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   340篇
  免费   11篇
  国内免费   2篇
电工技术   33篇
化学工业   75篇
金属工艺   3篇
机械仪表   5篇
建筑科学   5篇
能源动力   11篇
轻工业   56篇
水利工程   2篇
无线电   17篇
一般工业技术   36篇
冶金工业   44篇
原子能技术   11篇
自动化技术   55篇
  2022年   1篇
  2021年   2篇
  2020年   6篇
  2019年   4篇
  2018年   4篇
  2017年   3篇
  2016年   6篇
  2015年   9篇
  2014年   4篇
  2013年   18篇
  2012年   14篇
  2011年   24篇
  2010年   13篇
  2009年   21篇
  2008年   18篇
  2007年   12篇
  2006年   17篇
  2005年   12篇
  2004年   13篇
  2003年   10篇
  2002年   10篇
  2001年   5篇
  2000年   6篇
  1999年   6篇
  1998年   14篇
  1997年   17篇
  1996年   7篇
  1995年   11篇
  1994年   2篇
  1993年   5篇
  1992年   4篇
  1991年   5篇
  1990年   7篇
  1989年   3篇
  1988年   4篇
  1987年   3篇
  1986年   4篇
  1985年   2篇
  1984年   4篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1977年   4篇
  1976年   2篇
  1974年   2篇
  1973年   2篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
排序方式: 共有353条查询结果,搜索用时 15 毫秒
51.
BACKGROUND/AIMS: Close observation and evaluation of the function of the transposed stomach after esophagectomy is essential. The present study uses the sulfamethizole capsule meal test to evaluate differences in gastric emptying between the anterior and posterior mediastinal approaches in patients undergoing esophagectomy. METHODOLOGY: Thirty-eight patients who underwent the esophagectomy and esophagogastrostomy for esophageal cancer were randomly divided into 2 groups: Group 1: anterior mediastinal approach, and Group 2: posterior mediastinal approach. Gastric emptying was studied using the sulfamethizole capsule meal test. Patients received sulfamethizole food capsules, 65 g of bread, and 150 ml of water. Plasma sulfamethizole levels were determined by high performance liquid chromatography (HPLC). RESULTS: Gastric emptying in both groups was significantly accelerated compared to healthy volunteers. Gastric emptying did not differ significantly between groups 1 and 2. CONCLUSIONS: The present data show that the sulfamethizole capsule meal test is an effective means of evaluating the emptying of the transposed stomach. Furthermore, when the stomach is used as an esophageal substitute following esophagectomy, gastric emptying does not differ according to the access route.  相似文献   
52.
The hybrid catalytic combustor concept proposed by the authors has an advantage concerned with catalyst durability, because the catalyst is maintained below 1000°C even for application to 1300°C class gas turbines. A full-scale hybrid catalytic combustor has been designed for a 200 MW (1300°C) class gas turbine. The catalyst bed was 450 mm in diameter and consisted of a Pd/ alumina washcoat on a cordierite monolith. In experiments, the combustor has demonstrated the capability of meeting the NOx emission level of SCR (selected catalytic reduction) during atmospheric pressure testing. To predict the catalyst performance at an elevated pressure, the characteristics of the catalyst were studied using a small scale reactor test, and a material property test using a DTA/TGA-Q.MASS system. The catalyst showed a higher activity in the oxidized state (PdO) than in the metallic state (Pd). This activity difference was governed by the equilibrium of the oxygen release from PdO in bulk. It was considered that oxidation rate of the metallic Pd in bulk was not so high and this caused self-oscillation for the Pd catalyst around the temperature of the oxygen release equilibrium. Even below the temperature of the oxygen release equilibrium, both surface and bulk (lattice) oxygen of the PdO was consumed by the methane oxidation reaction, and resulted in a lack of surface oxygen on the catalyst. This caused a reversible decrease in the catalyst activity during combustion testing, and indicated that the oxygen dissociation step was a rate limiting step in the catalytic combustion.  相似文献   
53.
