全文获取类型
收费全文 | 772篇 |
免费 | 22篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 9篇 |
综合类 | 2篇 |
化学工业 | 96篇 |
金属工艺 | 24篇 |
机械仪表 | 33篇 |
建筑科学 | 36篇 |
矿业工程 | 3篇 |
能源动力 | 17篇 |
轻工业 | 27篇 |
水利工程 | 5篇 |
石油天然气 | 5篇 |
无线电 | 56篇 |
一般工业技术 | 118篇 |
冶金工业 | 279篇 |
原子能技术 | 9篇 |
自动化技术 | 79篇 |
出版年
2022年 | 14篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 19篇 |
2013年 | 47篇 |
2012年 | 22篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 16篇 |
2008年 | 23篇 |
2007年 | 15篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 16篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 17篇 |
1998年 | 36篇 |
1997年 | 23篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 14篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 15篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1979年 | 12篇 |
1977年 | 13篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1974年 | 14篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1971年 | 8篇 |
1964年 | 8篇 |
1955年 | 7篇 |
排序方式: 共有798条查询结果,搜索用时 0 毫秒
1.
2.
Patrick R. Taylor Ph.D. Milton Manrique Ph.D. 《JOM Journal of the Minerals, Metals and Materials Society》1996,48(6):43-45
Due to several inherent advantages, plasma processing technology may become a very useful tool in the production of new materials. An increasing research effort based on experimental as well as theoretical investigations has been invested in this area for the synthesis of advanced materials. In describing the thermal-plasma processing technique, this article employs examples from research at the Plasma Processing Laboratory at the University of Idaho. 相似文献
3.
Under carefully chosen conditions, solidification theory may be applied to solid-state transformations, and this has been
done here for composition-invariant diffusion transformations. The predictions of the modeling are compared with isovelocity
experiments in two iron systems, Fe-7.29 wt pct Cr and Fe-3.1 wt pct Ni. The ferrite to austenite phase transformation is
used to demonstrate that stabilization of a planar transformation front at absolute stability is the natural lower velocity
limit for a composition-invariant (massive) transformation. The results of the model, which includes nonequilibrium effects,
clearly show that steady-state plane-front growth leading to composition invariance can be obtained at various temperatures
depending on the growth velocity. In the lower velocity range, at the limit of absolute stability (of the order of 10 μm/s in the systems studied), the transformation interface moves under conditions of local equilibrium, and the temperature
corresponds to the lower solvus temperature. At higher velocity (of the order of the interface diffusion rate, which in these
systems is of the order of cm/s), the transformation is predicted to proceed at temperatures close to T
0. At even higher rates, atom attachment kinetic undercooling will decrease the transformation temperature with respect to
T
0. In some cases, this temperature might even drop below the lower solvus.
This article is based on a presentation made at the symposium entitled “The Mechanisms of the Massive Transformation,” a part
of the Fall 2000 TMS Meeting held October 16–19, 2000, in St. Louis, Missouri, under the auspices of the ASM Phase Transformations
Committee. 相似文献
4.
5.
6.
Sack E.A. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1994,82(4):465-468
Consumer electronics has played an important role in the development of integrated circuit technology. Inversely, the integrated circuit has made possible low-cost but highly complex products that we have come to depend upon for enjoyment and convenience in our lives as family units or individual consumers. Integrated circuit production economics favor volume applications and the ”one per human being” opportunity presented by consumer products can be a powerful driver. The performance requirements for consumer applications, including low cost, low power, battery operation, nonvolatile memory, high-frequency amplification and scanning, lightweight and pleasing as well as convenient input/output means have led to many innovations in the evolution of the integrated circuit 相似文献
7.
8.
S Dawson D Bennett SD Carter M Bennett J Meanger PC Turner MJ Carter I Milton RM Gaskell 《Canadian Metallurgical Quarterly》1994,56(2):133-143
Twelve specific pathogen-free cats were infected either by intra-articular inoculation or by contact exposure to one of two strains of feline calicivirus (FCV), either F65, a field strain originating from an outbreak of lameness in a group of cats, or a vaccine strain. Following either route of exposure, both strains induced signs typical of FCV infection including oral and nasal ulceration, conjunctivitis and ocular discharge. These signs were of equal severity for both virus strains, but overall, following either route of infection, F65 induced more severe disease than the vaccine strain, with marked pyrexia, lethargy and lameness. Vaccine virus only induced a relatively mild lameness following intra-articular inoculation. Gross pathological and histopathological lesions were seen in some of the joints, but again changes were more severe in the F65-exposed cats. Virus was isolated from both normal and affected joints from both groups of F65-exposed cats, and from a joint from each cat inoculated intra-articularly with vaccine virus. Mild transient lameness was also seen in one of two control cats inoculated intra-articularly, but no pathological changes were seen or virus isolated from joints. A cDNA probe used in RNA dot blot hybridisation experiments was found to be specific and more sensitive than virus isolation in detecting FCV in selected tissues. This may be useful in future studies on the pathogenesis of FCV disease and in studies on viral persistence in FCV carriers. 相似文献
9.
It has been suggested recently that in congenitally hypothyroid infants with organification defect there is a maternal-fetal transfer of thyroxine (T4). The present study was conducted to evaluate how effective the maternal-fetal transfer is and whether the maternal T4 can prevent intrauterine hypothyroidism. The clinical, laboratory and radiological data on 271 full-term infants with persistent primary congenital hypothyroidism, detected by the national screening program, were used to assess the degree of in utero hypothyroidism. For 6 out of 50 athyroid infants, two pretreatment blood samples spotted on filter paper were available for calculating the T4 disappearance rate. Most infants with agenesis of the thyroid had very low T4 and very high levels of thyroid-stimulating hormone compared to infants with ectopic thyroid. In the athyroid infants the initial T4 declined to low and undetectable levels. Bone maturation was significantly delayed while the clinical symptomatology was more prominent in the athyroid congenital hypothyroid infants, as compared with the ectopic thyroid infants. In conclusion, there is some maternal-fetal transfer of T4. However, this transfer is insufficient to suppress the fetal levels of thyroid-stimulating hormone and prevent intrauterine hypothyroidism. 相似文献
10.
Isolation of Shigella dysenteriae serotypes 11, 12, and 13 from patients with diarrhea in Bangladesh
M Ansaruzzaman AK Kibriya AK Mitra RB Sack MJ Albert 《Canadian Metallurgical Quarterly》1993,31(5):1392-1393
Nine isolates of bacteria biochemically resembling Shigella dysenteriae but not belonging to the 10 recognized serotypes were isolated from patients with diarrhea in Bangladesh. Further studies suggested that two, one, and six isolates belonged to the recently recognized S. dysenteriae serotypes 11, 12, and 13, respectively. 相似文献