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1.
We have studied carrier dynamics in In2O3 nanocrystals grown on a quartz substrate using chemical vapor deposition. Transient differential absorption measurements have been employed to investigate the relaxation dynamics of photo-generated carriers in In2O3 nanocrystals. Intensity measurements reveal that Auger recombination plays a crucial role in the carrier dynamics for the carrier densities investigated in this study. A simple differential equation model has been utilized to simulate the photo-generated carrier dynamics in the nanocrystals and to fit the fluence-dependent differential absorption measurements. The average value of the Auger coefficient obtained from fitting to the measurements was γ = 5.9 ± 0.4 × 10−31 cm6 s−1. Similarly the average relaxation rate of the carriers was determined to be approximately τ = 110 ± 10 ps. Time-resolved measurements also revealed ~25 ps delay for the carriers to reach deep traps states which have a subsequent relaxation time of approximately 300 ps.  相似文献   
2.
On-package graphics have the potential to influence consumers’ product-related attitudes and behaviours. In the reported study graphics designs on the labels of two products (water and vodka) were manipulated with respect to shape angularity, orientation, and left–right alignment. Participants’ evaluations indicated a preference for rounded shapes that could not be accounted for by differences in design typicality; and preference for upward shape orientation. An interaction between these response variables for ratings of purchase likelihood suggested that congruence between graphical and product form (droplet shape) may be advantageous. Effects of alignment were not consistent with existing theories, with right-aligned graphics being preferred. An explanation that distinguishes processing efficiency and hemispheric efficiency is proposed. Finally, as predicted, a halo effect was apparent, such that effects of aesthetic manipulations extended to ratings of product attributes that were not experienced. Theoretical and practical implications of these results are discussed.  相似文献   
3.
Straight In2O3 nanowires (NWs) with diameters of 50 nm and lengths ≥2 μm have been grown on Si(001) via the wet oxidation of In at 850°C using Au as a catalyst. These exhibited clear peaks in the X-ray diffraction corresponding to the body centred cubic crystal structure of In2O3 while the photoluminescence (PL) spectrum at 300 K consisted of two broad peaks, centred around 400 and 550 nm. The post-growth nitridation of In2O3 NWs was systematically investigated by varying the nitridation temperature between 500 and 900°C, flow of NH3 and nitridation times between 1 and 6 h. The NWs are eliminated above 600°C while long nitridation times at 500 and 600°C did not result into the efficient conversion of In2O3 to InN. We find that the nitridation of In2O3 is effective by using NH3 and H2 or a two-step temperature nitridation process using just NH3 and slower ramp rates. We discuss the nitridation mechanism and its effect on the PL.  相似文献   
4.
在世界范围使用的非自动衡器OIML R76建议的修改工作在世界范围早就进行了。大概最后草案已于今年10月完成提出了。为了协调一致,把草案分发给非自动衡器OIML工作组成员。  相似文献   
5.
In light of the increasing acceptance of the notion of next generation networks (NGN), which results from the convergence of the fixed and mobile telecommunications, Internet, and entertainment sectors, there is a need for the realization of next-generation service delivery platforms to allow seamless and adaptive provisioning of multimedia information and communication services to mobile users. This means that in such an NGN environment different end systems, access networks, and service platforms have to be integrated. For this highly heterogeneous communications and services environment, we propose a self-adaptive service provisioning middleware framework (ASPF), which, by interoperating with existing wireless and wireline service delivery platforms, aims to enable seamless omnipresent service provisioning to mobile users anywhere, anytime, and in any context. The ASPF is intended to "liberate" applications from space and time limitations, networks, platforms, and device dependences, minimize time-to-market constraints, and eliminate major hurdles that hinder the rapid deployment of new mobile services and applications. Key to this goal is interworking/integration with current SDPs, such as IN/CAMEL, OSA/Parlay, and the emerging IMS.  相似文献   
6.
In gradient elasticity strain gradient terms appear in the expression of virtual work, leading to the need for C1 continuous interpolation in finite element discretizations of the displacement field only. Employing such interpolation is generally avoided in favour of the alternative methods that interpolate other quantities as well as displacement, due to the scarcity of C1 finite elements and their perceived computational cost. In this context, the lack of three‐dimensional C1 elements is of particular concern. In this paper we present a new C1 hexahedral element which, to the best of our knowledge, is the first three‐dimensional C1 element ever constructed. It is shown to pass the single element and patch tests, and to give excellent rates of convergence in benchmark boundary value problems of gradient elasticity. It is further shown that C1 elements are not necessarily more computationally expensive than alternative approaches, and it is argued that they may be more efficient in providing good‐quality solutions. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
7.
