fen Xie Department of Tumor Center Foshan Hospital of Traditional Chinese MedicineFoshan 528000Guangdong ProvinceChina

BACKGROUND Intestinal colic is a common complication in patients who have undergone radical surgery for colorectal *** Chinese medicine has advantages,including safety and stability,for the treatment of intestinal *** irra-diation for abdominal ironing has been applied in the treatment of many gas-trointestinal *** gromwell oil has the effects of clearing heat,cooling blood,reducing swelling,and relieving *** The general effective rate in the observation group was 95.00%,which was significantly higher than that in the control group(86.67%,P0.05).After 1,2,3,and 4 d of treatment,the duration of symptoms in both groups were decreased,and the duration in the observation group was significantly lower than that in the control group(96.54±9.57 vs 110.45±11.23,87.26±12.07 vs 104.44±11.68,80.45±16.21 vs 99.44±14.95,73.18±15.58 vs 92.17±14.20;P0.05).CONCLUSION The use of lamp irradiation combined with purple gromwell oil gauze in patients with intestinal colic after radical surgery for colorectal cancer can reduce symptom duration,alleviate intestinal colic,and improve treatment efficacy,and this approach is *** is worth promoting the use of this treatment in clinical practice.

关键词： Lamp irradiation Purple gromwell oil gauze Intestinal colic Radical surgery for colorectal cancer Therapeutic effect

Genesis of the Nuri Cu-W-Mo Deposit,Tibet,China:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第1期98卷 117-131页

作者： WANG Yiyun wu Zhishan CHEN Wenqing DU Qing’an TANG Liwei SHI Hongzhao MA Guotao ZHANG Zhi liang Wei wu Bo MIAO Hengyi Chengdu Center China Geological Survey(Geoscience Innovation Center of Southwest China)Chengdu 610081China The Second Geological Institute of China’s Metallurgical Geology Bureau Fuzhou 351111China

The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,***,the genetic type of this deposit has been controversial since its *** on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,*** LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are *** Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth *** contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and *** normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock *** the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric *** intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a

关键词： trace elements in situ Sr isotopes tungsten mineralization Gangdese metallogenic belt Tibet

Enhanced visible-light photocatalytic hydrogen evolution using two-dimensional carbon nitride sheets with the removal of amine groups

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 446-450页

作者： Yu Zhang Liting wu Shaopeng Wang Dingyi Yang Huan liang Yizhang wu Jian Hao Youqing Wang Jianke Liu Yong Wang Department of Physics Shaanxi University of Science and TechnologyXi'an 710021China School of Advanced Materials and Nanotechnology Academy of Advanced Interdisciplinary ResearchXidian UniversityXi'an 710126China The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology Xidian UniversityXi'an 710126China Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State MicrostructuresNanjing UniversityNanjing 210093China State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering Ningxia UniversityYinchuan 750021China

Two-dimensional(2D)carbon nitride sheets(CNs)with atomically thin structures are regarded as one of the most promising materials for solar energy ***,due to their substantially enlarged bandgap caused by the strong quantum size effect and their incomplete polymerisation with a large number of non-condensed surface amino groups,the practical applicability of CNs in photocatalysis is *** this study,CNs with broad visible-light absorption were synthesised using a 5-min fast thermal *** removal of uncondensed amine groups reduces the bandgap of CNs from 3.06 eV to 2.60 eV,increasing their absorption of visible ***,the CNs were distorted after annealing,which can differentiate the spatial positions of electrons and holes,enhancing the visible-light absorption *** a result,when exposed to visible light,the photocatalytic hydrogen production activity of atomically thin 2D CNs rose by 8.38 *** research presents a dependable and speedy method for creating highly effective visible-light photocatalysts with narrowed bandgaps and improved visible-light absorption.

关键词： 2D carbon nitride sheets Rapid thermal annealing DFT calculations Visible-light absorption visible-light photocatalysis

Oxidation behavior of Ni-based superalloy GH4738 under tensile stress

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3913-3920页

作者： Ji-Chong Hu Hai-liang Huang Chong-Chong wu Xiao-Yu Sun Jie Wang Yan-Hong Yang Jing-Long Qu liang Jiang Jin-He Dou Yang Chen Institute for Advanced Studies in Precision Materials Yantai UniversityYantai 264005China Department of Management and Engineering Linkoping University58183LinkopingSweden Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Gaona Aero Material Co. LtdBeijing 100081China College of Artificial Intelligence and big Data Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117China

Revealing the oxidation behavior of superalloys is crucial for optimizing material properties and extending service *** study investigated the oxidation behavior of superalloy GH4738 under stress states at 850℃.High-throughput specimens were fabricated to withstand different stresses at the same *** oxidation s amples were analyzed using the mass gain method to obtain oxidation kinetic *** results show that the external stress below 200 MPa could improve the oxidation resistance of the *** tensile stress increasing,the oxide layer becomes thinner,denser and more complete,while internal oxidation *** tensile stress alters the structure of the external oxide layer from a two-layer to a threelayer *** Cr_(2)O_(3) oxide layer inhibits the outward diffusion of Ti,leading to Ti enrichment at the oxide-matrix interface and altering the oxidation mechanism of GH4738.

