全文获取类型
收费全文 | 1198篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 66篇 |
综合类 | 2篇 |
化学工业 | 288篇 |
金属工艺 | 25篇 |
机械仪表 | 16篇 |
建筑科学 | 18篇 |
矿业工程 | 2篇 |
能源动力 | 24篇 |
轻工业 | 115篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 138篇 |
一般工业技术 | 155篇 |
冶金工业 | 254篇 |
原子能技术 | 35篇 |
自动化技术 | 91篇 |
出版年
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 22篇 |
2017年 | 11篇 |
2016年 | 21篇 |
2014年 | 14篇 |
2013年 | 58篇 |
2012年 | 35篇 |
2011年 | 43篇 |
2010年 | 40篇 |
2009年 | 42篇 |
2008年 | 34篇 |
2007年 | 34篇 |
2006年 | 44篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 26篇 |
2000年 | 22篇 |
1999年 | 26篇 |
1998年 | 96篇 |
1997年 | 55篇 |
1996年 | 31篇 |
1995年 | 34篇 |
1994年 | 33篇 |
1993年 | 37篇 |
1992年 | 17篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1977年 | 10篇 |
1976年 | 14篇 |
1972年 | 15篇 |
1971年 | 12篇 |
1961年 | 12篇 |
1960年 | 11篇 |
1959年 | 11篇 |
1958年 | 12篇 |
1957年 | 13篇 |
1955年 | 10篇 |
排序方式: 共有1232条查询结果,搜索用时 15 毫秒
81.
We present a local Dissemination of EPIC, a project which has been devised to support health and social primary care by an information system. One key point of the EPIC project was a standardization effort at European level, providing a standardized basis for the management system based on client needs for planning and manpower control. Whilst EPIC has been designed as a general community information system, the main EPIC applications focus is on the care of the elderly. Savona is a middle size Italian town with a high percentage of elderly people and has already had an experience of integration of health and social care within an Italian project. It has therefore been regarded as a suitable site for the dissemination of EPIC. The EPIC application solved some of the information problems which emerged during the validation of the previous Italian project, such as the definition of the requirements; the collection, processing and retrieval of the clinical/social data; the definition of responsibilities and relations of the operators. 相似文献
82.
Inductance has a particularly important role in power circuits. The authors have proposed the Variable Active–Passive Reactance (VAPAR), which can produce a virtual variable inductance. In this paper, the transient power characteristics of a balanced three‐phase variable inductance are analyzed using the instantaneous active and reactive power theorem. With an ideal voltage source or an ideal current source connected to a balanced three‐phase variable inductance, the transient power characteristics are analyzed theoretically, and then the results are verified through simulations. In the other cases, it is difficult to solve for the transient power, but it is shown that the transient power characteristics can easily be estimated from the results of simulations in which an ideal voltage source or an ideal current source is connected to a balanced three‐phase variable inductance. Experiments are also carried out to verify the theoretical analysis and simulations. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 49–57, 2001 相似文献
83.
Bagchi S. Biswas G. Kawamura K. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2000,30(6):639-650
As robotics and automation applications extend to the service sector, researchers have to increasingly deal with performing robotic actions in uncertain and unstructured environments. A traditional solution to this problem models uncertainty about the effects of actions by probabilities conditioned on the state of the environment, making it possible to select plans that have the highest probability of success in a given situation. Reactive systems use another approach to handling uncertainty, by employing a set of predefined situation-response rules that make it possible to move toward the goal from any situation, whether expected or unexpected. This paper describes a planner that combines the two approaches. A proactive component generates plans that are biased toward picking the most reliable action in a given situation, and a reactive component can alter the selected actions based on unexpected situations that may arise in uncertain environments. Action selection is driven by a spreading activation mechanism on a probabilistic network that encodes the domain knowledge. A decision-theoretic framework incorporates quantitative goal utilities and action costs into the action selection mechanism. Experiments conducted demonstrate the ability of the planner to plan with hard and soft domain constraints and action costs, modify plans as a reaction to unexpected changes in the environment or goal utilities, and plan in situations with multiple conflicting goals 相似文献
84.
Non-invasive surgery techniques and drug delivery system with acoustic characteristics of ultrasound contrast agent have been studied intensively in recent years. Many ultrasound contrast agents are commercially available, and they are usually composed of a microbubble coated by a surfactant or lipid bilayer, i.e., a hollow microsphere. We show that the hollow microsphere with polymer shell can be fabricated just blowing vapor of commonly-used instant adhesive into water as microbubbles. The hollow microspheres are composed of cyanoacrylate, a biocompatible material used for adhesion to human tissue such as skin, blood vessels, and organs. Moreover these are less than 10 μm in diameter, which is smaller than a blood capillary (approximately 10 μm). Therefore, with their stable polymer shells, the hollow microspheres are possible ultrasound contrast agents, and are expected to be generated at low cost on the medical frontline, and not in a pharmaceutical factory. 相似文献
85.
