全文获取类型
收费全文 | 407篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 40篇 |
金属工艺 | 4篇 |
机械仪表 | 1篇 |
建筑科学 | 26篇 |
矿业工程 | 2篇 |
能源动力 | 7篇 |
轻工业 | 41篇 |
水利工程 | 3篇 |
无线电 | 28篇 |
一般工业技术 | 74篇 |
冶金工业 | 130篇 |
原子能技术 | 3篇 |
自动化技术 | 57篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 25篇 |
2012年 | 17篇 |
2011年 | 21篇 |
2010年 | 11篇 |
2009年 | 23篇 |
2008年 | 32篇 |
2007年 | 31篇 |
2006年 | 16篇 |
2005年 | 10篇 |
2004年 | 10篇 |
2003年 | 15篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有418条查询结果,搜索用时 187 毫秒
1.
Cathy Lawson Douglas C. Montgomery 《Quality and Reliability Engineering International》2006,22(8):971-984
Variation exists in all processes. Significant work has been done to identify and remove sources of variation in manufacturing processes resulting in large returns for companies. However, business process optimization is an area that has a large potential return for a company. Business processes can be difficult to optimize due to the nature of the output variables associated with them. Business processes tend to have output variables that are binary, nominal or ordinal. Examples of these types of output include whether a particular event occurred, a customer's color preference for a new product and survey questions that assess the extent of the survey respondent's agreement with a particular statement. Output variables that are binary, nominal or ordinal cannot be modeled using ordinary least‐squares regression. Logistic regression is a method used to model data where the output is binary, nominal or ordinal. This article provides a review of logistic regression and demonstrates its use in modeling data from a business process involving customer feedback. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
2.
McEvoy Cathy L.; Nelson Douglas L.; Holley Patricia E.; Stelnicki Glennda S. 《Canadian Metallurgical Quarterly》1992,7(3):401
Reports 2 cued recall experiments in which younger and older Ss studied target words varying in number of preexperimental associates. In Exp 1, targets were studied in either the absence or presence of meaning-related context cues, with recall always prompted by the cues. In the absence of context, words with smaller sets of associates were easier to recall than those with larger sets, but this effect was reduced for older Ss. The presence of a study context cue facilitated recall and eliminated the effect of associative set size for both ages. In Exp 2, targets were studied and tested in the presence of unrelated words. In this situation, words with smaller sets of associates were less likely to be recalled than words with larger sets; again the effect was reduced for older Ss. The results are interpreted as an age decrement in processing implicitly activated information. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
M Prade A Spatz P Duvillard C Bognel G Michel MA Belda N Mourra C Lagorce 《Canadian Metallurgical Quarterly》1993,13(5):317-323
From 4 cases recently seen at the Institut Gustave-Roussy, this report describes the pathological and evolutive features of benign glandular inclusions in inguinal, pelvic or abdominal lymph nodes. These lesions are defined by the presence of tubular formations in lymph nodes, lined by a single layer of epithelium which is cuboidal or columnar and resembled that of tubal epithelium with ciliated, secretory and intercalary cells. In most cases, benign glandular inclusions in lymph nodes still quiescent. In rare instances, they may proliferate and become papillary. The association of proliferating glandular inclusions in lymph nodes with borderline tumor of the ovary raises the problem of their primary or metastatic origin. However, their pathological features argues for a primary origin in lymph nodes. Thus, we think that a metastatic potential of borderline tumors of the ovary is not supported by any convincing argument. 相似文献
4.
It was proposed that individuals' responses to information regarding their relative position in a performance distribution would depend on how they frame the information. To the degree that they focus selectively on the positive features of the feedback (i.e., the number of others who performed worse than them) rather than the negative features (i.e., the number of others who performed better than them) they should report higher ability levels and more positive affective reactions. In Study I, Ss received feedback indicating that they occupied a particular percentile standing in either a large or small distribution. Individuals with negative orientations (depressives and pessimists) reported lower ability levels as a function of increases in comparison group size, whereas individuals with positive orientations (nondepressives and optimists) reported higher ability levels. Presumably, these effects occurred because negatively oriented persons focused on the negative features of the feedback and positively oriented persons focused on the positive features of the feedback. The results of Study 2 support this explanation. Implications for the social comparison literature are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
H.‐G. Boyen G. Kstle K. Zürn T. Herzog F. Weigl P. Ziemann O. Mayer C. Jerome M. Mller J.P. Spatz M.G. Garnier P. Oelhafen 《Advanced functional materials》2003,13(5):359-364
Starting with Co‐salt‐loaded inverse micelles, which form if the diblock copolymer polystyrene‐block‐poly(2‐vinylpyridine) is dissolved in a selective solvent like toluene and CoCl2 is added to the solution, monomicellar arrays of such micelles exhibiting a significant hexagonal order can be prepared on top of various substrates with tailored intermicellar distances and structure heights. In order to remove the polymer matrix and to finally obtain arrays of pure Co nanoparticles, the micelles are first exposed to an oxygen plasma, followed by a treatment in a hydrogen plasma. Applying in‐situ X‐ray photoelectron spectroscopy, it is demonstrated that: 1) The oxygen plasma completely removes the polymer, though conserving the original order of the micellar array. Furthermore, the resulting nanoparticles are entirely oxidized with a chemical shift of the Co 2p3/2 line pointing to the formation of Co3O4. 2) By the subsequent hydrogen plasma treatment the nanoparticles are fully reduced to metallic Co. 3) By exposing the pure Co nanoparticles for 100 s to various oxygen partial pressures pequation/tex2gif-inf-5.gif, a stepwise oxidation is observed with a still metallic Co core surrounded by an oxide shell. The data allow the extraction of the thickness of the oxide shell as a function of the total exposure to oxygen (pequation/tex2gif-inf-7.gif × time), thus giving the opportunity to control the ferromagnetic–antiferromagnetic composition of an exchange‐biased magnetic system. 相似文献
6.
