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991.
Interactions of dietary energy and fat with recombinant bST (sometribove) injections were tested for their effects on ovarian function. Lactating dairy cows were fed one of three diets differing in energy concentration (NEL) and percentage of DM of calcium salts of long-chain fatty acids: diet 1, 1.68 Mcal/kg and 0%; diet 2, 1.68 Mcal/kg and 2.2%; and diet 3, 1.78 Mcal/kg and 2.2%. Cows were injected daily with bST or saline during one of two 19-d interestrous periods (crossover design) in which ovarian follicles were measured by ultrasonography. The bST-treated cows produced more FCM and were in lower energy balance than saline-treated cows. Before d 12 (first follicular wave, estrus = d 0), bST-treated cows had more ovarian follicles in classes 1 (3 to 5 mm; cows on diet 3) or 2 (6 to 9 mm; cows on diets 1 and 2) than saline-treated cows. After d 12 (preovulatory follicular wave), numbers of follicles in different size classes were similar for bST-treated and saline-treated cows, but cows fed diet 2 had larger preovulatory follicles. Lower dietary energy and bST treatment were both associated with larger subordinate follicles. Ovarian follicles less than 10 mm were stimulated by bST, and calcium salts of long-chain fatty acids increased diameters of preovulatory follicles. 相似文献
992.
TS Yeh CR Wang SH Huang SF Huang PC Yang CY Chuang 《Canadian Metallurgical Quarterly》1993,92(2):192-194
This paper explores nursing's current fascination with defining and exploring the term 'caring'. Fear of caring is proposed as the reason for this fascination. Factors at the root of this fear are identified and an expanded definition of caring (one which arises from the dispelling of such fear) is proposed. This expanded definition is given a new label--loving. For, as this author contends, has not loving always been at the heart of nursing? 相似文献
993.
In a previous paper, we reported the isolation and structure determination of three new steroidal saponins, dongnosides C (3), D (2) and E (1) from the dried fermented residues of leaf-juices of Agave sisalana forma Dong No. 1. In a continuing study on this plant, two additional new major steroidal saponins, named dongnosides B (4) and A (5), were obtained. Their structures were characterized respectively as tigogenin 3-O-alpha-L-rhamonpyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)- [beta-D- glucopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactop yranoside and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)-[beta- D- xylopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)]-beta-D- glucopyranosyl-(1-->4)-beta-D-galactopyranoside on the basis of chemical and physicochemical evidence. 相似文献
994.
E Rakovitch W Mellado EJ Hall SG Sawant CR Geard RA Newman TK Pandita 《Canadian Metallurgical Quarterly》1999,6(1):161-165
Acarbose reduces the absorption of monosaccharides derived from dietary carbohydrates, which play an important role in the metabolism and toxicity of some chemical compounds. We studied the effects of acarbose on the hepatotoxicity of carbon tetrachloride (CCl4) and acetaminophen (AP) in rats, both of which exert their toxic effects through bioactivation associated with cytochrome P450 2E1 (CYP2E1). Male Sprague-Dawley rats were kept on a daily ration (20 g) of powdered chow diet containing 0, 20, 40, or 80 mg/100 g of acarbose, with drinking water containing 0% or 10% of ethanol (vol/vol). Three weeks later, the rats were either killed for an in vitro metabolism study or challenged with 0.50 g/kg CCl4 orally or 0. 75 g/kg AP intraperitoneally. The ethanol increased the hepatic microsomal CYP2E1 level and the rate of dimethylnitrosamine (DMN) demethylation. The 40- or 80-mg/100 g acarbose diet, which alone increased the CYP2E1 level and the rate of DMN demethylation, augmented the enzyme induction by ethanol. The 40- or 80-mg/100 g acarbose diet alone potentiated CCl4 and AP hepatotoxicity, as evidenced by significantly increased levels of both alanine transaminase (ALT) and aspartate transaminase (AST) in the plasma of rats pretreated with acarbose. Ethanol alone also potentiated the toxicity of both chemicals. When the 40- or 80-mg/100 g acarbose diet was combined with ethanol, the ethanol-induced potentiation of CCl4 and AP hepatotoxicity was augmented. Our study demonstrated that high doses of acarbose, alone or in combination with ethanol, can potentiate CCl4 and AP hepatotoxicity in rats by inducing hepatic CYP2E1. 相似文献
995.
CR Marinho MR D'Império Lima MG Grisotto JM Alvarez 《Canadian Metallurgical Quarterly》1999,67(1):308-318
To obtain low and high parasite loads in the acute phase of Chagas' disease, A/J mice were infected with 10(3) or 10(5) Trypanosoma cruzi trypomastigotes of the Y strain and treated on day 6 with benznidazol. One year later, chronically infected mice were screened for subpatent parasitemias, tissue pathology, and immune response. Mice infected with the high parasite inoculum showed higher levels of chronic parasitemias, heart and striated muscle inflammation, and activation of the immune system than did mice infected with the low inoculum. Concerning the activation of the immune system, the main findings for high-dose-infected mice were (i) increased numbers of splenocytes, with preferential expansion of CD8(+) and B220(-) CD5(-) cells, many of them bearing a macrophage phenotype; (ii) higher frequencies of B (B220(+)), CD4(+), and CD8(+) large lymphocytes; (iii) a shift of CD4(+) cells towards a CD45RBLow phenotype; (iv) increased frequencies of both CD45RBLow and CD45RBHigh large CD4(+) cells; (v) augmented numbers of total immunoglobulin (Ig)-secreting cells, with predominance of IgG2a-producing cells; and (vi) increased production of gamma interferon and interleukin 4. In addition, these mice presented lower IgM and higher IgG2a and IgG1 parasite-specific serum antibody levels. Our results indicate that the parasite load at the acute phase of T. cruzi infection influences the activation of the immune system and development of Chagas' disease pathology at the late chronic phase of the disease. 相似文献
996.
Recent studies of peer victimization have demonstrated the importance of studying relational as well as physical forms of peer maltreatment for understanding children's social-psychological adjustment problems. Studies in this area have been limited thus far by a focus on school-age children (9–12-year olds). Given the significance of early identification of children's social difficulties for intervention and prevention efforts, this research was designed to assess relational and physical peer victimization among preschool-age children (3–5-year-olds). Results indicated that boys were significantly more physically victimized than girls whereas girls were more relationally victimized. Both relational and physical victims experienced greater adjustment problems than did their peers. Relational victimization contributed unique information about adjustment beyond that provided by physical victimization. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
抽油井井下管杆偏磨问题分析 总被引:3,自引:0,他引:3
通过对马厂,桥口二油田抽油机生产井工况的大量矿场统计,并对形成抽油井中的油管与套管内壁、抽油杆与油管内壁间的偏磨的多种因素进行较为系统的分析,提出了解决偏磨的方法,从而有效地延长抽油机井的生产周期。 相似文献
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