Yoshiki Nakachi Takayuki Fukae Toshinori Sugahara Hayato Nakamura Mitsuaki Koyama Fukashi Ueda 《Electrical Engineering in Japan》2013,185(1):36-47
It is well known that a voltage drop due to inrush current at an energizing transformer may at times interrupt electrical equipment. Generally, the voltage drop is calculated by using a sophisticated tool such as EMTP, so that the transformer saturation phenomenon has been properly represented. However, it is not practical for distribution system engineers to calculate the voltage drop with transformer inrush by using EMTP, because there are many network access requests needing such calculations with many kinds of transformers. Therefore, in this paper, a simplified and easy‐to‐use calculation tool for voltage drops caused by transformer inrush in a distribution system is developed. In order to understand the voltage drop by inrush current during the planning stage, it is formulated by considering the transformer saturation/unsaturation periods in each winding type. The newly developed tool is based on versatile spreadsheet software such as Microsoft Excel ýO.R. It can be used with accuracy similar to that of EMTP. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(1): 36–47, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22394 相似文献
86.
K Ishihara H Ichikawa T Takeuchi M Kawamura K Sugita 《Canadian Metallurgical Quarterly》1997,37(6):509-513
We describe a patient who presented with isolated retrograde amnesia of 2-year duration after recovery from viral encephalitis. The patient was a 29-year-old right-handed male dentist and was admitted to our hospital with a complaint of generalized convulsion. Cerebrospinal fluid (CSF) showed mononuclear pleocytosis. Neuroradiological examinations (X-ray CT, MRI and 123I-IMP SPECT) revealed no significant abnormality. Immunological method showed no specific increase of viral antibody titers. However, with a tentative diagnosis of viral encephalitis, administration of acyclovir was started. After 3 weeks he became comprehensive, and several kinds of neuropsychological tests were performed. His intelligence and immediate memory were normal, and his procedural memory of dentist was intact. On the other hand, he could not recall any information about events, both personal and public, occurred within 2 years before the onset of present illness. His autobiographical memory disorder was also demonstrated using a series of weekly comic. In isolated retrograde amnesia following viral encephalitis like this case, memory of relatively short time duration, acquired prior to the onset of present illness, tend to be disturbed. 相似文献
87.
M Hibi A Matsuura H Ohshima Y Tomida F Murakami K Yoshida M Kawamura 《Canadian Metallurgical Quarterly》1998,51(2):106-107
A 24-year-old white man had a six-month history of nontender nodules on the dorsal aspect of the right hand. The lesions were diagnosed as lymphocutaneous sporotrichosis based on clinical appearance, histopathologic examinations, and fungal culture. Therapy with itraconazole was started. Considerable improvement was recorded after two months, when all of the lesions diminished in size and were no longer nodular in appearance. 相似文献
88.
Vincent Keryvin Marie-Laure Vaillant Tanguy Rouxel Marc Huger Thierry Gloriant Yoshihito Kawamura 《Intermetallics》2002,10(11-12)
An original in situ ultrasonic echography technique was used to study the thermal stability and crystallisation of a Zr55Cu30Al10Ni5 bulk metallic glass between RT and 630 °C. Changes in Young's modulus with temperature were reported allowing to study the supercooled-liquid state and the crystallisation process. Investigations of viscoelastic properties gave information on the correlation factor (hierarchically correlated motion theory) and three distinct crystallisation stages were observed. Their kinetics were studied using Voigt's and Reuss' approximations for a two-phase material and comparisons with the Johnson–Mehl–Avrami–Kolmogorov theory allowed us to consider a mixed surface/internal nucleation for the first stage and a surface nucleation for the two last stages. 相似文献
89.
T Kawamura Y Ohisa Y Abe A Ishimori R Shineha K Yokota 《Canadian Metallurgical Quarterly》1992,40(8):881-884
Lipid peroxides are formed by autooxidation of polyunsaturated fatty acids found primarily in cell membranes. An increase level of lipid peroxides in the tissue therefore reflects membrane damage. We reported that water immersion restraint rats caused significant increase of gastric mucosal lipid peroxide which reflected on gastric mucosal injury. The gastric mucosal injury is also known as the post-operative complication due to physical stress. So we studied plasma lipid peroxide and its related substances in the operation of esophageal cancer. Lipid peroxide levels increased significantly in pre- and post-operation but temporal decrease was found during the operation. Vitamin E is thought to be an important structural component of biologic membranes and is believed to act as a free radical scavenger in lipid peroxidation. Vitamin E also increased in the patients of esophageal cancer and decreased significantly during the operation. Superoxide dismutase changed frequently during the operation but there was no deficit tendency in its changes. Catalase levels also changes frequently and showed temporal but statistical elevation after the operation. These results indicated that lipid peroxidation may contribute to the development of organic damage in the operation of esophageal cancer. 相似文献
90.
T. Kagawa H. Asai Y. Kawamura 《Photonics Technology Letters, IEEE》1991,3(9):815-817
The authors describe the fabrication of an InGaAs/InAlAs superlattice avalanche photodiode with a gain-bandwidth product of 90 GHz. The device is composed of an InGaAs/InAlAs superlattice multiplication region and an InGaAs photoabsorption layer. The effect of the superlattice multiplication region thickness on the gain-bandwidth product was studied. A gain-bandwidth product of 90 GHz was obtained for the device with a multiplication region thickness of 0.52 mu m. Low noise performance is compatible with the high gain-bandwidth product due to improvement of the ionization rate ratio made by introducing a superlattice structure into the multiplication region.<> 相似文献