全文获取类型
收费全文 | 348篇 |
免费 | 24篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 114篇 |
金属工艺 | 8篇 |
机械仪表 | 10篇 |
建筑科学 | 13篇 |
能源动力 | 8篇 |
轻工业 | 96篇 |
水利工程 | 6篇 |
石油天然气 | 2篇 |
无线电 | 19篇 |
一般工业技术 | 42篇 |
冶金工业 | 16篇 |
原子能技术 | 2篇 |
自动化技术 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 25篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 15篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 16篇 |
2013年 | 18篇 |
2012年 | 30篇 |
2011年 | 26篇 |
2010年 | 15篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1978年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1959年 | 4篇 |
1933年 | 2篇 |
排序方式: 共有373条查询结果,搜索用时 9 毫秒
351.
Fourth through 6th graders (n?=?418) completed the Children's Depression Inventory (CDI; M. Kovacs, 1980). Each teacher (n?=?31) rated 6 students with high, low, or medium CDI scores (n?=?181) using the CDI items (teacher-CDI) and a single global rating. Remaining students received the global rating only. 16 teachers were randomly assigned to receive instruction on childhood depression. Contrary to earlier studies, moderate correspondence was found for both measures. Familiarity was related to correspondence, whereas confidence and student gender were unrelated to correspondence. Instruction improved knowledge, but not correspondence. School-related behaviors yielded the highest correspondence. The teacher-CDI displayed high test–retest reliability. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
352.
Günter Weickert Ines Henschel Bernd Platzer Rolf-Dieter Klodt Klaus-Dieter Weißenborn 《大分子材料与工程》1989,165(1):35-45
In this part properties and efficiency of the developed model1,2 are discussed. A variation of the parameters shows that vigorous effects are caused by the effective aggregation. All calculations show that at low conversion there are little temporal steps between the sequential aggregation steps. In the range of 5% to 20% conversion the velocity of aggregation decreases and the aggregative stability agrees with experiences given in the literature. It is shown that the calculated results are in agreement with the experimental results and therefore the presented model is a suitable possibility to describe the formation of some PVC-morphology properties. 相似文献
353.
McGaugh James L.; Introini-Collison Ines B.; Juler Ronald G.; Izquierdo Ivan 《Canadian Metallurgical Quarterly》1986,100(6):839
These experiments examined the effect of posttraining administration of naloxone and β-endorphin in rats with lesions of the stria terminalis (ST). Rats with sham or bilateral ST lesions were trained either in an inhibitory avoidance task or in a Y-maze discrimination task and, immediately after training, received an ip injection of saline, naloxone (0.5, 2.0, or 5.0 mg/kg in the avoidance task; 3.0 mg/kg in the Y-maze task), or β-endorphin (10.0 μg/kg). Retention of each task was tested 24 hrs following training. In the Y-maze task, retention was assessed by training on a reversed discrimination. The ST lesions did not affect retention of either task in otherwise untreated animals. However, in both tasks, ST lesions attenuated the memory-enhancing effects of naloxone as well as the memory-impairing effects of β-endorphin. These findings are consistent with other recent evidence suggesting that the amygdala may be involved in posttraining memory modulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
354.
Maria Ines Silvani Gevaldo L. de Almeida Rosanne C.A.A. Furieri 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,263(1):253-257
The impact of the divergence of a thermal neutron beam and the scattered neutrons on the quality of tomographic images acquired by transmission have been evaluated by using a third generation tomographic system incorporating neutron collimators under several different arrangements. The system equipped with a gaseous position sensitive detector has been placed at the main channel outlet of the Argonauta Research Reactor in Instituto de Engenharia Nuclear (CNEN-Brazil) which furnishes a thermal neutron flux of 2.3 × 105 n cm−2 s−1. Experiments have then been conducted using test-objects with well-known inner structure and composition to assess the influence of the collimators arrangement on the quality of the acquired images. Both, beam divergence and scattering - expected to spoil the image quality - have been reduced by using properly positioned collimators between the neutron source and the object, and in the gap between the object and the detector, respectively. The shadow cast by this last collimator on the projections used to reconstruct the tomographic images has been eliminated by a proper software specifically written for this purpose. Improvement of the tomographic images has been observed, demonstrating the effectiveness of the proposed approach to improve their quality by using properly positioned collimators. 相似文献
355.
356.
Nafiseh Zaker Chenxi Geng Divya Rathore Ines Hamam Ning Chen Penghao Xiao Chongyin Yang J. R. Dahn Gianluigi A. Botton 《Advanced functional materials》2023,33(16):2211178
Nickel-rich cathode materials with small amounts of tungsten (W) dopants have attracted extensive attention in recent years. However, the chemical state, crystalline form, compound chemistry, and location of W in these layered cathodes are still not well-understood. In this study, these missing structural properties are determined through a combination of macro-, to atomic-sensitive characterization techniques and density functional theory (DFT). W-doped LiNiO2 (LNO) particles, prepared with mechanofusion and coprecipitation methods, are used to probe changes in the structure and location of W-species. The results indicate that W is mainly distributed on the surfaces and inside grain boundaries of the secondary particles, regardless of the doping method. Electron energy loss spectroscopy (EELS) mapping confirms the simultaneous presence of W, O, with and without Ni in the grain boundaries as well as W- and O-rich regions on the very surface. The W-rich areas inside the grain boundaries are found to be in two forms, crystalline and amorphous. This paper suggests the presence of kinetically stabilized-Li4+xNi1-xWO6 (x = 0, 0.1) with the possibility of LixWyOz phases in LNO which are consistent with the electron microscopy, X-ray absorption and diffraction data. The multiple roles of W in this complex microstructure are discussed considering the W distribution. 相似文献
357.
Four different activated methacrylatic monoliths, acting as pore-through-flow membrane reactors in order to reduce enzyme costs and mass-transfer limitations, were characterized as support for immobilization of β-galactosidase to produce galacto-oligosaccharides (GOS). GOS synthesis was studied in different operation modes. A higher affinity of the immobilized enzyme towards the transgalactosylation reaction could be obtained, which results in desired GOS with higher degree of polymerisation. Kinetic models were successfully parametrized forming a basis for process modeling and optimization. 相似文献
358.
Ines Nitoi Tatiana Oncescu Petruta Oancea 《Journal of Industrial and Engineering Chemistry》2013,19(1):305-309
Because application of classical treatment methods cannot allow an easily Lindane (gamma 1α,2α,3β,4α,5α,6β-hexachlorocyclohexane) degradation, development of more powerful water treatment techniques, like advanced oxidation processes (AOPs), was necessary. The degradation of lindane (γ-HCH) has been studied using the photo-Fenton reaction. The degradation kinetics under irradiation was optimized in respect to H2O2 concentration and Fe2+ concentration at a constant lindane concentration. The degradation rate follows pseudo-first order kinetics with respect to lindane and organic clorine mineralization. Application of photo-Fenton system also assures total organic carbon removal with 95% efficiency at 2 h irradiation. The possible pathways of lindane photodegradation is also proposed. 相似文献
359.
360.