检索结果-南通市图书馆

基于分布式最大功率跟踪的光伏系统输出特性分析

在线全文

学校读者我要写书评

暂无评论

电工技术学报 2015年第24期30卷 127-134页

作者：王丰孔鹏举 Fred C.lee 卓放西安交通大学电气工程学院西安710049 iWatt公司加州美国95008 弗吉尼亚理工大学弗吉尼亚州美国24060

分布式最大功率跟踪(DMPPT)光伏系统可以有效地抑制实际环境中因为光照不均影响所造成的产电率下降的问题。以DMPPT的光伏系统为研究对象,针对多个分布式最大功率跟踪模块组网的优化问题,基于系统静态输出特性对多个光伏优化模块级联的... 详细信息

分布式最大功率跟踪(DMPPT)光伏系统可以有效地抑制实际环境中因为光照不均影响所造成的产电率下降的问题。以DMPPT的光伏系统为研究对象,针对多个分布式最大功率跟踪模块组网的优化问题,基于系统静态输出特性对多个光伏优化模块级联的结构进行了分析,提出了一种新型的DMPPT光伏系统结构。通过分析和研究,阐明了光照条件、系统结构及单个光伏优化模块本身限压值、限流值等参数与光伏阵列最大输出功率之间的关系。所提出的新型DMPPT光伏系统结构可以保证在不同的光照条件下每块光伏板都可以工作在各自的最大功率点,该结构有效地提高了光伏阵列在失配问题下产电率,并且适用于高电压母线系统。最后搭建了实验平台,通过硬件实验平台验证了所提出的新型DMPPT光伏系统结构对光伏系统产电率的优化效果。

关键词：分布式最大功率跟踪光伏光照不均结构优化

Changes of the gastric endocrine cells in the C57BL/6 mouse after implantation of murine lung carcinoma: An immunohistochemical quantitative study

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第9期11卷 1317-1323页

作者： Sae-Kwang Ku Hyeung-Sik lee Joon-Seok Byun Bu-Il Seo Jae-Hyun lee Pharmacology and Toxicology Laboratory Department of Herbal Biotechnology College of Oriental Medicine Lab.of Histology

AIM: The regional distributions and relative frequencies of some gastric endocrine cells of C57BL/6 mice were studied by immunohistochemical method using seven types of specific antisera against chromogranin A (CGA), serotonin, somatostatin, gastrin, cholecystokinin (CCK)-8, glucagon and human pancreatic polypeptide (HPP) after subcutaneous implantation of murine lung carcinoma (3LL) cells. METHODS: The experimental animals were divided into two groups, one is non-implanted sham and the other is 3LL-implanted group. Samples were collected from the two regions of stomach (fundus and pylorus) at 28 d after implantation of 3LL cells (1x105 cell/mouse). RESULTS: In this study, all the seven types of immunoreactive (IR) cells were identified except for HPP. Most of these IR cells in the gastric portion were generally spherical or spindle in shape (open-type cell) while cells showing round in shape (closed-type cell) were found occasionally. The regional distributions of gastric endocrine cells in the 3LL-implanted group were similar to those of non-implanted sham. However, significant decreases of some types of IR cells were detected in 3LL-implanted group compared to those of non-implanted sham. In addition, the IR cells showing degranulation were numerously detected in 3LL-implanted group. CGA-, serotonin- and somatostatin-IR cells in the fundus and pylorus regions, and gastrin-IR cells in the pylorus regions of 3LL-implanted groups significantly decreased compared to those of non-implanted sham. However, no changes on frequencies of CCK-8- and glucagon-IR cells were demonstrated between 3LL-implanted and non-implanted groups. CONCLUSION: Endocrine cells are the anatomical units responsible for the production of gut hormones, and the change in their density would reflect a change in the capacity of producing these hormones. Implantation of tumor cell mass (3LL) induced severe quantitative changes of gastric endocrine cell density, and the abnormality in density of gast

关键词： Gastric endocrine cells Gut hormones 3LL

ST-Segment Depression in Leads I and aVL: Artifactual or Pathophysiological Findings ?

