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81.
Diguer Louis; Pelletier Sylvie; Hébert étienne; Desc?teaux Jean; Rousseau Jean-Pierre; Daoust Jean-Philippe 《Canadian Metallurgical Quarterly》2004,21(2):259
This study examined the hypothesis that psychotic, borderline, and neurotic personality organizations (POs) present a progressive differentiation between self and object representations and an increasing integration of their bad and good aspects. Fifty patients participated in the study. Measures included scales of self and object representations (S. J. Blatt, S. A. Bers, & C. E. Schaffer, 1993; S. J. Blatt, H. Wiseman, E. Prince-Gibson, & C. Gatt, 1991), as well as the Personality Organization Diagnostic Form (L. Diguer & L. Normandin, 1997) and estimations of psychiatric severity. Results showed that PO groups differed in terms of the integration of the object and its valence. It was also observed that although object and self representations were closely intertwined, the latter showed more discrimination between POs than the former. Psychiatric severity was shown to correlate more with object representations than self representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
82.
This paper presents an investigation into the hydraulics of regular ogee-profile spillways. The free-surfaces of the fluid for several flow heads as measured in the hydraulics laboratory are used as benchmarks. The finite element computational fluid dynamics software, ADINA, was used to predict the free surface over an ogee spillway and thus model the flow field. Since the actual flow is turbulent the k-ε flow model was used. For the cases considered in this paper, ADINA predicted reasonable free surface results that are consistent with general flow characteristics over spillways. The results are also in close agreement with measured free-surface profiles over the entire length of the spillway. 相似文献
83.
Suárez-Orozco Carola; Gaytán Francisco X.; Bang Hee Jin; Pakes Juliana; O'Connor Erin; Rhodes Jean 《Canadian Metallurgical Quarterly》2010,46(3):602
Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological–developmental and stage–environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
84.
This paper considers an adaptive version of the problem of Klimov. There are N nodes with a Bernoulli routing and exogenous Poisson arrival processes. The service times are independent and are identically distributed in each node, with an unknown distribution. There is a single server to be allocated in a nonpre-emptive way to the customers. The problem is to minimize the long term average waiting cost per unit of time, for given cost rates in the nodes.The result is that the certainty equivalence controller, that assigns the server optimally assuming that the sample means of the service times are the correct means, is optimal.The analysis is based on results about last exit times of random walks. 相似文献
85.
Mahue V Mari JM Eckersley RJ Tang MX 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(1):73-81
In this paper, a new Doppler technique based on pulse subtraction imaging (PSD) is described and compared with pulse inversion Doppler (PID). Combining a nonlinear contrast agent imaging technique with a Doppler process provides a tool for detecting motion of both contrast agents and tissues. This has potential in targeted imaging in which attached microbubbles need to be separated from moving ones and surrounding tissues. The results from both simulation and experiment show that PSD is able to differentiate bubble motion from tissue motion. For Doppler processing conducted at the fundamental frequency, the contrast-to-tissue ratio (CTR) in PSD was 3.3 (±0.4) times higher on average than PID at a mechanical index (MI) of 0.1. At the harmonic frequency, PID was shown to have a 3.1 (±0.4) times higher CTR than PSD. Overall, taken in their optimum processing conditions, PID has a CTR up to 1.9 (±0.4) times higher than PSD. The CTRs for both techniques have also been shown to increase with increasing MI. However, for the same axial Doppler resolution. PSD also allows less energy to be transmitted into the medium, which makes it less disruptive. The relative performances of PSD and PID in terms of the bandwidth of the imaging system are also discussed. 相似文献
86.
Bernard Charra Guillaume Jean Charles Chazot Thierry Vanel Jean-Claude Terrat Guy Laurent 《Hemodialysis international. International Symposium on Home Hemodialysis》1999,3(1):16-22
Long, slow hemodialysis (3 × 8 hours/week) has been used without significant modification in Tassin, France, for 30 years with excellent morbidity and mortality rates. A long dialysis session easily provides high Kt/Vurea and allows for good control of nutrition and correction of anemia with a limited need for erythropoietin (EPO). Control of serum phosphate and potassium is usually achieved with low-dose medication. The good survival achieved by long hemodialysis sessions is essentially due to lower cardiovascular morbidity and mortality than in short dialysis sessions. This, in turn, is mainly explained by good blood pressure (BP) control without the need for antihypertensive medication. Normotension in this setting is due to the gentle but powerful ultrafiltration provided by the long sessions, associated with a low salt diet and moderate interdialytic weight gains. These allow for adequate control of extracellular volume (dry weight) in most patients without important intradialytic morbidity. Therefore, increasing the length of the dialysis session seems to be the best way of achieving satisfactory long-term clinical results. 相似文献
87.
