全文获取类型
收费全文 | 58篇 |
免费 | 6篇 |
专业分类
化学工业 | 19篇 |
建筑科学 | 1篇 |
轻工业 | 10篇 |
无线电 | 4篇 |
一般工业技术 | 13篇 |
冶金工业 | 5篇 |
自动化技术 | 12篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2019年 | 5篇 |
2018年 | 1篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1996年 | 1篇 |
1988年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有64条查询结果,搜索用时 0 毫秒
1.
Adherent and coherent deposits of nickel sponge similar to sintered nickel may be made from sulphate, chloride, fluoborate or sulphamate nickel plating solutions containing nickel powder in suspension, providing the concentration of free acid is maintained sufficiently high to inhibit co-depesition of Ni(OH) In nitrate solution, cathodic reduction of nitrate and deposition of Ni(OH)2 predominates. 相似文献
2.
This article tackles the problem of predicting effort (in person–hours) required to fix a software defect posted on an Issue Tracking System. The proposed method is inspired by the Nearest Neighbour Approach presented by the pioneering work of Weiss et al. (2007) [1]. We propose four enhancements to Weiss et al. (2007) [1]: Data Enrichment, Majority Voting, Adaptive Threshold and Binary Clustering. Data Enrichment infuses additional issue information into the similarity-scoring procedure, aiming to increase the accuracy of similarity scores. Majority Voting exploits the fact that many of the similar historical issues have repeating effort values, which are close to the actual. Adaptive Threshold automatically adjusts the similarity threshold to ensure that we obtain only the most similar matches. We use Binary Clustering if the similarity scores are very low, which might result in misleading predictions. This uses common properties of issues to form clusters (independent of the similarity scores) which are then used to produce the predictions. Numerical results are presented showing a noticeable improvement over the method proposed in Weiss et al. (2007) [1]. 相似文献
3.
Journal of Porous Materials - The aim of this study was to encapsulate 2-tert-butylhydroquinone (TBHQ), as a common synthetic antioxidant in food industries, by mesoporous silica nanoparticles... 相似文献
4.
Hajar Abbasi Karamatollah Rezaei Ladan Rashidi 《Journal of the American Oil Chemists' Society》2008,85(1):83-89
In this study, essential oils from pomegranate seeds of the Malas variety from Shahreza, Iran, were extracted using hexane
and petroleum benzene applying four extraction methods: normal stirring, soxhlet, microwave irradiation, and ultrasonic irradiation.
Also, supercritical fluid extraction (SFE) using CO2 under different conditions was used for comparison. Different methods of extraction with organic solvents (normal stirring,
soxhlet, microwave irradiation, and ultrasonic irradiation) showed significant differences in the extraction yields. However,
no differences were found when a given method (e.g., microwave irradiation) was applied using different organic solvents.
On the other hand, different extraction conditions from the various runs of SFE resulted in different extraction yields, all
of which were lower than those of the other extraction methods using organic solvents. No significant differences were observed
in the fatty acid compositions of the extracted oils using organic solvents. However, the fatty acid compositions of the oils
extracted under different conditions of the SFE system indicated significant differences among several fatty acids including
unsaturated fatty acids. 相似文献
5.
Synthesis and Characterization of NiO Nano‐Spheres by Templating on Chitosan as a Green Precursor 下载免费PDF全文
Cheng Keong Choo Tze Lim Goh Ladan Shahcheraghi Gek Cheng Ngoh Ahmad Zuhairi Abdullah Bahman Amini Horri Babak Salamatinia 《Journal of the American Ceramic Society》2016,99(12):3874-3882
In this study, nickel oxide was prepared through the calcination of extrusion dripped chitosan/nickel nitrate beads. The morphology and structural properties of the products were studied using various characterization techniques. Uniformly distributed nickel oxide was formed as observed from the studies of surface morphology where the processing parameters play a huge role on the resulting morphology. TEM results have shown that nickel oxide with crystallite sizes of 10–30 nm was obtained. The Fourier‐transform infrared spectra studies show an intense peak at 525 cm?1, which is attributed to the vibration of Ni–O bond. Furthermore, the XRD results show NiO diffraction peaks correspond to (111), (200), (220), (311), and (222) which indicates that a bunsenite structure with a face‐centered cubic phase was produced in this study. The usage of 500°C as the lower limit in this study is justified due to the complete removal of the templating material as seen in the thermalgravimetric analysis studies. Furthermore, it was obtained that the largest surface area of nickel oxide synthesized using this technique is 48.024 m2/g with pore sizes of 19.843 nm. The usage of chitosan as a green template for the synthesis of nanoparticles has shown promising results which allows a more economical and sustainable approach for the fabrication of nanomaterials. 相似文献
6.
