检索结果-南通市图书馆

一种含独立材料参数的Pairs公式疲劳评估概率模型

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

中国造船 2020年第4期61卷 95-104页

作者：张杰吕晨豪 gert Van der Heijden 郭文云上海海事大学海洋科学与工程学院上海201306 伦敦大学学院土木环境与地理工程系伦敦WC1E 6BT

为了完善船海工程结构疲劳可靠性评估,弥补Paris公式概率模型在理论和应用上的不足,提出了一种含独立材料参数的Pairs公式的疲劳评估概率模型。基于修正的Paris公式da/dN=C0(△K/K0)^m,应用数理统计理论推导了材料参数C0和m不相关的条件... 详细信息

为了完善船海工程结构疲劳可靠性评估,弥补Paris公式概率模型在理论和应用上的不足,提出了一种含独立材料参数的Pairs公式的疲劳评估概率模型。基于修正的Paris公式da/dN=C0(△K/K0)^m,应用数理统计理论推导了材料参数C0和m不相关的条件,并根据不相关条件确定K0的值,得到一个材料参数相互独立的Paris公式。通过Ni-Mn-Cr-Mo钢疲劳裂纹扩展速率试验,获得了材料参数的分布特性和特征值,建立疲劳评估概率模型,并验证其正确性。应用该模型对船体板格单元的疲劳可靠性进行分析,给出了不同疲劳寿命下的失效概率。研究表明,这个含独立参数的Paris公式概率模型,避免了疲劳可靠性计算和Monte Carlo仿真中由于参数相关而出现的问题;利用该模型分析船体结构疲劳寿命,计算准确可靠,对于结构耐久性和损伤容限设计、在役安全评价等有重要的参考价值。

关键词：疲劳校核 Paris公式独立材料参数概率模型可靠性分析

Molecular markers of phase transition in locusts

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 2006年第1期13卷 3-12页

作者： ARNOLD DE LOOF ILSE CLAEYS gert SIMONET PETER VERLEYEN TIM VANDERSMISSEN FILIP SAS JURGEN HUYBRECHTS Laboratory for Developmental Physiology Genomics and Proteomics Zoological Institute Leuven Belgium

The changes accompanying the transition from the gregarious to the solitary phase state in locusts are so drastic that for a long time these phases were considered as distinct species. It was Boris Uvarov who introduced the concept of polyphenism. Decades of research revealed that phase transition implies changes in morphometry, the color of the cuticle, behavior and several aspects of physiology. In particular, in the recent decade, quite a number of molecular studies have been undertaken to uncover phase-related differences. They resulted in novel insights into the role of corazonin, neuroparsins, some protease inhibitors, phenylacetonitrile and so on. The advent of EST-databases of locusts （e.g. Kang et al., 2004） is a most encouraging novel development in physiological and behavioral locust research. Yet, the answer to the most intriguing question, namely whether or not there is a primordial molecular inducer of phase transition, is probably not within reach in the very near future.

关键词： corazonin Locusta neuroparsin pacifastin phase polyphenism,phenylacetonitrile Schistocerca

Resource Acquisition, Internationalization, and the Catch-up Path of Chinese Construction Machinery Champions--The Case of Sany, XCMG, and Zoomlion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Business Research in China 2016年第2期10卷 290-323页

作者： gert Bruche Yingying Hong Department of International Management Berlin School of Economics and Eaw Berlin 10825 Germany Department of Enterprise Application Deloitte Consulting GmbH Berlin 10719 Germany

This study investigates the internationalization and resource accumulation process of the three largest Chinese construction machinery companies： Sany, XCMG and Zoomlion. It takes a longitudinal approach to analyze the internationalization process of the three companies over the last 25 years. Although the three companies＇ paths in the early acquisition of technologies and firm-specific advantages （FSA） differ significantly, however, their internationalization process exhibits similar pattern. They all exploit the same home-country based FSAs in their south-south expansion into other emerging markets, and seem to mimic each other in their strategic moves. In the south-north expansion into advanced economies they skip the export stage and rely almost exclusively on foreign direct investment of both forms, greenfield and M＆A, to pursue asset augmenting objectives and overcome their ＂liability of origin＂. The study concludes by discussing several topics of interest, such as the implications of accelerated resource accumulation, the impact on competition with advanced multinationals in the home market or possible effects on the level of state support and risk taking behavior in the internationalization process by the companies＇ ownership type.

