检索结果-南通市图书馆

High Voltage 2024年第2期9卷 267-274页

作者： Xianhao Fan Shu Niu Hanhua Luo Jizhong liang fang liu Wenqiang li Weidong liu Wensheng Gao Yulong Huang Chuanyang li Jinliang He School of Electrical Engineering Tsinghua UniversityBeijingChina Electric Power Research Institute Shangxi Power Grid CorporationTaiyuanShanxiChina Shandong Taikai Electrical Insulation Co. Ltd.TaianShandongChina

The micro-defects in epoxy-based insulation materials generate a local high electric field which results in continuous degradation,seriously endangering the insulation system of gas-insulated switchgears.A highly sensitive detection technique is reported for micro-defects of insulation pull rods based on the photon counting(PC)*** re-sults demonstrated that for an epoxy-based insulation pull rod,the photons released during electroluminescence and ionisation at 2 kV,which is less than the partial discharge inception voltage,can be clearly *** findings presented a strong correlation between photon counts and defect *** has been conducted to elucidate the mechanism behind defect-induced PC,employing the amplification of ionising luminescence through electric field distortion induced by micro defects and the augmentation of electroluminescence through the aggregation of trap *** this regard,the authors verified that PC can serve as a potential tool in the detection of micro-insulation defects,which also has huge potential in online insulation condition monitoring.

关键词： technique. insulation defect

Effect of yttrium and manganese addition on catalytic soot combustion activity and anti-high-temperature stability of CeO_(2) catalyst

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第2期42卷 334-344,I0004页

作者： Yi Zhu Xingyu liu Wei Shi Jia li Changbing Ye Ruimei fang Huifeng Zhu Shanhu Chen li Lan College of Chemistry Biology and Environment Yuxi Normal UniversityYuxi 653100China Institute of Biology and Environmental Engineering Yuxi Normal UniversityYuxi 653100China College of Environment and Resources Chongqing Technology and Business UniversityChongqing 400067China College of Chemistry and Chemical Engineering Jiangxi Science and Technology Normal UniversityNanchang 330013China College of Materials and Mechatronics Jiangxi Science and Technology Normal UniversityNanchang 330013China

In order to analyze the influence of the addition of yttrium and manganese on the soot combustion performance and high temperature stability of CeO_(2) catalyst,a series of Y/Mn-modified CeO_(2) catalysts were *** effects of structural properties,textural properties,oxygen vacancies,Ce^(3+),surface adsorbed oxygen species,reduction properties and desorption properties of oxygen species on the activity were analyzed by various characterization *** results of the activity test show that the addition of manganese is beneficial to enhancement of the activity,while the addition of yttrium increases the amount of reactive oxygen species,but decreases the *** aging at 700℃,the activity of the CeMn catalyst decreases most sharply,while the catalytic activity of the CeY catalyst can be maintained to a certain ***,the addition of yttrium and manganese at the same time can stabilize the *** fundamental reason is that yttrium and manganese move to the surface of the solid solution after aging,which increases the reduction performance of the catalyst,thus contributing to the increase of *** the activity of CeYMn catalyst decreases after aging at 800℃,it is still higher than that of other catalysts aged at 700℃.

关键词： CeO_(2)catalyst Soot catalytic combustion Diesel pollution control Rare earths High temperature stability Low temperature reduction performance

Junshanyinzhen tea extract prevents obesity by regulating gut microbiota and metabolic endotoxemia in high-fat diet fed rats

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

Food Science and Human Wellness 2024年第4期13卷 2036-2047页

作者： Jian Ouyang Xiuping li Changwei liu Danmin Lu Jie Ouyang fang Zhou Qi liu Jianan Huang Zhonghua liu Key Laboratory of Tea Science of Ministry of Education Hunan Agricultural UniversityChangsha 410128China National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals Hunan Agricultural UniversityChangsha 410128China Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients Hunan Agricultural UniversityChangsha 410128China Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops Ministry of Agriculture and Rural AffairsHunan Agricultural UniversityChangsha 410128China

Obesity is associated with gut dysbiosis and metabolic *** tea extract(JSTE)reduced fat accumulation and body weight in obese ***,the effects and mechanism of JSTE in preventing obesity were ***,we used different doses of JSTE(75,150 and 300 mg/(kg·day))to evaluate the effect on high-fat diet(HFD)-induced rats under 8 weeks of ***,our results showed that JSTE could significantly reduce body weight gain,blood lipid levels and fat accumulation,improve fatty damage in liver tissue(Plieved metabolic endotoxemia(Plic endotoxemia and chronic low-grade infl ammation in HFD-induced rats.

