全文获取类型
收费全文 | 218篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 41篇 |
金属工艺 | 3篇 |
机械仪表 | 7篇 |
建筑科学 | 7篇 |
矿业工程 | 4篇 |
能源动力 | 3篇 |
轻工业 | 17篇 |
水利工程 | 4篇 |
一般工业技术 | 46篇 |
冶金工业 | 51篇 |
原子能技术 | 2篇 |
自动化技术 | 30篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 5篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有224条查询结果,搜索用时 15 毫秒
91.
The structural integrity of a flap-track beam (FTB) made from non-crimp fabric composites and assembled using mechanical fasteners and adhesively bonded joints is investigated using full-scale experiments and numerical modeling. The FTB, being an aircraft structural component, has been selected as the verification structure and demonstrator of a novel material-driven design concept aiming to progressively replace mechanical fasteners by adhesively bonded joints and introduce fabric composites of enhanced through-thickness properties in aero-structures. For the sake of investigation, the FTB has been subjected to a combination of static and fatigue loading conditions taken from realistic load-scenarios. Due to size and complexity of the structure and testing demands, a special test-rig was developed for the occasion. During loading, the response of the structure has being fully monitored using a network of sensors along with an optical measurement system. After loading, the health of the structure was monitored using non-destructive inspection. Complementary to mechanical testing, a 3D detailed FE model was developed for virtual experimenting. On the basis of the model, progressive damage modeling has been implemented to simulate initiation and progression of composite failure as well as debonding. Both experiments and model have shown that the composite FTB is capable to effectively carry the load which the original fastened metallic FTB has been designed to carry. Localized damage that has no significant effect on the integrity of the structure has been detected at fastener areas and bonded joints containing initial defects. Between experiments and model a satisfactory agreement has been achieved considering the uncertainties in experimental procedure and numerical errors of the model. 相似文献
92.
Dolasetron mesylate (MDL 73,147EF, Anzemet; Hoechst Marion Roussel, Laval, Canada) is a 5-HT3 receptor antagonist undergoing clinical evaluation for use as an antiemetic agent. The pharmacokinetics of dolasetron and its reduced metabolite (MDL 74,156) were studied after administration of single intravenous and oral doses of dolasetron mesylate 2.4 mg/kg in 18 healthy elderly subjects. Expressed as the dolasetron base, this dose was 1.8 mg/kg. Dolasetron was rapidly metabolized to the reduced metabolite, which appeared in plasma within 10 minutes after intravenous or oral administration. The mean half-life (t1/2) of dolasetron was 0.24 hours after intravenous administration and 0.50 hours after oral administration. The pharmacokinetic parameters of the reduced metabolite were similar after intravenous and oral administration. The apparent absolute bioavailability of the reduced metabolite was 89%, and it had an elimination t1/2 of approximately 7 hours and an apparent volume of distribution (Vd beta) of 4.69 L/kg. Dolasetron was not detected in urine. Metabolites were excreted in urine almost completely within 24 hours of administration. The primary metabolite detected in urine was the (+)-enantiomer of the reduced metabolite, which accounted for 25.35% (+/- 7.79%) and 18.88% (+/- 7.65%) of the intravenous and oral doses, respectively. Hydroxylated metabolites accounted for 5% or less of the total dose via either route. The pharmacokinetics of the reduced metabolite after single intravenous or oral doses in elderly volunteers were consistent with pharmacokinetics observed in both young healthy men and cancer patients receiving high-dose cisplatin chemotherapy. Dosage adjustments of dolasetron mesylate on the basis of age do not appear to be necessary. 相似文献
93.
M Thyberg P Ertzgaard L H?kansson A Sp?ngberg G Granerus 《Canadian Metallurgical Quarterly》1995,33(1):40-45
There is a group of malignant intrascrotal tumours which represent a very small number when compared to testicular neoplasias and which are known as paratesticular neoplasias. More than 90% belong to the sarcomatous species. From a clinical point of view and based on the patient's age, two groups can be distinguished: sarcomas affecting children and adolescents (primarily rabdomiosarcomas) and those occurring in adulthood, the more frequent histopathological variants being fibrosarcoma, leiomiosarcoma and liposarcoma. This work contributes five paratesticular sarcomas (two rabdomiosarcomas, one liposarcoma, one leiomiosarcoma and one fibrosarcoma). The features related to histogenesis, diagnosis (revealing signs and clinical examination), natural history (dissemination routes based on histopathology) and treatment are reported. With regard to treatment, both the local surgery (total orchiectomy by inguinoscrotal approach with or without hemiscrotectomy), and indications for lymphadenectomy and radiotherapy in relation to staging are discussed though insisting on the chemotherapy approach. 相似文献
94.
H. Späth 《Computing》1996,57(2):179-185
In reflectometry and in the aircraft industry the problem of fitting data points by a circle is relevant. In contrast with other authors we realize a very special iterative method to determine such a circle. Former approximations for the parameters are used as starting values and are improved. Numerical examples are given. 相似文献
95.
96.
97.
98.
Dr. H. Späth 《Computing》1973,11(2):175-177
A set ofn ordered real numbers is partitioned by complete enumeration intok clusters such that the sum of the sum of squared deviations from the mean-value within each cluster is minimized. 相似文献
99.
Quantum control plays a key role in quantum technology, in particular for steering quantum systems. As problem size grows exponentially with the system size, it is necessary to deal with fast numerical algorithms and implementations. We improved an existing code for quantum control concerning two linear algebra tasks: the computation of the matrix exponential and efficient parallelisation of prefix matrix multiplication.For the matrix exponential we compare three methods: the eigendecomposition method, the Padé method and a polynomial expansion based on Chebyshev polynomials. We show that the Chebyshev method outperforms the other methods both in terms of computation time and accuracy. For the prefix problem we compare the tree-based parallel prefix scheme, which is based on a recursive approach, with a sequential multiplication scheme where only the individual matrix multiplications are parallelised. We show that this fine-grain approach outperforms the parallel prefix scheme by a factor of 2–3, depending on parallel hardware and problem size, and also leads to lesser memory requirements.Overall, the improved linear algebra implementations not only led to a considerable runtime reduction, but also allowed us to tackle problems of larger size on the same parallel compute cluster. 相似文献
100.
In the present work an automated Continuous Compression Moulding Technique for the manufacture of stringers in continuous length is presented. The method combines pultrusion and hot-pressing. The technique is utilized for the production of L-shape stringers which are widely applied in aerospace constructions. The investigation was carried out on carbon reinforced PEEK (C/PEEK), as well as, for comparison, on the thermoplastic composites carbon reinforced polyethersulfon (C/PES), glass and carbon reinforced polyphenylene-sulfide (G/PPS, C/PPS) and Kevlar reinforced Polyamide 6 (K/PA 6).
For the materials investigated the optimized process parameters for manufacturing the L-shape stringers were derived experimentally. To achieve this goal, the quality of the produced parts was controlled by using non-destructive testing techniques. Parts providing satisfactory quality were also tested destructively to measure their mechanical properties. The investigation results have shown the suitability of the technique to produce continuous length stringers. 相似文献