关键词： resource acquisition internationalization emerging market multinationals Chinese multinationals catch-up construction machinery

Nanostructure and thermal power of highly-textured and single-crystal-like Bi_(2)Te_(3) thin films

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 2022年第3期15卷 2382-2390页

作者： Heng Zhang Jamo Momand Joshua Levinsky Qikai Guo Xiaotian Zhu gert H ten Brink Graeme R.Blake George Palasantzas Bart J.Kooi Zernike Institute for Advanced Materials University of GroningenNijenborgh 49747 AG GroningenThe Netherlands

Bi_(2)Te_(3)-based alloys are known to have outstanding thermoelectric *** structure–property relations have been studied,still,detailed analysis of the atomic and nano-scale structure of Bi_(2)Te_(3)thin film in relation to their thermoelectric properties remains poorly ***,highly-textured(HT)and single-crystal-like(SCL)Bi_(2)Te_(3)films have been grown using pulsed laser deposition(PLD)on Si wafer covered with(native or thermal)SiOx and mica *** films are highly textured with c-axis out-of-plane,but the in-plane orientation is random for the films grown on oxide and single-crystal-like for the ones grown on *** power factor of the film on thermal oxide is about four times higher(56.8μW·cm^(−1)·K^(−2))than that of the film on mica(12.8μW·cm^(−1)·K^(−2)),which is comparable to the one of the polycrystalline ingot at room temperature(RT).Reduced electron scattering in the textured thin films results in high electrical conductivity,where the SCL film shows the highest ***,its Seebeck coefficient shows a low *** measured properties are correlated with the atomic structure details unveiled by scanning transmission electron *** instance,the high concentration of stacking defects observed in the HT film is considered responsible for the increase of Seebeck coefficient compared to the SCL *** study demonstrates the influence of nanoscale structural effects on thermoelectric properties,which sheds light on tailoring thermoelectric thin films towards high performance.

关键词： Bi_(2)Te_(3)films highly-textured structure single-crystal-like structure thermoelectric properties pulsed laser deposition

Management of extracranial carotid artery stenosis during endovascular treatment for acute ischaemic stroke:results from the MR CLEAN Registry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2023年第3期8卷 229-237,I0074-I0085页

作者： Sabine L Collette Michael P Rodgers Marianne A A van Walderveen Kars C J Compagne Paul J Nederkoorn Jeannette Hofmeijer Jasper M Martens gert J de Borst gert Jan R Luijckx Charles B L M Majoie Aad van der Lugt Reinoud P H Bokkers Maarten Uyttenboogaart University Medical Centre Groningen University of GroningenGroningenThe Netherlands Leiden University Medical Centre LeidenThe Netherlands Erasmus MC University Medical CentreRotterdamThe Netherlands Amsterdam University Medical Centres University of AmsterdamAmsterdamThe Netherlands Rijnstate Hospital ArnhemThe Netherlands University Medical Centre Utrecht University of UtrechtUtrechtThe Netherlands

