全文获取类型
收费全文 | 1629篇 |
免费 | 0篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 20篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 1篇 |
轻工业 | 13篇 |
无线电 | 8篇 |
一般工业技术 | 25篇 |
冶金工业 | 1530篇 |
自动化技术 | 27篇 |
出版年
2022年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 44篇 |
1998年 | 428篇 |
1997年 | 233篇 |
1996年 | 163篇 |
1995年 | 98篇 |
1994年 | 85篇 |
1993年 | 85篇 |
1992年 | 23篇 |
1991年 | 24篇 |
1990年 | 25篇 |
1989年 | 33篇 |
1988年 | 34篇 |
1987年 | 28篇 |
1986年 | 34篇 |
1985年 | 18篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 44篇 |
1976年 | 102篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1629条查询结果,搜索用时 15 毫秒
51.
52.
A case of split notochord syndrome associated with a prolapsed colostomylike dorsal enteric opening, a foreshortened colon, imperforate anus, and meningocele is presented. The surgical management of this disorder is discussed and available literature is reviewed. The patient was successfully treated with a combined, single-stage surgical correction. 相似文献
53.
Isoelectronic x-ray spectroscopy to determine electron temperatures in long-scale-length inertial-confinement-fusion plasmas 总被引:1,自引:0,他引:1
54.
DH Werker AE Singh H Artsob J Hockin 《Canadian Metallurgical Quarterly》1995,21(9):77-9; discussion 79-80
55.
56.
57.
MK Lee TH You BA Young JA Cotrill AP Valaitis DH Dean 《Canadian Metallurgical Quarterly》1996,62(8):2845-2849
We have evaluated the binding of Bacillus thuringiensis Cry toxins to aminopeptidase N (APN) purified from Lymantria dispar (gypsy moth) brush border membrane vesicle (BBMV). CryIAc toxin bound strongly to APN, while either the structurally related CryIAa and CryIAb toxins or CryIC, CryIIA, and CryIIIA toxins showed weak binding to APN. An in vitro competition binding study demonstrated that the binding of CryIAc to L. dispar BBMV was inhibited by APN. Inhibition of short circuit current for CryIAc, measured by voltage clamping of whole L. dispar midgut, was substantially reduced by addition of phosphatidylinositol-specific phospholipase C, which is known to release APN from the midgut membrane. In contrast, addition of phosphatidylinositol-specific phospholipase C had only a marginal effect on the inhibition of short circuit current for CryIAa. These data suggest that APN is the major functional receptor for CryIAc in L. dispar BBMV. A ligand blotting experiment demonstrated that CryIAc recognized a 120-kDa peptide (APN), while CryIAa and CryIAb recognized a 210-kDa molecule in L. dispar BBMV. In contrast, CryIAa and CryIAb bound to both the 120- and 210-kDa molecules in Manduca sexta BBMV, while CryIAc recognized only the 120-kDa peptide. The 120-kDa peptide (APN) in L. dispar BBMV reacted with soybean agglutinin, indicating that N-acetylgalactosamine is a component of this glycoprotein. 相似文献
58.
59.
Dual energy X-ray absorptiometry (DXA) is one of the most widely used techniques in the management of osteoporosis and other skeletal diseases. Although patient doses from DXA are generally low, it is still necessary to measure them to assess the risk of radiation injury. We report on a study to estimate the effective dose (ED) to patients and staff from a new DXA scanner--the Lunar EXPERT, and make a comparison with a similar study carried out on a Lunar DPX-L. The entrance surface doses were measured to be 895 microGy and 10.25 microGy for the EXPERT and DPX-L, respectively. The EXPERT maximum EDs were calculated to be 74.7 microSv and 44.9 microSv for the anteroposterior (AP) lumbar spine and the proximal femur, respectively. More than 50% reduction in ED could be achieved by using a smaller scanning width. The maximum EDs for the DPX-L were calculated to be 0.21 microSv and 0.15 microSv for the AP lumbar spine and the proximal femur, respectively. The scattered dose rates (ambient dose equivalent) were measured to be less than 2 and less than 1 microSv h-1 at 50 cm and 100 cm, respectively, for the DPX-L, and the equivalent values for the EXPERT were 240 and 64 microSv h-1. Although both the patient dose and scattered dose rates are quite low relative to other radiological examinations, good practice aimed at dose reduction should still be implemented. Whilst protection for the operator is not needed for the DPX-L system, it may be (depending on the size of the room) for the EXPERT system. 相似文献
60.
DH Turnbull JA Ramsay GS Shivji TS Bloomfield L From DN Sauder FS Foster 《Canadian Metallurgical Quarterly》1996,22(7):845-853
The incidence and mortality rate of cutaneous melanoma continue to increase throughout the world, making the study of melanoma biology an important area of current research. While recent breakthroughs in transgenic mouse technology have led to promising mouse skin models of melanoma, there is presently no technique available for quantitatively studying subsurface melanoma progression, in vivo. We demonstrate the first application of an imaging method called ultrasound backscatter microscopy (UBM) for imaging early murine melanomas with spatial resolution of 30 microns axial and 60 microns lateral. Murine B16 F10 melanomas have been imaged from their earliest detection, over several days, until they are 2 to 5 mm in diameter. Melanoma dimensions measured by UBM were found to be in excellent agreement with those determined histopathologically on the excised tumours. The relative rms errors in UBM-determined melanoma height and width were found to be 8.7% and 4.2%, respectively. The mean rate of increase in tumour height of early murine melanoma was found to be 0.37 +/- 0.06 mm/day. Computer-generated volumetric renderings of melanomas have been produced from three-dimensional image data, allowing quantitative comparisons of tumour volumes to be made. Using a priori assumptions of ellipsoid tumour shape, the relative error in UBM-determined volume was shown to be less than 17%. These results should be of considerable interest to investigators studying melanoma biology using mouse skin models, and have implications in the use of high frequency ultrasound imaging for the clinical assessment of cutaneous melanoma. 相似文献