High added-value squalene (SQ) was purified in one step from olive oil deodorizer distillates (OODD) using preparative centrifugal partition chromatography (CPC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane–acetonitrile–butanol (1.8:1.4:0.7, v/v/v), leading to the isolation of the target compound in 4 hours, using a preparative 1L column. Furthermore, a fast UHPLC-DAD method was developed and applied for the identification and quantification of SQ in both OODD and purified form. The content of SQ in the initial material was 23.4%, while the purity of the isolated SQ was 95.5%. The recovery of SQ was calculated at 76.3%. The productivity of the process was calculated at 234 mg/h/L.  相似文献   
8.
Wind power development in Europe   总被引:3,自引:0,他引:3  
More than 70% of the total worldwide electricity-generating wind turbines (17500 MW total) has been installed in Europe. Of these, 3500 MW were installed in 2000 alone, continuing an impressive pace of development over the last several years. At the same time, the European wind manufacturing industry is booming with two-thirds of the world market share. These developments are attributed to the effective support of the European Union and of the national European states, following their commitment to reduce greenhouse gas (GHG) emissions. Wind power is now seen as a clean, cost-effective alternative to other forms of conventional electricity production with clear benefits to the environment and to the economy, as a whole. In this review paper the current state and prospects of wind power in Europe are described, with special emphasis on the three countries leading wind power development in Europe, i.e., Germany, Denmark, and Spain. The investment models applied in Europe play a decisive role in this development. Their differences and effects are shown and the role of renewables in reducing CO2 (the primary GHG) emissions is highlighted. Finally, current trends and prospects of the European Wind Turbine technology are discussed  相似文献   
9.
Laboratory testing of railway ballast poses practical difficulties because the particle size is often too large for most standard apparatus. There are therefore advantages in developing a scaled material whose behavior is representative of the full size material. A first stage in validating such an approach is to investigate whether the particle shape is affected by the change in scale. This paper sets out methods for evaluating form and roundness (aspects of shape) and proposes a new measure for evaluating roundness, termed ellipseness. These methods are then applied to a crushed rock railway ballast over a range of particle sizes. Statistical analysis demonstrates a measurable variation in the distributions of form and roundness with particle size over a range of sieve intervals, although the differences are slight and do not necessarily rule out the use of a scaled material for investigating the factors influencing macro mechanical behavior.  相似文献   
10.
BACKGROUND: This study was performed on female Wistar rats allocated to eight groups of six animals each. Groups 1 and 2 were fed the basal diet, groups 3 and 4 were fed the basal diet supplemented with ground oregano at 20 g kg?1 level, groups 5 and 6 were fed the basal diet supplemented with ground rosemary at 20 g kg?1 level, while groups 7 and 8 were fed the basal diet supplemented with both oregano and rosemary, each at 20 g kg?1 level. Following 6 weeks feeding, groups 2, 4, 6 and 8 were injected with CCl4 at 1 mL kg?1 body weight, and 6 h thereafter all animals were sacrificed. RESULTS: Administration of CCl4 to the control rats enhanced (P < 0.05) aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) activities, decreased cholesterol and triglycerides content in serum, increased (P < 0.05) lipid peroxidation and decreased (P < 0.05) the ABTS radical cation, the hydroxyl anion radical, the superoxide anion radical, and the hydrogen peroxide scavenging activities in all tested tissues, as compared to the control. Feeding oregano, rosemary or both before CCl4 treatment resulted in decline (P < 0.05) of the increase in AST, ALT and ALP activities, increase (P < 0.05) of cholesterol and triglycerides in serum, decrease (P < 0.05) of lipid peroxidation, and increase (P < 0.05) of the ABTS radical cation, hydroxyl anion radical, superoxide anion radical and hydrogen peroxide scavenging activity. CONCLUSION: The results of this study suggest that long‐term dietary administration of oregano and rosemary has the potential to quench free radicals and alleviate CCl4‐induced oxidative stress in rats. Copyright © 2009 Society of Chemical Industry  相似文献   
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