全文获取类型
收费全文 | 165篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 2篇 |
化学工业 | 54篇 |
金属工艺 | 5篇 |
机械仪表 | 6篇 |
建筑科学 | 15篇 |
能源动力 | 1篇 |
轻工业 | 39篇 |
石油天然气 | 2篇 |
无线电 | 5篇 |
一般工业技术 | 31篇 |
冶金工业 | 8篇 |
自动化技术 | 17篇 |
出版年
2023年 | 9篇 |
2022年 | 3篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 15篇 |
2012年 | 20篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2001年 | 1篇 |
排序方式: 共有186条查询结果,搜索用时 312 毫秒
101.
102.
Following the gaze direction of conspecifics is an adaptive skill that enables individuals to obtain useful information about the location of food, predators, and group mates. In the current study, the authors compared the gaze-following skills of all 4 great ape species. In the 1st experiment, a human either looked to the ceiling or looked straight ahead. Individuals from all species reliably followed the human's gaze direction and sometimes even checked back when they found no target. In a 2nd experiment, the human looked behind some kind of barrier. Results showed that individuals from all species reliably put themselves in places from which they could see what the experimenter was looking at behind the barrier. These results support the hypothesis that great apes do not just orient to a target that another is oriented to, but they actually attempt to take the visual perspective of the other. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Gloria Kirste Juliane Brandt-Slowik Christian Bocker Michael Steinert Reinhard Geiss Delia S. Brauer 《International Journal of Applied Glass Science》2017,8(4):438-449
Degradation and apatite precipitation of Bioglass 45S5 were characterized in two different tris(hydroxymethyl)aminomethane (Tris) buffer solutions. In the conventional one, pH was adjusted to 7.4 using hydrochloric acid (Tris-HCl buffer). In the other one, acetic acid was used instead, thereby obtaining a Tris buffer solution, which was virtually free of chloride ions (Tris-HAc). EDX results showed that chloride ions present in Tris-HCl buffer solution were incorporated into the apatite formed during immersion experiments, forming a (partially) substituted chlorapatite. No chloride ions were detected in apatite precipitated in Tris-HAc. Although no significant differences in the rate of apatite formation were observed during the time points studied here (6 hours to 7 days), the presence of chloride ions may affect very early stages of apatite formation. It may therefore be advantageous to use modified Tris buffer solutions, which do not contain high concentrations of ions involved in apatite formation, when studying early time point release kinetics or apatite precipitation of bioactive glasses. 相似文献
104.
Knauert S Escher B Singer H Hollender J Knauer K 《Environmental science & technology》2008,42(17):6424-6430
Mixture toxicity of three herbicides with the same mode of action was studied in a long-term outdoor mesocosm study. Photosynthetic activity of phytoplankton as the direct target site of the herbicides was chosen as physiological response parameter. The three photosystem II (PSII) inhibitors atrazine, isoproturon, and diuron were applied as 30% hazardous concentrations (HC30), which we derived from species sensitivity distributions calculated on the basis of EC50 growth inhibition data. The respective herbicide mixture comprised 1/3 of the HC30 of each herbicide. Short-term laboratory experiments revealed that the HC30 values corresponded to EC40 values when regarding photosynthetic activity as the response parameter. In the outdoor mesocosm experiment, effects of atrazine, isoproturon, diuron and their mixture on the photosynthetic activity of phytoplankton were investigated during a five-week period with constant exposure and a subsequent five-month postexposure period when the herbicides dissipated. The results demonstrated that mixture effects determined at the beginning of constant exposure can be described by concentration addition since the mixture elicited a phytotoxic effect comparable to the single herbicides. Declining effects on photosynthetic activity during the experiment might be explained by both a decrease in water herbicide concentrations and by the induction of community tolerance. 相似文献
105.