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

Cardiovascular Innovations and Applications 2021年第4期6卷 109-111页

作者： Sharen lee Gary Tse Xin Wang Adrian Baranchuk Tong Liu Cardiovascular Analytics Group Laboratory of Cardiovascular PhysiologyHong KongChina Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of CardiologyTianjin Institute of CardiologySecond Hospital of Tianjin Medical UniversityTianjinChina Department of Medicine Kingston General HospitalQueen’s UniversityKingstonOntarioCanada

The 12-lead electrocardiogram(ECG)is a routinely performed test but is susceptible to misinterpretation even by experienced *** report a case of a 72-year-old lady with no prior cardiac history presented to our hospital with atypical chest *** initial electrocardiogram shows an initial ST depression followed by positive defl ections leads I and ***-physiological ST segment and T-wave changes are also observed in the precordial leads V2 to *** contrast,these abnormalities are notably absent in lead II.A repeat of the ECG taken 30 minutes later reveals the resolution of most abnormalities seen in the initial ECG on a background of high-frequency noise in the limb *** was referred to the cardiology department for further *** urgent echocardiogram revealed no regional wall motion abnormalities with preserved ejection fraction,and her coronary angiogram revealed no signifi cant coro-nary *** case illustrates the importance of understanding different factors that can cause ST segment abnor-malities,notably artifactual changes that can mimic ST segment myocardial infarction.

关键词： ST segment artifact

Machining characteristics of complex prism pattern on electroplated roll by copper

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

中国有色金属学会会刊：英文版 2009年第B09期19卷 288-294页

作者： Tae-Jin JE Sang-Cheon PARK Kang-Won lee Yeong-Eun YOO Doo-Sun CHOI Kyung-Hyun WHANG Myung-Chang KANG Nano-Machining Laboratory Division of Nano-Mechanical Systems Korea Institute of Machinery and Materials Nano-Mechatronics Department University of Science and TechnologySinseongnoYouseong-GuDaejeonKorea National Core Research Center for Hybrid Materials Solution Pusan National University

The BLU (back light unit) is the core component of the LCD for notebook, mobile-phone, navigation, as well as large sized TV, PID (public information display), etc. In order to enhance optical efficiency of LCD, optical films with the uniform prism patterns have been used for BLU by stacking two films up orthogonally. In this case, light interference-phenomenon occurred such as Morie, wet-out, u-turning, etc. It caused several problems such as low brightness, spots and stripes in LCD. Recently, the high-luminance micro complex prism patterns are actively studied to avoid the light interference-phenomenon and enhance the optical efficiency. In this study, the roll master to manufacture complex micro prism pattern film was machined by using the high precision lathe. The machined patterns on the roll master were 50, 45, 40, 35, 30, 25, 20, 15, 10 and 5 μm in the pitch with 25.0, 22.5, 20.0, 17.5, 15.0, 12.5, 10.0, 7.5, 5.0 and 2.5 μm in the peak height, respectively. The roll was 2 000 mm in length and 320 mm in diameter. The electroplated roll by copper and the natural single crystal diamond tool was used for machining the patterns. The cutting force was measured and analyzed for each cutting condition by using the dynamometer. The chips and the surfaces after being machined were analyzed by SEM and microscope.

关键词：车床加工微棱镜铜电镀特征光学效率光学薄膜笔记本电脑金刚石工具

Risk factors and therapeutic response in Chinese patients with peptic ulcer disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第16期16卷 2017-2022页

作者： Shou-Wu lee Teng-Yu lee Hong-Zen Yeh Chun-Fang Tung Yen-Chun Peng Division of Gastroenterology and Hepatology Department of Internal MedicineTaichung Veterans General Hospital

AIM:To assess the risk factors and the eff icacy of medications of patients with gastric and duodenal ulcers among Chinese patients in ***:Patients with peptic ulcers,diagnosed by upper endoscopy,were retrospectively collected between January 2008 and December *** differences were ***:Among all 448 cases,254(56.6%) and 194(43.4%) patients had gastric ulcers and duodenal ulcers *** with gastric ulcers were younger than those with duodenal *** more men existed,there was a female predominance in middle-aged *** with duodenal ulcers had a higher rate of Helicobacter pylori(***) infection(62.4% vs 43.3%,P = 0.001),and those with gastric ulcers owned a significantly higher amount of aspirin and nonsteroidal anti-inflammatory drug(NSAID) use(7.5% vs 1.5%,6.7% vs 2.1%,P = 0.001).Tobacco smoking and alcohol drinking had no different impact between these two ***-pump inhibitors and H2-receptor antagonists(H2RA) were effective,but significantly less so in cases with duodenal ulcers receiving H2RAs,or in those with *** infection and a history of NSAID ***:Patients with gastric ulcers had lower *** infection but more aspirin or NSAID *** therapy was ineffective in gastric ulcers underwent H2RA treatment,and cases combined *** infection and NSAID use.

