全文获取类型
收费全文 | 1810篇 |
免费 | 2篇 |
专业分类
电工技术 | 12篇 |
综合类 | 1篇 |
化学工业 | 18篇 |
金属工艺 | 1篇 |
建筑科学 | 1篇 |
轻工业 | 2篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
一般工业技术 | 17篇 |
冶金工业 | 1755篇 |
自动化技术 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 5篇 |
1999年 | 46篇 |
1998年 | 596篇 |
1997年 | 316篇 |
1996年 | 204篇 |
1995年 | 126篇 |
1994年 | 75篇 |
1993年 | 100篇 |
1992年 | 12篇 |
1991年 | 17篇 |
1990年 | 23篇 |
1989年 | 19篇 |
1988年 | 10篇 |
1987年 | 15篇 |
1986年 | 8篇 |
1985年 | 20篇 |
1983年 | 1篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1978年 | 4篇 |
1977年 | 47篇 |
1976年 | 89篇 |
1955年 | 1篇 |
排序方式: 共有1812条查询结果,搜索用时 15 毫秒
81.
82.
1. Out of 494 infants none was breastfed within 2 hours of delivery. 36% infants received first breastfeed after 24 hours of delivery 91.2% of the mothers used prelacteal feeds. 2. Only 31.06% of the infants were weaned, out of these only 7 received complementary foods between 4-6 months. 3. Thus, it can be concluded that though breastfeeding is practiced by all mothers, there is need for early initiation of breastfeeding and proper weaning habits. 相似文献
83.
Assessment of regional left ventricular long-axis motion with MR velocity mapping in healthy subjects 总被引:1,自引:0,他引:1
SP Karwatowski R Mohiaddin GZ Yang DN Firmin MS Sutton SR Underwood DB Longmore 《Canadian Metallurgical Quarterly》1994,4(2):151-155
We present a case of trichothiodystrophy associated with a hypereosinophilic syndrome. This case had been followed for 30 years. Trichothiodystrophy was characterized by lamellar ichthyosis, hair and nail dystrophies, kyphoscoliosis, congenital luxation of the hip. The hypereosinophilic syndrome was characterized by an itching urticaria-like eruption. Although the patient's general condition had remaining stable for 30 years, during the last year it worsened and the patient suddenly died. The authors discuss about the significance of this association. 相似文献
84.
B Buisson L Laflamme SP Bottari M de Gasparo N Gallo-Payet MD Payet 《Canadian Metallurgical Quarterly》1995,270(4):1670-1674
In non-differentiated NG108-15 cells, both angiotensin II (Ang II) (100 nM) and CGP 42112 (100 nM) decreased the T-type calcium current amplitude by 24 +/- 2% and 21 +/- 3%, respectively. cGMP is not a mediator of the Ang II effect, since loading of cells with 50 microM cGMP did not prevent the inhibitory effects of Ang II. The effects of Ang II involves a non-identified GTPase activity since incubation with GDP beta S (3 mM) completely reversed the inhibitory effect of Ang II while GTP gamma S mimicked its effect. However, Ang II binding was not affected by GTP gamma S, and the effect of Ang II was not modified in pertussis toxin-treated cells. The inhibitory effect of Ang II on the T-type Ca2+ current involves a phosphotyrosine phosphatase activity since sodium orthovanadate prevented the effects of Ang II, although microcystin-LR, a selective Ser/Thr phosphatase 1 and 2A inhibitor, did not modify the effect of Ang II. These results provide the first evidence of a modulation of membrane conductance by Ang II through the AT2 receptor and demonstrate the involvement of a phosphotyrosine phosphatase and a G protein in the AT2 transduction mechanism in NG108-15 cells. Moreover, our data suggest that phosphotyrosine phosphatase activation is proximal to receptor occupation, since sodium orthovanadate inhibits both GTPase activity and T-type current blockage induced by Ang II or CGP 42112, while GTP gamma S inhibition of the T-type calcium current is not impaired. 相似文献
85.
86.