Bassel Shaer Jean‐Pierre Kenné Claude Kaddissi Honorine Angue Mintsa 《国际强度与非线性控制杂志
》2017,27(18):4968-4991
》2017,27(18):4968-4991
Electrohydraulic actuators are an attractive choice for active suspension, because these systems provide a high power‐to‐weight ratio. However, their dynamics are highly nonlinear. In addition, the use of one simple controller for both position and force is complicated, because there is a compromise between them in the case of active suspension. Most existing controllers do not efficiently fulfill the requirements, because only one state variable is considered. In this paper, we address these problems by developing a new hybrid controller for both position and force and implementing it in a real‐time test bench. Our goal is to control the vertical position of the passenger seat while tracking the force transmitted to passengers and keeping it within tolerable and comfortable limits. Therefore, the proposed controller is a combination of two controllers. Its flexible structure redirects the control signal to control the proper controlled state variable. The real‐time results of the newly designed hybrid controller are compared with those obtained using a classical proportional integral derivative controller, because this is the most widely used controller in the industry. As expected, the proposed controller demonstrates better performance in real‐time operation. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
88.
Ligand‐Free Synthesis of Aluminum‐Doped Zinc Oxide Nanocrystals and their Use as Optical Spacers in Color‐Tuned Highly Efficient Organic Solar Cells 下载免费PDF全文
Meriem Gaceur Sadok Ben Dkhil David Duché Fatima Bencheikh Jean‐Jacques Simon Ludovic Escoubas Mahdi Mansour Antonio Guerrero Germà Garcia‐Belmonte Xianjie Liu Mats Fahlman Walid Dachraoui Abdou Karim Diallo Christine Videlot‐Ackermann Olivier Margeat Jörg Ackermann 《Advanced functional materials》2016,26(2):243-253
The color of polymer solar cells using an opaque electrode is given by the reflected light, which depends on the composition and thickness of each layer of the device. Metal‐oxide‐based optical spacers are intensively studied in polymer solar cells aiming to optimize the light absorption. However, the low conductivity of materials such as ZnO and TiO2 limits the thickness of such optical spacers to tenths of nanometers. A novel synthesis route of cluster‐free Al‐doped ZnO (AZO) nanocrystals (NCs) is presented for solution processing of highly conductive layers without the need of temperature annealing, including thick optical spacers on top of polymer blends. The processing of 80 nm thick optical spacers based on AZO nanocrystal solutions on top of 200 nm thick polymer blend layer is demonstrated leading to improved photocurrent density of 17% compared to solar cells using standard active layers of 90 nm in combination with thin ZnO‐based optical spacers. These AZO NCs also open new opportunities for the processing of high‐efficiency color tuned solar cells. For the first time, it is shown that applying solution‐processed thick optical spacer with polymer blends of different thicknesses can process solar cells of similar efficiency over 7% but of different colors. 相似文献
89.
Hierarchial Zeolites: Beyond Creation of Mesoporosity: The Advantages of Polymer‐Based Dual‐Function Templates for Fabricating Hierarchical Zeolites (Adv. Funct. Mater. 12/2016) 下载免费PDF全文
90.
Jean Berthier Sébastien Mermoz Kenneth Brakke Loic Sanchez Christian Frétigny Léa Di Cioccio 《Microfluidics and nanofluidics》2013,14(5):845-858
Capillary-driven self-alignment using droplets is currently extensively investigated for self-assembly and microassembly technology. In this technique, surface tension forces associated to capillary pinning create restoring forces and torques that tend to bring the moving part into the alignment. So far, most studies have addressed the problem of square chip alignment on a dedicated patch of a wafer, aiming to achieve 3D microelectronics. In this study, we investigate the shift-restoring forces for more complex moving parts such as regular—convex and non-convex—polygons and regular polygons with regular polygonal cavities. A closed-form approximate expression is derived for each of these polygonal geometries; this expression agrees with the numerical results obtained with the Surface Evolver software. For small shifts, it is found that the restoring force does not depend on the shift direction or on the polygonal shape. In order to tackle the problem of microsystem packaging, an extension of the theory is done for polygonal shapes pierced with connection vias (channels), and a closed form of the shift-restoring force is derived for these geometries and again checked against the numerical model. In this case, the restoring force depends on the shift direction. Finally, a non-dimensional number, the shift number, is proposed that indicates the isotropic or anisotropic behavior of the chip according to the shift direction. 相似文献