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   226篇
  免费   12篇
化学工业   95篇
机械仪表   9篇
建筑科学   2篇
能源动力   12篇
轻工业   41篇
水利工程   2篇
石油天然气   1篇
无线电   13篇
一般工业技术   40篇
冶金工业   7篇
原子能技术   1篇
自动化技术   15篇
  2023年   4篇
  2022年   3篇
  2021年   14篇
  2020年   8篇
  2019年   14篇
  2018年   6篇
  2017年   11篇
  2016年   12篇
  2015年   1篇
  2014年   9篇
  2013年   24篇
  2012年   13篇
  2011年   24篇
  2010年   14篇
  2009年   14篇
  2008年   9篇
  2007年   14篇
  2006年   8篇
  2005年   3篇
  2004年   4篇
  2003年   1篇
  2001年   3篇
  2000年   2篇
  1999年   3篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
排序方式: 共有238条查询结果,搜索用时 0 毫秒
71.

Background

Systematic literature reviews and systematic mapping studies are becoming increasingly common in software engineering, and hence it becomes even more important to better understand the reliability of such studies.

Objective

This paper presents a study of two systematic mapping studies to evaluate the reliability of mapping studies and point out some challenges related to this type of study in software engineering.

Method

The research is based on an in-depth case study of two published mapping studies on software product line testing.

Results

We found that despite the fact that the two studies are addressing the same topic, there are quite a number of differences when it comes to papers included and in terms of classification of the papers included in the two mapping studies.

Conclusions

From this we conclude that although mapping studies are important, their reliability cannot simply be taken for granted. Based on the findings we also provide four conjectures that further research has to address to make secondary studies (systematic mapping studies and systematic literature reviews) even more valuable to both researchers and practitioners.  相似文献   
72.
In this article we propose a role based model for the specification of organized collective agency, based on the legal concept of artificial person and on the normative perspective of organizational systems. We focus on the analysis of groups of agents (humans or not) that want to act collectively in a (more or less) permanent basis, and in a stable and organized way, as it is the typical case of organizations. We argue that in those cases such groups of agents should give rise to a new agent, that we call of institutionalized agent, with its own identity, whose structure is essentially defined through the characterization of a set of roles and whose behavior is determined by the acts of the agents that play such roles. We also present a deontic and action modal logic that captures the concept of acting in a role and relates it with the deontic notions of obligation, permission and prohibition. This logic is used in the formal specification of institutionalized agents and of societies of agents and in the rigorous analysis of them. We pay particular attention to the interaction between agents through contracts or other normative relations. A high level specification language is also suggested.  相似文献   
73.
This paper presents a plug-and-play module for wireless electroencephalogram (EEG) applications. The wireless module is composed by an electrode, processing electronics, a radio-frequency (RF) transceiver, and an associated antenna. The RF transceiver was fabricated in the UMC RF 0.18 mum CMOS process, and operates in the 2.4-GHz ISM band. The receiver has a sensitivity of -60 dBm and a power consumption of 6.3 mW from a 1.8 V supply. The transmitter delivers an output power of 0 dBm with a power consumption of 11.2 mW, for a range of 10 m. It is also presented the electrical performance and comparison between different electrodes for EEG applications, namely sputtered titanium nitride (TiN) electrodes, standard sintered silver/silver chloride (Ag/AgCl) ring electrodes and sputtered iridium oxide (IrO2) electrodes. The experimental results show a better performance of the sputtered IrO2 electrodes compared with the standard sintered Ag/AgCl ring electrodes. These results promise a new opportunity for the application of a dry IrO2 electrodes in wireless modules for using in a wearable EEG braincap. These wireless EEG modules will allow patients to wear a brain cap and maintain their mobility, while simultaneously having their electrical brain activity monitored.  相似文献   
74.
The electrical and magnetic properties of GaSb:Mn layers deposited on (100)GaAs substrates from a laser plasma in vacuum have been studied. It is shown that the films deposited at 200–440 °C are mosaic single crystalline and epitaxial to the substrate, with p-type conduction. Manganese-doped layers had a hole concentration higher than 1×1019 cm−3 and fairly high values of mobility (up to 40 cm2/V s at 300 K). The layers grown at 200 °C exhibited an anomalous Hall effect up to approximately room temperature. On the contrary, a normal Hall effect was observed in the layers grown at 440 °C. Ferromagnetic resonance measurements have revealed the existence of ferromagnetism in the sample grown at 200 °C. The transition temperature is close to room temperature, in full agreement with the Hall data. In the sample grown at 440 °C, the formation of ferromagnetic clusters has tentatively been concluded.  相似文献   
75.
The AC conductivity of a percolation model with local energetical disorder for porous Silicon in three dimensions, (), is studied by Monte Carlo simulations. The model includes both diffusion and recombination processes and () is obtained by a Fourier transform of the mean-square displacement of the carriers, where hopping diffusion of a single type of carrier (either an electron or an exciton) and two types of carriers (an electron and a hole) are considered. It is found that at low temperatures, the behavior of () depends sensitively on the type of carrier considered.  相似文献   
76.
Uniqueness and multiplicity criteria for the steady state are derived following previous analyses for a bimolecular Langmuir—Hinshelwood reaction occurring in a porous catalyst, in both the isothermal and non-isothermal cases. The criteria compare well with exact numerical computations in all cases, except when the mass and heat Biot numbers are unequal. Recently reported criteria for the isothermal case are shown to be always much more restrictive than the ones developed here. Also, numerical calculations show that up to five distinct steady state solutions exist for the sphere, in both the isothermal and non-isothermal cases, while only up to three solutions are obtained for the slab catalyst.  相似文献   
77.
78.
79.
80.
Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis that carries a high morbidity and mortality. Although its pathogenesis is still not clear, the “two hit theory” suggests that long term deterioration of the peritoneum combined with intraperitoneal inflammation is needed in the pathogenesis of EPS. To date, there is no proven effective therapy with an absence of randomized controlled trials. Individual case reports and small case series have reported on the use of tamoxifen and corticosteroids for medical management of EPS. Here, we present the first case of EPS treated successfully with a combination of sirolimus, low dose corticosteroid and intradialytic parenteral nutrition. A critical review of the relevant literature on this subject is also presented to determine the best approach.  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