检索结果-南通市图书馆

Large Eddy Simulation of Turbulent Fluid Flow in liquid Metal of Continuous Casting

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2013年第1期20卷 34-39,46页

作者： JI Chuan-bo li Jing-she YANG Shu-feng sun li-yuan School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The transient turbulent flow in continuous casting steel plays a key role in minimizing defects. Compared with the k-ε model, the large eddy simulation （LES） of turbulence provides much more accurate representation of turbulent flow by resolving large-scale dynamics. The turbulent flow in a liquid metal model of continuous casting has been simulated by LES and measured using ultrasonic Doppler velocimetry （UDV）. The result of measurement and LES has been compared to validate the LES model and furthermore enhance the understanding of the transient turbulent feature in the flow field. The results show that the jet exiting from the nozzle port swings, which is not steady, and turbulent velocity variation frequencies decreased with distance from the nozzle port region and also the LES mode can capture the high frequency fluctuation, which the measurement cannot detect.

关键词： LES turbulent flow nozzle mold continuous casting

Mechanism and prediction of failure of diamond films deposited on various substrates by HFCVD

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第Z1期14卷 229-233页

作者： ZHOU ling-ping sun Xin-yuan li Shao-lu li De-yi CHEN Xiao-hua College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China

Diamond films were deposited on the WC-Co cemented carbide and Si3N4 ceramic cutting tool substrates by hot-filament-assisted chemical vapour deposition. The adherence property of diamond films was estimated using the critical load (Pcr) in the indentation test. The adhesive strength of diamond films is related to the intermediate layer between the film and the substrate. Poor adhesion of diamond films to polished cemented carbide substrate is owing to the formation of graphite phase in the interface. The adhesion of diamond films deposited on acid etched cemented carbide substrate is improved, and the peeling-off of the films often happens in the loosen layer of WC particles where the cobalt element is nearly removed. The diamond films' adhesion to cemented carbide substrate whose surface layer is decarbonizated is strengthened dramatically because WC phase forms by reaction between the deposited carbon and tungsten in the surface layer of substrates during the deposition of diamond, which results in chemical combination in the film-substrate interface. The adhesion of diamond films to silicon nitride substrate is the firmest due to the formation of chemical combination of the SiC intermediate layer in the interfaces. In the piston-turning application, the diamond-coated Si3N4 ceramic and the cemented carbide cutting tools usually fail in the form of collapsing of edge and cracking or flaking respectively. They have no built-up edge(BUE) as long as coating is *** it wears through, BUE develops and the cutting force on it increases 1 - 3 times than that prior to failure. This can predict the failure of diamond-coated cutting tools.

关键词： diamond film cutting tool adhesion failure prediction cemented carbide

Peripheral mitochondrial DNA as a neuroinflammatory biomarker for major depressive disorder

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

Neural Regeneration Research 2025年第6期20卷 1541-1554页

作者： Jinmei Ye Cong Duan Jiaxin Han Jinrong Chen Ning sun yuan li Tifei yuan Daihui Peng Division of Mood Disorder Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina Department of Psychiatry First Hospital of Shanxi Medical UniversityTaiyuanShanxi ProvinceChina Shanghai Key Laboratory of Psychotic Disorders Brain Health InstituteNational Center for Mental DisordersShanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina Co-Innovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina

In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may be an inflammatory trigger, after its release from stress-induced dysfunctional central nervous system mitochondria into peripheral circulation. This evidence supports the potential use of peripheral mitochondrial DNA as a neuroinflammatory biomarker for the diagnosis and treatment of major depressive disorder. Herein, we critically review the neuroinflammation theory in major depressive disorder, providing compelling evidence that mitochondrial DNA release acts as a critical biological substrate, and that it constitutes the neuroinflammatory disease pathway. After its release, mitochondrial DNA can be carried in the exosomes and transported to extracellular spaces in the central nervous system and peripheral circulation. Detectable exosomes render encaged mitochondrial DNA relatively stable. This mitochondrial DNA in peripheral circulation can thus be directly detected in clinical practice. These characteristics illustrate the potential for mitochondrial DNA to serve as an innovative clinical biomarker and molecular treatment target for major depressive disorder. This review also highlights the future potential value of clinical applications combining mitochondrial DNA with a panel of other biomarkers, to improve diagnostic precision in major depressive disorder.