Background The optimal management of ipsilateral extracranial internal carotid artery(ICA)stenosis during endovascular treatment(EVT)is *** compared the outcomes of two different strategies:EVT with vs without carotid artery stenting(CAS).Methods In this observational study,we included patients who had an acute ischaemic stroke undergoing EVT and a concomitant ipsilateral extracranial ICA stenosis of≥50%or occlusion of presumed atherosclerotic origin,from the Dutch Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands(MR CLEAN)Registry(2014-2017).The primary endpoint was a good functional outcome at 90 days,defined as a modified Rankin Scale score≤*** endpoints were successful intracranial reperfusion,new clot in a different vascular territory,symptomatic intracranial haemorrhage,recurrent ischaemic stroke and any serious adverse *** Of the 433 included patients,169(39%)underwent EVT with *** 123/168(73%)patients,CAS was performed before intracranial *** 42/224(19%)patients who underwent EVT without CAS,a deferred carotid endarterectomy or CAS was *** with and without CAS were associated with similar proportions of good functional outcome(47%vs 42%,respectively;adjusted OR(aOR),0.90;95%CI,0.50 to 1.62).There were no major differences between the groups in any of the secondary endpoints,except for the increased odds of a new clot in a different vascular territory in the EVT with CAS group(aOR,2.96;95%CI,1.07 to 8.21).Conclusions Functional outcomes were comparable after EVT with and without *** during EVT might be a feasible option to treat the extracranial ICA stenosis but randomised studies are warranted to prove non-inferiority or superiority.

关键词： stenosis carotid treatment

Inhibition of P-glycoprotein by two artemisinin derivatives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Natural Products and Bioprospecting 2012年第2期2卷 59-64页

作者： Babette STEGLICH Anne MAHRINGER Ying LI Gary H.POSNER gert FRICKER Thomas EFFERTH Department of Pharmaceutical Biology Institute of Pharmacy and BiochemistryJohannes Gutenberg UniversityStaudinger Weg 5551 MainzGermany Institute of Pharmacy and Molecular Biotechnology Karl Ruprecht UniversityHeidelbergGermany Department of Synthetic Chemistry Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghaiChina Department of Chemistry Johns Hopkins UniversityBaltimore MDUSA

P-Glycoprotein/MDR1 represents an important component of the blood brain barrier and contributes to multidrug *** investigated two derivatives of the anti-malarial artemisinin,SM616 and GHP-AJM-3/23,concerning their ability to interact with *** ability of the two compounds to inhibit P-glycoprotein(P-gp)activity was examined in sensitive CCRF-CEM and P-gp over-expressing and multidrug-resistant CEM/ADR5000 cells as well as in porcine brain capillary endothelial cells(PBCEC)by means of calcein-AM *** as well-known P-gp inhibitor was used as control ***/ADR5000 cells exhibited cross-resistance to GHP-AJM-3/23,but slight collateral sensitivity to ***,SM616 inhibited calcein efflux both in CEM/ADR5000 and PBCEC,whereas GHP-AJM-3/23 did only increase calcein fluorescence in PBCEC,but not CEM/*** may be explained by the fact that CEM/ADR5000 only express P-gp but not other ATP-binding cassette transporters,whereas PBCEC are known to express several ABC transporters and calcein is transported by more than one ABC ***,SM616 may be the more specific P-gp *** conclusion,the collateral sensitivity of SM616 as well as the inhibition of calcein efflux in both CEM/ADR5000 cells and PBCEC indicate that this compound may be a promising P-gp inhibitor to treat cancer therapy and to overcome the blood brain barrier.

关键词： blood brain barrier calcein multidrug resistance P-glycoprotein

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

具有消费者相关服务的智能供暖计量

暖通空调 2014年第E6期44卷 11-13页

作者： gert Skriver 丹麦卡姆鲁普有限公司

智能能量计面向终端消费者的界面具备的主要特征在其专业的工作方式。集成智能装置安装在面板后．从这个位置通常采用第三方程序，通过自动运行向消费者和用户提供高度的舒适性和改善经济效益。下面对集成智能装置的情况进行概述．并揭... 详细信息

