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   10841篇
  免费   144篇
  国内免费   11篇
电工技术   89篇
综合类   5篇
化学工业   1227篇
金属工艺   163篇
机械仪表   227篇
建筑科学   281篇
矿业工程   55篇
能源动力   164篇
轻工业   696篇
水利工程   69篇
石油天然气   20篇
武器工业   2篇
无线电   747篇
一般工业技术   1342篇
冶金工业   5059篇
原子能技术   81篇
自动化技术   769篇
  2022年   48篇
  2021年   54篇
  2020年   40篇
  2019年   55篇
  2018年   78篇
  2017年   73篇
  2016年   85篇
  2015年   78篇
  2014年   100篇
  2013年   354篇
  2012年   193篇
  2011年   252篇
  2010年   252篇
  2009年   238篇
  2008年   256篇
  2007年   250篇
  2006年   213篇
  2005年   237篇
  2004年   178篇
  2003年   196篇
  2002年   189篇
  2001年   159篇
  2000年   173篇
  1999年   226篇
  1998年   1455篇
  1997年   946篇
  1996年   627篇
  1995年   425篇
  1994年   371篇
  1993年   395篇
  1992年   136篇
  1991年   135篇
  1990年   145篇
  1989年   161篇
  1988年   149篇
  1987年   116篇
  1986年   102篇
  1985年   135篇
  1984年   113篇
  1983年   92篇
  1982年   88篇
  1981年   83篇
  1980年   94篇
  1979年   79篇
  1978年   95篇
  1977年   179篇
  1976年   380篇
  1975年   62篇
  1974年   63篇
  1973年   58篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Wood shaving samples were heated in both cubic baskets and in a previously described system realising the conditions of the ‘infinite slab’ in thermal ignition. Results from the two sets of experiment were found to be totally consistent with each other.  相似文献   
12.
13.
We cloned the murine full-length cDNA encoding Ahch, the mouse homologue of DAX1 (DSS-AHC Region on Human X Chromosome, Gene1) which is the gene responsible for human X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH). Sequence analysis revealed that the murine and human cDNAs have 65% aa identity and 75% aa similarity overall. The cysteine residues in the putative DNA binding domain, which may interact with Zn2+ ions to form zinc fingers, are 100% conserved between the two species, indicating that the novel zinc-finger structures in DAX1 may be functional. In addition, mouse interspecific backcrosses show that the Ahch gene is closely linked to the glycerol kinase locus, GyK, on the mouse X chromosome, indicating that the order of the loci is conserved in this syntenic region between mouse and human.  相似文献   
14.
15.
A new method of impulse magnetic therapy was studied in the treatment of neurologic complications of osteochondrosis and deforming spondylarthrosis in 225 patients with neurologic manifestations of pathology in cervical or sacral parts of spinal column. To assess the results obtained, EMG, thermography and determination of the levels of blood plasma lipid peroxidation were used.  相似文献   
16.
A new type of fiber laser modelocking is examined where a phase modulator is driven asynchronously with respect to a harmonic of the roundtrip cavity frequency. An asynchronous drive is able to produce high repetition rate (>1 GHz) soliton pulses that are shorter than the classic, active modelocking pulse width limit. It is shown that with a proper choice of fiber parameters, noise cleanup and soliton pulse shaping can be obtained using filtering and asynchronous phase modulation. Limits of asynchronous detuning are derived and a comparison with the parameters ranges for synchronous phase modulation is also presented  相似文献   
17.
18.
19.
The present study investigates 1085 previously untreated patients with squamous cell carcinoma of the head and neck for factors that influence recurrence following treatment with definitive radiotherapy. In the second part of this study, those diagnosed with recurrence were studied with regard to treatment and were further analysed with regard to identification of prognostic factors which may affect outcome in the patient who actually develops a recurrence.  相似文献   
20.
Experiments using high-efficiency neutron detectors have detected neutron emission from various forms of Pd and Ti metal in pressurized D2 gas cells and D2O electrolysis cells. Four independent neutron detectors based on3He gas tubes were used. Both random neutrons (0.05–0.2 n/s) and time-correlated neutron bursts (10–280 n) of 100-s duration were measured using time-correlation counting techniques. The majority of the neutron burst events occurred at –30°C as the samples were warming up from the liquid nitrogen temperature.  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