关键词： biomarker cytokine exosomes inflammasome major depressive disorder microglia mitochondrial DNA mitochondrial dysfunction neuroinflammation Toll-like receptor

Innovative dual-mode device integrating capacitive desalination and solar vapor generation for high-efficiency seawater desalination

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 171-179页

作者： Jiacheng Wang Zhaoyu Chen Ruduan yuan Jiaxin Luo Ben Zhang Keju Ji Meng li Juanxiu Xiao Kuan sun National Innovation Center for Industry-Education Integration of Energy Storage Technology MOE Key Laboratory of Low-grade Energy Utilization Technologies and SystemsCollege of Energy & Power Engineering Chongqing University Xuefeng Mountain Energy Equipment Safety National Observation and Research Station CQU-NUS Renewable Energy Materials & Devices Joint Laboratory Chongqing University Southwest Technology and Engineering Research Institute Jiangsu Provincial Key Laboratory of Bionic Functional Materials College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University

Solar-driven interface evaporation with high solar-to-steam conversion efficiency has shown great potential in seawater ***,due to the influence of latent heat and condensation efficiency,the water yield from solar-driven interface evaporation remains insufficient,posing a significant challenge that requires *** this work,we designed a dual-mode high-flux seawater desalination device that combines solar-driven interface evaporation and capacitive *** utilizing coupled desalination materials exhibiting both photothermal conversion and capacitance activity,the device demonstrated photothermal evaporation rates of 1.41 and 0.97 kg m-2h-1for condensate water yield under one-sun ***,the device exhibited a salt adsorption capacity of up to48 mg g-1and a salt adsorption rate of 2.1 mg *** addition,the salt adsorption capacity increased by approximately 32% under one-sun ***,photo-enhanced capacitive desalination performance was explored through numerical simulations and theoretical *** calculations and characterizations confirmed that the defect energy levels formed by the introduction of sulfur vacancies can effectively widen the light absorption range,improve photothermal conversion performance,and stimulate more photoelectrons to participate in capacitive ***,the electron distribution state of molybdenum disulfide with sulfur vacancies and surface defect sites contributes to ion/electron transport at the solid-liquid *** work provides a novel pathway for integrating solar vapor generation with other low-energy desalination technologies.

关键词： Desalination

Atmospheric reductive catalytic fractionation of lignocellulose integrated with one-pot catalytic conversion of carbohydrate yielding valuable lignin monomers and platform chemicals from corn straw

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2025年第1期10卷 161-172页

作者： Meng-Ying liu Zhe-Hui Zhang Xue-Qi Wang Qian sun Chen Zhang Yu li Zhuohua sun Katalin Barta Feng Peng Tong-Qi yuan State Key Laboratory of Efficient Production of Forest Resources Beijing Forestry UniversityBeijing100083China Beijing Key Laboratory of lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China Department of Chemistry Organic and Bioorganic ChemistryUniversity of GrazHeinrichstrasse 28/II8010 GrazAustria

Developing a cost-effective and environmentally friendly process for the production of valuable chemicals from abundant herbal biomass receives great attentions in recent ***,taking advantage of the“lignin first”strategy,corn straw is converted to valuable chemicals including lignin monomers,furfural and 5-methoxymethylfurfural via a two steps *** key of this research lies in the development of a green and low-cost catalytic process utilizing magnetic Raney Ni catalyst and high boiling point ethylene *** utilization of neat ethylene glycol as the sole slovent under atmospheric conditions obviates the need for additional additives,thereby facilitating the entire process to be conducted in glass flasks and rendering it highly convenient for scaling *** the initial step,depolymerization of corn straw lignin resulted in a monomer yield of 18.1 wt%.Subsequently,in a dimethyl carbonate system,the carbohydrate component underwent complete conversion in a one-pot process,yielding furfural and 5-methoxymethylfurfural as the primary products with an impressive yield of 47.7%.

关键词： Atmospheric reductive catalytic fractionation Corn straw Ethylene glycol Raney Ni 5-Methoxymethylfurfural

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

碳酸二甲酯作甲基化试剂合成丁香酚甲醚

林产化学与工业 2013年第2期33卷 139-143页

作者：孙丽媛朱凯南京林业大学化学工程学院江苏南京210037

以绿色化学原料碳酸二甲酯(DMC)代替传统有毒有害试剂作为甲基化试剂,以丁香酚为原料,在固体碱K2CO3催化作用下合成丁香酚甲醚。对几种不同催化剂进行筛选,确定K2CO3为催化剂;以丁香酚甲醚得率为评价指标,采用中心复合设计法对丁香酚和... 详细信息

