全文获取类型
收费全文 | 2134篇 |
免费 | 188篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 21篇 |
综合类 | 2篇 |
化学工业 | 629篇 |
金属工艺 | 20篇 |
机械仪表 | 51篇 |
建筑科学 | 86篇 |
矿业工程 | 2篇 |
能源动力 | 83篇 |
轻工业 | 366篇 |
水利工程 | 26篇 |
石油天然气 | 7篇 |
无线电 | 143篇 |
一般工业技术 | 314篇 |
冶金工业 | 115篇 |
原子能技术 | 7篇 |
自动化技术 | 454篇 |
出版年
2024年 | 13篇 |
2023年 | 40篇 |
2022年 | 111篇 |
2021年 | 149篇 |
2020年 | 82篇 |
2019年 | 101篇 |
2018年 | 117篇 |
2017年 | 107篇 |
2016年 | 135篇 |
2015年 | 80篇 |
2014年 | 117篇 |
2013年 | 173篇 |
2012年 | 132篇 |
2011年 | 178篇 |
2010年 | 105篇 |
2009年 | 103篇 |
2008年 | 90篇 |
2007年 | 86篇 |
2006年 | 77篇 |
2005年 | 45篇 |
2004年 | 35篇 |
2003年 | 28篇 |
2002年 | 36篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 18篇 |
1998年 | 34篇 |
1997年 | 19篇 |
1996年 | 24篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有2326条查询结果,搜索用时 0 毫秒
1.
Precil Diego M. M. Neves Fernanda M. Freitas Christiane A. Kojima Beatriz L. Carmello Rodrigo Bazan Pasqual Barretti Luis C. Martin 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(1):143-145
Antibiotics are potentially a cause of neurotoxicity in dialysis patients, the most common are the beta‐lactams as ceftazidime and cefepime, and few cases have been reported after piperacillin/tazobactam use. This report presents a case of a hypertensive and diabetic 67‐year‐old woman in regular hemodialysis, which previously had a stroke. She was hospitalized presenting pneumonia, which was initially treated with cefepime. Two days after treatment, she presented dysarthria, left hemiparesis, ataxia, and IX and X cranial nerves paresis. Computed tomography showed no acute lesions and cefepime neurotoxicity was hypothesized, and the antibiotic was replaced by piperacillin/tazobactam. The neurologic signs disappeared; however, 4 days after with piperacillin/tazobactam treatment, the neurological manifestations returned. A new computed tomography showed no new lesions, and the second antibiotic regimen withdrawn. After two hemodialysis sessions, the patient completely recovered from neurological manifestations. The patient presented sequentially neurotoxicity caused by two beta‐lactams antibiotics. This report meant to alert clinicians that these antibiotics have dangerous neurological effects in chronic kidney disease patients. 相似文献
2.
Enzo Benedetti Aldo D'Alessio Mauro Aglietto Giacomo Ruggeri Piergiorgio Vergamini Francesco Ciardelli 《Polymer Engineering and Science》1986,26(1):9-14
Polyolefins functionalized with diethylmaleate were mixed with poly(vinylchloride) (PVC) in different compositions. Intermolecular interactions involving the carbonyl groups of the side chains of the functionalized polyolefins and methine hydrogens of PVC were investigated by means of infrared spectroscopy. The major flexibility of the ester groups attached to the backbone chains, with respect to polyesters, seems to increase the capability of such groups to interact with groups of more polar polymers, thus allowing prediction of easier miscibility, which however also depends on the starting polyolefin structure and function-alization degree. 相似文献
3.
Fault-accommodation with intelligent sensors 总被引:1,自引:0,他引:1
Giacomo Tortora Author Vitae Author Vitae David Clarke Author Vitae 《Automatica》2003,39(7):1227-1233
Optimal sensor fault-accommodation is considered for faults modelled by an increase in measurement noise. This noise is taken to be bounded and its probabilistic properties unknown. It is assumed that intelligent (e.g. self-validating) instrumentation is in use and estimates of the noise bounds are available. The fault-tolerant controller is designed to optimize a noise rejection and a nominal reference tracking index and leads to a mixed norm minimization problem (l1/l2). We exploit known results and a particular feedback configuration to show that it is possible to optimize simultaneously without a trade-off the two performance indices. The results are applied to systems where the presence of auxiliary measurements allows for an optimal fault-accommodation strategy. Using properties of the optimal solution, we define a factorization for the optimal controller alternative to the Youla parametrization, leading to an algorithm which is optimal, transparent and efficient. 相似文献
4.
Participating media with an inhomogeneous index of refraction make light follow curved paths. Simulating this in a global
illumination environment has usually been neglected due to the complexity of the calculations involved, sacrificing accurate
physical simulations for efficient visual results.
