全文获取类型
收费全文 | 235篇 |
免费 | 18篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 80篇 |
金属工艺 | 8篇 |
机械仪表 | 5篇 |
建筑科学 | 9篇 |
矿业工程 | 1篇 |
能源动力 | 14篇 |
轻工业 | 26篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 20篇 |
一般工业技术 | 42篇 |
冶金工业 | 16篇 |
原子能技术 | 1篇 |
自动化技术 | 25篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 13篇 |
2020年 | 12篇 |
2019年 | 14篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 18篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 7篇 |
2011年 | 20篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1983年 | 1篇 |
1980年 | 3篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有256条查询结果,搜索用时 31 毫秒
71.
Scientometrics - The study utilizes a unique dataset of 16,575 research papers published in 68 national Business and Economics journals to investigate editorial bias towards insiders in Turkish... 相似文献
72.
Ibrahim O. Alade Tajudeen A. Oyehan Idris K. Popoola Sunday O. Olatunji Aliyu Bagudu 《Advanced Powder Technology》2018,29(1):157-167
Enhancing thermal conductivity of nanofluids is an important objective in heat transfer applications. Experimental measurement of thermal conductivity is time consuming, laborious and expensive. One of the common ways to address these limitations involves developing theoretical models to study thermo-physical properties of nanofluid. However, most classical and empirical models fail in predicting experimental results with good precision. In this study, we developed support vector regression (SVR) models that are capable of predicting the thermal conductivity enhancement for metallic and metallic-oxide nanofluids. The accuracy and reliability of the developed models were assessed using statistical parameters such as correlation coefficient (R2), root mean square error (RMSE) and mean absolute error (MAE). The models were characterized with very high correlation coefficients of 99.3 and 96.3% for the metallic and metallic oxide nanofluids, respectively. While the RMSE obtained were 1.11 and 1.33 for the metallic and metallic oxide nanofluids, respectively. In addition, the results of the models were compared with Hamilton-Crosser (HC) model and other empirical models. The SVR models performed much better than all the models examined. Furthermore, the effects of temperature, volume fractions, nanoparticle size and type, and basefluids types were correlated with experimental data in order to assess the performance of the developed models. The results indicate that SVR predictions were accurate and better than common theoretical models. 相似文献
73.
Nurul H. Idris Xiaoli Deng Ole B. Andersen 《International journal of remote sensing》2013,34(5):1729-1740
A new approach for improving the accuracy of altimetry-derived sea level anomalies (SLAs) near the coast is presented. Estimation of SLAs is optimized using optimal waveform retracking through a fuzzy multiple retracking system and the most appropriate detiding method. With the retracking system, fuzzy-retracked SLAs become available within 5 km of the coast; meanwhile it becomes more important to use pointwise tide modelling rather than state-of-the-art global tidal models, as the latter leave residual ocean tide signals in retracked SLAs. These improvements are demonstrated for Jason-2 waveforms in the area of the Great Barrier Reef, Australia. Comparing the retrieved SLAs with in situ tide gauge data from Townsville and Bundaberg stations showed that the SLAs from this study generally outperform those from conventional methods, demonstrating that adequate waveform retracking and detiding are equally important in bringing altimetry SLAs closer to the coast. 相似文献
74.
Process profitability is an yes or no criterion for the successful long-term operation of industrial processes. This article describes the use of dynamic online economic process optimization to improve the performance of chemical processes. Different model-predictive control techniques have progressively been applied to coupled multivariable control problems and in many cases, especially in the petrochemical industry, the reference values are adjusted infrequently by stationary optimization based upon a rigorous nonlinear stationary plant model (real-time optimization, RTO). In between these optimizations, however, the process may be operated suboptimally due to the presence of disturbances. Nonlinear dynamic model-based optimization has been proposed recently to combine optimal operation and feedback control. In this paper, a model of the complex dynamics of a pilot-scale continuous catalytic distillation process is used to explore the potential benefits of online economics optimizing control strategies. We compare the direct economic optimization scheme with a compromise scheme, the economics-oriented tracking controller. The outcome of this work indicates that by using direct economics optimizing NMPC the plant economics can be handled better while guaranteeing the product specifications which are formulated as explicit constraints. 相似文献
75.
This paper presents an improved stator flux estimation technique based on a voltage model with some form of low-pass (LP) filtering. In voltage-model-based stator flux estimation, an LP filter is normally used instead of a pure integrator to avoid integration drift problem due to DC offset, noise, or measurement error present in the back electromotive force. In steady-state condition, the LP filter estimator will degrade the performance and efficiency of the direct torque control (DTC) drive system since it introduced magnitude and phase errors, thus resulting in an incorrect voltage vector selection. The stator flux steady-state error between the LP filter and a pure integrator estimator technique is derived and its effect on the steady-state DTC drive performance is analyzed. A simple method is proposed to compensate for this error which results in a significant improvement in the steady-state drive performance. Simulation based on this technique is given and it is verified by experimental results 相似文献
76.
