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   89篇
  免费   5篇
电工技术   4篇
化学工业   21篇
金属工艺   2篇
机械仪表   1篇
建筑科学   1篇
轻工业   7篇
水利工程   1篇
无线电   10篇
一般工业技术   20篇
冶金工业   18篇
自动化技术   9篇
  2022年   2篇
  2021年   6篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   4篇
  2016年   2篇
  2015年   5篇
  2014年   7篇
  2013年   4篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2009年   3篇
  2008年   3篇
  2007年   1篇
  2006年   3篇
  2005年   2篇
  2004年   1篇
  2003年   3篇
  2002年   6篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   6篇
  1997年   4篇
  1996年   1篇
  1995年   2篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1980年   2篇
  1977年   2篇
  1976年   1篇
  1970年   1篇
排序方式: 共有94条查询结果,搜索用时 609 毫秒
1.
2.
Circular RNAs (circRNAs) are a large class of RNAs with regulatory functions within cells. We recently showed that circSMARCA5 is a tumor suppressor in glioblastoma multiforme (GBM) and acts as a decoy for Serine and Arginine Rich Splicing Factor 1 (SRSF1) through six predicted binding sites (BSs). Here we characterized RNA motifs functionally involved in the interaction between circSMARCA5 and SRSF1. Three different circSMARCA5 molecules (Mut1, Mut2, Mut3), each mutated in two predicted SRSF1 BSs at once, were obtained through PCR-based replacement of wild-type (WT) BS sequences and cloned in three independent pcDNA3 vectors. Mut1 significantly decreased its capability to interact with SRSF1 as compared to WT, based on the RNA immunoprecipitation assay. In silico analysis through the “Find Individual Motif Occurrences” (FIMO) algorithm showed GAUGAA as an experimentally validated SRSF1 binding motif significantly overrepresented within both predicted SRSF1 BSs mutated in Mut1 (q-value = 0.0011). U87MG and CAS-1, transfected with Mut1, significantly increased their migration with respect to controls transfected with WT, as revealed by the cell exclusion zone assay. Immortalized human brain microvascular endothelial cells (IM-HBMEC) exposed to conditioned medium (CM) harvested from U87MG and CAS-1 transfected with Mut1 significantly sprouted more than those treated with CM harvested from U87MG and CAS-1 transfected with WT, as shown by the tube formation assay. qRT-PCR showed that the intracellular pro- to anti-angiogenic Vascular Endothelial Growth Factor A (VEGFA) mRNA isoform ratio and the amount of total VEGFA mRNA secreted in CM significantly increased in Mut1-transfected CAS-1 as compared to controls transfected with WT. Our data suggest that GAUGAA is the RNA motif responsible for the interaction between circSMARCA5 and SRSF1 as well as for the circSMARCA5-mediated control of GBM cell migration and angiogenic potential.  相似文献   
3.
Journal of Applied Electrochemistry - In this paper, additive layer-by-layer fabrication of a fully screen printed monolithic supercapacitor exhibiting performance comparable with supercapacitors...  相似文献   
4.
"Tanks to Tumors" succeeded in bringing several different communities together--medical, military, academic, industrial, and engineering. They worked together in panels to determine how the United States might adopt thermal imaging diagnostic technology in an orderly and demonstrable way for the early detection of breast cancer and other conditions. The panel recommendations will serve to guide the transition of military technology developments in ATR, the VDL, and IR sensors to the civilian medical community. The result will be a new tool in the war against breast cancer--a major benefit to the military and civilian population. A CD of the workshop proceedings is available at no cost through Advanced Concepts Analysis, Falls Church, Virginia; +1 703 914 9237; e-mail: diakides@erols.com.  相似文献   
5.
The analysis of FTIR absorption spectra of CO and of12CO-13CO isotopic mixtures is reported for gold catalysts supported on a number of oxides. Relationships between the nanostructure and the CO adsorbing properties of the different gold catalysts are discussed. In particular, on titania supported gold, where particles of metallic nature are present, two kinds of surface sites do adsorb CO, the 6-coordinated corners and the 7- coordinated edges, while the terrace sites, 8 coordinated, are not able to adsorb even at 90 K. Moreover, the adsorbing sites are not isolated, but mutually interacting. On zirconia supported gold, the adsorbing sites, mutually interacting, are exposed at the surface of non metallic gold nanoclusters. Almost isolated and negatively charged gold adsorbing nanoclusters have been highlighted on the sample supported on reduced ceria, and, finally, isolated cationic sites on oxidized gold supported on a mixed ceria-titania oxide have been detected.  相似文献   
6.
