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   54篇
  免费   1篇
化学工业   10篇
建筑科学   1篇
轻工业   2篇
石油天然气   1篇
无线电   24篇
一般工业技术   1篇
冶金工业   14篇
自动化技术   2篇
  2021年   1篇
  2020年   1篇
  2018年   1篇
  2012年   1篇
  2011年   1篇
  2009年   1篇
  2008年   5篇
  2007年   1篇
  2006年   5篇
  2005年   3篇
  2004年   1篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   5篇
  1997年   5篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   5篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1985年   2篇
  1982年   2篇
  1978年   1篇
  1973年   1篇
排序方式: 共有55条查询结果,搜索用时 15 毫秒
1.
这个综合学校包括一个主建筑,一个体育馆和各种户外设施,朝向一片处在前军事基地上的住宅开发区。整个主建筑沿纵向被一个由顶部采光的回廊从中间分开,由此可以进入两侧的教室,回廊局部变宽的部分构成一个公共空间。这个构想与将城市设计理论运用于建筑内部设计的概念相符合:街道、广场和建筑被看成了建筑内部空间部分。虽然这个建筑从外部看来是个大体块,但内部空间却设计流畅,通道有的通向楼层的各个角落,也有的依着倾斜的地势因势而建。由墙面反射的散射光线加强了内部空间的肃穆和厚重感。在具有宗教感的整体风格下,整个学校的设计和装饰也显得古香古色,如一部宽阔的观光楼梯、两个塔形和壁炉形的建筑构成元素等。不同历史风格建筑的叠加给这个校区带来一种复杂的味道,堪比阿尔多·罗西(Aldo Rossi)的设计或泰辛(Tessin)新理性主义的代表作。  相似文献   
2.
n-Butylvinylether sorbed from the vapor phase onto hydrogen mordenite powder has been found to polymerize readily near room temperature. In a polymer sample from this reaction the polymer molecules were found to contain a number average of ten monomer units. The reaction over a considerable time interval followed the relations Qt = kt + γk = (ap + b)F(H2O) where Qt is the mass uptake (mainly as polymer) at pressure p in time t; k, γ, a and b are coefficients and F(H2O) is a function of the amount of water in the zeolite. The kinetics have been taken to indicate partial control by a diffusion process in which the monomer penetrates a growing layer of polymer formed around each catalyst particle. The monomer migrates to the catalyst-polymer interface and polymerizes at or near the interface. In small quantities water functioned as a cocatalyst, but around 5% weight uptake F(H2O) passed through a maximum. The rate of the reaction appeared to reach a maximum between 28 and 30 °C. A carbonium ion mechanism of polymerization is proposed.  相似文献   
3.
4.
A self-switching mechanism in Mach-Zehnder interferometers (MZIs) is described. The input light signal is distributed unequally over the interferometer arms using an multimode interference (MMI) coupler. In the arms, semiconductor optical amplifiers are placed as nonlinear phase shifters. Unequal intensities yield a nonlinear phase shift. The signals from the two arms are then recombined in an output MMI coupler. If an obtained nonlinear phase shift in the arms can compensate the coupler-induced phase difference between the arms, the signals are in phase at the output port. Choosing an appropriate output coupler, 2/spl times/1 and 2/spl times/2 devices can be obtained. The 2/spl times/2 and 2/spl times/1 MZIs can be used as pattern effect compensators and 2R-regenerators or low-loss combiner circuits, respectively. An active-passive integration technique is applied in order to realize the interferometric structures. Fabrication, simulation, and characterization of these devices are presented in this letter.  相似文献   
5.
Loss measurements on ridge waveguides in LPE-grown GaInAsP at a wavelength of 1.3 mu m are presented. An attenuation of 4.5 dB/cm has been obtained for straight waveguides, and for curved waveguides an excess loss at low as 0.7 dB was found for a 20.8 degrees S-bend with a radius of 300 mu m ( approximately=1.5 dB/90 degrees ).<>  相似文献   
6.
Patients' level of satisfaction with their therapeutic experience is a concept that is important for understanding treatment efficacy; however, patient satisfaction has received little empirical attention. The Satisfaction With Therapy and Therapist Scale (STTS) developed for group psychotherapy by T. P. S. Oei and G. J. Shuttlewood (1999) was designed to assess patients' level of satisfaction with their therapeutic endeavor. This article aims to strengthen the STTS's psychometric properties by using confirmatory factor analysis (CFA) with a large sample of patients with mood and anxiety disorders. Outpatients (N = 344) took part in the study. Exploratory factor analysis indicated 2 conceptually coherent factors that accounted for 66.9% of the variance. The 2 factors, which were similar to those found in Oei and Shuttlewood (1999), namely, Satisfaction With Therapy and Satisfaction With Therapist, were replicated. CFA revealed a 2-factor solution to be the best-fitting model. Overall, this article demonstrated that the STTS-R has sound psychometric properties and would serve as a useful instrument in assessing a patient's level of satisfaction with both group therapy and therapist in research as well as in clinical settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
The first integrated InP-based polarization independent optical crossconnect is reported. The device can crossconnect signals at four wavelengths independently from two input fibers to two output fibers. Total on-chip loss is less then 16 dB. Device size is 7×9 mm2   相似文献   
8.
This paper discusses functional and architectural aspects and suitable networks scenarios for the integration of international fixed satellite systems, such as the INTELSAT system, in and between digital networks implementing the new CCITT synchronous digital hierarchy (SDH). The paper presents SDH transmission network functional requirements, and combines them with current and anticipated future FSS operational requirements. It is shown that integration permits the use of SDH functions and features for enhanced network service provisioning by FSS in the international network fabric, and leads to new FSS system design criteria.  相似文献   
9.
In this paper a tunable integrated semiconductor optical pulse shaper is presented. The device consists of a pair of arrayed waveguide gratings with an array of electrooptical phase modulators in between. It has been fabricated in InP-InGaAsP material for operation at wavelengths around 1.55 mum. Multimode inputs to the waveguide gratings are used to flatten their optical passband. We have used a new short-pulse characterization technique to fully characterize pulse shaping by the device, i.e., both the power and the phase profile. A fourfold decrease in pulse ringing was observed for the devices with flattened passbands. Moreover these devices showed a 25% increase in pulse peak power. The possibilities for using the device as a dispersion (pre-) compensator have been investigated. Pulse reconstruction could be obtained for dispersion values of up to 0.2 ps/nm. The fabrication technology of the pulse shaper is compatible with the fabrication of integrated mode-locked lasers, which makes further integration of complete arbitrary pulse generators possible.  相似文献   
10.
A series of bis(4‐pentylpyridinium) compounds with a variety of spacers between the pyridinium headgroups was synthesised, and the antifungal activity of these compounds was investigated. Lengthening the alkyl spacer between the pentylpyridinium headgroups from 12 to 16 methylene units resulted in increased antifungal activity against C. neoformans and C. albicans, but also resulted in increased hemolytic activity and cytotoxicity against mammalian cells. However, inclusion of an ortho‐substituted benzene ring in the centre of the alkyl spacer resulted in decreased cytotoxicity and hemolytic activity, while maintaining antifungal potency. Replacement of the alkyl and aromatic‐containing spacers by more hydrophilic ethylene glycol groups resulted in a loss of antifungal activity. Some of the compounds inhibited fungal PLB1 activity, but the low correlation of this inhibition with antifungal potency indicates PLB1 inhibition is unlikely to be the predominant mode of antifungal action of this class of compounds, with preliminary studies suggesting they may act via disruption of fungal mitochondrial function.  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