全文获取类型
收费全文 | 209篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 9篇 |
化学工业 | 47篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 6篇 |
轻工业 | 39篇 |
水利工程 | 5篇 |
无线电 | 7篇 |
一般工业技术 | 35篇 |
冶金工业 | 16篇 |
自动化技术 | 25篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 10篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 15篇 |
2012年 | 9篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1976年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有217条查询结果,搜索用时 15 毫秒
41.
Sara Abbaspour Asadollah Daniel Sundmark Sigrid Eldh Hans Hansson Wasif Afzal 《Software Quality Journal》2017,25(1):49-82
Debugging—the process of identifying, localizing and fixing bugs—is a key activity in software development. Due to issues such as non-determinism and difficulties of reproducing failures, debugging concurrent software is significantly more challenging than debugging sequential software. A number of methods, models and tools for debugging concurrent and multicore software have been proposed, but the body of work partially lacks a common terminology and a more recent view of the problems to solve. This suggests the need for a classification, and an up-to-date comprehensive overview of the area. This paper presents the results of a systematic mapping study in the field of debugging of concurrent and multicore software in the last decade (2005–2014). The study is guided by two objectives: (1) to summarize the recent publication trends and (2) to clarify current research gaps in the field. Through a multi-stage selection process, we identified 145 relevant papers. Based on these, we summarize the publication trend in the field by showing distribution of publications with respect to year, publication venues, representation of academia and industry, and active research institutes. We also identify research gaps in the field based on attributes such as types of concurrency bugs, types of debugging processes, types of research and research contributions. The main observations from the study are that during the years 2005–2014: (1) there is no focal conference or venue to publish papers in this area; hence, a large variety of conferences and journal venues (90) are used to publish relevant papers in this area; (2) in terms of publication contribution, academia was more active in this area than industry; (3) most publications in the field address the data race bug; (4) bug identification is the most common stage of debugging addressed by articles in the period; (5) there are six types of research approaches found, with solution proposals being the most common one; and (6) the published papers essentially focus on four different types of contributions, with “methods” being the most common type. We can further conclude that there are still quite a number of aspects that are not sufficiently covered in the field, most notably including (1) exploring correction and fixing bugs in terms of debugging process; (2) order violation, suspension and starvation in terms of concurrency bugs; (3) validation and evaluation research in the matter of research type; (4) metric in terms of research contribution. It is clear that the concurrent, parallel and multicore software community needs broader studies in debugging. This systematic mapping study can help direct such efforts. 相似文献
42.
A kinetic study was performed to describe the initial specific rate of multi-walled carbon nanotube synthesis by catalytic chemical vapor deposition (CCVD) on a bimetallic cobalt-iron catalyst at high temperature using ethylene decomposition to solid carbon and gaseous hydrogen. The study uses a mass spectrometer that allows reaction rate to be inferred from the exhaust gas composition measurements. The aim is to obtain a better understanding of the elementary steps involved in the production of carbon nanotubes so as to derive phenomenological kinetic models in agreement with experimental data. The best models assume the elimination of the first hydrogen atom from adsorbed ethylene as rate determining step and involve a hydrogen adsorption weak enough to be neglected. It was proved that hydrogen partial pressure has no influence on initial reaction rate of carbon nanotube synthesis with the catalyst used for this study. Activation energy and ethylene adsorption enthalpy were found to be equal to around 130 and −130 kJ mol−1, respectively. 相似文献
43.
Øyvind Borg Sølvi Storsæter Sigrid Eri Hanne Wigum Erling Rytter Anders Holmen 《Catalysis Letters》2006,107(1-2):95-102
The effect of water on the activity and selectivity for a series of γ-Al2O3 supported cobalt Fischer–Tropsch catalysts has been studied in an isothermal fixed-bed reactor at T = 483 K, P = 20 bar, and H2/CO = 2.1. The catalysts were produced applying incipient wetness impregnation and consisted of 20 wt.% cobalt and 0.5 wt.%
rhenium deposited on γ-Al2O3 supports with different pore characteristics. For the narrow-pore catalysts, addition of water corresponding to an inlet
partial pressure ratio of PH2O/PH2 = 0.4 reduced the reaction rates. In contrast, for a catalyst with larger pores the same water pressure increased the reaction
rates. For all catalysts, water amounts equal to PH2O/PH2 = 0.7 at the reactor inlet suppressed the reaction rates and led to permanent deactivation. The addition of water increased
the C5+ selectivity and decreased the CH4 selectivity for all catalysts. The pore characteristics seem to determine the effect of water on the rates. 相似文献
44.
