全文获取类型
收费全文 | 429篇 |
免费 | 64篇 |
专业分类
化学工业 | 168篇 |
金属工艺 | 4篇 |
机械仪表 | 20篇 |
建筑科学 | 6篇 |
能源动力 | 16篇 |
轻工业 | 162篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 12篇 |
一般工业技术 | 46篇 |
冶金工业 | 14篇 |
自动化技术 | 41篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 24篇 |
2021年 | 37篇 |
2020年 | 21篇 |
2019年 | 33篇 |
2018年 | 29篇 |
2017年 | 32篇 |
2016年 | 36篇 |
2015年 | 18篇 |
2014年 | 26篇 |
2013年 | 29篇 |
2012年 | 26篇 |
2011年 | 33篇 |
2010年 | 26篇 |
2009年 | 22篇 |
2008年 | 25篇 |
2007年 | 11篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1978年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有493条查询结果,搜索用时 15 毫秒
1.
The paper proposes and describes several tools enabling their user to estimate the efficiency of Pascal or C-like programs. The approach consists of generating symbolic formulas expressing the efficiency of the programs being analyzed. The formulas are applicable to a variety of compiler-machine configurations. The actual numeric values of the variables in the symbolic formula are determined using linear programming techniques. The proposed approach reduces considerably the amount of benchmarking needed to analyze programs. Several examples are presented showing the applicability of the tools. The effort necessary to implement them is considerably reduced by the combined usage of Prolog and a symbolic formula manipulation package (Maple). 相似文献
2.
Zinn-Justin Sophie; Pillet Laurence; Ducancel Frdric; Thomas Aline; Smith Jeremy C.; Boulain Jean-Claude; Mnez Andr 《Protein engineering, design & selection : PEDS》1994,7(7):917-923
Structural features associated with the ability of a monoclonalantibody (mAb) to discriminate between protein variants areidentified and engineered. The variants are the curaremimetictoxin from Naja nigricollis and erabutoxin a or b from Laticaudasemifasciata which differ from each other by 16 substitutionsand one insertion. The neutralizing mAb M1 recognizes with highaffinity a topographical epitope on the surface of toxin , butfails to recognize the erabutoxins although they possess mostof the residues forming the presumed epitope. Examinations ofthe toxin and erabutoxin 3-D structures and molecular dynamicssimulations reveal several differences between the variants.In particular, the region involving the ß-turn 1724is organized differently. Analysis of the differences foundin this region suggests that the insertion (or deletion) atposition 18 of the variant amino add sequences is particularlyimportant in determining the differential cross-reactivity.To test this proposal, residue 18 was deleted in one erabutoxinusing sitedirected mutagenesis, and the biological propertiesof the resulting mutant were examined. We found that full antigenicitywas restored in the previously unrecognized variant. The implicationsof this finding are discussed. 相似文献
3.
4.
5.
Emilly Sigoli Rosangela Aline Anto Maria Paula Guerreiro Tatiana Oliveira Passos de Araújo Patty Karina dos Santos Daiane Leite da Roza Dilson E. Rassier Anabelle Silva Cornachione 《International journal of molecular sciences》2022,23(9)
Duchenne muscular dystrophy (DMD) is a muscle disease characterized by the absence of the protein dystrophin, which causes a loss of sarcolemma integrity, determining recurrent muscle injuries, decrease in muscle function, and progressive degeneration. Currently, there is a need for therapeutic treatments to improve the quality of life of DMD patients. Here, we investigated the effects of a low-intensity aerobic training (37 sessions) on satellite cells, peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α protein (PGC-1α), and different types of fibers of the psoas muscle from mdx mice (DMD experimental model). Wildtype and mdx mice were randomly divided into sedentary and trained groups (n = 24). Trained animals were subjected to 37 sessions of low-intensity running on a motorized treadmill. Subsequently, the psoas muscle was excised and analyzed by immunofluorescence for dystrophin, satellite cells, myosin heavy chain (MHC), and PGC-1α content. The minimal Feret’s diameters of the fibers were measured, and light microscopy was applied to observe general morphological features of the muscles. The training (37 sessions) improved morphological features in muscles from mdx mice and caused an increase in the number of quiescent/activated satellite cells. It also increased the content of PGC-1α in the mdx group. We concluded that low-intensity aerobic exercise (37 sessions) was able to reverse deleterious changes determined by DMD. 相似文献
6.
