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Influence of Spot Welding on Welding Fatigue Properties of CR340 Steel Joints

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Journal of Iron and Steel Research International 2016年第8期23卷 822-827页

作者： Rui-bin GOU Wen-jiao DAN wei-gang ZHANG Department of Engineering Mechanics and Innovation Center for Advanced Ship and Deep-Sea Exploration School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong University School of Mechanical Engineering Anhui Science and Technology University

Total 72 lapped specimens including six different kinds of CR340 steel structures were prepared to study the influence of the spot welding technology on their fatigue *** test and group method were employed and performed on each sample to obtain the fatigue experimental data of each structure under four stress *** results show that the spot welding technology had a notable impact on the fatigue performance of both the shear and tensile *** can significantly improve the fatigue strength of the structure,the consistency and repeatability of experimental data,as well as the stability and reliability of the structure under dynamic load *** shear spot welding structure demonstrates the best fatigue performance which is very important for wide application in engineering of this method.

关键词： Welding welding joints fatigue welded tensile consistency Spot fitting notable

静电纺丝法制备自支撑Zn_(2)VO_(4)/N-CNFs复合中间层及电化学性能研究

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热加工工艺 2024年第12期53卷 41-47页

作者：吴丁丁曲来涛陈利萍魏刚王娟西安建筑科技大学陕西省纳米材料与技术重点实验室西安清洁能源重点实验室陕西西安710055 中国船舶集团有限公司第十二研究所陕西兴平713102

应用静电纺丝技术设计了一种具有3D网状结构的Zn、V双金属化合物-氮掺杂碳纳米纤维自支撑中间层(Zn_(2)VO_(4)4/N-CNFs),被用于锂硫电池。结果表明,吡啶氮和吡咯氮能与锂离子发生强的相互作用,Zn_(2)VO_(4)4对多硫化锂有极强的吸附和催... 详细信息

应用静电纺丝技术设计了一种具有3D网状结构的Zn、V双金属化合物-氮掺杂碳纳米纤维自支撑中间层(Zn_(2)VO_(4)4/N-CNFs),被用于锂硫电池。结果表明,吡啶氮和吡咯氮能与锂离子发生强的相互作用,Zn_(2)VO_(4)4对多硫化锂有极强的吸附和催化效果。碳纳米纤维网络捕捉多硫化锂的同时还可以提供长程电子传导路径,在促进电子转移的同时又能存储电解液,提供了电化学反应空间。Zn_(2)VO_(4)4/N-CNFs中间层发挥了对多硫化锂从捕捉到促进转化的双功能作用。因此,采用Zn_(2)VO_(4)4/N-CNFs中间层的锂硫电池在0.2 C下的初始放电比容量为796.1 mAh·g^(-1),循环100圈后仍可保持727.2 mAh·g^(-1)的容量,容量保持率为91.3%。在1.0 C时,电池的初始容量为593.4 mAh·g^(-1),循环1000圈后仍保有353.3 mAh·g^(-1)的容量,每圈的容量衰减仅为0.0024%。

关键词：双金属化合物碳纳米纤维中间层多硫化锂

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中药石斛研究的回顾与展望

中国现代中药 2024年第7期26卷 1111-1118页

作者：顺庆生魏刚何祥林上海健康医学院上海200237 广州中医药大学中药学院广东广州510006 道地药材品质保障与资源持续利用全国重点实验室北京100700 安徽省霍山县长冲中药材有限责任公司安徽霍山237200

中药石斛基原复杂,其主流品种有霍山石斛Dendrobium huoshanense *** et ***、铁皮石斛*** Kimura et Migo、金钗石斛*** Lindl.,《中华人民共和国药典》(以下简称《中国药典》)2005年版石斛项下增加了“及其近似种”的描述,难以确定具... 详细信息

