全文获取类型
收费全文 | 2067篇 |
免费 | 67篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 51篇 |
综合类 | 2篇 |
化学工业 | 792篇 |
金属工艺 | 32篇 |
机械仪表 | 36篇 |
建筑科学 | 161篇 |
矿业工程 | 4篇 |
能源动力 | 70篇 |
轻工业 | 150篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 107篇 |
一般工业技术 | 224篇 |
冶金工业 | 187篇 |
原子能技术 | 11篇 |
自动化技术 | 304篇 |
出版年
2022年 | 13篇 |
2021年 | 22篇 |
2020年 | 20篇 |
2019年 | 25篇 |
2018年 | 25篇 |
2017年 | 17篇 |
2016年 | 49篇 |
2015年 | 53篇 |
2014年 | 72篇 |
2013年 | 76篇 |
2012年 | 91篇 |
2011年 | 104篇 |
2010年 | 69篇 |
2009年 | 87篇 |
2008年 | 93篇 |
2007年 | 81篇 |
2006年 | 91篇 |
2005年 | 79篇 |
2004年 | 81篇 |
2003年 | 57篇 |
2002年 | 50篇 |
2001年 | 40篇 |
2000年 | 49篇 |
1999年 | 48篇 |
1998年 | 48篇 |
1997年 | 42篇 |
1996年 | 39篇 |
1995年 | 29篇 |
1994年 | 44篇 |
1993年 | 39篇 |
1992年 | 38篇 |
1991年 | 31篇 |
1990年 | 24篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 23篇 |
1985年 | 31篇 |
1984年 | 31篇 |
1983年 | 23篇 |
1982年 | 27篇 |
1981年 | 24篇 |
1980年 | 21篇 |
1979年 | 11篇 |
1978年 | 17篇 |
1977年 | 14篇 |
1976年 | 9篇 |
1975年 | 21篇 |
1973年 | 14篇 |
1972年 | 13篇 |
排序方式: 共有2136条查询结果,搜索用时 15 毫秒
41.
Nordahl R Turchet L Serafin S 《IEEE transactions on visualization and computer graphics》2011,17(9):1234-1244
We propose a system that affords real-time sound synthesis of footsteps on different materials. The system is based on microphones, which detect real footstep sounds from subjects, from which the ground reaction force (GRF) is estimated. Such GRF is used to control a sound synthesis engine based on physical models. Two experiments were conducted. In the first experiment, the ability of subjects to recognize the surface they were exposed to was assessed. In the second experiment, the sound synthesis engine was enhanced with environmental sounds. Results show that, in some conditions, adding a soundscape significantly improves the recognition of the simulated environment. 相似文献
42.
Michael A. Bender Gerth Stølting Brodal Rolf Fagerberg Riko Jacob Elias Vicari 《Theory of Computing Systems》2010,47(4):934-962
We study the problem of sparse-matrix dense-vector multiplication (SpMV) in external memory. The task of SpMV is to compute
y:=Ax, where A is a sparse N×N matrix and x is a vector. We express sparsity by a parameter k, and for each choice of k consider the class of matrices where the number of nonzero entries is kN, i.e., where the average number of nonzero entries per column is k. 相似文献
43.
Arnaud Grasset Philippe Millet Philippe Bonnot Sami Yehia Wolfram Putzke-Roeming Fabio Campi Alberto Rosti Michael Huebner Nikolaos S. Voros Davide Rossi Henning Sahlbach Rolf Ernst 《International journal of parallel programming》2011,39(3):328-356
Reconfigurable computing offers a wide range of low cost and efficient solutions for embedded systems. The proper choice of the reconfigurable device, the granularity of its processing elements and its memory architecture highly depend on the type of application and their data flow. Existing solutions either offer fine grain FPGAs, which rely on a hardware synthesis flow and offer the maximum degree of flexibility, or coarser grain solutions, which are usually more suitable for a particular type of data flow and applications. In this paper, we present the MORPHEUS architecture, a versatile reconfigurable heterogeneous System-on-Chip targeting streaming applications. The presented architecture exploits different reconfigurable technologies at several computation granularities that efficiently address the different applications needs. In order to efficiently exploit the presented architecture, we implemented a complete software solution to map C applications to the reconfigurable architecture. In this paper, we describe the complete toolset and provide concrete use cases of the architecture. 相似文献
44.
Holger Maune Mohsen Sazegar Yuliang Zheng Xianghui Zhou Andre Giere Patrick Scheele Florian Paul Joachim R. Binder Rolf Jakoby 《Microsystem Technologies》2011,17(2):213-224
The research on materials and systems for tunable microwave devices has gained attraction within the last years. The radio
frequency characterization and the component design of tunable microwave components based on dielectric ceramics especially
barium-strontium-titanate (BST) are presented in this second part, whereas the basic material properties are discussed in
detail in the first part. After a short introduction to the processing technology used for the fabrication of tunable components
based on a BST thick film, the relations between microwave properties and material properties as well as the microstructure
are presented in detail. The design process for tunable microwave components based on BST thick films is described. Especially
the considerations related to micro- and macrostructure and their connection are highlighted. The paper closes with two different
application examples: a reconfigurable array antenna for satellite communication and varactors for high power applications. 相似文献
45.
