全文获取类型
收费全文 | 131篇 |
免费 | 5篇 |
专业分类
化学工业 | 7篇 |
金属工艺 | 8篇 |
机械仪表 | 7篇 |
建筑科学 | 5篇 |
能源动力 | 3篇 |
轻工业 | 11篇 |
水利工程 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 21篇 |
冶金工业 | 55篇 |
自动化技术 | 8篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 10篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 14篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1987年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1976年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有136条查询结果,搜索用时 46 毫秒
51.
The paper shows that, in certain circumstances, wind convectors have economic and technical advantages over conventional fan-assisted heat-pump evaporators. This assessment compares wind convectors with conventional fin-tube evaporators from energy, maintenance, capital cost and other viewpoints. Compared to conventional fan-assisted heat pump evaporators, wind convector technology is estimated to provide energy savings of between 10 and 20%, maintenance savings of approximately 50% and a reduction of heat pump capital costs of approximately 10 to 15%. 相似文献
52.
We perform a numerical analysis of the double random phase encryption-decryption technique to determine how, in the case of both amplitude and phase encoding, the two decryption keys (the image- and Fourier-plane keys) affect the output gray-scale image when they are in error. We perform perfect encryption and imperfect decryption. We introduce errors into the decrypting keys that correspond to the use of random distributions of incorrect pixel values. We quantify the effects that increasing amounts of error in the image-plane key, the Fourier-plane key, and both keys simultaneously have on the decrypted image. Quantization effects are also examined. 相似文献
53.
Nguyen Thi Bang Tuyen Mitra Subhasish Evans Geoffrey M. Monaghan Brian J. Zulli Paul Jang Kyoung-oh O’Dea Damien Honeyands Tom 《Metallurgical and Materials Transactions A》2021,52(11):4841-4851
Metallurgical and Materials Transactions A - Study of drag force on dendritic particles in highly viscous fluids is essential for understanding the dynamic sinking/floating behavior of particles in... 相似文献
54.
Surface-enhanced Raman signatures of pigmentation of cyanobacteria from within geological samples in a spectroscopic-microfluidic flow cell 总被引:2,自引:0,他引:2
A simple surface-enhanced Raman spectroscopy (SERS) microflow cell was developed to investigate distributions of scytonemin pigment within cyanobacteria from samples of rock collected from an arctic desert that contained endolithic cyanobacteria. The assay, which has future potential use in a variety of applications, including astrobiology and analysis of microorganisms in remote environments, involved studying SERS spectra of bacteria from within geological samples. By using a dispersed colloidal substrate in the microfluidic device, surface enhancement of the order >10(5) was obtained for the determination of the pigment in the microorganisms when compared to the native Raman spectra. The SERS assay, which had a nM sensitivity for scytonemin, showed that the concentration of pigment was highest in samples that had experienced the highest stress environments, as a result of high doses of UV irradiation. 相似文献
55.
There is concern regarding microbial water quality in many pastoral catchments in New Zealand which are home to numerous livestock and wild animals. Information on microbial impacts on water quality from these animals is scarce. A framework is needed to summarise our current knowledge and identify gaps at the scale of an individual farm. We applied a Monte Carlo modelling approach to a hypothetical dairy farm based on the extensive data sets available for the Toenepi Catchment, Waikato, New Zealand. The model focused on quantifiable direct inputs to the stream from ducks, cows and farm dairy effluent (FDE) during base-flow conditions. Most of the inputs of Escherichia coli from dairy farms occur sporadically and, therefore, have little effect on the expected median stream concentrations. These sporadic inputs do however, have a strong influence on extrema such as 95th percentile values. Current farm mitigations of fencing streams and using improved management practices for applying FDE to land, such as low application rate deferred FDE irrigation systems, would appreciably reduce faecal microbial inputs to the stream. However, the concentrations of E. coli in rural streams may not reduce as much as expected as wild fowl living in streams would have a larger effect on water quality than a farm in which environmental mitigations are widely implemented. 相似文献
56.
