检索结果-南通市图书馆

Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface Materials

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： yuan Ji Shi-Da Han hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

Regulation of AMPK activation by extracellular matrix stiffness in pancreatic cancer

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第3期11卷 338-350页

作者： Xin xu yuan Fang Somaira Nowsheen Ye-Xiong Li Zhenkun Lou Min Deng State Key Laboratory of Molecular Oncology and Department of Radiation Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of General Surgery Shanghai General HospitalShanghai Jiaotong University School of MedicineShanghai 200080China Department of General Surgery Zhongshan HospitalFudan UniversityShanghai 200032China Department of Dermatology University of California San DiegoSan DiegoCA 92093USA Department of Oncology Mayo ClinicRochesterMN 55905USA

The adenosine monophosphate(AMP)-activated protein kinase(AMPK)sits at a cen-tral node in the regulation of energy metabolism and tumor *** is best known to sense high cellular ADP or AMP levels,which indicate the depletion of energy *** studies have shown that the low expression of phosphorylated AMPK is associated with a poor prognosis of pancreatic *** this study,we report that AMPK is also highly sensitive to extracellular matrix(ECM)*** found that AMPK is activated in cells when cultured under low ECM stiffness conditions and is functionally required for the metabolic switch induced by ECM *** regulation of AMPK requires the Hippo kinases but not LKB1/*** kinases directly phosphorylate AMPKa at Thr172 to activate AMPK at low ECM ***,we found AMPK activity is inhibited in patients with pancreatic ductal adenocarcinoma(PDAC)with high ECM stiffness and is associated with a poor survival *** activation of Hippo kinases by ROCK inhibitor Y-27632 in combination with the mitochondrial inhibitor metformin synergistically activates AMPK and dramatically inhibits PDAC ***,these findings establish a novel model for AMPK regulation by the mechanical properties of ECMs and provide a rationale for simultaneously targeting the ECM stiffness-Hippo kinases-AMPK signaling and low glucose-LKB1-AMPK signaling pathways as an effective therapeutic strategy against PDAC.

关键词： AMPKactivity Cellularmetabolic switch ECM stiffness Hippokinase signaling Pancreaticductal adenocarcinoma

Data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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

China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang Da Shu Shou-qin Zhu Xiao-yuan Ji Bao-de Sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and Forging Factory of Anhui Heli Co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** collected data includes four types of defects and corresponding process parameters were used to construct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production conditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance

Effect of burial depth of a new tunnel on the seismic response of an existing tunnel

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2024年第4期23卷 863-882页

作者： Ma Runbo Cao Qikun Lu Shasha Zhao Dongxu Zhang Yanan xu hong College of Civil Engineering Liaoning Technical UniversityFuxin 123000China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China

Burial depth is a crucial factor affecting the forces and deformation of tunnels during *** key issue is a lack of understanding of the effect of a change in the buried depth of a single-side tunnel on the seismic response of a double-tunnel *** this study,shaking table tests were designed and performed based on a tunnel under construction in Dalian,*** models were established using the equivalent linear method combined with ABAQUS finite element software to analyze the seismic response of the interacting *** results showed that the amplification coefficient of the soil acceleration did not change evidently with the burial depth of the new tunnel but decreased as the seismic amplitude *** addition,the existing tunnel acceleration,earth pressure,and internal force were hardly affected by the change in the burial depth;for the new tunnel,the acceleration and internal force decreased as the burial depth increased,while the earth pressure *** shows that the earth pressure distribution in a double-tunnel system is relatively complex and mainly concentrated on the arch spandrel and arch springing of the relative ***,when the horizontal clearance between the center of the two tunnels was more than twice the sum of the radius of the outer edges of the two tunnels,the change in the burial depth of the new tunnel had little effect on the existing one,and the tunnel structure was deemed *** results provide a preliminary understanding and reference for the seismic performance of a double-tunnel system.