201Tl-99mTc subtraction scintigraphy has been recognized as a useful procedure in the preoperative localization of hyperfunctioning parathyroid glands. We experienced a case which showed 99mTc-pertechnetate uptake in a parathyroid hyperplasia. This case warned us to focus a lot of attention on the detection for preoperative localization. There has been no such case reported in the previous Japanese literatures. Hypervascularity and thick fibrous capsule presumed explanation for a rare case of marked pertechnetate uptake into a parathyroid hyperplasia.  相似文献   
54.
The genetics of resistance to disease is an area of great interest in agriculturally important plant and animal species. Selective breeding for resistance to pathogens in plants, animals and insects has demonstrated that resistance and susceptibility to pathogens are controlled by both genetic and environmental factors. The immune loci causally involved in susceptibility and resistance to disease are currently unknown. However, novel enabling molecular technologies promise to assist in unravelling the genetics of the host response to infectious diseases in new ways, and ultimately to improve seed stock genetics.  相似文献   
55.
56.
Endobronchial hamartomas are only rarely encountered. They cause irreversible lung damage due to bronchial obstruction if not diagnosed early and treated properly. Among the various treatments for this rare disease, a surgical resection remains the most popular. We herein report a case of a 53-year-old man presenting with an endobronchial hamartoma which was successfully excised by laser irradiation via a rigid bronchoscope, along with a review of 113 patients with this disease reported in the literature.  相似文献   
57.
Compared Maudsley reactive (MR) and nonreactive (MNR) (n = 40) and Roman high-avoidance (RHA) and low-avoidance (RLA) (n = 20) male albino rats with respect to emotional reactivity and conditionability. The degree of suppression of water-drinking behavior by unsignaled electric shocks was a measure of emotionality, and the rate of recovery of drinking behavior when the unsignaled shock became signaled was a measure of conditionability. The MR Ss were the most emotional, the MNR Ss were the least emotional, and the 2 Roman strains were intermediate. The RLA Ss were shown to have poor conditionability, while the other 3 strains did not differ from each other. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
58.
Suggested by the structure of the visual nervous system, a new algorithm is proposed for pattern recognition. This algorithm can be realized with a multilayered network consisting of neuron-like cells. The network, “neocognitron”, is self-organized by unsupervised learning, and acquires the ability to recognize stimulus patterns according to the differences in their shapes: Any patterns which we human beings judge to be alike are also judged to be of the same category by the neocognitron. The neocognitron recognizes stimulus patterns correctly without being affected by shifts in position or even by considerable distortions in shape of the stimulus patterns.  相似文献   
59.
In recent years, a new effective method of processing for polychlorinated biphenyls (PCBs) has been developed: It enables PCBs to become harmless by dechlorinating them using a 2.45 GHz microwave (MW). Compared with conventional thermal heating, MW processing hardly produces any harmful byproduct materials, and has high reaction velocity. To investigate such promotion of chemical reaction by MW irradiation, the surface temperature of the catalyst is measured by an infrared camera just after the irradiation by MW. It is recognized that there are some heated regions on the catalyst and the temperature is not uniform. It is natural to say that chemical reaction is promoted well on such a heated region. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.  相似文献   
60.
A world economy expands over boundaries between countries and regions. In Japan, there are many splendid technologies which the world requires. In order to transfer these technologies to the world an international standard which includes them as a standard is necessary. Activities by which 1100 kV UHV technologies are standardized in the IEC standard were conducted by starting with discussions in IEC/SB1. The activity has been followed by IEC/JICCG which coordinates IEC and CIGRE activities. The horizontal standards were started in advance at TC 8 and TC 28. The equipment standards will start from 2009 after the CIGRE committee finishes their reports by the end of 2008. Activities by the IEEJ standard committee have been carried horizontally to proceed with the UHV standardization rapidly and efficiently. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.  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