This paper aims to simulate non-linear media in a more reasonable time than previous works without losing physical correctness.
Accuracy is achieved by solving the Eikonal equation of geometrical optics, which describes the path followed by a light beam
that traverses a non-linear medium. This equation is used in the context of a photon mapping extension. 相似文献
5.
F Venuta T De Giacomo EA Rendina C Ricci GF Coloni 《Canadian Metallurgical Quarterly》1998,66(5):1833-1834
Lung volume reduction has been performed in patients with advanced emphysema to relieve dyspnea and improve exercise tolerance. Median sternotomy and video-assisted thoracoscopy have been proposed as equally adequate approaches; however, prolonged postoperative air leakage is the most prevalent complication in all series. For this reason, on the basis of the experience achieved with the median sternotomy approach, buttressing of the suture line with different materials and techniques for space reduction have been proposed. We describe a technique to create a pleural tent after thoracoscopic volume reduction. The thoracoscopic creation of a pleural tent is feasible and results in a duration of postoperative air leaks and hospital stays similar to that achieved with stapler line buttressing. 相似文献
6.
A 2-layer drawing represents a bipartite graph where each vertex is a point on one of two parallel lines, no two vertices on the same line are adjacent, and the edges are straight-line segments. In this paper we study 2-layer drawings where any two crossing edges meet at right angle. We characterize the graphs that admit this type of drawing, provide linear-time testing and embedding algorithms, and present a polynomial-time crossing minimization technique. Also, for a given graph G and a constant k, we prove that it is $\mathcal{NP}$ -complete to decide whether G contains a subgraph of at least k edges having a 2-layer drawing with right angle crossings. 相似文献
7.
Massimo Guglielmi Giovanna Brusatin Giacomo Facchin Mario Gleria Roger De Jaeger Marco Musiani 《Journal of Inorganic and Organometallic Polymers》1996,6(3):221-236
In this paper the sol-gel preparation of hybrid materials made of metal oxide and polytorganophosphazenel components is described. The main problem focused on during this research was to avoid phase separation in order to get homogeneous materials. This problem was pursued looking at the formation of genuine chemical bonds between the exploited polyphosphazenes and the inorganic composite networks. Investigations on the thermal, mechanical, and electroconductive properties of the synthesized, phosphazene-containing composite materials showed that these matrices presented improved mechanical and thermal features with respect to those of the original phosphazene macromolecule, while the ionic conductivities of the prepared molecular hybrids doped with lithium or silver trillate are of the same order of magnitude as those measured for the neat, original phosphazene substrate.Presented at the Ist Italian Workshop on Cyclo- and Polytphosphazenel Materials. February 15–16, 1996. at the CNR Research Area in Padova, Italy. 相似文献
8.
Valter Castelvetro Cinzia De Vita Giacomo Giannini Simone Giaiacopi 《应用聚合物科学杂志》2006,102(4):3083-3094
The evolution of the main colloidal parameters in the seeded starved‐feed semi‐continuous emulsion polymerization of butyl methacrylate (BMA) was investigated, with the main purpose of assessing the effectiveness of the semi‐empirical relationship S = K · SS · ΔA/AS as a tool to define the surfactant/monomer feed ratio (∝ K) best suited to achieve a target particle size. In particular, the effect of the type and amount of surfactant [i.e., anionic, sodium dodecyl sulfate (SDS), or nonionic, Brij 58P] added during the semi‐continuous stage was considered. Coagulum formation was never observed under the adopted experimental conditions. To detect the occurrence of secondary nucleation or particle aggregation, or both, the particle size and number of particles, the surface tension and the particle surface coverage ratio were correlated. The best results were obtained with SDS and 0.8 ≤ K ≤ 3. In fact, under the selected experimental conditions, only with SDS did the number of particles remain nearly constant throughout the polymerization at the value defined by the seed latex; the particle size distribution was highly monodisperse, and the final particle diameter closely matched the calculated one (~ 120 nm). The above semi‐empirical relationship based on the adjustable parameter K was validated by running test polymerizations aimed at lattices with well‐defined particle size. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3083–3094, 2006 相似文献
9.
This study investigates the whole-body vibration exposure in kite surfing, alpine skiing, snowboarding and cycling. The vibration exposure was experimentally evaluated following the ISO 2631 guidelines. Results evidenced that the most critical axis is the vertical one. The weighted vibration levels are always larger than 2.5 m/s2 and the vibration dose values are larger than 25 m/s1.75. The exposure limit values of the EU directive are reached after 8–37 min depending on the sport. The vibration magnitude is influenced by the athletes’ speed, by their skill level and sometimes by the equipment. The large vibration values suggest that the practice of sport activities may be a confounding factor in the aetiology of vibration-related diseases. 相似文献
10.