检索结果-南通市图书馆

A Comparison Study of Synkinematic Illite Isolation,Quantitative X-ray Powder Diffraction,and K-Ar Dating for Direct Fault Gouge Analyses

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

Acta Geologica sinica(English Edition) 2023年第2期97卷 636-650页

作者： ZHENG yong LI Haibing LI Junjie ZHANG Guohe si jialiang Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China jiangsu Donghai Continental Deep Hole Crustal Activity National Observation and Research Station DonghaiJiangsu 222300China Beijing Research Institute of Uranium Geology Beijing 100029China Military and Civilian Integration Geological Survey Center Chengdu 610000China

K-Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal *** of efficient sample preparation and quantitative identification of illite polytypes are critical to acquiring K-Ar isotope data for authigenic *** this respect,we compared the commonly used clay size separation method through centrifugation with vacuum filtration technology,showing that the former is prone to extract fractions with finer particle sizes under similar conditions,thus improving the error in the authigenic end-member ***,we demonstrated that the side-packed mounting method for X-ray diffraction analysis can significantly enhance the randomness in powder samples,thus improving the quantification accuracy compared with the front-packed and back-packed *** validity of our quantification method was confirmed by comparing Profex■modeling patterns with a suite of synthetic mixtures of known compositions,yielding an average analytical error of 3%.Dating results of these artificial mixtures and the reference materials indicated that a large range in percentages of detrital illite and a sufficient amount of age data will produce reliable results for ages of both extrapolated ***,if the range is limited,the extrapolated age close to those of datasets is still reliable.

关键词： illite polytypes fault gouge clay size separation mounting method Profex■ extrapolated K-Ar age

Instability of single-walled carbon nanotubes conveying Jeffrey fluid

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第4期30卷 328-332页

作者： Bei-Nan jia yong-Jun jian School of Mathematical Science Inner Mongolia UniversityHohhot 010021China

We report instability of the single-walled carbon nanotubes(SWCNT) filled with non-Newtonian Jeffrey *** objective is to get the influences of relaxation time and retardation time of the Jeffrey fluid on the vibration frequency and the decaying rate of the amplitude of carbon *** elastic Euler-Bernoulli beam model is used to describe vibrations and structural instability of the carbon nanotubes.A new vibration equation of an SWCNT conveying Jeffrey fluid is first derived by employing Euler-Bernoulli beam equation and Cauchy momentum equation taking constitutive relation of Jeffrey fluid into *** complex vibrating frequencies of the SWCNT are computed by solving a cubic eigenvalue problem based upon differential quadrature method(DQM).It is interesting to find from computational results that retardation time has significant influences on the vibration frequency and the decaying rate of the ***,the vibration frequency decreases and critical velocity increases with the retardation *** is to say,longer retardation time makes the SWCNT more stable.

关键词： single-walled carbon nanotubes Jeffrey fluid relaxation time retardation time

Extreme value theory applied to the auroral electrojet indices

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第2期8卷 375-381页

作者： si Chen Hong Yuan yong Wei Guang Yang FengZheng Yu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The study of extreme weather and space events has gained paramount importance in modern society owing to rapid advances in high *** and describing exceptional occurrences plays a crucial role in making decisive assessments of their potential impact on technical,economic,and social aspects in various *** research focuses on analyzing the hourly values of the auroral electrojet(AE)geomagnetic index from 1957 to 2019 by using the peak over threshold method in extreme value *** fitting the generalized Pareto distribution to extreme AE values,shape parameter indices were derived,revealing negative values that establish an upper bound for this time ***,it became evident that the AE values had reached a plateau,suggesting that extreme events exceeding the established upper limit are *** a result,although the need for diligent precautions to mitigate the consequences of such extreme events persists,surpassing the upper limit of AE values becomes increasingly *** is also possible to observe an aurora in the middle-and low-latitude regions during the maximum period of the AE index.

