Synthesis of RC transfer immittance functions with a minimum number of capacitors     

H.C. Reddy  C.P. Reddy  M.N.S. Swamy  V. Ramachandran 《Journal of The Franklin Institute》1982,313(4):197-206

In this paper a method for the realization of RC transfer immittance functions with an unsymmetrical lattice is presented. The method yields minimal capacitor realizations for Z₁₂(s) with no pole at s = 0 and ?y₁₂(s) having no pole at s = ∞. The number of resistors needed are only two more than the minimum needed.  相似文献   

图书馆采编系统新模式结构的设计与研究   总被引：4，自引：0，他引：4  

刘爱心  张登凯 《情报理论与实践》2004,27(2):180-182

针对某些高校图书馆管理系统的缺陷 ,本文提出合理利用标准书目信息 ,将其转化为初始馆藏书目数据的改造方法 ;同时 ,提出使图书馆采访部与读者进行快速交互的网络系统解决方案  相似文献   

Beyond Access: Psychosocial Barriers to Computer Literacy     

Laura D. Stanley 《The Information Society》2003,19(5):407-416

Research consistently indicates that Latinos and African-Americans are less likely to own and use computers than either Caucasians or Asians. While conventional wisdom holds that high computer costs and lack of access are the primary reasons for this discrepancy, my ethnographic research with 100 low-income adults reveals three non-cost-related psychosocial obstacles that significantly undermine motivation for acquiring computer skills: “relevance,” “fear,” and “self-concept.” My research thus suggests that a more complex relationship exists between ethnicity, identity, and attitudes associated with computers than previously examined; this relationship may better explain why some people are choosing not to use computers at this time. My research also indicates that while community technology centers (CTCs) play an important role in helping adults overcome their resistances and achieve computer literacy, they are presently an underutilized resource—less than 5% of San Diegans use them to meet their computing needs. Hence, my research also questions why more residents do not avail themselves of these community resources. I conclude that efforts to increase computer literacy in underserved communities must go beyond physical access and connectivity and consider the role of cultural factors.  相似文献   

Cardioprotective activity of synthetic guggulsterone (E and Z-isomers) in isoproterenol induced myocardial ischemia in rats: A comparative study     

Ramesh Chander  Farhan Rizvi  A. K Khanna  Ram Pratap 《Indian journal of clinical biochemistry : IJCB》2003,18(2):71-79

Guggulsterone, a mixture of cis (E) and trans (Z) isomers (7∶3 w/w) was synthesized from 16-DPA. The isomers were separated by column chromatography and evaluated for cardioprotective and antioxidant activities. Myocardial necrosis induced by isoproterenol in rats caused marked increase in serum creatine phosphokinase and glutamate pyruvate transaminase. Simultaneously in ischemic heart, phospholipase, xanthine oxidase and lipid peroxides were enhanced following depletion of glycogen, phospholipids and cholesterol. Treatment with guggulsterone and its both isomers at the dose of 50 mg/kg po., significantly protected cardiac damage as assessed by the reversal of blood and heart biochemical parameters in ischemic rats. The cardioprotective activity of guggulsterone and of both the isomers were compared with that of gemfibrozil at the same doses. Guggulsterone and both the isomers at tested concentrations (5–20mM) inhibited oxidative degradation of lipids in human low-density lipoprotein and rat liver microsomes induced by metal ionsin vitro. The drug counteracted against the generation of superoxide anions (O₂) and hydroxyl radicals (OH⁻) in non-enzymic test systems. It is suggested that cardioprotective and antioxidant activities of synthetic guggulsterone and guggulsterone obtained from gum resinCommiphora mukul that contains isomers E & Z in the ratio of 46∶54w/w are the same.  相似文献   

Immune response to n-terminal and c-terminal deletion mutants of Aspergillus fumigatus major allergen ASP F 3     

Bhanu P. Singh  Banani Banerjee  Puspanita Naik  Jordan N. Fink  Viswanath P. Kurup 《Indian journal of clinical biochemistry : IJCB》2006,21(2):20-27

The ubiquitous fungus Aspergillus fumigatus causes allergic rhinitis, asthma, sinusitis and allergic bronchopulmonary aspergillosis. A number of major allergens from A. fumigatus are purified, but their structure-function role in the pathogenesis of disease is not known. Such information is essential for devising alternative therapy of fungal allergic diseases. In the present study, N-terminal and C-terminal deletion mutants ofAsp f 3 were constructed and their immunopathological responses studied in a mice model of allergy. Three mutants viz,Asp f 3 (aa 33–168), (aa 1–142), and (aa 23–142) were made by deleting certain amino acids from epitopic regions of full lengthAsp f 3, a major allergen of A. furnigatus. TheAsp f 3 and three mutated proteins were expressed in pET vector. The C-terminal deletion mutantAsp f 3 (aa 1–142) induced elevated IFN-γ but low levels of IL-4 by spleen cells. This mutant also showed significant downregulation of peripheral blood eosinophils and lung inflammation in immunized mice. The N-terminal deletion mutantAsp f 3 (aa 33–168) also exhibited an immuno-suppressive effect in terms of IgE production and induction of Th2 cytokine. The results indicate thatrAsp f 3 and its deletion mutants induced distinct immune-inflammatory responses in mice on challenge with these proteins. The non-IgE binding deletion mutants ofAsp f 3 (aa 1–142 and aa 33–168) could deviate Th2 immune response with a concomitant reduction in airway inflammation and infiltration of inflammatory cells.  相似文献   

Aims of IFCC and my own goals     

Jocelyn M. Hicks PhD  FACB  FRCPath 《Indian journal of clinical biochemistry : IJCB》2006,21(2):1-3

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英国国防科技信息管理体制和保障体系研究     

汤珊红  曹宽增  秦利  周慧贞 《情报理论与实践》2006,29(4):508-512

英国是当今世界国防科技信息工作发展水平较高的国家，合理地分析其管理体制、保障体系和相应的政策法规环境，借鉴其成功经验，对于加快我国国防科技信息事业的发展进程具有重要的指导与启示意义。  相似文献   

The Grammar of Teleportation     

Timpson  Christopher G. 《The British journal for the philosophy of science》2006,57(3):587-621

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网上协作式数字参考咨询服务的质量控制综述   总被引：9，自引：1，他引：9  

焦玉英  罗栋 《情报理论与实践》2005,28(1):58-60

本文主要讨论网上协作式 (又称合作式 )数字参考咨询服务中的质量控制要素 ,及在其服务各环节各阶段实施质量控制的基本理念、方法、措施。  相似文献   

DC元数据登记系统中国镜像建设     

梁娜  李宇  张晓林 《情报理论与实践》2005,28(1):91-93,103

在简略介绍元数据登记系统基本概念的基础上，介绍了都柏林核心(DC)元数据登记系统的基本技术、DC元数据登记系统中国镜像站点的建设，以及该镜像站点对DC元数据规范的检索、浏览和登记功能。  相似文献