全文获取类型
收费全文 | 803篇 |
免费 | 32篇 |
国内免费 | 58篇 |
专业分类
电工技术 | 1篇 |
综合类 | 10篇 |
化学工业 | 210篇 |
金属工艺 | 2篇 |
机械仪表 | 6篇 |
矿业工程 | 3篇 |
能源动力 | 36篇 |
轻工业 | 1篇 |
石油天然气 | 618篇 |
无线电 | 1篇 |
自动化技术 | 5篇 |
出版年
2024年 | 2篇 |
2023年 | 5篇 |
2022年 | 17篇 |
2021年 | 43篇 |
2020年 | 36篇 |
2019年 | 27篇 |
2018年 | 20篇 |
2017年 | 24篇 |
2016年 | 39篇 |
2015年 | 27篇 |
2014年 | 31篇 |
2013年 | 74篇 |
2012年 | 51篇 |
2011年 | 56篇 |
2010年 | 37篇 |
2009年 | 28篇 |
2008年 | 27篇 |
2007年 | 47篇 |
2006年 | 30篇 |
2005年 | 36篇 |
2004年 | 22篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 29篇 |
2000年 | 30篇 |
1999年 | 19篇 |
1998年 | 17篇 |
1997年 | 8篇 |
1996年 | 26篇 |
1995年 | 13篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有893条查询结果,搜索用时 0 毫秒
891.
892.
The upgradation of the bottom of the barrel has gained much interest across the refineries due to severe environmental rules, limitations of conventional oil reserves, and its flexibility to produce light end products which benefit end users. Slurry phase hydrocracking is one of the growing technologies to fulfil the increasing demand for light cut. Modelling of an industrial slurry phase reactor (SPR) for vacuum residue hydrocracking using different kinetic models is proposed. The axial dispersion model (ADM) is used for modelling an industrial SPR. The mathematical model of the reactors is incorporated for the three different lump kinetic models. This study deals with the continuous stirred tank reactor (CSTR) and SPR modelling, followed by industrial SPR modelling. The small lab-scale reactor models are validated with the experimental data reported in the literature. The study's objective was to investigate the one-dimensional and two-dimensional concentration dynamics of each lump along the axial and radial positions of industrial SPR. The vacuum residue conversion into the light fractions was obtained by more than 73% in industrial SPR. Also, the yield of vacuum gas oil and resins were evaluated as 49% and 63%, respectively. The sensitivity analysis was performed to explain the effect of process variables. The optimum range was found as a length of 15 m, liquid hourly space velocity (LHSV) of 0.2 h−1, 1% catalyst concentration, and 420°C reaction temperature to enhance the throughput of the reactor. 相似文献
893.
Jiannan Zhu Vladimir Mahalec Chen Fan Minglei Yang Feng Qian 《Frontiers of Chemical Science and Engineering》2023,17(6):759
This work introduces a deep-learning network, i.e., multi-input self-organizing-map ResNet (MISR), for modeling refining units comprised of two reactors and a separation train. The model is comprised of self-organizing-map and the neural network parts. The self-organizing-map part maps the input data into multiple two-dimensional planes and sends them to the neural network part. In the neural network part, residual blocks enhance the convergence and accuracy, ensuring that the structure will not be overfitted easily. Development of the MISR model of hydrocracking unit also benefits from the utilization of prior knowledge of the importance of the input variables for predicting properties of the products. The results show that the proposed MISR structure predicts more accurately the product yields and properties than the previously introduced self-organizing-map convolutional neural network model, thus leading to more accurate optimization of the hydrocracker operation. Moreover, the MISR model has smoother error convergence than the previous model. Optimal operating conditions have been determined via multi-round-particle-swarm and differential evolution algorithms. Numerical experiments show that the MISR model is suitable for modeling nonlinear conversion units which are often encountered in refining and petrochemical plants. 相似文献