关键词： auroral electrojet indices extreme value theory extreme events

Facile preparation of Nb_(2)O_(5) microspheres and their excellent electrochemical performance in aqueous zinc-ion hybrid supercapacitors

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第9期41卷 3129-3141页

作者： si-jia Zhang Han Chen Yi-Xue Xu Chang-Sheng An Kai-Xiong Xiang School of Materials and Advanced Manufacturing Liling Ceramic InstituteHunan University of TechnologyZhuzhou412007China Hunan Institute of Science and Technology Yueyang414000China Hunan Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha410022China

The aqueous solution-based zinc-ion hybrid supercapacitors(ZHSCs)have attracted immense attention as they are characterized by high power and energy *** materials with high performance should be developed for ZHSCs to resolve power imbalances between capacitor-and battery-type electrode *** address this issue,Nb_(2)O_(5) microspheres(with the structure like sweet dumplings with exposed stuffing)were produced following a hydrothermal process which was followed by a high-temperature calcination *** specific capacity of the as-synthesized Nb_(2)O_(5) microspheres was up to 324 F·g^(-1) when the current density was 0.1 A·g^(-1),and the long-term capacity retention was 85%at the end of 5000 *** results revealed that the nanospheres could be used as battery-type electrode materials for the fabrication of ***_(2)O_(5)//AC ZHSCs were fabricated with Nb_(2)O_(5) microspheres as the negative electrode materials,and activated carbon(AC)was used as the positive electrode *** a result,a specific capacity of 108 F·g^(-1) was achieved when the current density was 0.1 A·g^(-1).The power density was high(8020 W·kg^(-1))at 28 Wh·kg^(-1),and the energy density was high(60 Wh·kg^(-1))at 100 W·kg^(-1).The structurally novel Nb_(2)O_(5) microspheres can be potentially used for the development of the next-generation ZHSCs that exhibit excellent performance.

关键词： Hydrothermal Microspheres Nb_(2)O_(5) Zincion hybrid supercapacitors(ZHSCs) Fast kinetics

Multi-stage penetration characteristics of thick ultra-high molecular weight polyethylene laminates

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2023年第9期27卷 101-110页

作者： Ming-jin Cao Li Chen Rong-zheng Xu si-jia Liu Qin Fang Engineering Research Center of Safety and Protection of Explosion&Impact of Ministry of Education Southeast UniversityNanjing211189China Institute of Architectural Engineering Huanghuai UniversityZhumadian463000China State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing210007China

To further reveal the failure mechanisms of thick ultra-high molecular weight polyethylene(UHMWPE)laminates,field firing tests were conducted for 10-,20-,and 30-mm thick laminates against 12.7-mm calibre wedge-shaped fragment simulated projectiles at high velocities between 450 and 1200 m/*** ballistic performance,deformation process,and staged failure characteristics of the laminates with different thicknesses were compared and *** results demonstrate that the ballistic limits of the UHMWPE laminates increase almost linearly with laminate *** 10-mm thick laminate generally experiences two-stage failure characteristics,whereas three-staged failure occurs in the 20-and 30-mm thick laminates and the progressive delamination is *** energy limit concept representing the maximum energy absorption efficiency and the idea of reuse of the thick UHMWPE laminates are proposed in this *** findings of this research will be useful in the design of flexible and effective UHMWPE-based protective equipment.

关键词： UHMWPE laminates Ballistic limit Thickness Mechanism Energy limit

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： Hua Tang Ying Wang Shengling si Hongli Li David Da yong Chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China si Chuan Zhong Ce Biao Wu Technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment *** effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of *** affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were *** optimum conditions were found to be 120℃,10 min,and 3 cycles,***-MS/MS method was developed to obtain the optimal sensitivity specific to *** method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/*** ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent *** optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target ***,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to *** is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

Macrophage-secreted exosomes inhibit breast cancer cell migration via the miR-101-3p/DLG5 axis

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2023年第12期13卷 532-538页

作者： Yu Liu Chao-Qun Wang yong-Kang Zhu jia-Fang Xu si-Qi Yin Qing-Jie Hu Rui-Qi Yang First Clinical Medical College Nanjing University of Chinese MedicineNanjing 210001China Department of Breast Surgery The First Affiliated Hospital of Hainan Medical UniversityHaikou 570102China Department of Nuclear Medicine Hainan General HospitalHainan Affiliated Hospital of Hainan Medical UniversityHaikou 570311China Reproductive Medicine Center The First Affiliated Hospital of Hainan Medical UniversityHaikou 570102China

