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   229篇
  免费   11篇
电工技术   4篇
化学工业   80篇
金属工艺   7篇
机械仪表   2篇
建筑科学   5篇
能源动力   3篇
轻工业   35篇
水利工程   1篇
石油天然气   1篇
无线电   10篇
一般工业技术   22篇
冶金工业   29篇
原子能技术   14篇
自动化技术   27篇
  2023年   2篇
  2022年   3篇
  2021年   3篇
  2020年   2篇
  2019年   3篇
  2018年   4篇
  2017年   6篇
  2016年   6篇
  2015年   4篇
  2014年   4篇
  2013年   14篇
  2012年   12篇
  2011年   18篇
  2010年   23篇
  2009年   15篇
  2008年   15篇
  2007年   7篇
  2006年   8篇
  2005年   5篇
  2004年   5篇
  2003年   7篇
  2002年   3篇
  2001年   5篇
  2000年   5篇
  1999年   2篇
  1998年   5篇
  1997年   7篇
  1996年   7篇
  1995年   6篇
  1994年   4篇
  1993年   4篇
  1992年   3篇
  1991年   4篇
  1989年   3篇
  1988年   3篇
  1987年   1篇
  1985年   2篇
  1984年   3篇
  1983年   2篇
  1981年   1篇
  1979年   4篇
排序方式: 共有240条查询结果,搜索用时 0 毫秒
1.
In our Department, continuous isoproterenol inhalation therapy has been conducted on status asthmatics over the last 10 years. In the present study, we investigated whether there are any differences in the therapeutic efficacy of continuous inhalation of isoproterenol in the presence or absence of respiratory infections which may induce or aggravate asthma attacks. The treatment period was significantly longer in patients with pneumonia. Further prolongation of the treatment period was noted in patients with atelectasis. However, there were no apparent differences in therapeutic efficacy according to age or the severity of attacks. These findings suggest that continuous inhalation of isoproterenol is very effective for status asthmatics if respiratory infections are thoroughly controlled.  相似文献   
2.
Studies have been carried out on KrF excimer laser light (EX), X-ray or electron beam (EB) induced polymerization of 10,12-pentacosadiynoic acid (PDA) Langmuir-Blodgett (LB) films in relation to molecular density or molecular arrangement of the films using X-ray diffraction analysis, infrared (IR) spectroscopy and Raman spectroscopy. The molecular arrangement or density of the PDA LB films was controlled by subphase conditions when the films were built up, such as pH, temperature of a subphase or salt concentration in the subphase. Polymerization sensitivity of the PDA LB film was affected by the arrangement or molecular density. On low density (A type) films the polymerization occurred by irradiation with EX, X-ray or EB, but on high density (B type) films the polymerization occurred only when the irradiation was carried out by high energy beams such as X-ray or EB. Decomposition of polymerized films was observed further by excessive irradiation of EX or X-ray, but not on the B type films. It was revealed by X-ray diffraction analysis that in the A type film, the PDA molecules bent to a larger extent than those in the B type film and the polymerization proceeded topochemically, that is, the thickness decreased little after EB irradiation in a helium atmosphere. On the other hand, in the B type film, the thickness decreased by about 10% as a result of EB irradiation. By IR reflection-absorption (RA) and Raman measurements, it was confirmed that conjugated diacetylenic bonds disappeared and conjugated double and new conjugated triple bonds appeared after high energy beam irradiations. These results support the supposition that 1,4-polymerization, i.e. polydiacetylene type polymerization, occurs easily in the A type film and 1,2- or 3,4-polymerization, i.e. polyacetylene type polymerization, occurs in the B type film, and that the polymerized A type film was decomposed at the polydiacetylenic bond when the irradiation continued further. It was also shown that the polyacetylene type polymer was obtained only when the B type film was irradiated with the high energy beam.  相似文献   
3.
4.
A phenomenon was discovered wherein light scattering strength from cracks increases when tensile stress is applied to micro-cracks produced in the interlayer dielectric film by chemical mechanical polishing treatment. It is likely that the change in light scattering intensity occurs because a region of high stress concentration (region with high variation in index of refraction) is produced near the crack tip due to stress, thus forming a type of scatterer. With this method, it is possible to detect only scatterers which respond to stress, and thus, it is possible to classify and separately detect cracks and particles.  相似文献   
5.
Many applications lead to a nonlinear elliptic interface problem in which the discontinuous coefficient depends on the solution and the material properties. A finite difference method based on Cartesian grids and the maximum principle preserving immersed interface method is proposed for the nonlinear elliptic interface problems discussed in this paper. Numerical experiments against the exact solutions reveal that our method is nearly second order accurate in the infinity norm. The method is applied to study the magneto-rheological field-responsive fluids that contain iron particles. Numerical experiments are performed against the results from the literature.  相似文献   
6.
Triple-negative breast cancer (TNBC) has the poorest prognosis of all breast cancer subtypes. Recently, the activation of NF-κB, which is involved in the growth and survival of malignant tumors, has been demonstrated in TNBC, suggesting that NF-κB may serve as a new therapeutic target. In the present study, we examined whether dimethyl fumarate (DMF), an NF-κB inhibitor, induces apoptosis in TNBC cells and enhances the apoptosis-inducing effect of paclitaxel and adriamycin. Cell survival was analyzed by the trypan blue assay and apoptosis assay. Protein detection was examined by immunoblotting. The activation of NF-κB p65 was correlated with poor prognosis in patients with TNBC. DMF induced apoptosis in MDA-MB-231 and BT-549 cells at concentrations that were non-cytotoxic to the normal mammary cell line MCF-10A. Furthermore, DMF inhibited NF-κB nuclear translocation and Survivin, XIAP, Bcl-xL, and Bcl-2 expression in MDA-MB-231 and BT-549 cells. Moreover, DMF enhanced the apoptosis-inducing effect of paclitaxel and adriamycin in MDA-MB-231 cells. These findings suggest that DMF may be an effective therapeutic agent for the treatment of TNBC, in which NF-κB is constitutively active. DMF may also be useful as an adjuvant therapy to conventional anticancer drugs.  相似文献   
7.
The accelerator-driven transmutation system has been studied at the Japan Atomic Energy Research Institute. This system is a hydrid system which consists of a high intensity accelerator, a spallation target and a subcritical core region. In the conceptual design study, two types of system concepts, sodium cooled and lead-bismuth cooled system, are being studied. In this study, we fucus on our lead-bismuth cooled accelerator-driven transmutation system to investigate basic characteristics. The fuel compositions were optimized for efficient transmutation of minor actinide. The transmutation of long-lived fission products was also considered.  相似文献   
8.
9.
10.
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