中药石斛基原复杂,其主流品种有霍山石斛Dendrobium huoshanense *** et ***、铁皮石斛*** Kimura et Migo、金钗石斛*** Lindl.,《中华人民共和国药典》(以下简称《中国药典》)2005年版石斛项下增加了“及其近似种”的描述,难以确定具体物种,有必要对其进一步正本清源。对石斛属的起源进行本草考证,对霍山石斛、铁皮石斛、金钗石斛的本草起源进行梳理,为不同石斛属药材的应用提供参考。霍山石斛是最早作为中药石斛应用的品种,高效液相色谱法特征图谱等方法为《中国药典》2020年版收录霍山石斛提供了技术支撑;铁皮石斛应为石斛药材中应用时间最久、范围最广的品种,其主要为浙江、云南、贵州,以及广东、广西、福建、江西等地丹霞地貌上生长的种群,应高度重视并对其进行保护;***在历代文献中的中文名称混乱,应明确将其作为金钗石斛的拉丁学名。枫斗是我国名贵中药和传统保健品,起源于霍山石斛。古代名医对霍山石斛、铁皮石斛、金钗石斛、川石斛的用法各有特色,建议厘清品种来源、功效,加强现代研究,在修订《中国药典》时将其各自单列,充分发挥中药石斛的临床价值。

关键词：霍山石斛铁皮石斛金钗石斛种源《中国药典》

Harmonic Moments of Branching Processes in Random Environments

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Acta Mathematica Sinica,English Series 2009年第7期25卷 1087-1096页

作者： wei gang WANG Ping LV Di He HU School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 P. R. China Department of Science Hangzhou Normal University Hangzhou 310036 P. R. China School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China

We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every var... 详细信息

关键词： branching processes in random environments harmonic moments

An intriguing RNA species--perspectives of circularized RNA

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Protein & Cell 2015年第12期6卷 871-880页

作者： Ting Shen Miao Han gang wei Ting Ni MOE Key Laboratory of Contemporary Anthropology & State Key Laboratory of Genetics Engineering Collaborative InnovationCenter of Genetics and Development School of Life Sciences Fudan University Shanghai 200433 China

Circular RNAs （circRNAs）, a kind of covalently closed RNA molecule, were used to be considered a type of byproducts of mis-splicing events and were discovered sporadically due to the technological limits in the early years. With the great technological progress such as high-throughput next-generation sequencing, numerous circRNAs have recently been detected in many species. CircRNAs were expressed in a spatio-temporally specific manner, suggesting their regulatory functional potentials were overlooked previously. Intriguingly, some circRNAs were indeed found with critical physiological functions in certain circumstances. CircRNAs have a more stable molecular st;＇ucture that can resist to exoribonuclease comparing to those linear ones, and their molecular functions include microRNA sponge, regulatory roles in transcription, mRNA traps that compete with linear splicing, templates for translation and possibly other presently unknown roles. Here, we review the discovery and characterization of circRNAs, the origination and formation mechanism, the physiological functions and the molecular roles, along with the methods for detection of circRNAs. We further look into the future and propose key questions to be answered for these magical RNA molecules.

关键词： circular RNA back splice gene regulation

CONJUGATE FLOWS OVER A STEP IN A THREE-LAYER FLUID

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Journal of Hydrodynamics 2002年第4期14卷 15-23页

作者： wei, gang Le, Ja-Chun Dai, Shi-Qiang Inst. of Appl. Math. and Mech. Shanghai Univ. Shanghai 200072 China Sch. of Sci. P.L.A Univ. of Sci. and Eng. Nanjing 211101 China

The conjugate flows over a step with the height h_0, which might be positive or negative, was studied in a three-layer fluid and the coupled nonlinear equations were derived, with which the effects of varying height h_0 on the existence and evolution of conjugate flows were examined. It is concluded that the conjugate flow is sharply sensitive to the thickness of fluid layers and its characteristics alters remarkably due to the existence of the step. As the flow climbs up a step (h_0>0), the conjugate flow with a convex lower interface and a concave upper interface is allowed to appear, while the flow with the concave lower interface or the simultaneous concave interfaces will be depressed. As the flow goes down a step (i.e., h_0<0), on most occasions only one kind of conjugate flow could exist, which prossesses the form with the simultaneous convex interfaces and will disappear rapidly with the increase of the step depth.

