全文获取类型
收费全文 | 2345篇 |
免费 | 248篇 |
国内免费 | 152篇 |
专业分类
电工技术 | 157篇 |
综合类 | 210篇 |
化学工业 | 340篇 |
金属工艺 | 135篇 |
机械仪表 | 96篇 |
建筑科学 | 159篇 |
矿业工程 | 85篇 |
能源动力 | 45篇 |
轻工业 | 185篇 |
水利工程 | 103篇 |
石油天然气 | 108篇 |
武器工业 | 18篇 |
无线电 | 86篇 |
一般工业技术 | 489篇 |
冶金工业 | 276篇 |
原子能技术 | 6篇 |
自动化技术 | 247篇 |
出版年
2024年 | 8篇 |
2023年 | 21篇 |
2022年 | 29篇 |
2021年 | 93篇 |
2020年 | 69篇 |
2019年 | 85篇 |
2018年 | 58篇 |
2017年 | 95篇 |
2016年 | 103篇 |
2015年 | 82篇 |
2014年 | 151篇 |
2013年 | 153篇 |
2012年 | 160篇 |
2011年 | 148篇 |
2010年 | 126篇 |
2009年 | 131篇 |
2008年 | 113篇 |
2007年 | 145篇 |
2006年 | 124篇 |
2005年 | 135篇 |
2004年 | 123篇 |
2003年 | 113篇 |
2002年 | 90篇 |
2001年 | 81篇 |
2000年 | 59篇 |
1999年 | 55篇 |
1998年 | 28篇 |
1997年 | 34篇 |
1996年 | 23篇 |
1995年 | 29篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1964年 | 1篇 |
1959年 | 1篇 |
1956年 | 2篇 |
排序方式: 共有2745条查询结果,搜索用时 15 毫秒
991.
The fast initial response (FIR) feature for cumulative sum (CUSUM) quality-control schemes permits a more rapid response to an initial out-of-control situation than does a standard CUSUM quality-control scheme. This feature is especially valuable at start-up or after a CUSUM has given an out-of-control signal. This article presents the average run length and the distribution of run length for CUSUM schemes with the FIR feature and compares FIR CUSUM schemes to standard CUSUM schemes. The comparisons show that if the process starts out in control, the fast initial response feature has little effect; however, if the process mean is not at the desired level, an out-of-control signal will be given faster when the FIR feature is used. 相似文献
992.
Muhammad Riaz 《中国工程学刊》2013,36(2):208-219
In practice, we may not always have normally distributed quality characteristics of interest. This leads to the need for non-parametric techniques which are not dependent on the assumptions about the parent distribution. This study develops a non-parametric exponentially weighted moving average (EWMA) chart (namely the NPSSEWMA chart) for an improved monitoring of process location. The proposal is based on the use of sign statistics on a moving pattern in an EWMA setup. The design structure of the proposed chart is developed and its performance is evaluated in terms of different properties including average run length (ARL), standard deviation run length (SDRL), percentiles, relative ARL (RARL), extra quadratic loss (EQL), and performance comparison index (PCI). The proposal is compared with recently developed non-parametric counterparts namely NPSEWMA, NPASEWMA, and NPSCUSUM charts. It is observed that the design structure of the proposed NPSSEWMA chart outshines the existing counterparts. An application example is also included in the study for practical demonstration. 相似文献
993.
Exponentially weighted moving average (EWMA) control charts are very widely used for the detection of small shifts. Another similar charting structure is double EWMA (DEWMA) control chart for the improved detection of the shifts. Many interesting features of EWMA and DEWMA have been described in the literature. This study intends to investigate EWMA and DEWMA control charts under Type-I censoring for gamma-distributed lifetimes. The idea of conditional expected values is used to monitor the mean level. The performance evaluations are carried out using average run length as a measure in this study. The optimum sample size comparisons for the specified and unspecified parameter are also part of the study. To assess the overall performance of the control charts, we also used extra quadratic loss and it is found DEWMA is an efficient chart for the detection of shift in scale parameter. Moreover, an illustrative example for practical considerations is included in the study. It is observed that varying censoring rates affect the performance of the chart depending upon the type of chart, the method of estimation, and the amount of shift. 相似文献
994.
