检索结果-南通市图书馆

Preliminary studies for a new antibiotic from the marine mollusk melo melo(Lightfoot,1786)

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical medicine 2011年第4期4卷 310-314页

作者： kan.gasabapathy sivasubraman.an.samuthirapan.ian.ravichan.ran.kumaresan m Centre of Advanced Study in marine Biology Annamalai University

Objective:To search for new bioactive compounds from marine mollusks melo melo(***). methods:Preliminary work for bioactive compound was identified by using disc diffusion methods against human *** analyses of compound were done by using TLC, *** also estimate the amount of protein in the samples by following Biuret ***:In antibacterial activity the maximum diameter of 24 mm zone of inhibition was recorded against Klebsiella pneumoniae(***) strain of the mucus extract and minimum zone of inhibition of 11 mm was observed in Salmonella typhi(***) strain of body tissue *** antifungal activity of the extraction shows maximum activity against Trichophyton mentagarophytes(***)(14 mm) and minimum activity was recorded in Aspergillus flavus(***)(11 mm).The extract of mucus,nerve tissue,body tissue and kidney that showed antimicrobial activity was subjected to TLC to determine the presence of the peptides and amide groups,and also subjected to SDS-PACE to estimate the molecular weight of proteins in a clear band were detected in the gel that represented kidney,body tissue,brain and mucus represent 14,17,22,45 ***:The extracts from marine mollusks *** is the potential source of producing bioactive compounds against human pathogens and can be used for synthesis of new drugs.

关键词： Antibacterial Antifungal TLC SDS-PAGE melo melo

光催化CO_(2)还原多原子催化剂的设计与制备进展

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China materials 2024年第2期67卷 397-423页

作者：汪忠浩邹国军 Jong Hyeok Park 张侃 School of materials Science and Engineering and School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul120-749Republic of Korea Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515031China

光催化CO_(2)还原合成太阳能燃料对缓解CO_(2)排放引起的全球变暖和降低化石燃料消耗具有重要意义.然而,目前的光催化剂仍然存在反应动力学缓慢和选择性不理想的问题,特别是对于C_(2+)产物的生成,极大地限制了光催化的工业化进程.过去... 详细信息

光催化CO_(2)还原合成太阳能燃料对缓解CO_(2)排放引起的全球变暖和降低化石燃料消耗具有重要意义.然而,目前的光催化剂仍然存在反应动力学缓慢和选择性不理想的问题,特别是对于C_(2+)产物的生成,极大地限制了光催化的工业化进程.过去几十年中,关于太阳能驱动的CO_(2)还原的研究展示出鼓舞人心的结果,包括活性位点的构建.本综述重点介绍了通过构建活性位点制备原子级分散催化剂在光催化CO_(2)还原中的最新进展,包括两个独立的活性位点、成对双活性位点和基于活性位点构型的纳米团簇.此外,详细讨论了CO_(2)在活性位点上的活化机制和表征方法.特别是考虑到实验研究与实际应用之间的差距,整合实验和理论的结果,以实现潜在的结构-活性关系和高目标产物选择性发展.最后,概述了该领域存在的挑战,并展望了活性位点的合理设计和机理研究.

关键词： photocatalytic CO_(2)reduction precise engineering multiple active sites structure-activity relationships mechanistic investigation

Investigations on pool boiling critical heat flux, transient characteristics and bonding strength of heater wire with aqua based reduced graphene oxide nanofluids

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第3期26卷 445-454页

作者： R. Kamatchi G. kumaresan School of mechanical Engineering VIT University Vellore Institute of Technology 632014 Tamil Nadu India Department of mechanical Engineering Bannari Amman Institute of Technology Sathyamangalam 638401 Tamil Nadu India

In the present work, the pool boiling critical heat flux, transient heat transfer characteristics, and bonding strength of thin Ni-Cr wire with aqua based reduced graphene oxide(r GO) nanofluids are experimentally studied. Results indicate:(i) the critical heat flux(CHF) of 0.01, 0.05, 0.1, 0.2, and 0.3 g·L^(-1) concentrations of r GO-water nanofluids varies from 1.42 to 2.40 mW·m^(-2);(ii) the CHF remains same for the tested samples during transient heat transfer studies and(iii) a constant value of CHF upto 10 tests when the nanocoated Ni-Cr wire is tested with DI water and deterioration occurs beyond this which implies a chance of peel off of r GO layer below the critical coating thickness.

关键词： Reduced graphene oxide Pool boiling Nanoparticle deposition Transient characteristics

国有企业资产运营模式与劳动收入份额:轻资产还是重资产?

