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   254篇
  免费   6篇
  国内免费   1篇
电工技术   19篇
化学工业   39篇
金属工艺   2篇
机械仪表   8篇
建筑科学   7篇
能源动力   8篇
轻工业   14篇
水利工程   1篇
石油天然气   4篇
无线电   13篇
一般工业技术   69篇
冶金工业   67篇
原子能技术   5篇
自动化技术   5篇
  2022年   8篇
  2021年   4篇
  2020年   2篇
  2019年   5篇
  2018年   1篇
  2017年   5篇
  2016年   5篇
  2015年   1篇
  2014年   8篇
  2013年   7篇
  2012年   9篇
  2011年   3篇
  2010年   8篇
  2009年   9篇
  2008年   10篇
  2007年   10篇
  2006年   7篇
  2005年   6篇
  2004年   15篇
  2003年   10篇
  2002年   10篇
  2001年   2篇
  2000年   7篇
  1999年   5篇
  1998年   24篇
  1997年   16篇
  1996年   12篇
  1995年   11篇
  1994年   8篇
  1993年   4篇
  1992年   4篇
  1989年   3篇
  1988年   3篇
  1987年   5篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1978年   2篇
  1977年   1篇
  1976年   3篇
  1972年   1篇
排序方式: 共有261条查询结果,搜索用时 15 毫秒
1.
A right-handed patient with a haematoma in the left pulvinar showed impaired stereoacuity. In contrast with previous reports, he did not show peripheral visual extinction or prolonged reaction times for targets on the side contralateral to the lesion.  相似文献   
2.
We consider the effects of spin-phonon coupling within the slave-boson mean-field treatment of the extended t-J model. With no additional assumptions the theory is found to give a semi-quantitative account of the frequency and linewidth anomalies observed for certain phonon modes in Y Ba2Cu3O7 at the superconducting transition. We report also investigations of the role of this coupling in affecting thermodynamic properties and spin dynamics.  相似文献   
3.
4.
5.
Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. After our initial mapping of the FCMD locus to chromosome 9q31-33, we further defined the locus within a region of approximately 5 cM between loci D9S127 and CA246, by homozygosity mapping in patients born to consanguineous marriages and by recombination analyses in other families. We also found evidence for strong linkage disequilibrium between FCMD and a polymorphic microsatellite marker, mfd220, which showed no recombination and a lod score of (Z) 17.49. A "111-bp" allele for the mfd220 locus was observed in 22 (34%) of 64 FCMD chromosomes, but it was present in only 1 of 120 normal chromosomes. This allelic association with FCMD was highly significant (chi 2 = 50.7; P < .0001). Hence, we suspect that the FCMD gene could lie within a few hundred kilobases of the mfd220 locus.  相似文献   
6.
Scanning tunneling microscopy (STM) studies of two-dimensional (2D) cryocrystals 4 He, Kr, Xe) physisorbed on graphite surfaces are presented. Individual helium atoms, usually thought to be invisible with STM, were recently observed on graphite surfaces at a density corresponding to the commensurate solid. Here we show that a local elastic deformation seems to be the principal mechanism responsible to render the atoms visible. Recent tight-binding calculations of the local density of states (LDOS) of graphite which predict the appearance of an energy gap support this picture. I-z curve measurements for the case of 4 He show a sharp drop (increase) of the tunneling current I at a certain tip-surface distance z during retraction (approach) of the tip. This drop (increase) may be associated with the tunneling of a single He adatom, opening new possibilities to study the quantum tunneling of atoms via STM.  相似文献   
7.
Experimental methods and preliminary results of high-precision measurements of the 3 He melting curve in high magnetic fields have been described. The purpose of this work is twofold. One is to establish a reliable millikelvin temperature scale in high fields (T 10 mK, B 15 T), The other is to investigate a high field region of the magnetic phase diagram of solid 3 He by measuring the melting pressure down to temperatures below 1 mK. Besides the two superfluid transitions, the phase transition temperatures between the spin ordered solid and the paramagnetic solid, T HFP , were determined at B = 12 and 10 T with good accuracy, which is an extension of previous measurements up to 8 T. The present T HFP (B) line can not be scaled to that at a higher density with a single Grüneisen parameter, indicating a variation of density dependencies of the multiple-spin exchange interactions.  相似文献   
8.
Endomorphins are neuropeptides that bind strongly to μ-opioid receptors and are considered to play important roles in pain modulation and other biological functions. Two endomorphins have been identified, to date, endomorphine-1 and -2; both are tetrapeptides and differ by only a single amino acid in the third position. Both peptides were isolated from bovine brains; however, their precursor genes have not been identified. In this study, a nucleotide sequence corresponding to the endomorphin-1 peptide in an expressed sequence tag database has been found and a preproendomorphin-like precursor peptide from human brain complementary DNA (cDNA) has been cloned. The cDNA consists of nucleotide sequences of two already annotated predicted genes, and the putative peptide differs by one amino acid from the isolated endomorphin peptides. It is proposed herein that there is the possibility of unknown short proteins or peptide precursors being missed by automated gene prediction programs based on similarities of known protein sequences. A novel concept of how to produce endomorphins from a similar peptide is described. The oxidatively modified base might provide a clue for understanding discrepancies between nucleotide sequences on the genome and those on cDNAs.  相似文献   
9.
Explosion sensitivity involves many complex factors. A theory for evaluating and a method for testing have to be established. We have proposed an explosion sensitivity theory for explosive substances and have also tested the evaluating method. The results of our research reveal a satisfactory mutual relation between both theoretical and experimental values.  相似文献   
10.
Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807&nbsp;nm using an electromagnetic...  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