全文获取类型
收费全文 | 1345篇 |
免费 | 50篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 74篇 |
综合类 | 3篇 |
化学工业 | 371篇 |
金属工艺 | 30篇 |
机械仪表 | 33篇 |
建筑科学 | 27篇 |
矿业工程 | 1篇 |
能源动力 | 74篇 |
轻工业 | 99篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 85篇 |
一般工业技术 | 257篇 |
冶金工业 | 203篇 |
原子能技术 | 32篇 |
自动化技术 | 106篇 |
出版年
2023年 | 7篇 |
2022年 | 21篇 |
2021年 | 31篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 28篇 |
2017年 | 26篇 |
2016年 | 31篇 |
2015年 | 28篇 |
2014年 | 19篇 |
2013年 | 69篇 |
2012年 | 42篇 |
2011年 | 66篇 |
2010年 | 46篇 |
2009年 | 65篇 |
2008年 | 57篇 |
2007年 | 64篇 |
2006年 | 52篇 |
2005年 | 40篇 |
2004年 | 40篇 |
2003年 | 34篇 |
2002年 | 27篇 |
2001年 | 25篇 |
2000年 | 37篇 |
1999年 | 30篇 |
1998年 | 70篇 |
1997年 | 46篇 |
1996年 | 43篇 |
1995年 | 19篇 |
1994年 | 29篇 |
1993年 | 26篇 |
1992年 | 19篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 21篇 |
1988年 | 21篇 |
1987年 | 17篇 |
1986年 | 6篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1976年 | 16篇 |
1975年 | 9篇 |
1973年 | 11篇 |
排序方式: 共有1398条查询结果,搜索用时 15 毫秒
141.
S Matsubara S Akashi K Naitoh Y Nakahara S Hayashi 《Canadian Metallurgical Quarterly》1998,36(10):886-890
A 42-year-old man was admitted because of fever, productive cough, and progressive dyspnea. Chest x-ray films and computed tomographic scans disclosed dense consolidation in the left and right lung fields. No pathogenic agent was found despite extensive bacteriological examinations. Based on serological findings, the patient was given a diagnosis of acute pneumonia caused by Legionella micdadei. It has been reported that Legionnaire's disease is easily complicated by fatal systemic illnesses such as disseminated intravascular coagulation (DIC) and multiple organ failure. In fact, the patient suffered from severe hypotension and DIC on admission. Treatments against systemic complications were started together with intravenous administration of antibiotics including erythromycin. Continuous intravenous cathecolamin, however, failed to alleviate the patient's shock. We therefore applied endotoxin eliminating therapy using a polymyxin-B-column (PMX) and continuous hemofiltration (CHF). The patient recovered from critical shock immediately after the start of PMX, which together with CHF, alleviated his systemic complications. Although the factors responsible for fatal systemic complications in Legionnare's disease are not well-documented, our findings suggested that some substances removable by PMX and CHF play an important role in pathogenesis. 相似文献
142.
Hideaki Itoh Hisaaki Takao Hiroyasu Iwahara 《Journal of the American Ceramic Society》1993,76(11):2889-2895
Reaction sintering behavior of cBN, which is accompanied by the transformation from hBN to cBN in the presence of 30 wt% diamond seed grains, was investigated under high pressure conditions (6.0–7.5 GPa, 1400–1700°C, 0–30 min) using volatile catalysts such as NH4 NO3 , NH4 Cl, and NH2 NH2 . Fully dense sintered compacts having a Vickers microhardness of more than 5000 kg/mm2 were prepared with no residual catalytic solid components. The activation energy for the conversion from hBN to cBN was 200–230 kJ/mol. Adsorbed N2 , H2 , and/or NH x components which were formed by decomposition of these catalysts during high pressure and temperature treatments, would have a favorable kinetic effect on cBN formation from hBN and its simultaneous sintering. 相似文献
143.
Tokyo Electric Power Company, Inc. began operation of the Nishi-Gunma UHV trunk line, the first 1000 kV designed power line in Japan, in April, 1992. This line is expected to be the key line in a major trunk-line system that is being developed. It traverses high-altitude mountainous areas subject to severe environmental and meteorological conditions for a long distance. A system using composite fiber-optic overhead ground wire (OPGW) is constructed to obtain precise information on this line for maintenance purposes. This system comprises three major functions: (1) meteorological and facility's monitoring for gathering meteorological data on such elements as winds, and icing and snow accretion, and for evaluating the corresponding reaction of the components such as conductor tension, and strain in the tower structure; (2) industrial TV monitoring for visual observation of weather, surrounding conditions and site facilities; and (3) fault section location for pinpointing faults quickly and determining the maintenance office that should respond to the faults. This is done by estimating the fault section accurately around the boundaries of the maintenance jurisdictions. This paper describes the development of these functions and results obtained from practical operation 相似文献
144.
H Kikuchi-Hayakawa N Onodera S Matsubara E Yasuda O Chonan R Takahashi F Ishikawa 《Canadian Metallurgical Quarterly》1998,62(9):1688-1692
The effects of soy milk and fermented soy milk on lipid metabolism were studied in aged ovariectomized rats. Twenty 8-mo-old Wistar rats were randomly assigned to four treatment groups: sham-operated + control diet (sham-C); ovariectomized (OVX) + control diet (OVX-C); OVX + soy milk diet (OVX-SM); and OVX + fermented soy milk diet (OVX-FSM). The rats were fed on these diets for 6 weeks. Ovariectomy induced an increase in the plasma cholesterol level by 40%. The plasma total cholesterol level of the OVX-FSM rats was decreased by 20% compared to that of the OVX-C rats. The plasma total cholesterol level of the OVX-SM group was not significantly different from that of the OVX-C and sham-C rats. The plasma triglyceride level of the OVX-FSM rats was lower than that of the sham-C rats. The liver cholesterol content in OVX-SM and OVX-FSM rats was lower than that of the OVX-C rats. The liver triglyceride contents of the sham-C, OVX-SM, and OVX-FSM groups were lower than that of the OVX-C group. Fecal steroid excretion did not differ among the groups. Ovariectomy decreased the uterus weight. The OVX-SM and OVX-FSM groups had the same uterus weights as those of the OVX-C group. Thus, the diet including fermented soy milk prevented the cholesterol elevation induced in rats by ovarian hormone deficiency. 相似文献
145.
