全文获取类型
收费全文 | 110篇 |
免费 | 7篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 41篇 |
金属工艺 | 1篇 |
建筑科学 | 5篇 |
能源动力 | 1篇 |
轻工业 | 21篇 |
石油天然气 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 6篇 |
冶金工业 | 17篇 |
自动化技术 | 18篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 11篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
排序方式: 共有117条查询结果,搜索用时 0 毫秒
21.
The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic
performance of dye-sensitized solar cells (DSCs). The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface,
thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work,
we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine
concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of
GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced
by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high
as 8% were obtained. 相似文献
22.
Demerouti Evangelia; Bakker Arnold B.; Nachreiner Friedhelm; Schaufeli Wilmar B. 《Canadian Metallurgical Quarterly》2001,86(3):499
The job demands-resources (JD-R) model proposes that working conditions can be categorized into 2 broad categories, job demands and job resources, that are differentially related to specific outcomes. A series of LISREL analyses using self-reports as well as observer ratings of the working conditions provided strong evidence for the JD-R model: Job demands are primarily related to the exhaustion component of burnout, whereas (lack of) job resources are primarily related to disengagement. Highly similar patterns were observed in each of 3 occupational groups: human services, industry, and transport (total N?=?374). In addition, results confirmed the 2-factor structure (exhaustion and disengagement) of a new burnout instrument—the Oldenburg Burnout Inventory—and suggested that this structure is essentially invariant across occupational groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
23.
This study of 168 dual-earner couples examined the relationship between workaholism and relationship satisfaction. More specifically, on the basis of the literature, it was hypothesized that workaholism is positively related to work-family conflict. In addition, the authors predicted that workaholism is related to reduced support provided to the partner, through work-family conflict, and that individuals who receive considerable support from their partners are more satisfied with their relationship. Finally, the authors hypothesized direct crossover of relationship satisfaction between partners. The results of structural equation modeling analyses using the matched responses of both partners supported these hypotheses. Moreover, in line with predictions, the authors found that gender did not affect the strength of the relationships in the proposed model. The authors discuss workplace interventions as possible ways to help workaholics and their partners. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
24.
Stasinakis AS Thomaidis NS Mamais D Papanikolaou EC Tsakon A Lekkas TD 《Water research》2003,37(9):2140-2148
The effect of hexavalent chromium, Cr(VI), addition on various operating parameters of activated sludge process was evaluated. To accomplish this, two parallel lab-scale continuous-flow activated sludge plants were operated. One was used as a control plant, while the other received Cr(VI) concentrations equal to 0.5, 1, 3 and 5 mgl(-1). Cr(VI) concentrations of 0.5 mgl(-1) caused significant inhibition of the nitrification process (up to 74% decrease in ammonia removal efficiency). On the contrary, the effect of Cr(VI) on organic substrate removal was minor for concentrations up to 5 mgl(-1), indicating that heterotrophic microorganisms are less sensitive to Cr(VI) than nitrifiers. Activated sludge floc size and structure characterization showed that Cr(VI) concentrations higher than 1 mgl(-1) reduced the filaments abundance, causing the appearance of pin-point flocs and free-dispersed bacteria. Additionally, the variability of protozoa and rotifers was reduced. As a result of disperse growth, effluent quality deteriorated, since significant amounts of suspended solids escaped with the effluent. Termination of Cr(VI) addition led to a partial recovery of the nitrification process (up to 57% recovery). Similar recovery signs were not observed for activated sludge floc size and structure. Finally, shock loading to the control plant with 5 mgl(-1) Cr(VI) for 2 days resulted in a significant inhibition of the nitrification process and a reduction in filamentous microorganisms abundance. 相似文献
25.
Irene Kanellopoulou Evangelia K. Karaxi Anna Karatza Ioannis A. Kartsonakis Costas A. Charitidis 《Fatigue & Fracture of Engineering Materials & Structures》2019,42(7):1494-1509
This study presents the development of novel submicron super absorbent polymers (SAPs) used as admixtures in cement‐based matrices with significant advantages over conventional products. The produced SAPs were characterized in respect of their morphology and composition, while their water absorption capacity was determined in different electrolyte solutions. The hybrid core‐shell spherical structure of the fabricated materials offered significant compatibility enhancement with cement while the workability of the mixture was maintained. The assessment of the cement‐based composites including SAPs revealed that their flexural strength increased by 78%. Self‐healing/sealing behavior was assessed by monitoring the crack sealing via SEM, elemental analysis of the healing products, and determination of the water absorbance coefficient for different times of treatment. The cement/SAPs composites with a concentration of SAPs 2% by weight of cement exhibited self‐healing/sealing responsive capability when an artificial crack was induced. According to the SEM characterization, the crack demonstrated complete healing for the better part of its length after 28 days of treatment. 相似文献
26.
