全文获取类型
收费全文 | 1553篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 5篇 |
机械仪表 | 1篇 |
能源动力 | 1篇 |
轻工业 | 2篇 |
无线电 | 1篇 |
一般工业技术 | 4篇 |
冶金工业 | 1531篇 |
原子能技术 | 5篇 |
自动化技术 | 2篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2013年 | 1篇 |
2012年 | 5篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2003年 | 1篇 |
1999年 | 37篇 |
1998年 | 467篇 |
1997年 | 275篇 |
1996年 | 175篇 |
1995年 | 101篇 |
1994年 | 73篇 |
1993年 | 109篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 20篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 28篇 |
1985年 | 18篇 |
1983年 | 1篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 12篇 |
1978年 | 2篇 |
1977年 | 39篇 |
1976年 | 84篇 |
1975年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1553条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
75.
76.
77.
JR Schein D Gause DM Stier DP Lubeck MM Bates R Fisk 《Canadian Metallurgical Quarterly》1997,87(11):512-519
The investigators present an analysis of baseline quality-of-life and patient-management approaches from an observational study of 150 patients being treated by podiatric physicians and dermatologists for onychomycosis. The majority (73%) made the initial office visit specifically because of their onychomycosis. Both men and women indicated that they had substantial physical discomfort as well as concerns related to appearance. Women reported significantly more problems than did men as a result of their onychomycosis. Physicians reported that 54% of patients suffered from toenail discomfort, 36% had pain while walking, 40% reported that their condition limited wearing of shoes, and 67% were embarrassed by the condition. The results of this study suggest that the treatment approach of podiatric physicians is more likely to address the palliative concerns of patients with onychomycosis, while the approach of dermatologists is more likely to attempt a definitive cure. 相似文献
78.
Fluoride's role in decreasing dental caries has been recognized for decades. The professional fluoride treatment has recently been augmented with home-use fluoride products. The introduction of many attractive products makes it difficult for dental professionals to know which are effective. Both professional and home-use products are described, as are proven techniques for their use. Recognition of fluoride toxicity, and its prevention and treatment, are also discussed. 相似文献
79.
Prognostic classification for esophageal atresia and tracheoesophageal fistula: Waterston versus Montreal 总被引:1,自引:0,他引:1
S Teich DP Barton ME Ginn-Pease DR King 《Canadian Metallurgical Quarterly》1997,32(7):1075-9; discussion 1079-80
Since 1962, the Waterston classification has been used to stratify neonates who have esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) into prognostic categories based on birth weight, the presence of pneumonia, and the identification of other congenital anomalies. In response to advances in neonatal care, the surgeons from the Montreal Children's Hospital proposed a new categorization system in 1993 in an attempt to define the current risk factors for patients who have EA/TEF. In the Montreal experience only two characteristics independently affected survival: preoperative ventilator dependence and associated major anomalies. The goal of this study was to determine which system had the greatest validity for the evaluation of prognosis in our patients with EA/TEF. The charts of 94 patients who had EA/TEF treated between 1972 and 1991 were reviewed. Patients were classified using both the Waterston and Montreal systems. Groups were compared with Fisher's Exact test using a 95% confidence level for statistical significance. Eleven infants were ventilator dependent preoperatively; 62 children had major associated anomalies, 8 of which were considered life threatening. Sixteen children died within 4 years, eight during their initial hospital stay. Five of the eight early postoperative deaths occurred in the highest-risk patients (Waterston C or Montreal II). Analysis was performed for multiple risk factors and mortality. As in the Montreal study, the presence of life-threatening and major congenital anomalies represented significant risk factors for death. Pulmonary disease as delineated by ventilator dependence appeared to be more accurate than pneumonia. This study confirms the accuracy of the Montreal classification in defining prognosis for EA/TEF. The Montreal system more accurately identifies children at highest risk than the Waterston classification. 相似文献
80.