在线全文

学校读者我要写书评

暂无评论

金融评论 2024年第3期16卷 49-71,156页

作者：金凌刘欢阚沂伟中南财经政法大学金融学院武汉纺织大学经济学院厦门大学管理学院深圳国资国企改革创新研究院

做强做优做大国有企业是新时代国有经济的目标要求,资产运营模式在其中扮演着非常重要的角色。本文研究发现,国有企业向轻资产运营模式转型可以更好地与国有企业的职能目标相协调,发挥国有经济的战略支撑作用。具体来看,随着国有企业轻... 详细信息

做强做优做大国有企业是新时代国有经济的目标要求,资产运营模式在其中扮演着非常重要的角色。本文研究发现,国有企业向轻资产运营模式转型可以更好地与国有企业的职能目标相协调,发挥国有经济的战略支撑作用。具体来看,随着国有企业轻资产运营程度的提升,企业劳动收入份额显著增加,说明向轻资产运营转型有助于国有企业实现促进就业、分配公平的职能目标,这尤其体现在非公用事业行业和大型国有企业之中。机制分析发现,国有企业轻资产运营转型提升了高学历员工占比,缩小了企业内部劳动收入差距,轻资产运营转型对劳动收入份额的影响主要表现在融资约束较弱、专业化分工程度较低的国有企业中,推动人力资本升级是国有企业轻资产运营转型提升劳动收入份额的主要机制。进一步研究表明,国有企业轻资产运营转型不仅能降低投资现金流敏感性,缓解资产投资对现金流的占用,也能提升全要素生产率,改善生产经营效率。因此,轻资产运营转型是国有企业资产运营模式改革的可行路径。

关键词：国有企业改革轻资产运营企业劳动收入份额人力资本升级

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于拓扑优化方法的蛛网散热结构均温性研究

储能科学与技术 2024年第5期13卷 1721-1730页

作者：张坎付婷王江波武汉科技大学湖北武汉430081

仿生蛛网散热结构在高热流密度芯片散热方面有着广泛的应用,但仍然存在散热结构温度分布不均的问题。为进一步提升蛛网散热结构的温度均匀性,提出利用变密度拓扑优化方法对蛛网结构进行优化设计。以设计域温度方差最低为目标函数,采用... 详细信息

仿生蛛网散热结构在高热流密度芯片散热方面有着广泛的应用,但仍然存在散热结构温度分布不均的问题。为进一步提升蛛网散热结构的温度均匀性,提出利用变密度拓扑优化方法对蛛网结构进行优化设计。以设计域温度方差最低为目标函数,采用霍尔姆兹密度过滤保证求解的数值稳定性,采用双曲正切投影保证清晰的流道形态,通过分析不同进出口布置和不同设计域形状下得到的拓扑流道的传热性能,发现多入口多出口且交错布置的方式能有效提高拓扑流道的均温性,且设计域边数在十以内其拓扑流道均温性呈上升趋势。最后,通过有限元分析的方法,对传统结构m1和不同设计域边数的三维拓扑重构结构m2、m3进行模拟仿真。结果表明,设计域边数为十的m3温度均匀性优于传统通道m1和设计域边数为六的m2,在Re=1800时,m3热阻相比于m1降低了18.48%,热源面温差相比于m1降低了25%,综合传热性能评价因子PEC值达到1.22。本研究提出并验证了拓扑优化方法在提升蛛网散热结构均温性方面的有效性,有助于推动拓扑优化方法在散热结构上的应用。

关键词：蛛网结构拓扑优化数值模拟均温性

维普期刊数据库博看期刊

An improved delta-star switching scheme for reactive power saving in three-phase induction motors

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2014年第3期8卷 364-370页

作者： R RAJA, N. kumaresan m. SUBBIAH Department of Electrical and Electronics Engineering National Institute of Technology Tiruchirappalli Tamil Nadu 620015 India Department of Electrical and Electronics Engineering Rajalakshmi Engineering College Chennai 602105 India

It is proposed that a capacitor can be connected permanently across each phase winding of a three-phase induction motor along with the conventional delta-star switching, for further saving in VARh at reduced loads on the motor. The method of choosing a suitable value for the capacitor and the criteria to be adopted for calculating the power output at which the star to delta switching is to be made are also explained. The phase, 4-pole, 415 V, 50 Hz, 3 experimental results on a 3- 3 kW induction motor verify the advantages in adding the capacitor to the phase winding of the motor. Compared to using only a single delta connected stator winding or a delta-star switching, the advantages of the proposed addition of a capacitor, are also demonstrated through a case study conducted on a 400 V, 250 kW motor. Any further improvement in grid side power factor can be achieved by employing a static synchronous compensator （STATCOm） of reduced VAR rating.

关键词： delta-star switching induction motor powerfactor steady-state analysis

Laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian pacific Journal of Reproduction 2017年第3期6卷 97-103页

作者： Lone SA mohanty TK kumaresan A Bhakat m Artificial Breeding Research Centre ICAR-National Dairy Research InstituteKarnal132001HaryanaIndia Livestock Research Centre ICAR-National Dairy Research InstituteKarnal132001HaryanaIndia

This article presents a review pertains the laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals. To improve artificial insemination, laser is sensitive and cost effective technique, when compared to other conventional methods. Laser may have both positive and negative effects on spermatozoa functions. Since the effects of light are mediated by reactive oxygen species, and the levels of these reactive oxygen species following irradiating spermatozoa with laser may be responsible for determining the effects of laser on sperm. Dose of laser may be regarded as of great significance and this dosage of laser may be responsible for determining its effects on spermatozoa. Optimum dosage of laser for improving seminal attributes may vary among various species and this need to be standardized in each of them. The beneficial effects include improving sperm livability, acrosomal integrity, hypo-osmotic swelling response, mitochondrial function and computer-aided sperm analysis parameters. The increase in cytochrome c oxidase activity, ATP levels and mitochondrial membrane potential, in laser irradiated cells may be responsible for enhanced sperm quality parameters. Improving fertility with laser irradiated spermatozoa has been reported in few species like boar and need to be elaborated in other species. In conclusion laser may be regarded as an easy, cheap and time saving technology for improving artificial insemination;in addition, laser may have various potential applications in the field of reproductive biotechnology as well as in livestock farms and veterinary polyclinics.

