全文获取类型
收费全文 | 251篇 |
免费 | 14篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 68篇 |
金属工艺 | 5篇 |
机械仪表 | 2篇 |
建筑科学 | 14篇 |
能源动力 | 11篇 |
轻工业 | 15篇 |
水利工程 | 7篇 |
无线电 | 19篇 |
一般工业技术 | 42篇 |
冶金工业 | 52篇 |
原子能技术 | 4篇 |
自动化技术 | 24篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 11篇 |
2012年 | 10篇 |
2011年 | 13篇 |
2010年 | 22篇 |
2009年 | 10篇 |
2008年 | 4篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1970年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 0 毫秒
1.
The adsorption behavior of cadmium, copper and lead ions on holocellulosic materials containing various levels of polyacrylonitrile and poly(acrylic acid) grafts was examined. The amount of metal ions adsorbed per gram of the modified cellulosic substrate depended on the metal ion type, the nature and level of the incorporated graft polymer. In all cases grafting increased the metal ion-binding capacity of the cellulosic materials (by up to 50% for Cu (II) ions). The influence of temperature and initial metal ions concentration on the sorption behavior of the metal ions on the composite materials was investigated. 相似文献
2.
Pu J Paik DS Meng X Roos JE Rubin GD 《IEEE transactions on visualization and computer graphics》2011,17(1):115-124
In three-dimensional medical imaging, segmentation of specific anatomy structure is often a preprocessing step for computer-aided detection/diagnosis (CAD) purposes, and its performance has a significant impact on diagnosis of diseases as well as objective quantitative assessment of therapeutic efficacy. However, the existence of various diseases, image noise or artifacts, and individual anatomical variety generally impose a challenge for accurate segmentation of specific structures. To address these problems, a shape analysis strategy termed "break-and-repair" is presented in this study to facilitate automated medical image segmentation. Similar to surface approximation using a limited number of control points, the basic idea is to remove problematic regions and then estimate a smooth and complete surface shape by representing the remaining regions with high fidelity as an implicit function. The innovation of this shape analysis strategy is the capability of solving challenging medical image segmentation problems in a unified framework, regardless of the variability of anatomical structures in question. In our implementation, principal curvature analysis is used to identify and remove the problematic regions and radial basis function (RBF) based implicit surface fitting is used to achieve a closed (or complete) surface boundary. The feasibility and performance of this strategy are demonstrated by applying it to automated segmentation of two completely different anatomical structures depicted on CT examinations, namely human lungs and pulmonary nodules. Our quantitative experiments on a large number of clinical CT examinations collected from different sources demonstrate the accuracy, robustness, and generality of the shape "break-and-repair" strategy in medical image segmentation. 相似文献
3.
P Altmann K Eklund E Georgiades B Rudelstorfer 《Canadian Metallurgical Quarterly》1976,36(11):914-919
The paper refers to 126 patients on whom a plastic diaphragma operation was performed at the 1st Department of Obstet. and Gynec. of the University of Vienna. Based on the results one year after the operation, the success chances are shown and set into relation to several preexistent factors, such as severity of the incontinence, weight, parity, age and conduct of life. An increasing of the two first mentioned factors led to a significant deterioration of results. The influence of an incontinence remains incontested, yet a higher parity does not lead to significantly poorer operation results. As to the factor "age", there were no significant differences in our material. Conduct of life and additional stress in women employed in an occupation are being discussed. Furthermore it was possible to confirm the postoperative space of time needed until restoration of an undisturbed bladder function as a relatively reliable prognostic hint to the expected success of the operation. For this confirmation an objective examination method (sphincterotonometry) was used. 相似文献
4.
5.
This study takes inventory of available evidence on response repetition (RR) effects in task switching, in particular the evidence for RR cost when the task switches. The review reveals that relatively few task-switching studies in which RR effects were addressed have shown statistical support for RR cost, and that almost all are affected by 1 of 2 potential artifacts, either a response bias caused by disallowing stimulus repetitions or the effect of including stimulus repetitions in data analysis. New results with these factors controlled support an episodic retrieval model in which features of the retrieved trace, including the stimulus but also the task, task cue, and response, facilitate or interfere with performance depending on whether they match or mismatch the current processing context. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
6.