关键词： Junshanyinzhen tea Obesity Gut microbiota Gut barrier function Metabolic endotoxemia

The enhanced mechanical properties of SiC nanowires/Ba0.75Sr0.25Al2Si2O8 ceramics with embedded SiO2 interface

维普期刊数据库

同方期刊数据库

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

Journal of Advanced Ceramics 2024年第7期13卷 933-941页

作者： Xin li Xiaomeng Fan Haojie Luo Xiaoke Lu Jimei Xue fang Ye Yongsheng liu Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China Frontier Institute of Science and Technology Xi’an Jiaotong UniversityXi’an 710049China

In this work,low-softening-temperature and low-modulus SiO2 was introduced as an embedded interface between SiC nanowires(SiCnws)and a BaxSr1−xAl2Si2O8 ceramic matrix to enhance strength and toughness of the *** the sintering process,molten SiO2 enhances the flowability of the ceramic powders and modifies the dispersion of *** strengthening effect of SiCnws was fully realized,and the flexural strength of the optimized ceramics reached 193±16 MPa,which represents an increase of 52.6%.After the formation of the embedded SiO2 interface with a low modulus,cracks can deflect along the SiCnws surface,which is consistent with the criterion of He and *** can effectively extend the crack propagation path,and the fracture toughness(K_(IC))is thus improved by 94.0%,reaching 3.1±0.5 MPa·m^(1/2).

关键词： multiphase ceramics SiO2 interface densification mechanical properties

Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 6977-6983页

作者： Daolian liu Zihao Wang Yan Zhang Haiqing Zhou Yong Zhang Dongyang li fang Yu Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China State Key Laboratory of Marine Resource Utilization in South China Sea and Department of Materials Science and EngineeringHainan UniversityHaikou 570228China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China

Given the inherent potential of seawater,industrial wastewater,and residential water as inherent feedstocks for hydrogen production through water electrolysis,there is a critical demand for the exploration of robust and stable hydrogen-evolving catalysts that can operate effectively across a diverse range of pH ***,the pursuit of hydrogen-evolving electrocatalysts that demonstrate both good stability and high efficiency over a wide pH range remains a formidable *** we report the rational design and synthesis of an outstanding nanoporous hybrid electrocatalyst consisting of intermetallic cobalt-molybdenum alloy particles anchoring on MoO2 cuboid arrays,which demands very low overpotentials of 72,123 and 134 mV to deliver a current density of−100 mA·cm^(−2)for hydrogen evolution reaction under alkaline,neutral and acidic conditions,*** catalytic activities are superior to most non-precious-metal-based catalysts documented in the literatures,and are even comparable to noble metal *** particular,this alloy electrocatalyst exhibits excellent stability at 50 or 300 mA·cm^(−2)without obvious activity degradation,which is further supported by the undetectable changes in the surface chemical valence states on the basis of in-situ X-ray photoelectron spectroscopic *** study provides an innovative strategy for the design and synthesis of effective non-noble intermetallic catalysts for pH-universal hydrogen evolution over a wide pH range.

关键词： electrocatalyst hydrogen evolution reaction pH-universal non-noble water splitting

Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China

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 150-167页

作者： fang Chaogang ZHANG Chengcheng MENG Guixi XU Jinlong XU Naicen li Hualing liu Mu liu Bo Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650500China Nanjing Center China Geological SurveyNanjing 210016China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefei 230088China China United Coalbed Methane Corporation Ltd. Beijing 100015China Geological Survey of Anhui Province Hefei 230001China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source ***,the mechanism of organic matter(OM)enrichment throughout this period is still *** on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM *** Phases are distinguished based on the TOC and environmental *** Phase I,anoxic conditions driven by water restriction enhanced OM *** Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM *** Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation *** IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic *** Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary *** I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.

关键词： geochemistry redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region

Matrix metalloproteinase 2 contributes to adult eclosion and immune response in the small hive beetle,Aethina tumida

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

Insect Science 2024年第3期31卷 733-747页

作者： lixian Wu Yajing Xu liangbin li Dainan Cao fang liu Hongxia Zhao Guangdong Key Laboratssory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouChina

During the pupal-adult eclosion process of holometabolous insects,the old cuticle is shed and replaced by a completely different new cuticle that requires tanning and expansion,along with extensive extracellular matrix(ECM)*** vertebrates,matrix metalloproteinases(MMPs),a class of zinc-dependent endopeptidases,play key roles in regulating the ECM that surrounds ***,little is known about these extracellular proteinases available in *** small hive beetle(SHB),Aethina tumida,is a widespread invasive parasite of honey *** this study,6 MMP homologs were identified in the SHB *** interference experiments showed that all 6 AtMmps are not required for the larval-pupal transition,only AtMmp2 was essential for pupal-adult eclosion in *** of AtMmp2 resulted in eclosion defects and wing expansion failure,as well as mortality within 3 d of adult *** analysis revealed that knockdown of AtMmp2 significantly increased expression of the Toll and Imd pathways,chitin metabolism,and cross-linking(such as the pro-phenoloxidase activating cascade pathway and the tyrosine-mediated cuticle sclerotization and pigmentation pathway).These data revealed evolutionarily conserved functions of Mmp2 in controlling adult eclosion and wing expansion,also provided a preliminary exploration of the novel function of regulating Toll and Imd pathways,as well as new insights into how MMPs regulate insect development and defense barriers.