Objective:To investigate the role of macrophages in regulating breast cancer cell migration and its related ***:Human leukemia monocytic cell line THP-1-secreted exosomes were isolated using multi-step ultracentrifugation and verified using nanoparticle tracking *** expressed miRNAs were identified using RNA *** of inhibitors of hsa-miR-101-3p in breast cancer MDA-MB-231 cells was performed by infecting their lentiviral *** luciferase reporter assay was used to evaluate the interaction of DLG5 and ***5 expression was detected using qRT-PCR and Western blot ***:The migration of breast cancer cells was significantly inhibited after addition of *** sequencing results showed that miR-101-3p expression was significantly *** analysis predicted that miR-101-3p could target DLG5,and this prediction was verified using the luciferase *** addition of the miR-101-3p precursor significantly increased the expression of miR-101-3p,and the mRNA and protein levels of DLG5 were *** contrast,inhibiting the expression of miR-101-3p increased the mRNA and protein levels of ***,the scratch assay showed that inhibiting miR-101-3p could promote the migration of MDA-MB-231 ***:Macrophage exosomes can inhibit the migration of breast cancer cells,and increasing the expression of miR-101-3p to inhibit DLG5 expression may play an important role in this process,which needs further investigation.

关键词： Micro-RNA Tumor-associated macrophages Exosomes Breast cancer DLG5

Task assignment in ground-to-air confrontation based on multiagent deep reinforcement learning

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

Defence Technology（防务技术） 2023年第1期19卷 210-219页

作者： jia-yi Liu Gang Wang Qiang Fu Shao-hua Yue si-yuan Wang Air and Missile Defense College Air Force Engineering UniversityXi'an710051China Air Force Engineering University Changle East RoadXi'anShaanxi710051China

The scale of ground-to-air confrontation task assignments is large and needs to deal with many concurrent task assignments and random *** at the problems where existing task assignment methods are applied to ground-to-air confrontation,there is low efficiency in dealing with complex tasks,and there are interactive conflicts in multiagent *** study proposes a multiagent architecture based on a one-general agent with multiple narrow agents(OGMN)to reduce task assignment *** the slow speed of traditional dynamic task assignment algorithms,this paper proposes the proximal policy optimization for task assignment of general and narrow agents(PPOTAGNA)*** algorithm based on the idea of the optimal assignment strategy algorithm and combined with the training framework of deep reinforcement learning(DRL)adds a multihead attention mechanism and a stage reward mechanism to the bilateral band clipping PPO algorithm to solve the problem of low training ***,simulation experiments are carried out in the digital *** multiagent architecture based on OGMN combined with the PPO-TAGNA algorithm can obtain higher rewards faster and has a higher win *** analyzing agent behavior,the efficiency,superiority and rationality of resource utilization of this method are verified.

关键词： Ground-to-air confrontation Task assignment General and narrow agents Deep reinforcement learning Proximal policy optimization(PPO)

在线全文

学校读者我要写书评

暂无评论

基于绿色EVA视角的化工企业业绩评价研究

江苏商论 2025年第1期 112-116页

作者：贾永玉苗蕴慧沈阳化工大学辽宁沈阳110142

随着十四五规划的推进、“双碳”政策的实施,绿色化工及碳中和将是未来中国重要的经济增长动力之一,化工产业的可持续发展备受关注。本文以中国基础化工行业为研究样本,搜集整理了2020年和2021年相关数据,将绿色EVA值引入化工企业业绩... 详细信息

随着十四五规划的推进、“双碳”政策的实施,绿色化工及碳中和将是未来中国重要的经济增长动力之一,化工产业的可持续发展备受关注。本文以中国基础化工行业为研究样本,搜集整理了2020年和2021年相关数据,将绿色EVA值引入化工企业业绩评价体系。首先采用因子分析法分别提取各年化工行业业绩表现的主要影响因子,计算因子综合得分;再结合聚类分析对2021年和2020年化工行业业绩表现进行横向分类、纵向对比。以更全面地评价在疫情影响的经济动荡期内化工企业业绩现状、剖析原因并结合化工行业的特点提出相应发展建议。

关键词：绿色EVA 业绩评价因子分析聚类分析