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91.
A research study and discussion of antiinterferon immunoglobulin in the treatment of rheumatoid arthritis and systemic lupus erythematosus, and its possible value in the treatment of allergic diseases, autoimmune diseases and other diseases where it is presumed there may be an autoimmune genesis.  相似文献   
92.
The purpose of this study was to assess the possibility of measuring directional microphone hearing aids (DMHAs) using standard hearing aid test instruments in a sound field environment. The use of DMHAs is increasing and research has shown that under certain difficult listening situations, superior results are obtained by hearing impaired individuals with directional versus omnidirectional microphone arrangements. However, valid electroacoustic evaluation of the DMHAs cannot be accomplished using the conventional hearing aid test box. The ideal environment for such evaluations is an anechoic chamber, a facility not found in most audiological clinics. Results show that if the proper precautions are observed, the electroacoustic characteristics of DMHAs can be measured in a sound field environment using conventional hearing aid test instrumentation. Validation of this procedure was carried out by comparing sound field results with those obtained in an anechoic chamber.  相似文献   
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The reaction steps leading from the intermediate adenosine 5'-phosphosulfate (APS) to sulfide within the higher plant reductive sulfate assimilation pathway are the subject of controversy. Two pathways have been proposed: a 'bound intermediate' pathway in which the sulfo group of APS is first transferred by APS sulfotransferase to a carrier molecule to form a bound sulfite intermediate and is then further reduced by thiosulfonate reductase to bound sulfide; and a 'free intermediate' pathway in which APS is further activated to 3'-phosphoadenosine 5'-phosphosulfate (PAPS) by APS kinase followed by reduction of the sulfo group to free sulfite by PAPS reductase. Sulfite is then reduced to free sulfide by sulfite reductase. Sulfide, either free or bound, is then incorporated into organic form (as cysteine) by the enzyme O-acetylserine (thiol) lyase. In order to better characterize the pathway we attempted to clone PAPS reductase cDNAs by functional complementation of an Escherichia coli cysH mutant to prototrophy. We found no evidence for PAPS reductase cDNAs but did identify cDNAs that encode a small family of novel, chloroplast-localized proteins with APS reductase activity that are new members of the thioredoxin superfamily. We show here that the thioredoxin domain of these proteins is functional. We speculate that rather than proceeding via either of the pathways proposed above, reductive sulfate assimilation proceeds via the reduction of APS to sulfite by APS reductase and the subsequent reduction of sulfite to sulfide by sulfite reductase. In this scheme the product of the APS kinase reaction, PAPS, is not a direct intermediate in the pathway but rather acts as a substrate for sulfotransferase action and perhaps as a store of activated sulfate that can be returned to the pathway as APS via phosphohydrolase action on PAPS. Interactions between enzyme isoforms within the chloroplast stroma may bring about substrate channeling of APS and contribute to the partitioning of APS between sulfotransferase reactions on the one hand and the synthesis of cysteine and related metabolites via the reductive sulfate assimilation pathway on the other.  相似文献   
96.
OBJECTIVE: To determine the effect on the uptake of breast screening of a personalized letter from the general practitioner recommending mammography, sent to coincide with an invitation from the NHS breast screening programme. DESIGN: Randomised control trial with stratification of prognostic variables. SETTING: A group practice in Hackney, east London. SUBJECTS: 473 women invited for breast screening by the City and East London Breast Screening Service. OUTCOME MEASURE: Attendance for mammography. RESULTS: All women in the randomised trial were followed up; 134 of 236 (57%) randomly allocated to receive the prompting letter attended for mammography compared with 120 of 234 (51%) controls This difference was not significant (chi 2 = 1.43, p = 0.23) CONCLUSION: Personal recommendation by a letter prompting attendance for mammography from the general practitioner known best to women due to be screened did not improve uptake of breast screening in this east London practice. Other strategies are needed to increase uptake of mammography in inner cities.  相似文献   
97.
Light microscopy was used to study the structure and cellular organization of the osphradial organ of the pulmonary mollusque L. stagnalis. The osphradium unites the epithelial canal and the ganglion consisting of two cell populations. On the internal surface of the V-shaped osphradial canal there are three zones of cells: secretory, villous and epithelial. The villous zone of the canal is related with sensory bipolar and multipolar neurons of the ganglion. The irritation percepted by these cells seems to be transferred through numerous zones of neuropile to large unipolar neurons of the ganglion cortical layer.  相似文献   
98.
组合圆锥-圆柱形壳形式的钢贮罐是一种常见的用于储存液体的压力罐。大部分此类压力罐的破坏都由于钢壳的失稳而引起。引起这些破坏的主要原因是没有适当的设计方法来对这类结构进行设计。在本次研究中,提出了简化的设计方法,以保证静水加载的组合钢罐在发生屈曲时的安全。应用非线性有限元模型进行数值模拟,对大变形和几何缺陷对钢罐稳定性的破坏作用进行分析。采用有限元计算结果与非线性回归分析建立函数,将壳的总应力与膜应力关联起来。采用算例说明了所提议设计方法的应用。  相似文献   
99.
单光纤光栅实现位移、温度同时区分测量   总被引:10,自引:1,他引:9  
结合光纤光栅悬臂梁调谐的特点,采用悬臂梁矩形梁结构,将光纤光栅粘贴在悬臂梁侧面,利用反射波的带宽对应变敏感而对温度不敏感的特性解调悬臂梁自由端的垂直位移,和反射波的中心波长对温度敏感而对应变不敏感的特性解调温度,成功地实现了对位移和温度的同时测量.基于光谱分析仪0.1 nm的光谱分辨率,实验可得到位移、温度同时区分测量系统的带宽随位移变化的灵敏度为0.153 nm/mm,位移分辨率为0.193 mm,位移测量范围可达6.15 mm;中心波长随温度变化的灵敏度为0.029 nm/℃,温度分辨率为3.4℃,温度测量范围为45℃.实验结果与理论分析基本一致.  相似文献   
100.
To elicit the mechanism of facilitating the mammals' adaptation to repeated changed gravity influence, the pituitary, thyroid, blood and bone marrow were investigated morphologically in rats exposed to single and repeated hypergravity (2 g) and Coriolis accelerations for 5 days during rotation on centrifuge. No distinct difference in blood and bone marrow cytology was determined after single and repeated exposure to 2 g and the Coriolis accelerations. Compared to single and in contrast to single and repeated exposures to the Coriolis accelerations, a repeated 2 g influence produced some structural changes in somatotropic cells of the pituitary and thyroid parenchyma of the thyroid. These changes were indicative of a significant intensification of synthesis and secretion of somatotropic and thyroid hormones. Elevated functional activity of the somatotropic cells and thyroid parenchyma during repeated exposure to 2 g appears to be a part of mechanism that makes adaptation to repeated hypergravity easier and points to the ability of mammals "to remember" changed gravity. It also advocates for the potentiality of intermittent centrifugation as a means of generating artificial gravity forces in space flight.  相似文献   
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