Elizabeth Vafiadaki Demetrios A. Arvanitis Aristides G. Eliopoulos Evangelia G. Kranias Despina Sanoudou 《International journal of molecular sciences》2020,21(24)
The cytoskeleton has a primary role in cardiomyocyte function, including the response to mechanical stimuli and injury. The small heat shock protein 20 (Hsp20) conveys protective effects in cardiac muscle that are linked to serine-16 (Ser16) Hsp20 phosphorylation by stress-induced PKA, but the link between Hsp20 and the cytoskeleton remains poorly understood. Herein, we demonstrate a physical and functional interaction of Hsp20 with the cytoskeletal protein 14-3-3. We show that, upon phosphorylation at Ser16, Hsp20 translocates from the cytosol to the cytoskeleton where it binds to 14-3-3. This leads to dissociation of 14-3-3 from the F-actin depolymerization regulator cofilin-2 (CFL2) and enhanced F-actin depolymerization. Importantly, we demonstrate that the P20L Hsp20 mutation associated with dilated cardiomyopathy exhibits reduced physical interaction with 14-3-3 due to diminished Ser16 phosphorylation, with subsequent failure to translocate to the cytoskeleton and inability to disassemble the 14-3-3/CFL2 complex. The topological sequestration of Hsp20 P20L ultimately results in impaired regulation of F-actin dynamics, an effect implicated in loss of cytoskeletal integrity and amelioration of the cardioprotective functions of Hsp20. These findings underscore the significance of Hsp20 phosphorylation in the regulation of actin cytoskeleton dynamics, with important implications in cardiac muscle physiology and pathophysiology. 相似文献
27.
A method for the localization, characterization and computation of the stationary points of a continuously differentiable real-valued function ofn variables is presented. It is based on the combinatorial topology concept of the degree of a mapping associated with an oriented polyhedron. The method consists of two principal steps: (i) localization (and computation if required) of a stationary point in ann-dimensional polyhedron; (ii) characterization of a stationary point as a minimum, maximum or saddle point. The method requires only the signs of gradient values to be correct and it can be successfully applied to problems with imprecise values. 相似文献
28.
We reconsider the well-studied Selfish Routing game with affine latency functions. The Price of Anarchy for this class of games takes maximum value 4/3; this maximum is attained already for a simple network of two parallel links, known as Pigou’s network. We improve upon the value 4/3 by means of Coordination Mechanisms. We increase the latency functions of the edges in the network, i.e., if ? e (x) is the latency function of an edge e, we replace it by $\hat{\ell}_{e}(x)$ with $\ell_{e}(x) \le \hat{\ell}_{e}(x)$ for all x. Then an adversary fixes a demand rate as input. The engineered Price of Anarchy of the mechanism is defined as the worst-case ratio of the Nash social cost in the modified network over the optimal social cost in the original network. Formally, if $\hat{C}_{N} (r)$ denotes the cost of the worst Nash flow in the modified network for rate r and C opt (r) denotes the cost of the optimal flow in the original network for the same rate then $$\mathit{ePoA} = \max_{r \ge 0} \frac{\hat{C}_N(r)}{C_{\mathit{opt}}(r)}. $$ We first exhibit a simple coordination mechanism that achieves for any network of parallel links an engineered Price of Anarchy strictly less than 4/3. For the case of two parallel links our basic mechanism gives 5/4=1.25. Then, for the case of two parallel links, we describe an optimal mechanism; its engineered Price of Anarchy lies between 1.191 and 1.192. 相似文献
29.
Eleni Kosta Christos Kalloniatis Lilian Mitrou Evangelia Kavakli 《Requirements Engineering》2011,16(1):47-54
Nowadays, Internet users are depending on various search engines in order to be able to find requested information on the
Web. Although most users feel that they are and remain anonymous when they place their search queries, reality proves otherwise.
The increasing importance of search engines for the location of the desired information on the Internet usually leads to considerable
inroads into the privacy of users. A heated debate is currently ongoing at European level regarding the question if search
engine providers that are established outside the European Union are covered by the European data protection framework and
the obligations it imposes on entities that process personal data. The scope of this paper is to examine the applicability
of the European data protection legislation to non-EU-based search engine providers and to study the main privacy issues with
regard to search engines, such as the character of search logs, their anonymisation and their retention period. Ixquick, a
privacy-friendly meta-search engine, will be presented as an alternative to privacy intrusive existing practices of search
engines. 相似文献
30.
Ioanna E. Stergiou Konstantinos Kambas Aikaterini Poulaki Stavroula Giannouli Theodora Katsila Aglaia Dimitrakopoulou Veroniki Vidali Vasileios Mouchtouris Ismini Kloukina Evangelia Xingi Stamatis N. Pagakis Lesley Probert George P. Patrinos Konstantinos Ritis Athanasios G. Tzioufas Michael Voulgarelis 《International journal of molecular sciences》2021,22(8)