全文获取类型
收费全文 | 402篇 |
免费 | 12篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 98篇 |
金属工艺 | 12篇 |
机械仪表 | 7篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 20篇 |
轻工业 | 19篇 |
水利工程 | 1篇 |
石油天然气 | 15篇 |
无线电 | 65篇 |
一般工业技术 | 53篇 |
冶金工业 | 32篇 |
原子能技术 | 11篇 |
自动化技术 | 67篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 20篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 23篇 |
2012年 | 22篇 |
2011年 | 12篇 |
2010年 | 10篇 |
2009年 | 19篇 |
2008年 | 21篇 |
2007年 | 17篇 |
2006年 | 7篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 14篇 |
1999年 | 7篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有414条查询结果,搜索用时 0 毫秒
1.
EA Ismail IS Shabani M Badawi H Sanaa S Madi A Al-Tawari H Nadi M Zaki Q Al-saleh 《Canadian Metallurgical Quarterly》1998,13(10):488-492
We studied Guillain-Barré syndrome, affecting children 12 years old or less, throughout Kuwait, in the period between January 1, 1992, and March 31, 1997. Nineteen children had the diagnostic criteria of Guillain-Barré syndrome, with an overall annual incidence rate of 0.95/100,000 population at risk. Female patients outnumbered male patients with a sex ratio of 1.4:1. There was a clustering of cases in winter and spring and in the year 1996. The disease symptoms were relatively severe in our patients because only 16% (3 of 19) of them were able to walk at the height of their illness, whereas the rest were bed or chair bound or needed assisted ventilation. Two patients had the electrodiagnostic features of axonal neuropathy and both had residual deficits on follow-up, whereas the rest recovered fully. All the patients received intravenous immunoglobulin. The mean time to walk unaided was 23.5 days (range, 2-84 days) after intravenous immunoglobulin and excluding the two patients with axonal neuropathy, and full recovery was achieved in a mean time of 103 days (range, 30-300 days). Contrary to previous studies, we found no correlation between oral polio vaccine administration and Guillain-Barré syndrome in 2 successive years (1995 and 1996) during a nationwide campaign targeting children less than 5 years old. 相似文献
2.
The chemical oxidation of aniline to form polyaniline (PANI) films and powder samples was made using Fenton reagent as an oxidizing agent in aqueous sulfuric acid medium. The PANI films were monitored by using the quartz crystal microbalance and the electronic absorption techniques. The optimum concentration was determined and the results were justified by measuring the UV–vis absorption spectra for the in situ PANI films. The conductivity for the PANI films and powder samples, prepared in different conditions, was measured. Also, the IR spectra, X‐ray and the thermogravimetric analysis for the PANI powder formed in the bulk were measured and compared with the polymer prepared using ammonium peroxydisulfate. A preliminary investigation to the dielectric properties of the polymer powder was measured and discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
3.
Zaki Ahmad M. El-Nagar Ahmad M. El-Bardini Mohammad Soliman F. A. S. 《Neural computing & applications》2021,33(5):1515-1531
Neural Computing and Applications - For the current paper, the technique of feed-forward neural network deep learning controller (FFNNDLC) for the nonlinear systems is proposed. The FFNNDLC... 相似文献
4.
Driscoll MM Haynes JT Jelen RA Weinert RW Gavaler JR Talvacchio J Wagner GR Zaki KA Liang XP 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1992,39(3):405-411
Ultra-high Q, X-band resonators, used in a frequency discriminator for stabilization of a low-noise signal generator, can provide a means of obtaining significant reduction in phase noise levels. Resonator unloaded Qs on the order of 500 K can be obtained in sapphire dielectric resonator (DR) operating on a low-order (i.e. TE(01)) mode at 77 K and employing high-temperature superconducting (HTS) films installed in the DR enclosure covers. Rigorous analysis for the determination of resonator frequency, modes, and unloaded Q have been carried out using mode matching techniques. Trade-off studies have been performed to select resonator dimensions for the optimum mode yielding highest unloaded Q and widest spurious mode separation. Field distributions within the resonator have been computed to enable practical excitation of the required mode. The results of both analysis and prototype device evaluation experiments are compared for resonators fabricated using enclosures consisting of conventional, metal sidewalls and covers employing HTS films as a function of cover conductivity. 相似文献
5.
A rapid test to measure performance,emission and wear of a diesel engine fueled with palm oil diesel
H. Masjuki A. M. Zaki S. M. Sapuan 《Journal of the American Oil Chemists' Society》1993,70(10):1021-1025
Results of performance, emission and tribological evaluations of palm oil methyl ester and its blends with conventional diesel
in an automobile diesel engine test bed are presented. Polymerization and carbon deposits on the fuel injector were monitored.