关键词： burial depth new tunnel existing tunnel seismic response shaking table tests numerical simulations

Searching for plant NLR immune receptors conferring resistance to potyviruses

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第1期12卷 28-44页

作者： Xin hong Shufen Li Xiaofei Cheng Haijian Zhi Jinlong Yin Kai xu Jiangsu Key Laboratory for Microbes and Functional Genomics Jiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing 210023JiangsuChina College of Plant Protection Northeast Agricultural UniversityHarbin 150030HeilongjiangChina National Center for Soybean Improvement National Key Laboratory for Crop Genetics and Germplasm EnhancementKey Laboratory of Biology and Genetic Improvement of Soybean-Ministry of AgricultureNanjing Agricultural UniversityNanjing 210095JiangsuChina

To fight against invasion by pathogens,plants have evolved an elaborate innate immune system,of which the nucleotide-binding domain leucine-rich repeat-containing receptor(NLR)acts as the sensor and immune ***,comprising one of the largest genera of plant viruses,cause severe crop yield losses *** crop resistance to potyviruses can be used in breeding and plant transgenesis to control disease *** review summarizes achievements in mapping and cloning NLR genes conferring dominant resistance against potyvirus in the families Fabaceae,Solanaceae,Brassicaceae,and *** compares mechanisms of potyviral protein recognition and downstream signaling employed by NLRs and discusses strategies for exploiting NLRs to better control diseases caused by potyviruses.

关键词： NLR Potyvirus resistance Genetic diversity Mapping Engineer

Efficacy and safety of electroacupuncture for insomnia:A systematic review and meta-analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第4期22卷 459-472页

作者： Han-yu xu Lin-na Wu yuan Zhang Te Ba Xiao-feng Zhao Acupuncture and Moxibustion Department First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjin 300193China National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion Tianjin 300193China

Background:Electroacupuncture is often used to treat ***:To evaluate the efficacy and safety of electroacupuncture for *** strategy:Databases including PubMed,Cochrane Library,Embase,Web of Science,Chinese Biomedical Literature Database,China National Knowledge Infrastructure,Wanfang Data and VIP Fulltext e-Journals Database were searched up to January 15,*** criteria:Randomized clinical trials were included if they compared the clinical efficacy and safety of electroacupuncture with sham acupuncture,no treatment or usual care (UC) and general *** extraction and analysis:The full texts of the studies were reviewed to remove ineligible *** extracted data included authors,publication year,diagnostic criteria,sample size,population characteristics,interventions and *** above steps were performed independently by two reviewers and the data were cross ***15.0 software was used to analyze the extracted outcome *** continuous data (Pittsburgh Sleep Quality Index[PSQI]score and Insomnia Severity Index score),weighted mean difference (WMD) was calculated and 95% confidence interval (CI) was reported when the same scale was *** dichotomous variables (clinical response rate and adverse events),a meta-analysis was performed using risk ratio (RR) as the effect ***:Thirty-one trials with 2226 subjects were *** meta-analysis suggested that electroacupuncture was more effective in improving insomnia compared with the control group (sham acupuncture,no treatment,UC and general acupuncture)(RR=1.21;95 CI:[1.16,1.27]),significantly reducing the PSQI score in insomnia patients after treatment and at follow-up (WMD=-3.23;95%CI:[-4.29,-2.17];P<0.001).There was no significant difference in the incidence of adverse events between the EA and control groups (sham acupuncture and no treatment or ***=1.48;95%CI:[0.91,2.40];P=0.117).In addition,the regression results revealed t

关键词： Electroacupuncture Insomnia Systematic review Meta-analysis

Acaricidal effect of the antimicrobial metabolite xenocoumacin 1 on spider mite control

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第3期23卷 948-959页

作者： Jiaxing Wei hong Yan Jie Ren Guangyue Li Bo Zhang xuenong xu Institute of Plant Protection Chinese Academy of Agricultural SciencesBeijing 100193China State Key Laboratory for Biology of Plant Diseases and Insect Pests Beijing 100193China Key Laboratory of Natural Enemies Insects Ministry of Agriculture and Rural AffairsBeijing 100193China

The two-spotted spider mite,Tetranychus urticae Koch,is one of the most harmful pests in many agroecosystems *** effectively manage this pest,there is an urgent need to develop novel bio-active acaricides that support integrated pest management strategies targeting *** this study,we explored the acaricidal effects of xenocoumacin 1 (Xcn1) on *** and its predator Neoseiulus californicus using the highly puri?ed ***1 was extracted and purified from the cell-free supernatant of the Xenorhabdus nematophila CB6 mutant constructed by the easy promoter activated compound identi?cation (easyPACId) *** the concentration of Xcn1 exceeded 100μg mL~(–1),the survival rate of spider mite adults declined to below 40%and the fecundity was decreased by 80%at six days *** concentrations of 25 and 50μg mL~(–1),Xcn1 signi?cantly impeded spider mite development by inhibiting the ***,neither concentration had any adverse effects on the survival or reproduction of the predatory mite *** results from laboratory and semi-?eld experiments consistently demonstrated the effectiveness of the antimicrobial metabolite Xcn1 in controlling pest mites at both the molecular and physiological *** study offers a promising possibility that combines the compatible biocontrol agents of Xcn1 and predatory mites for integrated pest mite control.