关键词： Aethina tumida adult eclosion immune response matrix metalloproteinase RNAinterference

Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper, Empoaca vitis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2012年第2期19卷 229-238页

作者： Dan Mu lin Cui Jian Ge Meng-Xin Wang li-fang liu Xiao-Ping Yu Qing-He Zhang Bao-Yu Han Tea Research Institute of Chinese Academy of Agricuitural Sciences Zhejiang Provincial Key Laboratory of Biometrology and Inspection&Quarantine College of Life Sciences of China Jiliang UniversityHangzhouChina Sterling International Inc.SpokaneWAUSA

The tea green leafhopper, Empoasca vitis Gothe, is one of the most serious insect pests of tea plantations in China's Mainland. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography-mass spectrometry （GC-MS）：（E）-2-hexenal, （Z）-3-hexen-1- ol, （Z）-3-hexenyl acetate, 2-ethyl-1-hexanol, （E）-ocimene, linalool, nonanol, （Z）-butanoic acid, 3-hexenyl ester, decanal, tetradecane, β-caryophyllene, geraniol and hexadecane. In Y-tube olfactometer tests, the following individual compounds were identified：（E）-2- hexenal, （E）-ocimene, （Z）-3-hexenyl acetate and linalool, as well as two synthetic mixtures （called blend 1 and blend 2） elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, （Z）-3-hexen-l-ol and （E）-2-hexenal at a 1： 1：1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio：（E）-2-hexenal, （Z）- 3-hexen-l-ol, （Z）-3-hexenyl acetate, 2-penten-l-ol, （E）-2-pentenal, pentanol, hexanol and 1-penten-3-ol. In tea fields, the bud-green sticky board traps baited with blend 2, （E）-2- hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, foUowed by （E）-2-hexenal and hexane. Placing sticky traps baited with blend 2 or （E）-2-hexenal in the tea fields significantly reduced leathopper populations. Our results indicate that the bud-green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the

关键词： attractant behavior green leaf volatiles tea green leafhopper tea shoot volatiles

DGConv: A Novel Convolutional Neural Network Approach for Weld Seam Depth Image Detection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 1755-1771页

作者： Pengchao li fang Xu Jintao Wang Haibing Guo Mingmin liu Zhenjun Du State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110169China University of Chinese Academy of Sciences Beijing100049China Shenyang SIASUN Robot&Automation Co. Ltd.Shenyang110168China

We propose a novel image segmentation algorithm to tackle the challenge of limited recognition and segmentation performance in identifying welding seam images during robotic intelligent ***,to enhance the capability of deep neural networks in extracting geometric attributes from depth images,we developed a novel deep geometric convolution operator(DGConv).DGConv is utilized to construct a deep local geometric feature extraction module,facilitating a more comprehensive exploration of the intrinsic geometric information within depth ***,we integrate the newly proposed deep geometric feature module with the Fully Convolutional Network(FCN8)to establish a high-performance deep neural network algorithm tailored for depth image ***,we enhance the FCN8 detection head by separating the segmentation and classification *** enhancement significantly boosts the network’s overall detection ***,for a comprehensive assessment of our proposed algorithm and its applicability in real-world industrial settings,we curated a line-scan image dataset featuring weld *** dataset,named the Standardized linear Depth Profile(SLDP)dataset,was collected from actual industrial sites where autonomous robots are in ***,we conducted experiments utilizing the SLDP dataset,achieving an average accuracy of 92.7%.Our proposed approach exhibited a remarkable performance improvement over the prior method on the identical ***,we have successfully deployed the proposed algorithm in genuine industrial environments,fulfilling the prerequisites of unmanned robot operations.

关键词： Weld image detection deep learning semantic segmentation depth map geometric feature extraction

A Novel Fracturing Fluid with High-Temperature Resistance for Ultra-Deep Reservoirs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第5期20卷 975-987页

作者： lian liu liang li Kebo Jiao Junwei fang Yun Luo Northwest Oilfield Branch China Petroleum&Chemical CorporationUrumqi830011China Sinopec Key Laboratory for Enhanced Recovery in Fractured and Cavernous Reservoir Urumqi830011China

Ultra-deep reservoirs play an important role at present in fossil energy *** to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are *** response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking *** fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/*** with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction ***,the new fracturing fluid can significantly mitigate safety risks.

关键词： Ultra-deep reservoir high-temperature resistance weighted fracturing fluid guanidine gum potassium formatted