首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   161篇
  免费   1篇
  国内免费   3篇
教育   92篇
科学研究   34篇
各国文化   5篇
体育   4篇
文化理论   5篇
信息传播   25篇
  2023年   2篇
  2022年   1篇
  2021年   10篇
  2020年   2篇
  2019年   4篇
  2018年   10篇
  2017年   7篇
  2016年   5篇
  2015年   5篇
  2014年   4篇
  2013年   16篇
  2012年   11篇
  2011年   9篇
  2010年   5篇
  2009年   3篇
  2008年   6篇
  2007年   10篇
  2006年   2篇
  2005年   1篇
  2004年   4篇
  2003年   3篇
  2002年   3篇
  2001年   3篇
  2000年   2篇
  1998年   1篇
  1997年   5篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1992年   2篇
  1991年   1篇
  1989年   2篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1981年   2篇
  1980年   3篇
  1978年   3篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1967年   1篇
  1930年   2篇
  1929年   1篇
排序方式: 共有165条查询结果,搜索用时 15 毫秒
51.
52.
IntroductionHigh prolactin (PRL) concentrations are found in laboratory test results of patients on majority of antipsychotic drugs. Prevalence rates and degrees of severity of hyperprolactinemia (HPRL) based on PRL concentration may depend on the presence of macroprolactin in the serum. The aim of the study was to investigate the difference between PRL concentrations before and after precipitation of macroprolactin and to examine if there were any changes in the categorization of HPRL between samples prior and after precipitation.Materials and methodsTotal of 98 female patients (median age 33; range 19-47 years) diagnosed with a psychotic disorder, proscribed antipsychotic drugs, and with HPRL were included. Total PRL concentration and PRL concentration after macroprolactin precipitation with polyethylene glycol (postPEG-PRL) were determined by the chemiluminometric method on the Beckman Coulter Access2 analyser.ResultsTotal PRL concentrations (median 1471; IQC: 1064-2016 mlU/L) and postPEG-PRL concentrations (median 1453; IQC: 979-1955 mlU/L) were significantly correlated using intraclass correlation coefficient for single measurements (mean estimation 0.96; 95%CI 0.93-0.97) and average measurement (mean estimation 0.98; 95%CI 0.96-0.99), and all investigated female patient had HPRL according to PRL and postPEG-PRL concentration. The median PRL recovery following PEG precipitation was 95; IQC: 90-100%. There was substantial agreement (kappa test = 0.859, 95% CI: 0.764-0.953) between the categories of HPRL severity based on total PRL concentrations and postPEG-PRL concentrations.ConclusionThe study demonstrated that HPRL was present in all subjects using the reference interval for total PRL concentration and postPEG-PRL concentration with no significant impact of macroprolactin presence in the serum on the categorization of patients according to severity of HPRL.  相似文献   
53.
Hepatocellular carcinoma (HCC) remains one of the major public health problems throughout the world. Although originally associated with tumorigenic processes, liver angiogenesis has also been observed in the context of different liver inflammatory, fibrotic, and ischemic conditions. Here we investigate the fractal dimension as a quantitator of non-Euclidean two-dimensional vascular geometry in a series of paired specimens of primary HCC and surrounding non-tumoral tissue, and discuss why this parameter might provide additional information regarding cancer behavior. The application of fractal geometry to the measurement of liver vascularity and the availability of a computer-aided quantitative method can eliminate errors in visual interpretation, and make it possible to obtain closer-to-reality numerals that are compulsory for any measurement process.  相似文献   
54.
Abstract Throughout the cultural institution sector, shifts in audience participation call for new ways to share knowledge and view partnerships both online and onsite. Increasingly, this “transformation in cultural communication” suggests that a new type of mutually beneficial exchange is required between audiences and museums; and that those acting as agents of cultural change must be cognizant of how a participatory culture will drive our future institutional missions. This paper offers two examples of how the implementation of strategic social media programs can drive online cultural exchange and create new connections with diverse communities. It presents a convergence of initiatives undertaken within the sector over the past five years while offering a frame through which to view future innovations. Based on research undertaken with multiple organizations, it recognizes that the time is right to merge existing innovations with strategically developed communication programs to achieve a demonstrable, verifiable basis for the value of our museums.  相似文献   
55.