Sigrid A. Carle Anne L. Averill Geoffrey S. Rule W. Harvey Reissig Wendell L. Roelofs 《Journal of chemical ecology》1987,13(4):795-805
We conducted a comparative study of volatiles produced by wholeCrataegus hawthorn fruit and four cultivars of apple (Royal Red Delicious, Red Astrachan, McIntosh, and Wealthy) and determined quantitative and qualitative changes of volatiles associated with fruit ripening. Within the approximate range of the GLC fraction known to elicit behavioral activity in the apple maggot fly,Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), 52 esters were identified. 相似文献
45.
A Low Temperature Route toward Hierarchically Structured Titania Films for Thin Hybrid Solar Cells 下载免费PDF全文
Lin Song Amr Abdelsamie Christoph J. Schaffer Volker Körstgens Weijia Wang Tianyi Wang Efi Dwi Indari Thomas Fröschl Nicola Hüsing Tobias Haeberle Paolo Lugli Sigrid Bernstorff Peter Müller‐Buschbaum 《Advanced functional materials》2016,26(39):7084-7093
The requirement of high‐temperature calcination for titanium dioxide in (solid‐state) dye‐sensitized solar cells (DSSCs) implies challenges with respect to reduced energy consumption and the potential for flexible photovoltaic devices. Moreover, the use of dye molecules increases production costs and leads to problems related with dye bleaching. Therefore, fabrication of dye‐free hybrid solar cells at low temperature is a promising alternative for current DSSC technology. In this work the authors fabricate hierarchically structured titania thin films by combining a polystyrene‐block‐polyethylene oxide template assisted sol–gel synthesis with nano‐imprint lithography at low temperatures. The achieved films are filled with poly(3‐hexylthiophene) to form the active layer of hybrid solar cells. The surface morphology is probed via scanning electron microscopy and atomic force microscopy, and the bulk film morphology is examined with grazing incidence X‐ray scattering. Good light absorption by the active layer is proven by UV–vis spectroscopy. An enhancement in light absorption is observed and ascribed to light scattering in mesoporous titania films with imprinted superstructures. Accordingly a better photovoltaic performance is found for nano‐imprinted solar cells at various angles of light incidence. 相似文献
46.
Domig KJ Mayrhofer S Zitz U Mair C Petersson A Amtmann E Mayer HK Kneifel W 《International journal of food microbiology》2007,120(1-2):191-195
There is urgent need for having available suitable methods and data regarding the susceptibility levels of antibiotic resistant and sensitive strains of bifidobacteria. Based on a defined standard operation procedure, agar disc diffusion and broth microdilution were compared in order to evaluate the antimicrobial susceptibility profiles of 82 B. pseudolongum and 80 B. thermophilum strains mainly originating from the meat production chain. The methods that were assessed showed interpretable agreement within this study. The disc diffusion zone diameters are highly reproducible making the method a useful alternative to broth microdilution for antimicrobial susceptibility screening of bifidobacteria. 相似文献
47.
48.
49.
50.
Weigelt S Busse C Petersen L Rauls E Hammer B Gothelf KV Besenbacher F Linderoth TR 《Nature materials》2006,5(2):112-117
Self-assembly of adsorbed organic molecules is a promising route towards functional surface nano-architectures, and our understanding of associated dynamic processes has been significantly advanced by several scanning tunnelling microscopy (STM) investigations. Intramolecular degrees of freedom are widely accepted to influence ordering of complex adsorbates, but although molecular conformation has been identified and even manipulated by STM, the detailed dynamics of spontaneous conformational change in adsorbed molecules has hitherto not been addressed. Molecular surface structures often show important stereochemical effects as, aside from truly chiral molecules, a large class of so-called prochiral molecules become chiral once confined on a surface with an associated loss of symmetry. Here, we investigate a model system in which adsorbed molecules surprisingly switch between enantiomeric forms as they undergo thermally induced conformational changes. The associated kinetic parameters are quantified from time-resolved STM data whereas mechanistic insight is obtained from theoretical modelling. The chiral switching is demonstrated to enable an efficient channel towards formation of extended homochiral surface domains. Our results imply that appropriate prochiral molecules may be induced (for example, by seeding) to assume only one enantiomeric form in surface assemblies, which is of relevance for chiral amplification and asymmetric heterogenous catalysis. 相似文献