PURPOSE: To analyze the likelihood of perioperative transfusion using the data of the abstracted patient discharge records. MATERIAL AND METHODS: It was studied the data of the records of the pediatric patients in whom were done surgical procedures for 1996. The abstracted patient discharge records are codified according the ICD-9-CM codes. RESULTS: 1,166 pediatric patients were operated, of whom were transfused 25 (2.1%). The transfusion rate was higher in patients less than 3 years old, who were operated with three o more surgical procedures simultaneously, who were admitted newly after the admittance here studied, and patients operated of spine, dorsolumbar spine, pharynx, thorax and mediastinum, central nervous system, colon, vessels and hip. CONCLUSIONS: Given the variability of the transfusion rate, to know it will allow a better planning of the surgical transfusions, the policy of the hospital blood bank and to increase the information to patient about the risk of the elective surgery. 相似文献
87.
TM Mizuno H Bergen T Funabashi SP Kleopoulos YG Zhong WA Bauman CV Mobbs 《Canadian Metallurgical Quarterly》1996,93(8):3434-3438
Mutations in the obese (ob) gene lead to obesity. This gene has been recently cloned, but the factors regulating its expression have not been elucidated. To address the regulation of the ob gene with regard to body weight and nutritional factors, Northern blot analysis was used to assess ob mRNA in adipose tissue from mice [lean, obese due to diet, or genetically (yellow agouti) obese] under different nutritional conditions. ob mRNA was elevated in both forms of obesity, compared to lean controls, correlated with elevations in plasma insulin and body weight, but not plasma glucose. In lean C57BL/6J mice, but not in mice with diet-induced obesity, ob mRNA decreased after a 48-hr fast. Similarly, in lean C57BL/6J controls, but not in obese yellow mice, i.p. glucose injection significantly increased ob mRNA. For up to 30 min after glucose injection, ob mRNA in lean mice significantly correlated with plasma glucose, but not with plasma insulin. In a separate study with only lean mice, ob mRNA was inhibited >90% by fasting, and elevated approximately 2-fold 30 min after i.p. injection of either glucose or insulin. These results suggest that in lean animals glucose and insulin enhance ob gene expression. In contrast to our results in lean mice, in obese animals ob mRNA is elevated and relatively insensitive to nutritional state, possibly due to chronic exposure to elevated plasma insulin and/or glucose. 相似文献
88.
89.
SP Newman J Brown KP Steed SJ Reader H Kladders 《Canadian Metallurgical Quarterly》1998,113(4):957-963
STUDY OBJECTIVES: To compare lung deposition of fenoterol or flunisolide administered from a novel, multidose inhalation device delivering liquid droplets (RESPIMAT; Boehringer Ingelheim Ltd; Bracknell, UK) or from conventional metered-dose inhalers (MDIs) with and without spacers. DESIGN: Two randomized, three-way crossover studies. SETTING: Clinical research laboratory. PARTICIPANTS: Healthy, nonsmoking volunteers. INTERVENTIONS: In one study, radiolabeled aerosols of fenoterol from the RESPIMAT device and from a conventional MDI with or without an Aerochamber spacer (Trudell Medical; London, Ontario Canada). In the second study, radiolabeled aerosols of flunisolide from a RESPIMAT device, from a RESPIMAT device modified by inclusion of a baffle/impactor in the mouthpiece, and from a conventional MDI with an Inhacort spacer (Boehringer Ingelheim; Ingelheim, Germany). MEASUREMENTS AND RESULTS: Assessment of the deposition of fenoterol or flunisolide in the lung and oropharynx using gamma scintigraphy. Safety was assessed based on reported adverse effects and spirometry (FEV1, FVC, and peak expiratory flow rate) to detect any paradoxical bronchoconstriction. The RESPIMAT device delivered significantly more fenoterol to the lungs than either an MDI alone or an MDI with Aerochamber (39.2% vs 11.0% and 9.9% of metered dose, respectively; p<0.01). Oropharyngeal deposition of fenoterol from the new device was lower than that from the MDI (37.1% vs 71.7%, respectively; p<0.01). The RESPIMAT device deposited significantly more flunisolide in the lungs compared with MDI plus spacer (44.6% vs 26.4%, respectively; p<0.01), while resulting in similar oropharyngeal deposition (26.2% vs 31.2%, respectively). Introduction of a baffle into the RESPIMAT system reduced lung deposition of flunisolide to 29.5%, and oropharyngeal deposition to 7.8% (p<0.01). CONCLUSION: The RESPIMAT device may prove to be an effective alternative to MDIs for the administration of inhaled bronchodilators and corticosteroids. The high lung deposition and low oropharyngeal deposition may lead to improved efficacy and tolerability of inhaled medications, especially corticosteroids. 相似文献
90.