Perpendicular magnetic recording using a main-pole-driven perpendicular head was tested using electroless-plated flexible disks. Soft magnetic NiFeP films, also produced by electroless plating, were used as an underlayer of a perpendicular recording medium in this test. Two types of flexible double-layer media, composed of an electrodeless-plated CoNiReP film with two types of NiFeP underlayers with a coercivity of 2 and 5.5 Oe, were fabricated, and their recording characteristics were measured. A recording density value of 75 kFRPI was obtained for the medium with the softer magnetic 2-Oe underlayer, about twice as high a value as that for the medium with the 5.5-Oe underlayer 相似文献
146.
147.
Several samples of rare-earth oxides of perovskite structure were developed and investigated between 1.5 and 10 K. The measurements have shown, that these materials have large magnetic moments and most of them exhibit a magnetic phase transition below 4 K. The heat capacities of the samples have been measured with the adiabatic heat-pulse method. The dependence of the heat capacity on the preparation temperature of the samples has been studied. The results of the measurements are presented in this paper. The possibility of using these materials as regenerator materials in cryocoolers, e.g. pulse-tube refrigerators, is discussed. 相似文献
148.
Hideaki Inaba 《Journal of the American Ceramic Society》1995,78(11):2907-2912
The effect of oxygen nonstoichometry on physical and magnetic properties of a Mn-Zn ferrite has been studied by using annealed samples under various oxygen pressures and temperaure. The dependence of oxygen nonstoichiometry7 on disaccommodation and Fe2+ content changed at the stoichiometric composition, and the lattice parameter became maximum at the stoichiometric composition. These results suggest that Mn-Zn ferrites have two different defect structures: cation vacancies in cation-deficient regons and oxygen vacancies in anion-deficient regions. Initial permeability was maximum and power loss was minimum at the stoichiometric composition, suggesting he importance of the number of point defects for the magnetic properties. 相似文献
149.
Y Murakami Y Ishinaga K Sano R Murakami Y Kinoshita J Kitamura K Kobayashi S Okada K Matsubara T Shimada S Morioka 《Canadian Metallurgical Quarterly》1996,19(6):473-476
BACKGROUND: Platelet activation and coagulation abnormality have been observed during coronary spasm. It is crucial whether platelet activation occurs even during a nonischemic period. HYPOTHESIS: This study was designed to determine whether platelets might be activated across the coronary bed during a nonischemic interval in patients with vasospastic angina. METHODS: Plasma levels of serotonin, 6-keto-prostaglandin F1 alpha, and catecholamines in the aorta and the coronary sinus were simultaneously measured in 16 patients with vasospastic angina and 13 control patients with nonischemic heart disease. RESULTS: None of these patients showed myocardial ischemia during sampling. The difference in transcardiac plasma levels of serotonin in patients with vasospastic angina was significantly higher than that in controls (1.48 +/- 1.08 ng/ml vs. 0.07 +/- 0.12 ng/ml, respectively, p < 0.001). Coronary sinus plasma norepinephrine levels in these two groups were almost the same (204.8 +/- 110.8 pg/ml vs. 190.4 +/- 131.6 pg/ml, respectively). The ratio of 6-keto-prostaglandin F1 alpha in the coronary sinus and the aorta was not different between the two groups (1.17 +/- 0.96 in patients with vasospastic angina vs. 1.15 +/- 0.68 in controls). CONCLUSIONS: These data suggest that platelet activation across the coronary bed should be ascribed to endothelial dysfunction. Lack of compensatory enhancement of prostacyclin production might be concerned with dysfunction of coronary endothelial cells in these patients. 相似文献
150.
Hideki Nishida Kunio Matsumura Hideaki Kurokawa Atsushi Hoshino Seishi Masui 《Journal of the Society for Information Display》2005,13(10):841-848
Abstract— The perfluorocarbons (PFCs) used as etching‐process and chamber‐cleaning gases in the manufacture of LCD devices have a high global‐warming potential and a long atmospheric lifetime. Thus, to voluntarily reduce these environmentally harmful PFCs, in 2001 the Japanese LCD association established the World LCD Industry Cooperation Committee (WLICC), together with its counterpart associations in the Republic of Korea and Taiwan. Since that time involving many discussions, the WLICC reached a consensus on reducing the aggregate absolute PFC emissions to the equivalent of less than 0.82 million metric tons of carbon by 2010. Each association has been taking whatever emission reduction steps it considers best to achieve this goal. Thanks to these measures, the PFC emissions from the Japanese LCD industry have remained at the same level, or less, than those of the year 2000, in spite of the fact that PFC purchases have continually increased. In the interim, the Japanese LCD association has been obtaining experimental data for the 2006 IPCC Inventory Guidelines, which will give the emission factors needed to estimate the PFC emissions. As a result, some data are quite different from emission factors given in the current 2000 Inventory Guidelines. All the data obtained have been submitted to the IPCC to be adopted in the new 2006 Guidelines. 相似文献