以绿色化学原料碳酸二甲酯(DMC)代替传统有毒有害试剂作为甲基化试剂,以丁香酚为原料,在固体碱K2CO3催化作用下合成丁香酚甲醚。对几种不同催化剂进行筛选,确定K2CO3为催化剂;以丁香酚甲醚得率为评价指标,采用中心复合设计法对丁香酚和DMC甲基化反应的工艺进行优化,得到制备丁香酚甲醚的最佳工艺:反应温度155℃,K2CO3用量6.12%(占丁香酚的摩尔分数),n(DMC):n(丁香酚)4.3:1,反应时间6 h,在此条件下丁香酚甲醚得率的预测值为96.44%。对最佳工艺进行验证实验,丁香酚甲醚得率为96.16%,表明中心复合设计预测性良好,实验重复性好。采用气质联用、红外光谱对产物进行分析。

关键词：碳酸二甲酯丁香酚甲醚碳酸钾甲基化中心复合设计

Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 39-48页

作者： Peng li Meifeng Cai Shengjun Miao yuan li Yu Wang Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress *** investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution *** results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with *** is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and ***,there is no obvious relationship between the rock quality designation(RQD)and *** maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same *** addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.

关键词： overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification

Joint Feature Encoding and Task Alignment Mechanism for Emotion-Cause Pair Extraction

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2025年第1期82卷 1069-1086页

作者： Shi li Didi sun College of Computer and Control Engineering Northeast Forestry UniversityHarbin150040China

With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant ***-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying *** comprehension is crucial for making informed strategic decisions in various business and societal ***,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause *** address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment *** model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause ***,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among *** proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 *** results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its *** research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-c

关键词： Emotion-cause pair extraction interactive information enhancement joint feature encoding label consistency task alignment mechanisms

左氧氟沙星体外诱导马耳他布鲁杆菌耐药后gyrA基因的变异

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

中国地方病学杂志 2009年第5期28卷 480-483页

作者：孙丽媛李凡吉林大学白求恩医学院病原生物学教研室教育部人畜共患病重点实验室长春130021

目的探讨马耳他布鲁杆菌对喹诺酮类抗菌药物耐药性的产生机制，为指导临床合理用药提供依据。方法使用左氧氟沙星分别对6株马耳他布鲁杆菌（Bru1、Bru2、Bru3、Bru4、Bru5、Bru6）进行体外耐药诱导并筛选耐药菌株。采用琼脂稀释法测定... 详细信息

目的探讨马耳他布鲁杆菌对喹诺酮类抗菌药物耐药性的产生机制，为指导临床合理用药提供依据。方法使用左氧氟沙星分别对6株马耳他布鲁杆菌（Bru1、Bru2、Bru3、Bru4、Bru5、Bru6）进行体外耐药诱导并筛选耐药菌株。采用琼脂稀释法测定左氧氟沙星对6株马耳他布鲁杆菌及诱导耐药菌株的最低抑菌浓度（MIC），采用纸片扩散法（K—B法）测定6株马耳他布鲁杆菌和诱导耐药菌株对喹诺酮类抗菌药物（左氧氟沙星、环丙沙星、洛美沙星、诺氟沙星、氟罗沙星、氧氟沙星）的敏感性。应用PCR技术扩增6株马耳他布鲁杆菌及诱导耐药菌株的gyrA基因，并对获得的基因进行同源性分析及氨基酸序列推导。结果左氧氟沙星对Bru1，Bru2，Bru3，Bru4，Bru6菌株MIC为0．50μg／ml，对Bru5菌株为0．25μg／m1，菌株Bru3、Bru4经左氧氟沙星诱导后转变成耐药菌株，分别命名为LEVR3及LEVR4，其MIC分别为64．00、128．00μg／ml，与诱导前比较，增加了128倍和256倍．6株马耳他布鲁杆菌对上述喹诺酮类药物均敏感，2株诱导耐药菌株对上述喹诺酮类药物均耐药，并且其GyrA亚单位的喹诺酮耐药性决定区（Qninolone resistance—determing region，QRDR）发生突变：Ala87（GCU）置换为Val（GUU）、Asp91（GAU）置换为Gly（GGU）。结论马耳他布鲁杆菌可在左氧氟沙星短期作用后获得耐药性，诱导的耐药菌株gyrA基因发生突变，且对其他喹诺酮类药物产生交叉耐药。

关键词：布鲁杆菌属抗菌药 gyrA基因喹诺酮类