Because of the concise functionality of oblivious transfer (OT) protocols, they have been widely used as building blocks in secure multiparty computation and high-level protocols. The security of OT protocols built upon classical number theoretic problems, such as the discrete logarithm and factoring, however, is threatened as a result of the huge progress in quantum computing. Therefore, post-quantum cryptography is needed for protocols based on classical problems, and several proposals for post-quantum OT protocols exist. However, most post-quantum cryptosystems present their security proof only in the context of classical adversaries, not in the quantum setting. In this paper, we close this gap and prove the security of the lattice-based OT protocol proposed by Peikert et al. (CRYPTO, 2008), which is universally composably secure under the assumption of learning with errors hardness, in the quantum setting. We apply three general quantum security analysis frameworks. First, we apply the quantum lifting theorem proposed by Unruh (EUROCRYPT, 2010) to prove that the security of the lattice-based OT protocol can be lifted into the quantum world. Then, we apply two more security analysis frameworks specified for post-quantum cryptographic primitives, i.e., simple hybrid arguments (CRYPTO, 2011) and game-preserving reduction (PQCrypto, 2014). 相似文献
106.
Checking out sustainability aspects – life cycle assessments in building comparisons The topic of life cycle assessments at building level plays an increasing role in environmental and socio‐economic terms. This article analyzes the aspect of climate protection in the context of sustainability assessments of buildings. A summary of five life cycle assessment studies accepted by experts (LCEE, RUB, KÖNIG, FIW, STEINBEIS) is given with reference to building‐related life cycle assessments. In particular, the assumptions and framework conditions made in these studies and their effects on the results are assessed. Similarities as well as essential differences of the individual studies are shown in form of a comparative analysis. 相似文献
107.
A promising concept of aqueous two‐phase extraction (ATPE) is the Tunable Aqueous Polymer Phase Impregnated Resins (TAPPIR®) technology. Thereby, one phase of an aqueous two‐phase system (ATPS) is immobilized inside porous solids, which are then dispersed in the second aqueous phase. Beside extraction performance, the reusability of the impregnated solids for several cycles decides upon the competitiveness of TAPPIR®. Multistage extraction experiments using a polyethylene glycol 4000/citrate ATPS to partition lysozyme were investigated for TAPPIR® and ATPE. A stable impregnation was demonstrated for multiple cycles. Moreover, it was found that multistage extraction processes should not be designed on basis of the first extraction as the yield changes in the following stages. 相似文献
108.
109.
Effects of oxidative treatment on the physicochemical,rheological and functional properties of oat β-glucan 总被引:1,自引:0,他引:1
Fernanda Aline de Moura Juliane Mascarenhas Pereira Débora Oliveira da Silva Elessandra da Rosa Zavareze Angelita da Silveira Moreira Elizabete Helbig Alvaro Renato Guerra Dias 《Food chemistry》2011
The objective of this work was promote oxidation of β-glucan from oat bran with hydrogen peroxide at different concentration levels (0.3%, 0.6% and 0.9% H2O2) and reaction times (30 and 60 min), and evaluate the physicochemical and functional properties of isedoxidised β-glucan with in-vitro tests. An increase in carbonyl and carboxyl groups and alterations in swelling power were verified in the oxidised β-glucan. The cholic acid binding capacity increased in the oxidised β-glucan; however, the fat binding capacity was not affected. After chemical digestion, the available glucose of the oxidised β-glucan was increased. Oxidation with hydrogen peroxide decreased the viscosity, hardness, adhesiveness and gumminess of the β-glucan gels. More studies are necessary to determine the effect of the oxidative treatment of β-glucan on its technological properties in food products, and biological properties should be examined with in-vivo studies. 相似文献
110.
Commercial scanning white light interference microscopes are able to map surface topography to very high resolution and can thus measure very small amounts of wear on rubbed surfaces. These instruments are therefore being increasingly used to study aspects of mild wear. It is shown in this Technical Note that, when used on surfaces that have been rubbed in lubricants containing the antiwear additive zinc dialkyldithiophosphate (ZDDP), some white light interference microscopes can produce an apparent but spurious wear measurement. The transparent and relatively thick antiwear film generated by ZDDP on rubbed surfaces produces an optical path difference that is incorrectly interpreted as wear. It is thus suggested that surfaces that have been rubbed in lubricants containing ZDDP or other thick film-forming additives should be treated to remove tribofilms prior to wear measurement using scanning interference microscopy. 相似文献