关键词： Laser Irradiation Spermatozoa Function mechanism

市域列车救援工况溜逸风险分析及制动策略优化

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

都市快轨交通 2024年第3期37卷 90-96页

作者：朱戡史月昆张小龙北京市轨道交通建设管理有限公司北京100068 城市轨道交通全自动运行系统与安全监控北京市重点实验室北京100068 北京轨道交通技术装备集团有限公司北京100068

针对市域铁路在运营过程中的救援场景研究缺乏及现有市域动车组能力不能完全满足救援的及时性要求等问题,本文研究了市域列车救援工况的溜逸风险及制动策略。首先,建立多编组列车连挂时的纵向动力学模型;然后,以北京大兴机场线为例,分... 详细信息

针对市域铁路在运营过程中的救援场景研究缺乏及现有市域动车组能力不能完全满足救援的及时性要求等问题,本文研究了市域列车救援工况的溜逸风险及制动策略。首先,建立多编组列车连挂时的纵向动力学模型;然后,以北京大兴机场线为例,分析在救援工况下现有运营方式可能带来的列车溜逸风险;最后,结合相关标准,分析救援过程不同制动模式下乘客的舒适性。研究结果表明:在33‰坡道上救援车以5 km/h连挂时,保持制动模式下列车加速度和冲击率将会达到10.5 m/s^(2)和9.9 m/s^(3),且发生溜逸,而采用紧急制动模式时,列车的加速度和冲击率分别下降了63.1%和54.7%,未发生溜逸;当救援车连挂速度降低至3 km/h后,列车最大加速度和最大冲击率分别降低至2.1 m/s^(2)和2.4 m/s^(3),乘客舒适性明显提高。在坡道停车时,由于存在制动-牵引切换过程,为保证在最大坡道上不溜车,列车保持制动力需达到60%最大常用制动力以上。

关键词：市域列车救援制动力溜逸冲击率

股骨假体对位不齐对骨质疏松患者膝关节内侧单髁置换后外侧间室结构应力的影响

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第15期29卷 3153-3158页

作者：刘蒙飞孙荣鑫姜侃新疆医科大学第六附属医院新疆维吾尔自治区乌鲁木齐市830000

背景:假体对位不齐和患者骨质情况是影响单髁置换预后的重要因素,内侧单髁置换后外侧间室骨关节炎进展是导致其高翻修率的主要并发症。因此,这将成为今后的研究热点。目的:分析不同股骨假体倾斜角度对正常骨质和骨质疏松患者内侧单髁置... 详细信息

背景:假体对位不齐和患者骨质情况是影响单髁置换预后的重要因素,内侧单髁置换后外侧间室骨关节炎进展是导致其高翻修率的主要并发症。因此,这将成为今后的研究热点。目的:分析不同股骨假体倾斜角度对正常骨质和骨质疏松患者内侧单髁置换后外侧间室结构应力的影响,并探讨骨质疏松与术后外侧间室骨关节炎的相关性。方法:使用经验证的膝关节有限元模型,建立正常骨质(m1)和骨质疏松(m2)单髁置换模型,并分别建立股骨假体倾斜模型(正常骨质组:内倾3°,6°,9°,12°、标准位置0°、外倾3°,6°,9°,12°;骨质疏松组:内倾3°,6°,9°,12°、标准位置0°、外倾3°,6°,9°,12°),共计18种工况。评估不同股骨假体倾斜角度对外侧间室半月板、胫骨软骨和股骨软骨的应力大小和分布的影响。结果与结论:①两组模型外侧间室半月板表面和胫骨软骨表面的高应力值随假体内倾角度的增加而增加,随假体外倾角度的增加而减小,相同工况下骨质疏松组半月板表面的峰值应力大于正常骨质组,但骨质疏松组胫骨软骨表面的峰值应力却小于正常骨质组;②两组模型外侧间室股骨软骨的高应力值随假体内倾和外倾角度的增加而增加,相同工况下骨质疏松组股骨软骨的峰值应力大于正常骨质组;③提示固定平台股骨假体内倾时,正常骨质和骨质疏松膝关节内侧单髁置换后外侧间室结构的应力均将增加,骨质疏松膝关节外侧间室应力增加更为明显;所以单髁置换过程中应特别注意假体安放位置,尽量避免内倾和外倾;同时,研究结果证实了骨质疏松可能会加重内侧单髁置换后外侧间室骨关节炎的进展。

关键词：膝骨关节炎骨质疏松单髁置换股骨组件生物力学