智能能量计面向终端消费者的界面具备的主要特征在其专业的工作方式。集成智能装置安装在面板后．从这个位置通常采用第三方程序，通过自动运行向消费者和用户提供高度的舒适性和改善经济效益。下面对集成智能装置的情况进行概述．并揭示了两种智能并以消费者为导向的功能：自动泄漏保护和自动阀门控制。由于采用微处理技术和模块结构．除了提供合法账单数据的基本功能外．电子式能量计还可以提供一系列其他可选功能。能量计数器提供能耗数据．对消费者就已消耗的能量进行收费．这是能量计不变的核心任务；随着将大量高密度的消耗数据储存和放置在不同的寄存器上，使其具有额外的功能。这些额外的功能使能量计成为一个可进行编程、非常灵活的工具．能够提高供热公司和终端消费者的舒适性和经济性。

关键词：智能装置消费者计量供暖服务能量计微处理技术经济效益

Pharmacotherapeutic aspects of treating knee osteoarthritis with glucosamine sulfate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2010年第7期2卷 705-707页

作者： Steven Simoens gert Laekeman 不详

Glucosamine sulfate is a natural constituent of cartilage and is used in the treatment of knee osteoarthritis. The aim of this study is to provide a short but comprehensive pharmacotherapeutic update on treating knee osteoarthritis with glucosamine sulfate. A literature search was conducted of PubMed, Centre for Reviews and Dissemination databases, Cochrane Reviews and EconLit up to January 2010. The literature review indicated that the mechanism of action of glucosamine sulfate is based on hypothesis, but its treatment effects in knee osteoarthritis are symptomatic. With steady-state peak concentrations at the 1,500 mg dosage in the range of 10 µM, it is estimated that only 2% of glucosamine is incorporated in the cartilage. A once-daily dosage of 1,500 mg of glucosamine sulfate is licensed for the treatment of symptomatic osteoarthritis and has been shown to reduce pain, improve function and exhibit similar safety to placebo. Glucosamine sulfate is likely to be a cost-effective treatment of knee osteoarthritis. In conclusion, a once-daily dosage of 1,500 mg of glucosamine sulfate is likely to be a safe, effective and cost-effective treatment of knee osteoarthritis as compared to placebo.

关键词： Pharmacotherapy Glucosamine Sulfate Knee Osteoarthritis Pharmacokinetics Indication Safety Effectiveness Cost-Effectiveness

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

桨叶剖面空泡形态发展特性研究

水动力学研究与进展（A辑） 2018年第1期33卷 9-16页

作者：曾志波刘登成 KUIPER gert 中国船舶科学研究中心船舶振动噪声重点实验室江苏无锡214082 江苏省绿色船舶技术重点实验室江苏无锡214082 Soetendaalseweg 106721 XB BennekonThe Netherlands

船后螺旋桨空泡诱导脉动压力与空泡形态发展特性密切相关。该文基于单一介质输运方程和Singhal全空泡模型,对NACA翼型进行了局部空泡流的数值计算,计算的平均压力分布和空泡长度与试验结果吻合较好。采用该方法针对Eppler方法设计的叶... 详细信息

船后螺旋桨空泡诱导脉动压力与空泡形态发展特性密切相关。该文基于单一介质输运方程和Singhal全空泡模型,对NACA翼型进行了局部空泡流的数值计算,计算的平均压力分布和空泡长度与试验结果吻合较好。采用该方法针对Eppler方法设计的叶剖面的空泡形态发展进行了数值分析,提出了一种描述空泡形态几何参数(长度、体积)随新组合环境参数(攻角、空泡数、起始攻角及吸力面主压区压力系数)变化关系的统一表达式,并应用于描述平板空泡形态线性化理论结果、圆弧形水翼空泡形态试验结果以及Eppler方法设计的叶剖面空泡形态数值计算结果,并进行了理论说明。这为控制螺旋桨空泡行为,进而降低空泡脉动压力的螺旋桨设计奠定基础。

关键词：叶剖面数值分析空泡形态发展统一表达式