关键词： Ni-based Superalloy Oxidation behavior Tensile stress Oxide layer

Winter extreme precipitation over the Tibetan Plateau influenced by Arctic sea ice on interdecadal timescale

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 42-51页

作者： Qing-Quan LI Miao bi Song YANG Qing-Yuan wu Yi-Hui DING Xin-Yong SHEN Xiao-Ting SUN Meng-Chu ZHAO China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China CMA Key Open Laboratory of Transforming Climate Resources to Economy Chongqing Institute of Meteorological SciencesChongqing 401147China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Zhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The Tibetan Plateau(TP)and the Arctic are the most sensitive regions to global climate ***,the interdecadal varibility of winter extreme precipitation over the TP and its linkage with Arctic sea ice are still *** this study,the characteristics and mechisnems of the TP extreme precipitation(TPEP)influenced by Arctic sea ice on interdecadal timescale are studied based on the daily precipitation,monthly sea ice concentration and ERA5 reanalysis data from 1980 to *** found that the dominant mode of the TPEP in winter mostly exhibits a uniform spatial variation on the interdecadal timescale,with an opposite weak variation in the southeastern TP,and the Arctic sea ice concentration(SIC)before 2002 are larger than that after *** interdecadal variation of TPEP is affected by two teleconnection wave trains regulated by the Barents and Kara Sea *** the light ice years,a remarkable positive geopotential height(HGT)anomaly appears over the Barents-Kara Sea and a remarkable negative HGT anomaly is located over the Lake *** wave trains originating over the Barents-Kara Sea can be *** southern branch forms a wave train through the North Atlantic along the subtropical westerly jet stream,showing a‘+-+-+'pattern of HGT anomalies from Arctic to the *** HGT anomaly controls the western TP,which creates dynamic and water vapor conditions for the *** northern branch forms a wave train through the Lake Baikal and the southeast of the TP,showing a‘+-+'HGT anomaly *** HGT anomaly controls the southeastern TP,which is not conducive to precipitation in the *** the SIC in the Barents-Kara Sea increases,the situation is *** above analysis also reveals the reason for the difference in the east-west distribution of the TPEP.

关键词： Arctic sea ice Tibetan Plateau Winter extreme precipitation Rossby wave activity Interdecadal variation

A high-performance electromagnetic energy harvester for scavenging ultra-low frequency vibration energy of human foot movement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第5期67卷 1391-1400页

作者： HU JiaJun QIAN Shuo wu Hui HU DongXu NIU LiXin bi XiaoXue ZHANG Jie HOU XiaoJuan GENG WenPing MU Jiliang HE Jian CHOU XiuJian Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan030051China School of Software North University of ChinaTaiyuan030051China

In our daily lives,low-frequency kinetic energy primarily manifests as ***,effective harnessing of lowfrequency kinetic energy remains a formidable *** paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal *** rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick *** harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 ***,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 *** addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices *** study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.

关键词： electromagnetic energy harvester rope-shaft coupling structure human motion ultra-low frequency

Single thiolate replacement of metal nanoclusters

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen Yue Zhou Wanmiao Gu Qing You liang Fang Guoqing bian Nan Yan Nan Xia Zhikun wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

Surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal ***,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted ***,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption ***,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted *** bond length-related stability was also ***,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

在线全文

学校读者我要写书评

暂无评论

迷迭香叶中鼠尾草酸的分离纯化

林产化学与工业 2015年第5期35卷 105-110页

作者：夏田娟毕良武赵振东程贤邢雅丽中国林业科学研究院林产化学工业研究所生物质化学利用国家工程实验室国家林业局林产化学工程重点开放性实验室江苏省生物质能源与材料重点实验室江苏南京210042 中国林业科学研究院林业新技术研究所北京100091

以迷迭香叶为原料,采用超声波辅助乙醇提取、超声波辅助正己烷提取及p H值调节、硅胶柱层析3步骤复合提取纯化方法制备鼠尾草酸,结果表明：迷迭香叶经超声波辅助乙醇提取得到迷迭香叶提取物,其鼠尾草酸纯度为21.06%;迷迭香叶提取物经超... 详细信息

以迷迭香叶为原料,采用超声波辅助乙醇提取、超声波辅助正己烷提取及p H值调节、硅胶柱层析3步骤复合提取纯化方法制备鼠尾草酸,结果表明：迷迭香叶经超声波辅助乙醇提取得到迷迭香叶提取物,其鼠尾草酸纯度为21.06%;迷迭香叶提取物经超声波辅助正己烷提取和p H调节得鼠尾草酸粗品,其鼠尾草酸纯度为79.62%,超声波辅助正己烷提取的优化条件为：液固比20∶1（m L∶g）、超声波频率28 k Hz、超声波时间40 min、超声波功率140 W,鼠尾草酸的得率为2.0%;硅胶柱层析的优化条件为：硅胶粒径48~75μm、洗脱剂为乙酸乙酯/石油醚（体积比4∶7）、洗脱剂流速6 m L/min、上样量为0.3 g,鼠尾草酸回收率为54.12%。通过此种方法得到的鼠尾草酸纯度为95.18%。

关键词：鼠尾草酸超声波辅助提取纯化柱层析