全文获取类型
收费全文 | 287篇 |
免费 | 8篇 |
专业分类
电工技术 | 13篇 |
综合类 | 1篇 |
化学工业 | 78篇 |
金属工艺 | 13篇 |
机械仪表 | 9篇 |
建筑科学 | 9篇 |
能源动力 | 11篇 |
轻工业 | 26篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 44篇 |
冶金工业 | 37篇 |
原子能技术 | 18篇 |
自动化技术 | 24篇 |
出版年
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 16篇 |
2009年 | 28篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1968年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 890 毫秒
61.
T Ichikura K Fujino H Ikawa S Tomimatsu K Uefuji S Tamakuma 《Canadian Metallurgical Quarterly》1993,23(9):759-764
In this study, 168 patients who underwent curative resection for gastric cancer with prognostic serosal invasion [ps(+)] and 150 without prognostic serosal invasion [ps(-)] were analyzed separately to determine the prognostic importance of clinicopathological factors, and identify which patients were at high risk of recurrence. A multivariate analysis of survival time using Cox's proportional hazard model revealed the important prognostic factors to be: Lymph node involvement, the classification of gross appearance, macroscopic serosal invasion, and interstitial connective tissue in the ps(+) group; and lymph node involvement, macroscopic serosal invasion, and venous invasion in the ps(-) group. We proposed a risk score of recurrence based on the results of a further multivariate analysis called Hayashi's Quantification Analysis II, in which recurrence was chosen as an objective variable and the above prognostic factors were chosen as explanatory variables. Eighty-four percent of the patients with a score of 0 or higher in the ps(+) group and 83% of those with a score of +6 or higher in the ps(-) group showed recurrence. Thus, we believe that this score is useful for identifying those patients at high risk of recurrence, who should receive intensive chemotherapy even after curative resection. 相似文献
62.
Analysis of the ROSA-III test RUN 704 was performed by using the computer codes RELAP4J, RELAP4/MOD6 and RELAP5/MOD0 to verify the predictive capability of the codes for a BWR LOCA. The ROSA-III facility is a volumetrically scaled (1/424) BWR system with an electrically heated core, designed for in tegral LOCA/ECCS tests. The RUN 704 experiment at the ROSA-III test facility simulated a 200% double-ended offset shear break on the inlet side of the pump in the recirculation loop. From present analyses, key parameters which are important to predict major behavior during a BWR large break LOCA have been clarified and the promising predictive capability of the advanced code RELAP5 has been verified. 相似文献
63.
Miyoshi Ikawa Toinette Hartshorne Lu-Ann Caron Robert C. Iannitelli Linda J. Barbero Karin Wegener 《Journal of the American Oil Chemists' Society》1984,61(12):1877-1878
The activity of a number of unsaturated fatty acids in inhibiting the growth of the green algaChlorella pyrenoidosa has been studied using the paper disk-agar plate method. Acrylic and undecylenic acids were highly active, but other θ-unsaturated
fatty acids tested were only weakly active. Oleic and elaidic acids were inactive at 0.2 M, but other C18-C22 acids with 2 to 6 double bonds were generally active down to a concentration of 0.01–0.005 M. Activity with chaulmoogric
acid was noted down at 0.002–0.001 M. Diffusion rates of the acids through the agar seem to affect the size of the inhibition
zones. The implications that polyunsaturated fatty acids may play a role in algal ecology are discussed. 相似文献
64.
65.
K Kawagoe D Kitamura M Okabe I Taniuchi M Ikawa T Watanabe T Kinoshita J Takeda 《Canadian Metallurgical Quarterly》1996,87(9):3600-3606
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder characterized by complement-mediated hemolysis. Abnormal hematopoietic cells from patients with PNH are deficient in glycosylphosphatidylinositol (GPI)-anchored proteins and clonally dominate various hematopoietic lineages in the bone marrow and the peripheral blood. Analysis of many patients with PNH has showed that somatic mutation in the X-linked gene PIG-A is responsible for the GPI-anchor deficiency in PNH. The PIG-A mutation must also be relevant to the clonal dominance of GPI-anchor deficient (GPI-) blood cells because two or more PIG-A mutant clones become dominant in many patients. However, whether the PIG-A mutation alone is sufficient for clonal dominance is not known. To address this question, we generated chimeric mice using Pig-a (the murine homologue of PIG-A) disrupted embryonic stem (ES) cells, in which the animals are chimeric with respect to the surface expression of GPI-anchored proteins. The chimerism of hematopoietic and nonhematopoietic tissues in such mice was always low, suggesting that the higher contribution of Pig-a disrupted GPI- cells had a lethal effect on the chimera. GPI- cells appeared in the peripheral blood of some of the chimeric mice. However, the percentage of GPI- erythrocytes did not increase for 10 months after birth, implying that the Pig-a mutation alone does not immediately cause the clonal dominance of GPI- blood cells; another pathologic or physiologic change(s) in the hematopoietic environments or in the clone itself may be necessary. 相似文献
66.