关键词： pest management predatory mite Xcn1 morphology developmental inhibition transcriptome

Rare earth inorganic-organic hybrid compounds based on Keggin-type polyoxometalate {SiW_(12)} with fast-responsive photochromism and switchable luminescence properties

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第2期42卷 286-292,I0003页

作者： hong Cui Yanli Yang xue Bai xu Han Wensha Zhang Ying Lu Shuxia Liu Key Laboratory of Polyoxometalate and Reticular Material Chemistry of the Ministry of Education College of ChemistryNortheast Normal UniversityChangchun 130024China

Four rare earth inorganic-organic hybrid compounds based on Keggin-type polyoxometalate {SiW_(12)}with general formula [{RE(DMF)_(4)(H_(2)O)_4RE(DMF)_(6)}_(2){SiW_(12)O_(40)}_(3)](RE = La(1),Pr(2),Sm(3),Eu(4),DMF=N,N-dimethylformamide) were synthesized by the conventional solution *** analyses indicate that four compounds are isostructural and are all built from three [SiW_(12)O_(40)]^(4-) polyoxoanions and DMF ligands linked by RE^(3+).Compounds 1-4 are extremely sensitive to UV light and present excellent photochromic properties,in which the coloring and fading time of samples are both no more than 2 min,and the reversible coloring-fading process can be repeated for at least 10 cycles with little fatigue,suggesting that compounds 1-4 can be a series of fast-responsive and durable photochromic ***,the solid-state photoluminescence spectra of compounds 3(Sm) and 4(Eu)display strong characteristic emissions of rare earth ions based on f-f ***,compound4(Eu) has a longer fluorescence lifetime up to 566.74 μ***,co mpounds 3(Sm) and 4(Eu) exhibit the switchable luminescence behavior induced by photochromism,which allows them to be used as potential molecular switches.

关键词： Inorganic-organic hybrid Keggin-type polyoxometalates Rare earths Photochromism Photoluminescence

The Uptake and Distribution Evidence of Nano-and Microplastics in vivo after a Single High Dose of Oral Exposure

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第1期37卷 31-41页

作者： hong Tao SUN Wei DENG yuan LYU Jian Da JIN Cui hong BAI Ying Long NA Jun ZHANG Rui GAO yuan PAN Guo Wei YANG Zuo Sen YAN Ling Jun Research Center for Universal Health School of Public HealthChina Medical UniversityShenyang 110122LiaoningChina Department of Pain Management Shengjing Hospital of China Medical UniversityShenyang 110004LiaoningChina Department of Toxicology School of Public HealthChina Medical UniversityShenyang 110122LiaoningChina Department of Maternal and Child Health School of Public HealthChina Medical UniversityShenyang 110122LiaoningChina Institute of Preventive Medicine China Medical UniversityShenyang 110122LiaoningChina Institute of Chronic Diseases Liaoning Provincial Center for Disease Control and PreventionShenyang 110000LiaoningChina

Objective Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in *** Fluorescent microspheres(100 nm,3μm,and 10μm)were given once at a dose of 200 mg/(kg∙body weight).The fluorescence intensity(FI)in observed organs was measured using the IVIS Spectrum at 0.5,1,2,and 4 h after *** was performed to corroborate these *** In the 100 nm group,the FI of the stomach and small intestine were highest at 0.5 h,and the FI of the large intestine,excrement,lung,kidney,liver,and skeletal muscles were highest at 4 h compared with the control group(P<0.05).In the 3μm group,the FI only increased in the lung at 2 h(P<0.05).In the 10μm group,the FI increased in the large intestine and excrement at 2 h,and in the kidney at 4 h(P<0.05).The presence of nano-/microplastics in tissues was further verified by *** peak time of nanoplastic absorption in blood was *** Nanoplastics translocated rapidly to observed organs/tissues through blood circulation;however,only small amounts of MPs could penetrate the organs.

关键词： Microplastics Nanoplastics IVIS Spectrum small-animal imaging system Tissue distribution Blood