全文获取类型
收费全文 | 66篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
综合类 | 1篇 |
化学工业 | 14篇 |
金属工艺 | 1篇 |
机械仪表 | 9篇 |
轻工业 | 4篇 |
无线电 | 3篇 |
一般工业技术 | 21篇 |
冶金工业 | 3篇 |
自动化技术 | 13篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 14篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 15 毫秒
61.
An in vitro study reveals nutraceutical properties of Ananas comosus (L.) Merr. var. Mauritius fruit residue beneficial to diabetes
下载免费PDF全文
![点击此处可从《Journal of the science of food and agriculture》网站下载免费的PDF全文](/ch/ext_images/free.gif)
62.
Erwin Peng Eugene Shi Guang Choo Prashant Chandrasekharan Chang‐Tong Yang Jun Ding Kai‐Hsiang Chuang Jun Min Xue 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(23):3620-3630
In this study, MnFe2O4 nanoparticle (MFNP)‐decorated graphene oxide nanocomposites (MGONCs) are prepared through a simple mini‐emulsion and solvent evaporation process. It is demonstrated that the loading of magnetic nanocrystals can be tuned by varying the ratio of graphene oxide/magnetic nanoparticles. On top of that, the hydrodynamic size range of the obtained nanocomposites can be optimized by varying the sonication time during the emulsion process. By fine‐tuning the sonication time, MGONCs as small as 56.8 ± 1.1 nm, 55.0 ± 0.6 nm and 56.2 ± 0.4 nm loaded with 6 nm, 11 nm, and 14 nm MFNPs, respectively, are successfully fabricated. In order to improve the colloidal stability of MGONCs in physiological solutions (e.g., phosphate buffered saline or PBS solution), MGONCs are further conjugated with polyethylene glycol (PEG). Heating by exposing MGONCs samples to an alternating magnetic field (AMF) show that the obtained nanocomposites are efficient hyperthermia agents. At concentrations as low as 0.1 mg Fe mL?1 and under an 59.99 kA m?1 field, the highest specific absorption rate (SAR) recorded is 1588.83 W g?1 for MGONCs loaded with 14 nm MFNPs. It is also demonstrated that MGONCs are promising as magnetic resonance imaging (MRI) T2 contrast agents. A T2 relaxivity value (r2) as high as 256.2 (mM Fe)?1 s?1 could be achieved with MGONCs loaded with 14 nm MFNPs. The cytotoxicity results show that PEGylated MGONCs exhibit an excellent biocompatibility that is suitable for biomedical applications. 相似文献
63.
The problem of scheduling in two different types of flowshops (all jobs available at time zero, different job availability times known a priori) and in flowline-based manufacturing cells is considered with the objective of minimizing the sum of weighted flowtime and weighted tardiness of jobs. First, heuristic preference relations are developed by the consideration of lower bounds on the completion times, operation due-dates, and weights for holding and tardiness of jobs. A heuristic algorithm for scheduling is then proposed by making use of the heuristic preference relations. Two more heuristic algorithms are developed by implementing an improvement scheme to enhance the quality of the solution given by the first heuristic algorithm. The proposed and the existing heuristics are evaluated with respect to the three problem classes under consideration by solving a large number of randomly generated problems. The results of an extensive computational investigation for various problem sizes are presented. It has been observed that all three proposed heuristics perform better than the existing heuristics in giving a solution of superior quality and that the first proposed heuristic yields a good solution by requiring a negligible CPU time. In addition, an experimental investigation is carried out to evaluate the effectiveness of the improvement scheme when implemented in the existing heuristics, and also the effectiveness of heuristics based on simulated annealing. The results are discussed in detail. 相似文献
64.