BACKGROUND/AIMS: Long-term administration of spironolactone is reported to reduce portal pressure in cirrhotic patients. We examined the effects of acute administration of canrenoate potassium, an aldosterone antagonist, on portal hemodynamics in compensated cirrhotic patients using noninvasive duplex Doppler ultrasonography. MATERIALS AND METHODS: Baseline values were obtained in the fasting state, and then 200mg of canrenoate potassium in 10ml of saline solution was intravenously administered to 22 patients, whereas 10ml of saline solution was administered as a placebo to 8 patients. RESULTS: The portal cross-sectional area, portal blood velocity and portal blood flow decreased by 5.3 +/- 9.2, 10.4 +/- 8.7% and 13.0 +/- 12.4%, respectively at the nadir 60min after administration and these decreases persisted until 120min. Placebo did not affect these parameters of portal hemodynamics. Eleven responders, who had a more than 10% drop in portal blood flow 60min after administration, had significantly higher levels of plasma aldosterone than 8 non responders who had less than 10% drop. The reduction rate of portal blood flow was closely correlated with plasma aldosterone level. CONCLUSIONS: These findings suggest that aldosterone antagonist directly causes a reduction in portal blood flow, probably through inhibition of aldosterone-induced vasoconstrictive action. 相似文献
67.
Hidekatsu Yokoyama Nobuaki Tsuchihashi Tateaki Ogata Midori Hiramatsu Norio Mori 《Magma (New York, N.Y.)》1996,4(3-4):247-250
Electron spin resonance (ESR) measurements after intracerebroventricular injection of a nitroxide radical were carried out in rats (n=6) that received oral idebenone for 2 weeks and in control rats (n=5), using anin vivo rapid scan ESR spectrometer. The half-life of nitroxide, which was estimated from the change in the peak height (M=+1) of the ESR signals from the head, was used as a marker for the elimination of the nitroxide radical. The half-life in the rats treated with idebenone was significantly shorter than it was in the controls (p<0.05). This finding indicates that the treatment with idebenone can enhance the intracerebral-eliminating ability of the nitroxide radical. 相似文献
68.
Nobuaki Mizumoto 《Artificial Life and Robotics》2018,23(4):469-473
The collective activities of social insects often result in the formation of complex structures. Previous studies have revealed the building mechanisms of various species, where sophisticated colony-level structures emerge from the interactions among individuals. However, little is known about the building behaviors of primitive species, which would give us an insight into the evolutionary processes that gave rise to collective building of sophisticated structures. Therefore, in this study, I investigated the building behavior of the primitive termite Zootermopsis nevadensis, which constructs simple barricades to plug the openings to its nests. Observation of the time course of barricade construction showed that the building dynamics followed a logistic pattern, suggesting that their collective building involves an amplification phase, which plays an important role in self-organized building activities in social insects. Moreover, this species exhibited highly skewed task allocation during construction. Together, these results suggest that this primitive species possesses building mechanisms similar to species with more sophisticated collective behaviors. 相似文献
69.
Synthesis of 6-phosphatidyl-L-ascorbic acid by phospholipase D 总被引:1,自引:0,他引:1
Phospholipase D (EC 3.1.4.4) ofStreptomyces species was found to catalyze transphosphatidylation to L-ascorbic acid from phosphatidylcholine (PC) in a biphasic reaction
system. The product was identified as 1,2-diacyl-sn-glycero-3-phospho-6′-L-ascorbic acid (PA-AsA) by mass spectrometry and nuclear magnetic resonance spectroscopy. The optimal
pH of transphosphatidylation was 4.5 and the rate of PA-AsA formation increased as concentrations of L-ascorbic acid increased.
The conversion of PC to PA-AsA was greater than 80%. PA-AsA was found to be more resistant to hydrolysis by phospholipase
D than was PC. 相似文献
70.
A. Jayaraman E. J. Herbst M. Ikawa 《Journal of the American Oil Chemists' Society》1968,45(10):700-702
The “paper disc plate” method of antibiotic assay usingBacillus megaterium spores was tested for the assay of aflatoxins and related compounds. Significant inhibitions were obtained in the range of
1–4 μg/disc for aflatoxin B1 and 4–8 μg/disc for aflatoxin G1. Dicumarol was the most active of the compounds tested and inhibited at 0.1–1.0 μg/disc. Compounds were also tested using
nine-day-old chick embryos. It was found that embryos incubated in egg cartons were much more sensitive to toxins than eggs
incubated on cotton padding or in a commercial egg incubator. The LD100 of aflatoxin B1 to carton-incubated embryos was 0.01 μg, while to embryos from the commercial incubator the LD100 was >5.0 μg. The results of the two bioassay procedures did not correlate completely with each other.
Presented at the AOCS-AACC joint meeting in Washington, D.C., 1968. 相似文献