Sabine Schlabach Rolf Ochs Thomas Hanemann Doroth��e Vinga Szab�� 《Microsystem Technologies》2011,17(2):183-193
Regarding the development of nanoparticles for polymer matrix composites the particle/agglomerate size and particle/agglomerate
distribution in the composites, respectively, is often crucial. This is exemplarily shown for, e.g. optical applications with
measurements of refractive index and transmittance. Classical blending techniques, where nanoparticles are dispersed in polymers
or resins, are compared to a combination of a special gas-phase synthesis method with subsequent in-situ deposition of nanoparticles
in high-boiling liquids. The particles/agglomerates were characterized regarding particle size and particle size distribution
using transmission electron microscopy and dynamic light scattering. Additionally, important material properties like mechanical
properties, relevant for application, or like viscosity, relevant for processing, are determined. It is shown, that with in-situ
dispersed nanoparticles synthesized in a microwave plasma process composites with finely dispersed particles/agglomerates
are attainable. 相似文献
46.
Valence electron energy-loss spectroscopy (VEELS) performed in a monochromated scanning transmission electron microscope was used to measure the energy gaps of individual quantum dots (QDs). The gap energies of a series of CdSe QDs measured by VEELS reveal the expected quantum confinement effect; the gap energy increases with decreasing particle size. However, the values derived from these first VEELS measurements of single QDs are larger than the values commonly measured by optical spectroscopy. As standard optical methods lack the spatial resolution to probe individual nanoparticles, the particle-size distribution influences the optical response. It is suggested that the impact of the particle-size distribution accounts for the discrepancy between the energy-gap values derived from VEELS of single QDs and from optical methods of ensembles of QDs. 相似文献
47.
Physical workload of flight attendants when pushing and pulling trolleys aboard aircraft 总被引:2,自引:2,他引:0
Ulrich Glitsch Hans Jürgen Ottersbach Rolf Ellegast Karlheinz Schaub Gerhard Franz Matthias Jger 《International Journal of Industrial Ergonomics》2007,37(11-12):845
The musculoskeletal loads from moving trolleys aboard aircraft were assessed by observation of trolley handling on planes and by physical workload analyses of pushing and pulling of trolleys in a laboratory set up. Trolley handling by a total of 15 female flight attendants was observed on 10 short- and medium-distance flights in different types of aircraft. About 25 selected flight attendants (22 females; 3 males) of five German airlines took part in the laboratory study, which comprised three-dimensional (3D) measurements of posture and hand forces during pushing and pulling of trolleys in a variety of configurations. From the on-flight observations performed, between 150 and 250 trolley movements can be projected for a work shift. The greatest physical workload is to be expected at the beginning of service: The trolleys are fully laden then, and the cabin floor can still be inclined up to 8°, as the aircraft is still climbing, particularly on short-distance flights. The laboratory investigation revealed that the musculoskeletal workload from pushing and pulling depends essentially on the trolley load and on the gradient of the cabin floor. In addition, the degree of stressing depends significantly on the trolley type, mode of handling and personal dexterity. The up/down force component perpendicular to the direction of motion often achieved considerable amplitudes-in some cases equal to or exceeding the force in the direction of movement. The posture analysis demonstrated that pulling forced the flight attendants to adopt ergonomically unfavourable postures such as pronounced flexion of the back, particularly among female subjects. The highest values for flexion of the back occurred while pulling the half-size trolley. The results demonstrate that female flight attendants are likely to overload themselves if they frequently have to move heavily laden trolleys unaided on an inclined cabin floor.
Relevance to industry
On short distance flights, flight attendants have been complaining increasingly of high physical workload from manoeuvring trolleys. On the basis of the presented data airline companies may improve the trolley handling skills of their flight attendances by practical trainings and may ergonomically optimize the general service procedures aboard aircrafts. 相似文献48.
49.
Hyunjung Shim Rolf Adelsberger James Dokyoon Kim Seon-Min Rhee Taehyun Rhee Jae-Young Sim Markus Gross Changyeong Kim 《The Visual computer》2012,28(12):1139-1151
This paper presents a multi-view acquisition system using multi-modal sensors, composed of time-of-flight (ToF) range sensors and color cameras. Our system captures the multiple pairs of color images and depth maps at multiple viewing directions. In order to ensure the acceptable accuracy of measurements, we compensate errors in sensor measurement and calibrate multi-modal devices. Upon manifold experiments and extensive analysis, we identify the major sources of systematic error in sensor measurement and construct an error model for compensation. As a result, we provide a practical solution for the real-time error compensation of depth measurement. Moreover, we implement the calibration scheme for multi-modal devices, unifying the spatial coordinate for multi-modal sensors. The main contribution of this work is to present the thorough analysis of systematic error in sensor measurement and therefore provide a reliable methodology for robust error compensation. The proposed system offers a real-time multi-modal sensor calibration method and thereby is applicable for the 3D reconstruction of dynamic scenes. 相似文献
50.