DurgaPrasad Karnam Harshit Agrawal Pranay Parte Saurabh Ranjan Priyanka Borar Prasanna Prakash Kurup Amose Jebin Joel Pattamadai Sankaran Srinivasan Uddhav Suryawanshi Aniket Sule Sanjay Chandrasekharan 《Journal of Computer Assisted Learning》2021,37(2):446-474
Educational technology designs in developing countries mostly focus on making knowledge resources widely available, through MOOCs, repositories and computer-based tutoring. The use of digital media for cognitive augmentation, particularly interactive designs that help learners understand modelling topics in STEM, is underexplored. We report a 3-year design study examining this potential in the Indian context, testing two iterations of an interactive system, Touchy-Feely Vectors (TFV). The design supports learning vectors, a modelling topic pre-university students struggle with. Virtual lesson-plans were co-designed with teachers to augment — but not replace — their existing practices, and to address classroom and resource constraints. Pre-post testing of TFV-1 (a computer-based prototype) showed that it helped students develop a more integrated vector concept, and improved their reasoning. Field-implementation of TFV-2 (a textbook-linked touch-screen based design) in 6-classrooms (3-Control, N=135; 3-Experimental, N=131) showed that it fostered cognitive engagement in average-students and geometry-algebra integration (model-based reasoning) in good-students. These results, along with a requirements analysis based on textbooks, indicate that the interaction possibilities supported by different representational media critically shape student reasoning. The study also illustrates a systematic approach to design and test digital media systems that support cognitive augmentation in developing countries. 相似文献
65.
In a gas fluidised-bed, bubble coalescence gives rise to a very rapid mass exchange rate with the dense phase. The extent of this exchange rate is calculated from the observed changes in bubble size with height in the bed. It is calculated that with a catalytic reaction in progress, the difference in composition between the dense phase and bubble phase rapidly falls to a negligible value for all cases where the reaction rate and throughput are su that a significant height of bed is required for nearly complete conversion. A corresponding model of the fluidised-bed catalytic reactor is analysed f which it transpires that its behaviour is very close to that of a CSTR, as is apparent when published data on reactor performance is examined. The stat mixing of the dense phase, if it were to depart from the completely mixed condition assumed, would influence this conclusion. 相似文献
66.
The solubility of fenofibrate in pH 6.8 McIlvaine buffers containing varying concentrations of sodium lauryl sulfate was determined. The dissolution behavior of fenofibrate was also examined in the same solutions with rotating disk experiments. It was observed that the enhancement in intrinsic dissolution rate was approximately 500-fold and the enhancement in solubility was approximately 2000-fold in a pH 6.8 buffer containing 2% (w/v) sodium lauryl sulfate compared to that in buffer alone. The micellar solubilization equilibrium coefficient (k*) was estimated from the solubility data and found to be 30884 ± 213 L/mol. The diffusivity for the free solute, 7.15 × 10- 6 cm2/s, was calculated using Schroeder's additive molal volume estimates and Hayduk-Laurie correlation. The diffusivity of the drug-loaded micelle, estimated from the experimental solubility and dissolution data and the calculated value for free solute diffusivity, was 0.86 × 10- 6 cm2/s. Thus, the much lower enhancement in dissolution of fenofibrate compared to its enhancement in solubility in surfactant solutions appears to be consistent with the contribution to the total transport due to enhanced micellar solubilization as well as a large decrease ( ∼ 8-fold) in the diffusivity of the drug-loaded micelle. 相似文献
67.
Oliver Holthaus Chandrasekharan Rajendran 《The International Journal of Advanced Manufacturing Technology》1997,13(2):148-153
We present two new dispatching rules for scheduling in a job shop. These rules combine the process-time and work-content in the queue for the next operation on a job, by making use of additive and alternative approaches. An extensive and rigorous simulation study has been carried out to evaluate the performance of the proposed dispatching rules compared with those by the SPT rule, the WINQ rule, a random rule based on the SPT and WINQ rules, and the best existing rule. The important aspects of the results of the experimental investigation are also discussed in detail. 相似文献
68.
69.
The problem of finding a rectilinear minimum bend path (RMBP) between two designated points inside a rectilinear polygon has applications in robotics and motion planning. In this paper, we present efficient algorithms to solve the query version of the RMBP problem for special classes of rectilinear polygons given their visibility graphs. Specifically, we show that given an unweighted graph G = (V, E), with ¦V¦ = N and ¦E¦ = M, algorithms to preprocess G in linear space and time such that the shortest distance queries — queries asking for the distance between any pair of nodes in the graph — can be answered in constant time and space are presented in this paper. For the case of a chordal graph G, our algorithms give a distance which is at most one away from the actual shortest distance. When G is a K-chordal graph, our algorithm produces an exact shortest distance in O(K) time. We also present a non-trivial parallel implementation of the sequential preprocessing algorithm for the CREW-PRAM model which runs in O(log2 N) time using O(N + M) processors. After the preprocessing, we can answer the queries in constant time using a single processor. 相似文献