7.
Cathy H.Y. Lam K.L. Choy G.T.S. Ho C.K.M. Lee 《International journal of systems science》2014,45(6):1283-1295
Nowadays, customer orders with high product variety in small quantities are often received and requested for timely delivery. However, the order-picking process is a labour-intensive and costly activity to handle those small orders separately. In such cases, small orders are often grouped into batches so that two or more orders can be served at once to increase the picking efficiency and thus reduce the travel distance. In this paper, an order-picking operations system (OPOS) is proposed to assist the formulation of an order-picking plan and batch-handling sequence. The study integrates a mathematical model and fuzzy logic technique to divide the receiving orders into batches and prioritise the batch-handling sequence for picking, respectively. Through the proposed system, the order-picking process can be managed as batches with common picking locations to minimise the travel distance, and the batch-picking sequence can be determined as well. To demonstrate the use of the system, a case study in a third-party logistics warehouse is presented, and the result shows that both the order-picking activity and labour utilisation can be better organised. 相似文献
8.
The removal of sulphur and ash from coal treated with aqueous hydrogen peroxide/sulphuric acid solutions has been studied at ambient temperature, under a variety of experimental conditions. Almost complete elimination of the sulphate and the pyritic sulphur was observed in most cases, as well as substantial reduction in the ash content. The other components of the organic coal matrix were not affected to a significant extent, indicating high selectivity of the system towards sulphur oxidation. An optimal H2SO4 concentration was established, above which the acid was found to have an adverse effect on the oxidation of pyrite by hydrogen peroxide. 相似文献
9.
Yixuan Jia Christoph A. Spiegel Alexander Welle Stefan Heißler Elaheh Sedghamiz Modan Liu Wolfgang Wenzel Maximilian Hackner Joachim P. Spatz Manuel Tsotsalas Eva Blasco 《Advanced functional materials》2023,33(39):2207826
Manufacturing programmable materials, whose mechanical properties can be adapted on demand, is highly desired for their application in areas ranging from robotics, to biomedicine, or microfluidics. Herein, the inclusion of dynamic and living bonds, such as alkoxyamines, in a printable formulation suitable for two-photon 3D laser printing is exploited. On one hand, taking advantage of the dynamic covalent character of alkoxyamines, the nitroxide exchange reaction is investigated. As a consequence, a reduction of the Young´s Modulus by 50%, is measured by nanoindentation. On the other hand, due to its “living” characteristic, the chain extension becomes possible via nitroxide mediated polymerization. In particular, living nitroxide mediated polymerization of styrene results not only in a dramatic increase of the volume (≈8 times) of the 3D printed microstructure but also an increase of the Young's Modulus by two orders of magnitude (from 14 MPa to 2.7 GPa), while maintaining the shape including fine structural details. Thus, the approach introduces a new dimension by enabling to create microstructures with dynamically tunable size and mechanical properties. 相似文献
10.
Capital asset pricing model (CAPM) has become a fundamental tool in finance for assessing the cost of capital, risk management, portfolio diversification and other financial assets. It is generally believed that the market risks of the assets, often denoted by a beta coefficient, should change over time. In this paper, we model timevarying market betas in CAPM by a smooth transition regime switching CAPM with heteroscedasticity, which provides flexible nonlinear representation of market betas as well as flexible asymmetry and clustering in volatility. We also employ the quantile regression to investigate the nonlinear behavior in the market betas and volatility under various market conditions represented by different quantile levels. Parameter estimation is done by a Bayesian approach. Finally, we analyze some Dow Jones Industrial stocks to demonstrate our proposed models. The model selection method shows that the proposed smooth transition quantile CAPM?CGARCH model is strongly preferred over a sharp threshold transition and a symmetric CAPM?CGARCH model. 相似文献