全文获取类型
收费全文 | 535篇 |
免费 | 3篇 |
专业分类
综合类 | 1篇 |
化学工业 | 3篇 |
机械仪表 | 1篇 |
能源动力 | 1篇 |
轻工业 | 6篇 |
石油天然气 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 4篇 |
冶金工业 | 518篇 |
原子能技术 | 1篇 |
出版年
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2000年 | 1篇 |
1999年 | 16篇 |
1998年 | 152篇 |
1997年 | 91篇 |
1996年 | 76篇 |
1995年 | 31篇 |
1994年 | 29篇 |
1993年 | 33篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1977年 | 12篇 |
1976年 | 17篇 |
1973年 | 1篇 |
排序方式: 共有538条查询结果,搜索用时 31 毫秒
531.
532.
533.
534.
535.
Xiaoping Hu Minh N Luong Hai Zhang Hongshui Zhu Daniel CN Chan 《Journal of Adhesion Science and Technology》2013,27(21):2356-2368
This study aimed to compare the microshear bond strength (MSBS) of three universal adhesives and a three-step conventional adhesive to dentin after 24-hour and one-year storage in water. A new fluoride-releasing universal adhesive (Clearfil Universal Bond Quick: CUQ) and two commercially available adhesives (ScotchBond Universal: SBU and All-Bond Universal: ABU) were evaluated with phosphoric acid etching (PA-etch mode) or without it (self-etch mode). All-Bond 3 (AB3) served as control group. After bonding composite cylinders to dentin discs obtained from caries-free human teeth, the specimens were stored in deionized water at 37?°C for either 24 hours or one year (n?=?14) before MSBS measurement. Two-way ANOVA analysis of the results showed that the adhesives, storage time and their interactions had a significant effect on MSBS (p?<?0.01). In self-etch mode, there was no significant difference among universal adhesives at the baseline. In PA-etch, the CUQ and SBU showed significantly higher MSBS compared with AB3 (p?<?0.05). At baseline, no difference was found between the two modes for each universal adhesive (p?>?0.05). After one year, CUQ in self-etch mode showed a slight increase in nominal MSBS (p?>?0.05) and Weibull characteristic strength, which was significantly higher than SBU and ABU in the corresponding mode. There was no difference among the three universal adhesives in PA-etch mode after one year (p?>?0.05). In conclusion, the durability and reliability of dentin bonding with universal adhesives in different application modes depended on the material; and the self-etch approach showed promising results for the tested fluoride-releasing universal adhesive. 相似文献
536.
Evaluation of solubilized proteins as an alternative to phosphates for meat enhancement 总被引:1,自引:0,他引:1
ABSTRACT: Select grade strip loins ( n = 10) were enhanced 10% with either a phosphate or an acid solubilized protein solution. Color score, aerobic plate count, lipid oxidation, purge loss, cook yield, Warner–Bratzler shear force, and sensory analysis were measured to characterize storage quality. The phosphate injection consisted of 4.5% phosphate, 3.6% sodium chloride, 90.9% water, and 1% Herbalox seasoning. Two solutions were prepared for the protein injection: one consisting of 1:9 protein to water and the other an aqueous solution of 1% Herbalox seasoning and 3.6% sodium chloride. Enhancement solutions were injected twice at 5% to create a 10% total injection. It was found that the protein-enhanced steaks were comparable to phosphate-enhanced steaks for percent discoloration and overall acceptability. The phosphate-enhanced steaks performed better than the protein-enhanced steaks for lean color, fat color, aerobic plate count, lipid oxidation, percent purge, cook yield, and Warner–Bratzler shear force. It should be noted that for protein-enhanced steaks, lean color and cook yield, although statistically different, did perform similar to phosphate-enhanced steaks. 相似文献
537.
CE Iselin CN Robertson GD Webster J Vieweg DF Paulson 《Canadian Metallurgical Quarterly》1997,158(6):2123-2126
PURPOSE: We determined if urethral preservation and orthotopic bladder replacement in patients with transitional cell carcinoma within the prostatic urethra or prostate placed these patients at risk for urethral recurrence or death. MATERIALS AND METHODS: The clinical course of all patients undergoing urethral preservation and orthotopic bladder replacement was reviewed. The urethra was sacrificed only if the distal prostatic urethral margin was positive for transitional cell carcinoma. The pathological T stage and the grade of the primary malignancy, local recurrence, site of recurrence (urethral, pelvic, distant) and death were documented. RESULTS: Of 81 patients 70 were evaluable (June 1996) with a mean followup of 35 months. Of the 70 patients 48 were alive without evidence of disease for a mean of 38 months (range 8 to 107) and 5 died without evidence of disease. Eight of these 53 patients (15%) had prostatic involvement (carcinoma in situ in 6, intraductal carcinoma in 1 and stromal invasive transitional cell carcinoma in 1). Of the 70 patients 17 had disease recurrence (13 died of disease and 4 are alive, 1 of whom had urethral recurrence without initial prostatic transitional cell carcinoma). Of the 17 patients (35%) 6 had transitional cell carcinoma prostatic involvement (carcinoma in situ in 4 and stromal invasion in 2), and 5 of these 6 died, none with or of urethral recurrence but of the primary bladder pathology. Of these 5 patients 1 had stromal invasive transitional cell carcinoma of the prostate and experienced a bulbar urethra recurrence at 1 month and a pelvic recurrence at 3 months, and died at 5 months. Death was not secondary to the urethral recurrence. Thus, of the 14 patients who had prostatic transitional cell carcinoma, only 1 had urethral recurrence (7%), and this recurrence did not present as the cause of death. CONCLUSIONS: The guidelines for urethral resection can be relaxed, increasing the opportunities for orthotopic reconstruction, without placing the patients at increased risk for death of transitional cell carcinoma. 相似文献
538.
Recent studies demonstrate the relationship of microvessel density to malignant progression in breast cancer (N. Weidner, J. P. Semple, W. R. Welch, and J. Folkman, N. Engl. J. Med., 324: 1-8, 1991), underscoring the importance of angiogenesis in this tumor. Crucial in tumor angiogenesis are the paracrine actions of tumor-secreted factors (e.g., vascular endothelial growth factor), which have been thought to derive from the tumor epithelial cells themselves. We demonstrate that in response to hypoxic conditions, human mammary fibroblasts dramatically up-regulate vascular endothelial growth factor mRNA and increase vascular endothelial growth factor protein levels in accordance with the degree of oxygen deprivation. Thus, mammary stromal cells, only recently considered in the regulation of breast carcinomas, may play a hitherto unrealized role in breast cancer angiogenesis. 相似文献