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排序方式: 共有508条查询结果,搜索用时 10 毫秒
81.
Andrea Petrella Giuseppe Mascolo Sapia Murgolo Valentina Petruzzelli Ezio Ranieri Danilo Spasiano 《Chemical Engineering Communications》2016,203(10):1298-1307
An innovative pilot plant based on UVB and TiO2 (Anatase) allowed for photocatalytic degradation of organic micro-pollutants. The catalyst was immobilized onto a channel through which the solution containing a target molecule (methylene blue, MB) was re-circulated. Due to the cationic nature of the MB substrate, the adsorption reaction onto the catalyst surface provided a significant contribution to the overall degradation mechanism due to the negatively charged surface at neutral pH (TiO2 pHzpc = 6.8). The influence of the initial MB concentration was investigated in the range 0.3–2.0 mg L?1 with the Langmuir–Hinshelwood (LH) model showing good data correlations at concentrations up to 0.7 mg L?1, whereas at higher concentrations a pure zero-order (catalytic) kinetic trend was observed. Flow rate of the re-circulating solution sensibly influenced kinetics after the larger volumes of liquid exposed to UVB/TiO2 and to the better oxygen saturation in the liquid phase. UV?vis and HPLC-MS/MS experimental determinations allowed for identification of MB residual concentration and by-products. 相似文献
82.
The successful application of any remedial technology, including stabilisation/solidification, begins with the site investigation. Following a review of the data collected during the site investigation, a treatability study (TS) and pilot study (PS) are prerequisites to full-scale implementation as they show the effects and delivery of binders to the soils, the geochemistry of the soils, and binder dosages necessary for the existing geology. Further, evaluating the data gathered during the TS and PS can help in accurately estimating and executing full-scale operations. Invariably, deviations from the TS and PS regarding soil characteristics and soil chemistry may exist, but the experience gained via the TS and PS aids in making decisions when faced with new and unexpected conditions in the field. This paper will discuss the execution of typical TS and PS applications and their implementation for full-scale treatment. Because the long-term performance durability of design mixes and technology applications are not generally addressed in remediation, post-remediation monitoring and sampling data must be made available to the public to advance the science and art of stabilisation/solidification. As a first step in advancing this technology, this paper follows the lifecycle of stabilisation/ solidification projects from the site investigation through the completion of full-scale work. A 10-year post-remediation sampling event also evidences the long-term viability of the technology. 相似文献
83.
Jae-Hwa Chang Je-Kang Yoo Seung-Ho Ahn Kyu-Hyun Lee Suk-Moon Ko 《Korean Journal of Chemical Engineering》1998,15(1):28-36
This paper focuses on providing a pervaporation simulation method for ethanol dehydration from a practical point of view.
The simulation procedure is performed by setting up simulation equations which describe the pervaporation process, obtaining
the necessary data from pervaporation batch mode pilot tests, verifying the simulation tool through simulations of continuous
mode pilot tests, and comparing the simulation results with the real pilot test results. We considered the mass and energy
balances that describe separating an ethanol/water mixture by a pervaporation membrane. The simulation equations were mathematically
expressed into simultaneous non-linear differential equations based on these balances. The necessary data for simulation consist
of the thermophysical properties for the ethanol-water mixture and the characteristic data of a PVA composite membrane. The
membrane characteristic data are permeation flux and membrane selectivity, which are functions of feed composition and operating
conditions. These data were experimentally determined by a batch mode pilot test. The continuous mode pilot tests were simulated
and the simulation results were compared to the real test results. The resulte were fairly good. 相似文献
84.
上海自贸试验区由外高桥保税区、浦东机场保税区和洋山保税港区3大区域组成,作为自贸试验区的主体功能,金融、贸易、会展等商务设施快速发展,建树显著。但与其主体功能相辅的配套服务设施,则由于三区不同的阶段和特征都各不相同,在一定程度上影响着自贸试验区的软实力提升。探讨如何结合自贸试验区的特殊性,从特征分析和需求调查出发,寻求适合于当前需求及发展形势的配套服务优化之路。 相似文献
85.
In multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems, the channel state information should be known by the receiver for obtaining transmitted data. Channel estimation algorithms are used to examine the multipath effects of frequency selective Rayleigh fading channels. In this paper, Compressed Sensing (CS) based channel estimation technique is considered for reconstructing the signal with improved spectral efficiency. It requires transmitting the known pilot data to the receiver for estimating channel information. The optimum pilot patterns are selected through reducing the mutual coherence of measurement matrix. In order to maximize the accuracy of sparse channel estimation and to reduce the computational complexity, an optimization algorithm Improved Shuffled Frog Leaping (ISFL) is proposed. When compared with the traditional estimation methods like least squares (LS), and minimal mean square error (MMSE), 4.7% of spectral efficiency is increased with ISFLA based channel estimation. Implementation results show that, by using the proposed algorithm, the bit error rate (BER) and Mean Square Error (MER) performance of the system is increased with 1.5 dB and 2 dB respectively. 相似文献
86.