Aline Simo Bonex Mwakikunga Bertrand T. Sone Basil Julies Reginaldt Madjoe Malik Maaza 《International Journal of Hydrogen Energy》2014
Mott-type VO2 oxide nanobelts are demonstrated to be effective hydrogen gas sensors at room temperature. These nanobelts, synthesized by hydrothermal process and exhibiting the VO2 (A) crystallographic phase, display room temperature H2 sensitivity as low as 0.17 ppm. The nanobelts (ultralong belt-like) nanostructures could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides and for building functional devices based on individual nanobelts. 相似文献
7.
Aline Carla Farrapo Xavier Marli Leite de Moraes Marystela Ferreira 《Materials science & engineering. C, Materials for biological applications》2013,33(3):1193-1196
Layer-by-layer (LbL) films have been exploited in drug delivery systems that may be used in the form of patches, but the encapsulation of poor water soluble drugs and their release with a controlled rate are still major challenges to be faced. In this paper, we demonstrate the controlled release of aloin (barbaloin), an important component of the widely used Aloe vera, encapsulated into liposomes and immobilized in LbL films with a polyelectrolyte. With a systematic study using fluorescence spectroscopy of aloin release from solutions and from LbL films with different phospholipid liposomes, we inferred that optimized release was achieved with aloin incorporated into palmitoyl oleyl phosphatidyl glycerol (POPG) or dipalmitoyl phosphatidyl glycerol (DPPG) liposomes immobilized in LbL films. Significantly, with this optimized system aloin was almost completely released within 30 h, with a small release rate at the end, which followed a sharp release in the first 5 h. Upon comparing the rates of the distinct systems, we conclude that the main factors controlling the release are the electrostatic interactions involving the negatively charged phospholipids. Because these interactions can be tuned in LbL films, the approach used here opens the way for new drug delivery systems to be developed with fine control of the drug release. 相似文献
8.
Karin Förster-Fromme Regina Schuster-Wolff-Bühring Annette Hartwig Aline Holder Andreas Schwiertz Stephan C. Bischoff Jörg Hinrichs 《International Dairy Journal》2011,21(12):940-948
In a novel pilot plant scale process, lactulose was synthesized enzymatically, operating a maximum batch volume of 170 L. The test product was subjected to a randomized, double-blind, placebo-controlled pilot feeding study. Participants consumed a milk serum drink for 14 days, equalling a daily intake of about 3 g d−1 galactosyl-fructoses. Additionally, the effect of industrially produced lactulose and a placebo drink without lactulose was determined. So far, clinical studies on the prebiotic action of lactulose only focussed on the effects of industrially generated lactulose. The intake of enzymatically synthesized lactulose significantly increased (p = 0.001) faecal bifidobacterial counts, while there was no difference with industrially produced lactulose. Analysis of the compounds showed that the drink with enzymatically synthesized lactulose contained an additional disaccharide, β-1,1-galactosyl-fructose. Presumably, this sugar has a bifidogenic effect and may represent a novel prebiotic. 相似文献
9.
Maternal Flaxseed Oil During Lactation Enhances Bone Development in Male Rat Pups 总被引:1,自引:0,他引:1 下载免费PDF全文
Aline D’Avila Pereira Danielle Cavalcante Ribeiro Fernanda Carvalho de Santana Aline de Sousa dos Santos Jorge Mancini-Filho Celly Cristina Alves do Nascimento-Saba Luis Guillermo Coca Velarde Carlos Alberto Soares da Costa Gilson Teles Boaventura 《Lipids》2016,51(8):923-929
Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra‐abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha‐linolenic and eicosapentaenoic were higher (p < 0.0001). Intra‐abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (?44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups. 相似文献
10.
Aline Guimont Emmanuel Beyou Pierre Alcouffe Philippe Cassagnau Anatoli Serghei Gregory Martin Philippe Sonntag 《Polymer》2014
Covalent functionalization of pentadecane-decorated thermally reduced graphite oxide (GO) sheets has been studied as a tool for the preparation of polyethylene/GO composites exhibiting rheological and electrical percolation thresholds. It was accomplished through pentadecane based radical addition onto unsaturated bonds located on the GO sheets' surface using dicumyl peroxide as hydrogen abstractor. This chemical functionalization influences the affinity of the formed pentadecane grafted GO sheets for various solvents. Then, the compounding of the composites pentadecane grafted GO/PE was performed at a processing temperature of 140 °C with 25, 20, 15, 10, 8 and 5 wt% loadings. Rheological and electrical percolation thresholds were found between 10 and 15 wt% for polyethylene/pentadecane functionalized graphene oxide composites while the composite graphite/PE at the same loading percentage did not reach any percolation threshold. 相似文献