CO, CO2, O2, combustion efficiency and temperature of exhaust gases were also measured. Palm oil methyl ester and its blends have great
potential as alternative diesel fuel. Performance and exhaust gas emission for palm oil methyl ester and its blends with conventional
diesel are comparable with those of conventional diesel fuel. Palm oil methyl ester does not pose a severe environmental problem
and will not deteriorate engine and bearing components. 相似文献
6.
Nor?Azowa?IbrahimEmail author Faraj?Abu-Ilaiwi Mohamad?Zaki?Ab.?Rahman Mansor?B.?Ahmad Khairul?Zaman?M.?Dahlan Wan?Md?Zin?Wan?Yunus 《Journal of Polymer Research》2005,12(3):173-179
Grafting of acrylamide (AAm) onto oil palm empty fruits bunch fiber using hydrogen peroxide as initiator and methyl acrylate as comonomer was investigated. The amount of comonomer needed to make grafting of acrylamide possible was determined. The percentage of poly(acrylamide) and the comonomer in the final graft copolymer was estimated by elemental analysis. Results obtained indicated that methyl acrylate facilitated the incorporation of acrylamide monomer onto OPEFB. The reactivity ratios for both monomers were determined by using Fineman–Ross plot. The effects of reaction temperature and period as well as amount of the initiator, solvent, monomer and comonomer on the percentage of grafting at fixed amount of comonomer (11 mmol) were studied. Maximum percentage of grafting was achieved when the amount of initiator and solvent 3.98×10−3 mol and 50 mL respectively. The optimum reaction temperature was 50 ○C and the reaction period was 90 min. Highest percentage of grafting was 232% when 25.6 mmol of acrylamide was used under these optimum conditions. The presence of functional group in the grafted polymer is characterized by infrared spectroscopy and the surface morphology is observed by scanning electron microscopy. Thermoanalytic investigation on OPEFB and OPEFB-g-PAAM were carried out to evaluate the thermal stability and respective activation energy of the materials. 相似文献
7.
Nabil Zaki 《Metal Finishing》2007,105(10):425-435
8.
Mohammad Al Hasan Saeed Salem Mohammed J. Zaki 《Knowledge and Information Systems》2011,28(3):665-685
Clustering algorithms generally accept a parameter k from the user, which determines the number of clusters sought. However, in many application domains, like document categorization,
social network clustering, and frequent pattern summarization, the proper value of k is difficult to guess. An alternative clustering formulation that does not require k is to impose a lower bound on the similarity between an object and its corresponding cluster representative. Such a formulation chooses exactly one representative for
every cluster and minimizes the representative count. It has many additional benefits. For instance, it supports overlapping
clusters in a natural way. Moreover, for every cluster, it selects a representative object, which can be effectively used
in summarization or semi-supervised classification task. In this work, we propose an algorithm, SimClus, for clustering with lower bound on similarity. It achieves a O(log n) approximation bound on the number of clusters, whereas for the best previous algorithm the bound can be as poor as O(n). Experiments on real and synthetic data sets show that our algorithm produces more than 40% fewer representative objects,
yet offers the same or better clustering quality. We also propose a dynamic variant of the algorithm, which can be effectively
used in an on-line setting. 相似文献
9.
Safety performance of MOX fuel based PbBi cooled small fast power reactors has been analyzed and discussed. Though the thermal conductivity of MOX fuel is not large relative to that of nitride or metal fuel, but by proper combination of relatively small power density and relatively large natural circulation it can compensate fuel temperature decrease with coolant temperature increase smartly during unprotected loss of flow accident. Under such condition, accident analysis discussed in this paper show that under unprotected total loss of flow (ULOF) accident the reactor can survive inherently using combination of reactivity feedback. For unprotected rod run out transient over power (UTOP) accident the MOX reactor can overcome external reactivity by smaller power increase compared to that of nitride fueled reactors case. In this case doppler feedback plays much more important role compared to radial expansion component. So the MOX fueled small power reactors discussed here can survive both UTOP and ULOF accident with still enough temperature margin. 相似文献
10.
D. I. Bradley D. O. Clubb S. N. Fisher A. M. Guénault R.P. Haley C. J. Matthews G. R. Pickett K. L. Zaki 《Journal of Low Temperature Physics》2005,138(3-4):493-498
No Heading We have measured responses of vibrating wire resonators in superfluid 4He at millikelvin temperatures. We find evidence for turbulence generation above a critical velocity on the order of a few cm/s. At the critical velocity for the onset of turbulence, the resonator velocity abruptly decreases and shows hysteretic behavior. Surprisingly we find that the resonant frequencies of the resonators increase in the turbulent regime. We also find that the critical velocity may be reduced by the presence of turbulence generated by a neighboring vibrating wire resonator, allowing the detection of existing turbulence in the low temperature regime.PACS numbers: 67.40 Vs, 67.40 Pm 相似文献