关键词： conjugate flow flat solitary wave stratified flow step topography three-layer fluid

New Cutting Force Modeling Approach for Flat End Mill

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Chinese Journal of Aeronautics 2007年第3期20卷 282-288页

作者： WAN Min ZHANG wei-hong TAN gang QIN Guo-hua Sino-French Laboratory of Concurrent Engineering The Key Laboratory of Contemporary Design ＆ Integrated Manufacturing Technology Northwestern Polytechnical University Xi＇an 710072 China

A new mechanistic cutting force model for flat end milling using the instantaneous cutting force coefficients is proposed. An in-depth analysis shows that the total cutting forces can be separated into two terms: a nominal component independent of the runout and a perturbation component induced by the runout. The instantaneous value of the nominal component is used to calibrate the cutting force coefficients. With the help of the perturbation component and the cutting force coefficients obtained above, the cutter runout is identified. Based on simulation and experimental results, the validity of the identification approach is demonstrated. The advantage of the proposed method lies in that the calibration performed with data of one cutting test under a specific regime can be applied for a great range of cutting conditions.

关键词： runout cutting force flat end mill calibration cutting force coefficient

基于HPLC-ESI-MS^(n)和指纹图谱结合化学计量评价不同生长年限铁皮石斛黄酮类成分差异

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食品工业科技 2024年第18期45卷 239-249页

作者：李运容黄国东李锦妍吴樟桦陈松黄月纯魏刚广西中医药大学附属国际壮医医院广西南宁530201 广州中医药大学中药学院广东广州510006 广州中医药大学第一附属医院广东广州510405

目的:分析广西铁皮兰种铁皮石斛中的黄酮类成分,并探究不同生长年限对黄酮类成分积累的影响。方法:用Kromasil 100-5 C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈-甲醇(v:v=1:1)-0.01 mol/L乙酸铵溶液为流动相进行梯度洗脱,质谱使用ESI... 详细信息

目的:分析广西铁皮兰种铁皮石斛中的黄酮类成分,并探究不同生长年限对黄酮类成分积累的影响。方法:用Kromasil 100-5 C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈-甲醇(v:v=1:1)-0.01 mol/L乙酸铵溶液为流动相进行梯度洗脱,质谱使用ESI离子源,在负离子模式下采集数据;采用HPLC法建立25批广西铁皮石斛HPLC特征图谱,并运用主成分分析和聚类分析探讨不同生长年限对广西铁皮石斛黄酮类成分积累的影响。结果:通过HPLC-ESI-MS^(n)技术,从广西铁皮石斛中鉴定了19个黄酮类成分,涵盖了黄酮碳苷(9个)、黄酮醇氧苷(4个)、酰化黄酮碳苷(2个)、酰化黄酮醇氧苷(3个)及二氢黄酮(1个)。构建了广西铁皮石斛黄酮类成分特征图谱,并指认了9个共有峰;基于聚类与主成分分析,将25份样品按生长年限及杆色(绿杆1~3年、绿杆3~5年、红杆1~3年、红杆3~5年)划分为四类。此外,黄酮类特征峰峰面积随着生长年限的增长而增长;在1~3年生长年限时,‘红杆’与‘绿杆’间黄酮含量无显著差异;但3~5年,红杆样品中新西兰牡荆苷Ⅰ、Ⅲ、佛莱心苷及特定峰(峰8、峰9)含量显著高于绿杆。结论:本研究通过质谱分析结合化学模式识别,揭示了广西铁皮石斛黄酮类成分的共有特征,并强调了生长年限对黄酮类成分积累的关键作用。特别指出,生长至3~5年,‘红杆’样品中黄酮类成分含量显著高于‘绿杆’,此发现为铁皮石斛的药理活性探索、应用开发、种质资源评价及采收策略提供了坚实的理论基础。

关键词：广西铁皮兰种黄酮类成分化学模式识别品种生长年限

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Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

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World Journal of Gastroenterology 2008年第9期14卷 1419-1424页

作者： Wen-Cai Qiu Zhi-gang Wang wei-gang Wang Jun Yan Qi Zheng The Affiliated Sixth Hospital of Medical School Shanghai Jiaotong University Shanghai 200233 China

AIM:To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundicstrips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.

关键词： Gastric emptying Ghrelin Growth hormone releasing peptide 6 Growth hormone secretagogue receptor Diabetic mice