87.
Examining the Effects of Conformal Terrain Features in Advanced Head‐Up Displays on Flight Performance and Pilot Situation Awareness 下载免费PDF全文
Synthetic vision systems (SVS) render terrain features for pilots through cockpit displays using a GPS database and three‐dimensional graphical models. Enhanced vision systems (EVS) present infrared imagery of terrain using a forward‐looking sensor in the nose of an aircraft. The ultimate goal of SVS and EVS technologies is to support pilots in achieving safety under low‐visibility and night conditions comparable to clear, day conditions. This study assessed pilot performance and situation awareness (SA) effects of SVS and EVS imagery in an advanced head‐up display (HUD) during a simulated landing approach under instrument meteorological conditions. Videos of the landing with various HUD configurations were presented to eight pilots with a superimposed tracking task. The independent variables included four HUD feature configurations (baseline [no terrain imagery], SVS, EVS, and a combination of SVS and EVS), two visibility conditions, and four legs of the flight. Results indicated that SVS increased overall SA but degraded flight path control performance because of visual confusion with other display features. EVS increased flight path control accuracy but decreased system (aircraft) awareness because of visual distractions. The combination of SVS and EVS generated offsetting effects. Display configurations did not affect pilot spatial awareness. Flight performance was not different among phases of the approach, but levels and types of pilot SA did vary from leg to leg. These results are applicable to development of adaptive HUD features to support pilot performance. They support the use of multidimensional measures of SA for insight on pilot information processing with advanced aviation displays. © 2012 Wiley Periodicals, Inc. 相似文献
88.
Zhang Jiancheng Chen Jianwen Wang AilingLiu Chunrong Cao Xinming Zhou ShichangNortheastern University 《机械工程学报(英文版)》1995,(2)
APPLICATIONOFMAGNETIZATIONVISCOUSCHARACTEROFMAGNETICFLUIDINELECTRO-HYDRAULICSERVOAMPLIFIERAPPLICATIONOFMAGNETIZATIONVISCOUSCH... 相似文献
89.
Biochars (BCs) are widely produced and used for the remediation of environmental contaminants as bio-sorbents. In this review, statistical analysis of different BC physico–chemical properties was conducted. It was observed that woody materials are the most suitable for preparing BCs, among many other potential raw materials such as food wastes and agricultural materials. Currently BCs are produced through a variety of thermal treatment processes between 300 and 900 °C, among which slow pyrolysis is widely used due to its moderate operating conditions and optimization of BC yields. Hydrothermal carbonisation (HTC) is also an effective approach for BC production under certain conditions. As pyrolysis temperature is increased, the carbon content, ash content, surface area, and pore volume tend to be increased while the yield, hydrogen, oxygen, nitrogen content, and H/C and O/C molar ratios tend to decrease. The economic feasibility of BCs depends on a range of factors from raw material price to efficient production technologies. Thus, the overall cost equation of a pilot BC production plant together with the cost equation for BC regeneration has been proposed. The future research directions of BCs are also elaborated. 相似文献
90.
Rollout methodology is a constructive metaheuristic algorithm and its main characteristics are its modularity, the adaptability to different objectives and constraints and the easiness of implementation. Multi-heuristic Rollout extends the Rollout by incorporating several constructive heuristics in the Rollout framework and it is able to easily incorporate human experience inside its research patterns to fulfil complex requirements dictated by the application at hand. However, a drawback for both Rollout and multi-heuristic Rollout is often represented by the required computation time. This paper proposes some alternatives of the full multi-heuristic Rollout algorithm aimed at improving the efficiency by reducing the computational effort while preserving the effectiveness. Namely, we propose dynamic heuristics pruning and candidates reduction strategies. As illustrative case studies, we analyse complex deterministic identical parallel machine scheduling problems showing how Rollout procedures can be used to tackle several additional constraints arising in real contexts. More specifically, we considered both standard (batch production, family set-ups, release, due dates, etc.) and non-standard (machine unavailabilities, maximum campaign size) scheduling constraints. An extensive campaign of computational experiments shows the behaviour of the multi-heuristic Rollout approach and the effectiveness of the different proposed speed-up methods. 相似文献