全文获取类型
收费全文 | 3062篇 |
免费 | 0篇 |
专业分类
综合类 | 1篇 |
化学工业 | 11篇 |
建筑科学 | 1篇 |
轻工业 | 2篇 |
一般工业技术 | 2篇 |
冶金工业 | 3041篇 |
自动化技术 | 4篇 |
出版年
2019年 | 1篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2012年 | 1篇 |
2010年 | 3篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2003年 | 5篇 |
1999年 | 105篇 |
1998年 | 951篇 |
1997年 | 551篇 |
1996年 | 332篇 |
1995年 | 198篇 |
1994年 | 156篇 |
1993年 | 173篇 |
1992年 | 17篇 |
1991年 | 45篇 |
1990年 | 34篇 |
1989年 | 42篇 |
1988年 | 55篇 |
1987年 | 45篇 |
1986年 | 29篇 |
1985年 | 22篇 |
1983年 | 5篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 27篇 |
1979年 | 2篇 |
1978年 | 11篇 |
1977年 | 66篇 |
1976年 | 151篇 |
1975年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有3062条查询结果,搜索用时 15 毫秒
21.
TR Wrenn JR Weyant DL Wood J Bitman RM Rawlings KE Lyon 《Canadian Metallurgical Quarterly》1976,59(4):627-635
A practical means of protecting fats of a feed concentrate containing high polyunsaturated fatty acids is described. A ground mixture of 30% soybeans and 70% sunflower seeds was treated with 1% formaldehyde to protect the unsaturated lipids from microbial hydrogenation in the rumen. This was fed as a supplement to two Holstein cows in amounts that were doubled weekly. These ranged from 524 to 8384 g/day and provided successively increasing intakes of 100, 200, 400, 800, and 1600 g of linoleic acid daily. Percent milk fat increased by more than one, and linoleic acid (C18:2) of milk fat increased from 2.5 to 20% with compensatory declines in myristic (C14:0) and palmitic (C16:0) acids. Cholesterol and vitamin E of plasma both doubled at the highest supplementation. Milk yield, solids-not-fat, protein and milk cholesterol were unaltered. Fat in feces doubled from about 3 to 6%. Daily linoleic acid content of feces increased from 25 g to 120 g, indicating a dietary loss of 7 to 10% of this polyunsaturated acid. These cheaper feed ingredients elevated the polyunsaturated fats in milk as effectively as the expensive purified casein and safflower oil supplements in previous experiments. 相似文献
22.
FC Sparks AG Wile KP Ramming HK Silver RW Wolk DL Morton 《Canadian Metallurgical Quarterly》1976,111(10):1057-1062
Antibody against a breast carcinoma antigen was present in patients with breast carcinoma and other cancer more often (P less than .05) than in normal women. The incidence of antibody in women with breast carcinoma correlated with the presence or absence of gross tumor, and the titer of antibody paralleled the clinical course. These results suggest importance of a host-immune response to breast carcinoma. Fifty-seven patients with stage II carcinoma of the breast were entered into a prospective randomized adjuvant chemoimmunotherapy program of cyclophosphamide, methotrexate, and fluorouracil, and BCG vaccine +/- an irradiated allogeneic tumor cell vaccine. After 24 months of study, metastases occurred in two patients (3.5%) and a new primary carcinoma developed in the contralateral breast in two others, for an overall treatment failure rate of 7%. Adjuvant chemoimmunotherapy can delay early recurrence. Long-term follow-up is needed to assess the significance of these results. 相似文献
23.
Ion transport and electrical properties of rabbit and guinea pig gallbladders were investigated to gain further information about the active transport mechanism that mediates fluid absorption. The intracellular and transepithelial electrical potentials were measured simultaneously using the microelectrode technique. Exposure of the mucosal surface to Amphotericin B resulted in the prompt development of a serosa-positive electrical potential difference (PD) which could not be attributed to an alteration in ion diffusion potentials across either the cell membrane or across the tight junction. Because the Amphotericin B-induced PD was immediately dependent on warm temperatures and O2, and was independent of NA and K concentration gradients across the cell membrane, it is suggested that active ion transport is directly responsible for the PD. Since the PD was abolished in the absence of Na in the bathing solutions, a rheogenic Na pump is postulated; this pump also appears to be operative in tissues not exposed to Amphotericin B. The specific tissue properties altered by Amphotericin B to produce a serosa-positive PD remain incompletely defined. The results of the present study indicate that ion transport by rabbit gallbladder in vitro is a consequence of a rheogenic active Na transport mechanism at the basolateral membranes which, in conjunction with a coupled NaC1 influx process at the mucosal border, ultimately results in absorption of NaC1 and water. 相似文献
24.
25.
26.
The catecholamine hypothesis of progressive spinal cord necrosis following mechanical trauma was investigated with the histofluorometric method. Forty-four adult mongrel dog were examined as control, L1 crush-injured, and crush-injured with prior T1 total transection groups. In crush injured dogs, catecholamines were present in a 1 cm length of white matter at the crush site, with the greatest accumulation in the deep lateral and ventral funiculi. Gray matter fluorescence was not enhanced. Prior transection did not abolish the intense accumulation of catecholamines at the site of the cord injury. We propose that the catecholamines accumulating at the cord injured site are not central in origin, but represent an uptake mechanism into white matter as a reflection of cord microperfusion. 相似文献
27.
28.
M Dempsey DL Dunner RR Fieve T Farkas J Wong 《Canadian Metallurgical Quarterly》1976,133(9):1082-1084
Six female primary affective disorder patients who had gained an average of 9.5 kg while taking lithium lost an average of 2.9 kg on a 10-day 900 calorie a day hospital diet containing 100 mEq of sodium per day. No evidence of lithium toxicity was observed on this regimen. There was no evidence that fluid retention played a major role in the weight gain. 相似文献
29.
30.