The Ukrainian Society, after introducing the computer literacy course for secondary schools in 1986, is trying to reach the next stage of digital literacy through the development of a National Informatization Programme. Some results of the programme are described: the incorporation of telematics into the educational system and Internet literacy for teachers and students, free of charge and in local languages; the development of regional and local nodes of educational institutions and their incorporation into a national network; the participation of non-governmental organizations in the financing of educational programmes; and the development of a national ethics Net-Codex. Ukraine, as a typical “country in transition”, needs international support in digital literacy through co-operative projects; some proposals for such co-operation are given.  相似文献   
56.
In this study, we assessed the longitudinal effects of social-cognitive mechanisms on the self-reported use of doping substances and supplements among Italian high school students. In total, 1232 students completed questionnaires measuring various psychological factors hypothesized to influence students' intention to use substances. Three months later, 762 of the students completed the same questionnaires a second time and also reported their use of substances during the time between assessments. Overall, the percentages of students using doping substances (2.1%) or supplements (14.4%) were consistent with values reported in the literature. Analysis of the data showed that adolescents' intention to use doping substances increased with stronger attitudes about doping, stronger beliefs that significant others would approve of their use, a stronger conviction that doping use can be justified, and a lowered capacity to resist situational pressure or personal desires. In turn, stronger intentions and moral disengagement contributed to a greater use of doping substances during the previous 3 months. Doping use was also correlated significantly to supplementation. In conclusion, our results provide novel information about some of the psychological processes possibly regulating adolescents' use of doping substances and supplements. The results also highlight possible areas for future study and intervention, focusing on the prevention of adolescents' substance use.  相似文献   
57.
For a number of reasons, higher education in the Russian Federation has been able to benefit from a more stable financial situation than have most of the other “socio‐cultural areas” in Russia. It has nevertheless been severely affected by the problems besetting the other sectors of the Russian economy, most of them linked to the rigours of transition to a market economy. The situation will improve as the Russian economy as a whole improves and as higher education in Russia not only becomes more market‐oriented and quality conscious but adopts specific administrative measures designed to ensure efficiency.  相似文献   
58.
59.
This paper focuses on four fusion algorithms for the estimation of nonlinear cost function (NCF) in a multisensory environment. In multisensory filtering and control problems, NCF represents a nonlinear multivariate functional of state variables, which can indicate useful information of the target systems for automatic control. To estimate the NCF using multisensory information, we propose one centralized and three decentralized estimation fusion algorithms. For multivariate polynomial NCFs, we propose a simple closed-form computation procedure. For general NCFs, the most popular procedure for the evaluation of their estimates is based on the unscented transformation. The effectiveness and estimation accuracy of the proposed fusion algorithms are demonstrated with theoretical and numerical examples.  相似文献   
60.
In microcirculation, red blood cells (RBCs) flowing through bifurcations may deform considerably due to combination of different phenomena that happen at the micro-scale level, such as: attraction effect, high shear, and extensional stress, all of which may influence the rheological properties and flow behavior of blood. Thus, it is important to investigate in detail the behavior of blood flow occurring at both bifurcations and confluences. In the present paper, by using a micro-PTV system, we investigated the variations of velocity profiles of two working fluids flowing through diverging and converging bifurcations, human red blood cells suspended in dextran 40 with about 14% of hematocrit level (14 Hct) and pure water seeded with fluorescent trace particles. All the measurements were performed in the center plane of rectangular microchannels using a constant flow rate of about 3.0 × 10−12 m3/s. Moreover, the experimental data was compared with numerical results obtained for Newtonian incompressible fluid. The behavior of RBCs was asymmetric at the divergent and convergent side of the geometry, whereas the velocities of tracer particles suspended in pure water were symmetric and well described by numerical simulation. The formation of a red cell-depleted zone immediately downstream of the apex of the converging bifurcation was observed and its effect on velocity profiles of RBCs flow has been investigated. Conversely, a cell-depleted region was not formed around the apex of the diverging bifurcation and as a result the adhesion of RBCs to the wall surface was enhanced in this region.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号