Double diffusion convection in a cavity with a hot square obstacle inside is simulated using the lattice Boltzmann method. The results are presented for the Rayleigh numbers 104,105 and 106, the Lewis numbers 0.1, 2 and 10 and aspect ratio A (obstacle height/cavity height) of 0.2, 0.4 and 0.6 for a range of buoyancy number N=0 to?4 with the effect of opposing flow. The results indicate that for|N|b 1, the Nusselt and Sherwood numbers decrease as buoyancy ratio increases, while for|N|N 1, they increase with|N|. As the Lewis number increases, higher buoyan-cy ratio is required to overcome the thermal effects and the minimum value of the Nusselt and Sherwood num-bers occur at higher buoyancy ratios. The increase in the Rayleigh or Lewis number results in the formation of the multi-cell flow in the enclosure and the vortices wil vanish as|N|increases. 相似文献
7.
8.
Mehdi Amoui Mahdi Derakhshanmanesh Jürgen Ebert Ladan Tahvildari 《Journal of Systems and Software》2012,85(12):2720-2737
In this article, we present a generic model-centric approach for realizing fine-grained dynamic adaptation in software systems by managing and interpreting graph-based models of software at runtime. We implemented this approach as the Graph-based Runtime Adaptation Framework (GRAF), which is particularly tailored to facilitate and simplify the process of evolving and adapting current software towards runtime adaptivity. As a proof of concept, we present case study results that show how to achieve runtime adaptivity with GRAF and sketch the framework's capabilities for facilitating the evolution of real-world applications towards self-adaptive software. The case studies also provide some details of the GRAF implementation and examine the usability and performance of the approach. 相似文献
9.
Self‐adaptive software is a closed‐loop system, since it continuously monitors its context (i.e. environment) and/or self (i.e. software entities) in order to adapt itself properly to changes. We believe that representing adaptation goals explicitly and tracing them at run‐time are helpful in decision making for adaptation. While goal‐driven models are used in requirements engineering, they have not been utilized systematically yet for run‐time adaptation. To address this research gap, this article focuses on the deciding process in self‐adaptive software, and proposes the Goal‐Action‐Attribute Model (GAAM). An action selection mechanism, based on cooperative decision making, is also proposed that uses GAAM to select the appropriate adaptation action(s). The emphasis is on building a light‐weight and scalable run‐time model which needs less design and tuning effort comparing with a typical rule‐based approach. The GAAM and action selection mechanism are evaluated using a set of experiments on a simulated multi‐tier enterprise application, and two sample ordinal and cardinal action preference lists. The evaluation is accomplished based on a systematic design of experiment and a detailed statistical analysis in order to investigate several research questions. The findings are promising, considering the obtained results, and other impacts of the approach on engineering self‐adaptive software. Although, one case study is not enough to generalize the findings, and the proposed mechanism does not always outperform a typical rule‐based approach, less effort, scalability, and flexibility of GAAM are remarkable. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
10.
In order to study dynamically the resistive states which appear as jumps in the I–V curves of narrow bridges, we have submitted YBaCuO and Nb films to nanosecond current steps and laser pulses simultaneously. In constant current feed, the distinction between hot spots (HS) and phase-slip centers (PSCs) is unambiguous, since HS are compelled to grow or decay, at variance with the stable-in-time PSCs. Thanks to the transient method we show that, even if Joule dissipation associated to a current I is virtually sufficient to sustain the film above Tc, the zero resistance state remains metastable: a hot spot does not arise unless initiated by a PSC, which fact was not reported before. The domains of occurrence of HS and PSCs were then organized in a current–temperature plane. Finally, the theoretical problem of the HS velocity of growth is given an exact solution, in semiquantitative agreement with experiment. 相似文献