In this paper, we propose a mixed control chart to monitor the process quality using attribute data combined with variable data. The proposed control chart proceeds like an np control chart based on the number of nonconforming parts but requires variable data only when the decision is indeterminate. The control coefficients are determined by considering the in-control and the out-of-control average run lengths for various specified parameters. The extensive tables are provided for the industrial use. The advantages of the proposed control chart are discussed over the traditional np control chart. 相似文献
995.
Saddam Akber Abbasi Arden Miller Muhammad Riaz 《Quality and Reliability Engineering International》2013,29(7):1069-1080
Nonparametric control charts are widely used when the parametric distribution of the quality characteristic of interest is questionable. In this study, we proposed a nonparametric progressive mean control chart, namely the nonparametric progressive mean chart, for efficient detection of disturbances in process location or target. The proposed chart is compared with the recently proposed nonparametric exponentially weighted moving average and nonparametric cumulative sum charts using different run length characteristics such as the average run length, standard deviation of the run length, and the percentile points of the run length distribution. The comparisons revealed that the proposed chart outperformed recent nonparametric exponentially weighted moving average and nonparametric cumulative sum charts, in terms of detecting the shifts in process target. A real life example concerning the fill heights of soft drink beverage bottles is also provided to illustrate the application of the proposed nonparametric control chart. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
996.
Mu'azu Ramat Abujiya Muhammad Riaz Muhammad Hisyam Lee 《Quality and Reliability Engineering International》2013,29(8):1193-1206
For an improved monitoring of process parameters, it is generally desirable to have efficient designs of control charting structures. The addition of Shewhart control limits to the cumulative sum (CUSUM) control chart is a simple monitoring scheme sensitive to wide range of mean shifts. To improve the detection ability of the combined Shewhart–CUSUM control chart to off‐target processes, we developed the scheme using ranked set sampling instead of the traditional simple random sampling. We investigated the run length properties of the Shewhart–CUSUM with ranked set samples and compared their performance with certain established control charts. It is revealed that the proposed schemes offer better protection against different types of mean shifts than the existing counterparts including classical Shewhart, classical CUSUM, classical combined Shewhart–CUSUM, adaptive CUSUM, double CUSUM, three simultaneous CUSUM, combined Shewhart‐weighted CUSUM, runs rules‐based CUSUM and the mixed exponentially weighted moving average‐CUSUM. Applications on real data sets are also given to demonstrate the implementation simplicity of the proposed schemes Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
997.
Nasir Abbas Raja Fawad Zafar Muhammad Riaz Zawar Hussain 《Quality and Reliability Engineering International》2013,29(3):357-367
Control charts are widely used for process monitoring. They show whether the variation is due to common causes or whether some of the variation is due to special causes. To detect large shifts in the process, Shewhart‐type control charts are preferred. Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are generally used to detect small and moderate shifts. Shewhart‐type control charts (without additional tests) use only current information to detect special causes, whereas CUSUM and EWMA control charts also use past information. In this article, we proposed a control chart called progressive mean (PM) control chart, in which a PM is used as a plotting statistic. The proposed chart is designed such that it uses not only the current information but also the past information. Therefore, the proposed chart is a natural competitor for the classical CUSUM, the classical EWMA and some recent modifications of these two charts. The conclusion of this article is that the performance of the proposed PM chart is superior to the compared ones for small and moderate shifts, and its performance for large shifts is better (in terms of the average run length). Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
998.
999.
1000.
Bayesian hierarchical modelling techniques have some advantages over classic methods for the analysis of cluster-randomized trial. Bayesian approach is also becoming more popular to deal with measurement error and misclassification problems. We propose a Bayesian approach to analyze a cluster-randomized trial with adjusting for misclassification in a binary covariate in the random effect logistic model when a gold standard is not available. This Markov chain Monte Carlo (MCMC) approach uses two imperfect measures of a dichotomous exposure under the assumptions of conditional independence and non-differential misclassification. Both simulated numerical example and real clinical example are given to illustrate the proposed approach. The Bayesian approach has great potential to be used in misclassification problem in generalized linear mixed model (GLMM) since it allow us to fit complex models and identify all the parameters. Our results suggest that Bayesian approach for analyzing cluster-randomized trial and adjusting for misclassification in GLMM is flexible and powerful. 相似文献