Growing aligned carbon nanotubes (CNTs) on electrically conducting and/or optically transparent materials is potentially useful for accessing CNT properties through electrical and optical stimuli. Here, we report a new approach to growing aligned bundles of multiwalled CNTs on a porous back contact of optically transparent and electrically conducting indium tin oxide (ITO) films on silicon and silica substrates without the use of a predeposited catalyst. CNTs grow from a xylene/ferrocene mixture, which traverses through the pores in the thin ITO film, and decomposes on an interfacial silica layer formed via the reaction between ITO and the Si substrate. The CNTs inherit the topography of the silica substrate, enabling back‐contact formation for CNTs grown in any predetermined orientation. These features can be harnessed to form CNT contacts with other substrate materials which, upon reduction by Si, results in a conducting interfacial layer. The ITO‐contacted CNTs exhibit thermally activated ohmic behavior across a 100 ± 10 meV barrier at electric fields below ~ 100 V cm–1 due to carrier transport through the outermost shells of the CNTs. At higher electric fields, we observe superlinear behavior due to carrier tunneling and transport through the inner graphene shells. Our findings open up new possibilities for integrating CNTs with Si‐based device technologies.  相似文献   
7.
Electrically conductive elastomeric nanocomposites containing carbon nanotubes (CNT) and polyaniline (PANI) are reported in the present investigation. The synthesis procedure included an in situ inverse emulsion polymerization of aniline doped with dodecylbenzene sulfonic acid (DBSA) in the presence of CNT and dissolved styrene‐isoprene‐styrene (SIS) block copolymer. The PANI synthesis step was carried out by applying ultrasonic energy. The dispersions obtained were processed by two methods: a recently developed precipitation‐filtration procedure, and a conventional drop‐cast procedure. The techniques developed resulted in homogeneous exfoliated PANI coated nanotubes within the elastomeric matrix. The presence of CNT/PANI in the SIS elastomeric matrix affects thermal, mechanical, and electrical properties of the nanocomposites. The formation of continuous three‐dimensional CNT/PANI networks prepared via the precipitation‐filtration method enhances the nanocomposite properties. Contrarily, the intermittent three‐dimensional network prepared by conventional drop‐cast method leads to inferior properties. Nanocomposites produced by both techniques are observed by HRSEM. The two processing techniques result in different structures, which affect the physical properties of the materials produced. A relatively low percolation threshold for both methods was determined. The Young's modulus of the SIS/CNT/PANI significantly increased in the presence of CNT. The precipitation‐filtration technique yields an improved nanocomposite product compared to the drop‐cast route. POLYM. COMPOS., 35:788–794, 2014. © 2013 Society of Plastics Engineers  相似文献   
8.
We describe the use of weight-bearing foot tomograms. The outline of the food is drawn so as the axes of the metatarsal beyond the toes on the AP plain radiogram and the tomograms are done successively on each metatarsal. This morphological, but also functional, analysis enables exact diagnosis of excessive loading on the metatarsal head. This procedure is used in case of metatarsalgia with normal metatarsal length and in late post-traumatic sequellae of the forefoot. Surgical correction can then be precisely performed.  相似文献   
9.
Recent research on development of the implantable artificial pancreas for treatment of diabetes is reviewed, based on a Medline literature search that focused on glucose sensors, insulin pumps, and pump control systems. To achieve a closed feedback loop, a clinically applicable implantable artificial pancreas requires miniaturization and coordination of three components: an insulin pump, a blood glucose monitor, and a control system. Recent clinical studies have demonstrated that implantable insulin pumps are feasible for satisfactory control of diabetes for over a year, with the major complication being obstruction of the infusion catheter. Research on continuous glucose sensors has predominantly used the glucose-oxidase reaction or near-infrared light spectroscopy. Implantable glucose oxidase sensors have been limited by local factors causing unstable signal output, whereas optical sensors must overcome interference by substances with absorption spectra similar to glucose. Investigators have developed control algorithms in an effort to stabilize operation of the integrated artificial pancreas in the face of variations in sensor output and pump function. The ultimate goals of fully automatic glucose control by an artificial pancreas include prevention or delay of chronic complications of diabetes, lowered risk of hypoglycemia, and less patient inconvenience and discomfort than with multiple daily glucose self-tests and insulin injection. The recent developments of optical glucose sensing, radiotelemetry systems to link pump and sensor, and miniaturization and refinement of insulin pumps are significant steps toward a clinically applicable artificial pancreas.  相似文献   
10.
Following a short discussion of the anatomopathological and clinical features of respiratory signs during systemic l.e., some clinical cases in which involvement of the respiratory system (pleural and/or parenchymal) was observed alone or was clearly predominant are reported. The cases also presented some unusual clinical characteristics. Clinical investigations must be extended to the systemic mesenchyma in the presence of pleuritis or pulmonary fibrosis of unclear aetiology, even where there are no extra-respiratory signs of S.L.E.  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