RG Nager P Monaghan R Griffiths DC Houston R Dawson 《Canadian Metallurgical Quarterly》1999,96(2):570-573
Sex ratio theory predicts that, if prevailing ecological or social circumstances differentially influence the fitness benefits of offspring of each sex, parents should adjust their production accordingly to maximize fitness. For species in which sex is chromosomally determined, such as birds and mammals, a differential effect of maternal condition on the fitness of male and female young is one important route whereby selection is expected to favor a bias in the offspring sex ratio at birth or egg laying. However, despite its central place in sex allocation theory, this hypothesis has rarely been tested in wild populations. We manipulated maternal condition upward and downward in a sexually dimorphic wild bird and examined the effect on offspring survival and on offspring sex ratio. The survival to fledging of male, but not female, young was substantially reduced if they came from less well provisioned eggs produced by females in relatively poor condition. As female condition, and thereby her capacity to produce high quality eggs, declined, she progressively skewed the sex ratio of her eggs toward females; i.e., she produced more of the sex with the higher survival prospects. The decline in the survival of male offspring, and the sex ratio bias, was removed when maternal condition was enhanced. These results provide experimental evidence of an adaptive, facultative adjustment of sex ratio in response to changes in maternal condition in wild birds. 相似文献
57.
Three overlapping clones of cDNA, Mos43, Mos28 and Mos60, coding for methionyl-tRNA synthetase were obtained by screening the Oryza sativa lambda gt11 library. Their nucleotide sequence of 2850 bp was determined. The deduced amino-acid sequence of the isolated clones contains a HLGN and KFSKS motifs, which are conserved for this family of enzymes and have been proposed to be the signature sequences for class I aminoacyl-tRNA synthetases. A comparison of the rice MetRS primary structure with those deposited in EMBL/GenBank points to its high homology to yeast, human and Caenorhabditis elegans MetRSs. Interestingly, a great similarity of its C terminus to endothelial-monocyte-activating polypeptide II (EMAPII) and yeast protein G4p1 was observed. 相似文献
58.
GM Deeb DM Williams SF Bolling LE Quint H Monaghan J Sievers D Karavite M Shea 《Canadian Metallurgical Quarterly》1997,64(6):1669-75; discussion 1675-7
59.
SM Gormally W Bourke B Kierse H Monaghan J McMenamin B Drumm 《Canadian Metallurgical Quarterly》1995,154(10):815-818
Arterial thrombo-embolism is an unusual complication in inflammatory bowel disease in adults and children. Cerebral arterial disease has been reported on only a few occasions. There are only two previous case reports of arterial disease occurring in a child with Crohn disease. However in both instances the arterial disease was part of a generalised Takayasu arteritis which resulted in multi-organ involvement. This report describes a 14-year-old boy who developed seizures before a histological diagnosis of Crohn disease was made. These seizures were the result of a vascular lesion which was confined to the right middle cerebral artery. CONCLUSION. Crohn disease as well as ulcerative colitis should be considered as a possible cause of cerebrovascular accidents in children. 相似文献
60.
AJ Atherton MJ Warburton MJ O''Hare P Monaghan D Schuppan BA Gusterson 《Canadian Metallurgical Quarterly》1998,291(3):507-511
Immunolocalisation of type XIV collagen/undulin in the human mammary gland revealed greater deposition in the interlobular stroma than in the intralobular stroma. The interlobular stroma is located between the breast lobules and their associated intralobular stroma. Fibroblasts isolated from the interlobular stroma synthesised 3- to 5-fold more type XIV collagen/undulin than intralobular fibroblasts, but synthesised type I and type IV collagens in similar amounts. The differential expression of type XIV collagen/undulin was maintained with passage in culture. The results suggest a role for type XIV collagen/undulin in stabilising dense collagen fibrils. The maintenance of two types of structurally distinct stromas may be important during developmental processes in the mammary gland. 相似文献