Abiodun Ismail Lawal Adeyemi Emman Aladejare Moshood Onifade Samson Bada Musa Adebayo Idris 《国际煤炭科学技术学报(英文)》2021,(1):124-140
The elemental composition of coal and biomass provides significant parameters used in the design of almost all energy conversion systems and projects.The labora... 相似文献
77.
Noor Lida Habi Mat Dian Kalyana Sundram Nor Aini Idris 《Journal of the American Oil Chemists' Society》2006,83(8):739-745
Changes in DSC melting properties of palm oil (PO), sunflower oil (SFO), palm kernel olein (PKOo), and their belends in various
ratios were studied by using a combination of blending, and chemical interesterification (CIE) techniques and determining
total melting (ΔH
f
) and partial melting (ΔH
i°C
) enthalpies. Blending and CIE significantly modified the DSC melting properties of the PO/SFO/PKOo blends. PO and blends
containing substantial amounts of PO and PKOo experienced an increase in their DSC ΔH
f
and ΔH
i°C
following CIE. The DSC ΔH
f
and ΔH
i°C
of PKOo, blends of PO/SFO at 1∶1 and 1∶3 ratios, and all blends of PKOo/SFO significantly decreased after CIE. The DSC ΔH
f
and ΔH
i°C
of SFO changed little following CIE. Randomization of FA distribution within and among TAG molecules of PO and PKOo led to
modification in TAG composition of the PO/PKOo blends and improved miscibility between the two fats and consequently diminished
the eutectic interaction that occurred between PO and PKOo. 相似文献
78.
Mohd. Yamani Idna Idris Hamzah Arof Noorzaily Mohamed Noor Emran Mohd. Tamil Zaidi Razak 《Measurement》2012
Extended Kalman Filter (EKF) is a non-linear state estimation technique which is used to produce values that close to the true value when given with measurement containing noise and other inaccuracies. In Monocular Simultaneous Localization and Mapping (SLAM), EKF is used to estimate position and motion information. In this paper, Monocular SLAM software implementation on a general purpose computer is studied to find the most time consuming part of the estimation program. The analysis concentrates on the Monocular SLAM EKF estimation process which involves prediction, measurement prediction, matching and update. For this purpose, a form of dynamic programming analysis tool called software profiling is utilized to determine which section of the estimation program demands the highest processing time. Based on the analysis, it is found that EKF “matching” process contribute to the highest computation time. The reason behind the time-consuming process is because for every predicted feature in the matching stage, the acceptance region and their cross correlation have to be calculated. In a typical general purpose computer software implementation, the processing is limited to sequences of operations (i.e. sequential processing). Such implementation will delay the next process until the prior process completed. However, further analysis conducted in this paper shows that each feature does not depend on the prior process and can be processed individually. This would allow several features to be processed simultaneously to improve the execution speed. Therefore, an FPGA pipelined and parallel processing architecture is proposed. 相似文献
79.
Numerical modelling and mechanical behaviour analysis of ancient tunnel masonry structures 总被引:1,自引:1,他引:0
Jamal Idris Thierry Verdel Marwan Al-Heib 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2008,23(3):251-263
As with all older construction, ancient tunnels feature particular characteristics, especially as regards past construction methods, geometrical design considerations and the set of construction materials used. Old tunnels usually display a unique vaulted section shape built with masonry. The present paper proposes two numerical models of an old tunnel supported by masonry; these models were developed by the well-known Universal Distinct Element Code (UDEC). A masonry mechanical behaviour analysis and numerical simulation of the masonry ageing phenomenon will also be addressed by means of an experimental design to study the influence of masonry block physical properties on the mechanical behaviour of masonry structures in old tunnels. 相似文献
80.
Quality control in digital radiology can be time-consuming. Equipment self-tests may significantly decrease staff workload. The two most essential parameters for radiology systems are image quality and patient dose. Concerning patient dose, information on the dose-area product (DAP) values generally forms the basis for assessment of patient dose. DAP-values can be measured using a transmission ionisation chamber or calculated from equipment settings. In the present study, various image quality parameters were derived using a contrast-detail (C-D) phantom. The investigation included a computer-aided assessment of C-D images, which produced various parameters, and also parameters based upon scoring by human observers. In addition, another parameter was calculated from modulation transfer function (MTF) measurements. The automatically calculated parameters showed good correlation with human readings, although the number of X-ray systems studied is still limited. We propose a combined evaluation of DAP and automatically calculated C-D or MTF parameters for equipment self-tests. 相似文献