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141.
G. A. Galstyan 《Metallurgist》1968,12(11):602-602
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144.
G Seyoum MC Robertson TV Persaud JA Paterson RP Shiu 《Canadian Metallurgical Quarterly》1999,160(2):231-237
Rat placental lactogen-I (rPL-I), the first prolactin-like hormone expressed in the placenta during pregnancy in the rat, is known to influence maternal functions. In the present study, we have investigated the effects of rPL-I on the growth and development of cultured whole rat embryos. Rat embryos, with or without ectoplacental cone (EPC) attached, were explanted at day 9 of gestation. After 48 h of culture, the embryos, enclosed by the yolk sacs, were assessed by the presence of visible heart contractions ('heart beats'), crown-rump length (CRL) and yolk sac diameter (YSD). When intact embryos with EPC were cultured, the concentrations of rPL-I and rPL-II (products of EPC) in the medium were 850+/-841 and 92+/-181 ng/ml respectively (means+/-s.e.m.). In embryo cultures with the EPC removed, rPL-I levels decreased to=10 ng/ml, and only 70% of the embryos were viable, with visible heart beats. In the viable embryos, both CRL and embryonic DNA synthesis were reduced compared with controls, and the addition of rPL-I (1 microg/ml) did not prevent this reduction. YSD and yolk sac DNA synthesis were also reduced compared with control embryos, and the addition of rPL-I significantly prevented this decrease by 45%. In embryos cultured without EPC in the presence of neutralizing rabbit anti-rat prolactin serum (anti-rPRL), embryonic and yolk sac DNA synthesis were reduced by 35% compared with embryos exposed to normal rabbit serum. Addition of rPL-I significantly increased (P<0.05) embryonic and yolk sac growth. Thus the effects of rPL-I on embryo growth could only be seen in the absence of prolactin. The addition of human prolactin in the presence of anti-rPRL also resulted in significant increases (P<0.05) in embryonic DNA synthesis and CRL. These results suggest that rPL-I may substitute for prolactin to influence the growth of the rat embryo. 相似文献
145.
陶瓷窑炉的燃料与节能技术 总被引:1,自引:0,他引:1
本文对国内外陶瓷工业窑炉的燃料,燃烧现状及其节能技术作了简介,并对窑炉的节能效果进行评价。 相似文献
146.
以再现手指握拳的动作姿态和运动轨迹为主要目标,探讨一种带关节仿生手指的优化设计,重点讨论了手指运动矩阵的建立,预期目标的采集,仿生手指的结构模拟,确定优化目标与约束函数,求数学模型的副近解等问题。 相似文献
147.
VE Archer AD Renzetti RS Doggett JQ Jarvis TV Colby 《Canadian Metallurgical Quarterly》1998,40(5):460-474
Many uranium miners have been disabled by and died of pulmonary fibrosis that was not recognized as an occupational disease. A review of animal studies, complications from whole body irradiation, pulmonary function, and mortality studies of uranium miners led us to suspect radiation-induced chronic diffuse interstitial fibrosis in miners who had inhaled excessive radon progeny. A selected group of uranium miners (22) with severe respiratory disease (but no rounded nodules in chest films) were studied. Lung tissue from five disclosed severe diffuse interstitial fibrosis, with "honeycomb lung" in all. Some also had small anthrasilicotic nodules and birefringent crystals. Although quartz crystals probably contributed, we concluded that the predominant injurious agent in these cases was alpha particles from radon progeny. This disease, after a long latent period, usually results in pulmonary hypertension, shortness of breath, and death by cardiopulmonary failure. 相似文献
148.
Idiopathic pulmonary fibrosis (IPF) is generally defined as a progressive, fibrosing inflammatory disease of the lung parenchyma of unknown cause. It is characterized by slowly increasing dyspnea, diffuse interstitial lung infiltrates, restrictive lung dysfunction, and impaired gas exchange. Ultimately, it is fatal in most patients, and treatment options remain unsatisfactory. The advent of high-resolution computed tomography of the chest and modifications in the histopathologic classification of interstitial pneumonias have reshaped the concept of IPF. Although initially thought to be a relatively specific clinicopathologic entity, it seems likely that IPF as previously defined is a heterogeneous disorder consisting of several clinicopathologic entities with differing histopathologic patterns, clinical course, response to therapy, and prognosis. The most common histologic pattern in cases previously defined as IPF is usual interstitial pneumonia, which is associated with a median survival of less than 3 years. For accurate prognosis and optimal management of patients, the clinician should attempt to be as precise as possible in distinguishing various clinicopathologic entities that have been included under the clinical heading of IPF. In the future, we recommend that the use of the term "idiopathic pulmonary fibrosis" be restricted to patients with usual interstitial pneumonia and that clinicians recognize the fact that other idiopathic interstitial pneumonias do not have the same prognostic effect traditionally ascribed to IPF. 相似文献
149.
刍议计算机反病毒技术的产生、发展和现状 总被引:1,自引:0,他引:1
随着计算机病毒越来越猖撅,计算机安全越来越受到人们的重视,计算机反病毒技术也发展得越来越快。论文介绍了计算机反病毒的产生,介绍了当今最新最先进的计算机反病毒技术,有CPU反病毒技术、病毒码扫描技术、实时反病毒技术和虚拟机技术等。 相似文献
150.
随着因特网的发展与普及,产生了更多的商机,造就出各种不同型态的网络商店,同时也衍生出不同的付费方式,例如电子钱包、网上银行、在线ATM等等。面对众多付费方式的选择时,不同市场必须选搭各种付费制度,当市场导入新制付费制度后,除了增加新制付费制度给予消费者选择外,并能让原来的市场消费者对于新付费机制产生消费学习性,最终消费者会依个人意志选择最利己的付费机制。通过调查分析,网络商店提供付费机制使用的便利性、易用性、实时性、精确性、安全性对消费者态度有显著正向的影响。 相似文献