全文获取类型
收费全文 | 1148篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
化学工业 | 2篇 |
金属工艺 | 1篇 |
机械仪表 | 4篇 |
轻工业 | 5篇 |
无线电 | 4篇 |
一般工业技术 | 2篇 |
冶金工业 | 1131篇 |
自动化技术 | 1篇 |
出版年
2013年 | 4篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2005年 | 1篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 25篇 |
1998年 | 398篇 |
1997年 | 218篇 |
1996年 | 118篇 |
1995年 | 75篇 |
1994年 | 48篇 |
1993年 | 70篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 12篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 13篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 32篇 |
1976年 | 55篇 |
1975年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1150条查询结果,搜索用时 15 毫秒
11.
12.
13.
M Stucki R Moudry C Kempf A Omar A Schlegel PG Lerch 《Canadian Metallurgical Quarterly》1997,700(1-2):241-248
A chromatographic fractionation method has been developed for the production of a liquid-stable anti-D immunoglobulin product for intravenous and intramuscular use. An immunoglobulin fraction, highly enriched with anti-D immunoglobulins, was isolated by cation-exchange column chromatography and further polished, first by anion-exchange chromatography, followed by an aluminium hydroxide gel treatment. The process includes two specific steps for virus inactivation and removal, namely S/D treatment and nanofiltration. The overall anti-D process yield is about 56%. The final product is stabilised with human albumin and glycine and placed in ready-to-use syringes. The anti-D product was shown to be stable in liquid state for at least 30 months at 4 degrees C. 相似文献
14.
Manganese superoxide dismutase (MnSOD) genetic polymorphisms, dietary antioxidants, and risk of breast cancer 总被引:1,自引:0,他引:1
CB Ambrosone JL Freudenheim PA Thompson E Bowman JE Vena JR Marshall S Graham R Laughlin T Nemoto PG Shields 《Canadian Metallurgical Quarterly》1999,59(3):602-606
Oxidative stress, resulting from the imbalance between prooxidant and antioxidant states, damages DNA, proteins, cell membranes, and mitochondria and seems to play a role in human breast carcinogenesis. Dietary sources of antioxidants (chemical) and endogenous antioxidants (enzymatic), including the polymorphic manganese superoxide dismutase (MnSOD), can act to reduce the load of oxidative stress. We hypothesized that the valine-to-alanine substitution that seems to alter transport of the enzyme into the mitochondrion, changing its efficacy in fighting oxidative stress, was associated with breast cancer risk and that a diet rich in sources of antioxidants could ameliorate the effects on risk. Data were collected in a case-control study of diet and breast cancer in western New York from 1986 to 1991. Caucasian women with incident, primary, histologically confirmed breast cancer were frequency-matched on age and county of residence to community controls. Blood specimens were collected and processed from a subset of participants in the study (266 cases and 295 controls). Using a RFLP that distinguishes a valine (V) to alanine (A) change in the -9 position in the signal sequence of the protein for MnSOD, we characterized MnSOD genotypes in relation to breast cancer risk. We also evaluated the effect of the polymorphism on risk among low and high consumers of fruits and vegetables. Premenopausal women who were homozygous for the A allele had a 4-fold increase in breast cancer risk in comparison to those with 1 or 2 V alleles (odds ratio, 4.3; 95% confidence interval, 1.7-10.8). Risk was most pronounced among women below the median consumption of fruits and vegetables and of dietary ascorbic acid and alpha-tocopherol, with little increased risk for those with diets rich in these foods. Relationships were weaker among postmenopausal women, although the MnSOD AA genotype was associated with an almost 2-fold increase in risk (odds ratio, 1.8; confidence interval, 0.9-3.6). No appreciable modification of risk by diet was detected for these older women. These data support the hypothesis that MnSOD and oxidative stress play a significant role in breast cancer risk, particularly in premenopausal women. The finding that risk was greatest among women who consumed lower amounts of dietary antioxidants and was minimal among high consumers indicates that a diet rich in sources of antioxidants may minimize the deleterious effects of the MnSOD polymorphism, thereby supporting public health recommendations for the consumption of diets rich in fruits and vegetables as a preventive measure against cancer. 相似文献
15.
N Ram MV Rao L Prabhu CS Nirodi S Sultana PG Vatsala G Padmanaban 《Canadian Metallurgical Quarterly》1995,317(1):39-45
Polymeric films were deposited from hydroxyethylmethacrylate (HEMA) plasma on non-woven poly(butyleneterephtalate) (PBT) filter materials. To test the effect of deposition conditions on surface properties, film were deposited using a constant monomer flow rate and a discharge power ranging from 40-100 W. Surface composition and surface energetics were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA) and contact angle measurement, respectively. Albumin (Alb) and fibrinogen (Fg) adsorption from single protein solutions to the plasma-coated filters was measured. Results illustrate the marked effects of the deposition condition on the surface composition, the surface field of forces, and the protein adsorption behavior. The latter is modeled by the application of the Good-van Oss-Chaudhury theory of Lewis acid-base contribution to interfacial energetics. Materials endowed with widely different properties are obtained from the same monomer and different deposition conditions, a result that must be taken into account both in the production step, to assure constant quality, and in the development of specifically tailored materials. 相似文献
16.
17.
18.
19.
In the present paper, the literature on the development of methods for histometric monitoring the quality of meats is reviewed. The value of specific techniques, statistical interpretation of results and the practicability of automation of histometric analysis are examined more closely. It is concluded from the study of the literature that histometric examination of meats allows an objective assessment of volume percentages of tissue components. When a distinct difference in contrast between various tissues is achieved by specific staining methods, developments in the field of image analysis systems will allow automation of the quantitative histological examination of meats. 相似文献
20.