<正>如今,绿色屋面在建筑物设计中代表着一种重要元素,越来越受到人们的青睐。这是因为绿色屋面可以使屋面材料免受大风、火灾以及外界气候条件如紫外线辐射、极端温度的影响,从而有可能延长屋面防水系统的预期寿命。绿色屋面还可以延缓雨水进入排水系统,可以吸收二氧化 相似文献
7.
Stefan Weinschenk Carsten Weiss Justus Benrath Volker von Baehr Thomas Strowitzki Manuel Feißt 《International journal of molecular sciences》2022,23(6)
Background. Local anesthetics (LAs) have potent anti-inflammatory properties. Inflammatory down-regulation is crucial in diseases with overactive immune reactions, such as acute respiratory distress syndrome (ARDS) and chronic inflammation. We investigated the influence of four LAs, procaine, lidocaine, mepivacaine, and bupivacaine, on the reduction of tumor necrosis factor-alpha (TNF-α) secretion in lipopolysaccharide (LPS)-activated human leucocytes. Methods. Blood samples of 28 individuals were stimulated with LPS. The reduction of TNF-α production by each of the four LAs added (0.5 mg/mL) was measured and correlated with biometric variables. A response was defined as reduction to <85% of initial levels. Results. All four LAs down-regulated the TNF-α secretion in 44–61%: Bupivacaine (44.4%), lidocaine (61.5%), mepivacaine (44.4%), and procaine (50% of the individuals, “responders”). The TNF-α secretion was reduced to 67.4, 68.0, 63.6, and 67.1% of the initial values in responders. The effects in both patients and healthy persons were the same. Interindividual responses to LAs were not correlated with the duration or type of complaints, basal TNF-α serum level, sex, BMI, or age of responders. Conclusions. Four clinically relevant LAs (amid-LA and ester-LA) attenuate the inflammatory response provoked by LPS. They are potential candidates for drug repositioning in treating overactive immune reactions and chronic inflammation. 相似文献
8.
9.
Alaa Fahmy Karam S. El-Nasser Ibraheem O. Ali Tarek M. Salama Korinna Altmann 《Journal of Adhesion Science and Technology》2013,27(24):2641-2656
The electrospray ionization (ESI) method was used for deposition of thin films of poly(acrylic acid) (PAA) on Cu/ZSM-5 (5 wt.% Cu) and Ag–Cu/ZSM-5 (1 wt.% Ag and 4 wt.% Cu) composites. For comparative purposes, the ZSM-5 zeolite was synthesized under hydrothermal conditions and loaded with PAA under the same treating conditions as the composites. This method allowed the formation of uniform polymer films of controlled thickness on conductive substrates. The structural characteristics were characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy and X-ray diffraction (XRD). The deposited PAA layer over ZSM-5 acts as a common dispersing and stabilizing agent through coordination-driven guest-templated polymer via interaction of Ag+ and Cu2+ with carboxylic acid groups, thus increasing and controlling the adhesion and the release of metallic species. A short exposure to light and temperature has reduced the metal ions to Cu0 and Ag0 metallic nanoparticles. The results of XRD analysis let suggest that the interaction of Cu and Ag with carboxylic groups of PAA inhibits the formation of large metallic silver particles. These samples were being studied for their potential as antibacterial agents toward the bacterial strains such as Staphylococcus pneumonia, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa as Gram positive and Gram negative bacteria, respectively. Aspergillus fumigatus and Candida albicans as Fungi were also evaluated. The Cu/ZSM-5 and Ag–Cu/ZSM-5 nanocomposites coated with a 10 nm thick PAA layer exhibit significant antibacterial activity. 相似文献
10.
Richard A Dunn Joseph R Sharkey Justus Lotade-Manje Yasser Bouhlal Rodolfo M NaygaJr 《Nutrition journal》2011,10(1):6