关键词： Epidemiology Peptic ulcer disease Therapy

High speed continuous turning of hardened steel with newly developed low content PCBN

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

金刚石与磨料磨具工程 2008年第S1期28卷 80-82页

作者： lee Sang-Yong Park Byong-Joon Oh Jeang Ook ILJIN Diamond Co. Ltd.Eumsung-KunChucheongbuk-Do369-824KOREA

In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened *** new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater *** microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping *** result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.

关键词： High speed continuous turning of hardened steel with newly developed low content PCBN high

Design and implementation of user information sharing system using location-based services for social network services

在线全文

学校读者我要写书评

暂无评论

Journal of Measurement Science and Instrumentation 2012年第2期3卷 169-172页

作者： Donsu lee junghoon Shin Sangjun lee Computer Science Soongsil University

Internet takes a role as a place for communication between people beyond a space simply for the acquisition of ***,social network service(SNS)reflecting human’s basic desire for talking and communicating with others is focused on around the *** location-based service(LBS)is a service that provides various life conveniences like improving productivity through location information,such as GPS and *** paper suggests an application combining LBS and SNS based on Android *** using smart phone which is personal mobile information equipment,it combines location information with user information and SNS so that the service can be *** also maximizes sharing and use of information via twit based on locations of *** proposed system is aims for users to show online identity more actively and more conveniently.

关键词： android OS social network service(SNS) location-based service(LBS) Google maps Twitter Open API

Growth of single crystals in the (Na_(1/2)Bi_(1/2))TiO_(3)-(Sr_(1-x)Ca_(x))TiO_(3) system by solid state crystal growth

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2021年第5期10卷 973-990页

作者： Phan Gia LE Huyen Tran TRAN Jong-Sook lee John G.FISHER Hwang-Pill KIM Wook JO Won-Jin MOONC School of Materials Science and Engineering Chonnam National University77 Yongbong-roBuk-guGwangju 61186Republic of Korea School of Materials Science and Engineering Ulsan National Institute of Science and Technology50 UNIST-gilEonyang-eupUlju-gunUlsan 44919Republic of Korea Korea Basic Science Institute Gwangju Center77 Yongbong-roBuk-guGwangju 61186Republic of Korea

Ceramics based on(Na_(1/2)B_(1/2))TiO_(3) are promising candidates for actuator applications because of large strains generated by an electric field-induced phase *** example,the(1-x)(Na_(1/2)Bi_(1/2))TiO_(3)-xSrTiO_(3) system exhibits a morphotropic phase boundary at x=0.2-0.3,leading to high values of inverse piezoelectric constant d_(33),which can be further improved by the use of single *** our previous work,single crystals of (Na_(1/2)B_(1/2))TiO_(3)-SrTiO_(3) and (Na_(1/2)Bi_(1/2))TiO_(3)-TiO_(3) were grown by the solid state crystal growth *** in the(Nai/2Bi/2)TiO3-SrTiO3 system was sluggish whereas the (Na_(1/2)B_(1/2))TiO_(3)-CaTiO_(3) single crystals grew *** the present work,0.8(Na_(1/2)Bi_(1/2))Ti0_(3)-0.2(Sr_(1-x)Ca_(x))Ti0_(3) single crystals(with x=0.0,0.1,0.2,0.3,0.4)were produced by the solid state crystal growth technique in an attempt to improve crystal growth *** dependence of mean matrix grain size,single crystal growth distance,and electrical properties on the Ca concentration was investigated in *** investigations indicated that at x=0.3 the matrix grain growth was suppressed and the driving force for single crystal growth was *** Sr with Ca increased the shoulder temperature T_(s) and temperature of maximum relative permittivity T_(max),causing a decrease in inverse piezoelectric properties and a change from normal to incipient ferroelectric behavior.

关键词： (Na_(1/2)Bi_(1/2))TiO_(3) lead-free piezoelectric single crystal microstructure electrical properties

A NEW PRODUCT DEVELOPMENT METHODOLOGY BASED ON PRODUCT MASTER MODEL

在线全文

学校读者我要写书评

暂无评论

机电工程技术 2006年第1期35卷 67-70,94页

作者： Kunwoo lee School of Mechanical and Aerospace Engineering Seoul National University

Product Master Model(PMM)Technology is a philosophy and methodology for organizing,managing and controlling product development processes,sharing the information and knowledge of the product and its *** this paper,the concept of PMM is proposes,the basic theory of PMM technologies is studied,the blackboard architecture of PMM is proposed,the product development process framework is explored,and the prototype system of PMM is developed.

关键词：产品管理模型信息组织产品发展方法论 PMM