全文获取类型
收费全文 | 789篇 |
免费 | 2篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 60篇 |
金属工艺 | 4篇 |
机械仪表 | 42篇 |
建筑科学 | 41篇 |
矿业工程 | 4篇 |
能源动力 | 4篇 |
轻工业 | 185篇 |
水利工程 | 63篇 |
石油天然气 | 9篇 |
武器工业 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 313篇 |
冶金工业 | 13篇 |
自动化技术 | 29篇 |
出版年
2021年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 100篇 |
2011年 | 121篇 |
2010年 | 24篇 |
2009年 | 13篇 |
2008年 | 70篇 |
2007年 | 57篇 |
2006年 | 50篇 |
2005年 | 47篇 |
2004年 | 31篇 |
2003年 | 36篇 |
2002年 | 24篇 |
2001年 | 19篇 |
2000年 | 34篇 |
1999年 | 14篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 14篇 |
1995年 | 26篇 |
1994年 | 16篇 |
1993年 | 21篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 2篇 |
1965年 | 1篇 |
1954年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有791条查询结果,搜索用时 46 毫秒
11.
Localization of Luminescent Inhomogeneities in Turbid Media with Spatially Resolved Measurements of cw Diffuse Luminescence Emittance 总被引:1,自引:0,他引:1
We present a steady-state method for localizing a source ofluminescence (i.e., fluorescence or phosphorescence) buried in asemi-infinite turbid medium with unknown optical properties. Adiffusion theory expression describing the emittance of an isotropicpoint source is fit to spatially resolved surface measurements of thediffuse emittance from the luminescent source. The techniquereports the location of the center of a 6.0-mm-diameter, fluorophore-containing spherical bulb embedded in a liquid phantom withan accuracy of 1.0 mm or better for source depths as great as 40.0mm. Monte Carlo data are analyzed to investigate the range and thepossible sources of error in the reconstructed source depth. 相似文献
12.
Szymanski TH Au A Lafrenière-Roula M Tyan V Supmonchai B Wong J Zerrouk B Obenaus ST 《Applied optics》1998,37(2):264-275
The design of a scalable optical local area network formultiprocessing systems is described. Each workstation has aparallel-fiber-ribbon optical link to a centralized complementarymetal-oxide silicon (CMOS) switch core, implemented on a singlecompact printed circuit board (PCB). When the Motorola Optobusfiber technology is used, each workstation has a data bandwidth of 6.4Gbits/s to the core. A centralized switch core interconnecting 32workstations supports a 204-Gbit/s aggregate data bandwidth. Theswitch core is based on a conventional broadcast-and-selectarchitecture, implemented with parallel CMOS integrated circuits(IC's). The switch core scales well; by incorporation of theCMOS optoelectronic IC's with optical input-output, the electricalcore can be reduced to a single-chip optoelectronic IC with terabitcapacities. A prototype of an optoelectronic switch core has been fabricated and is described. The appeal of the architectureincludes its reliance on commercially available parallel-fibertechnology, its reliance on the well-developed markets of local areanetworks and networks of workstations, and its smooth scalability from the electrical to optical domains as technology matures. 相似文献
13.
Jian WS Hsu CY Hao TH Wen HC Hsu MH Lee YL Li YC Chang P 《Computer methods and programs in biomedicine》2007,88(2):102-111
Traditional electronic health record (EHR) data are produced from various hospital information systems. They could not have existed independently without an information system until the incarnation of XML technology. The interoperability of a healthcare system can be divided into two dimensions: functional interoperability and semantic interoperability. Currently, no single EHR standard exists that provides complete EHR interoperability. In order to establish a national EHR standard, we developed a set of local EHR templates. The Taiwan Electronic Medical Record Template (TMT) is a standard that aims to achieve semantic interoperability in EHR exchanges nationally. The TMT architecture is basically composed of forms, components, sections, and elements. Data stored in the elements which can be referenced by the code set, data type, and narrative block. The TMT was established with the following requirements in mind: (1) transformable to international standards; (2) having a minimal impact on the existing healthcare system; (3) easy to implement and deploy, and (4) compliant with Taiwan's current laws and regulations. The TMT provides a basis for building a portable, interoperable information infrastructure for EHR exchange in Taiwan. 相似文献
14.
Bursting, a dynamical phenomenon whereby episodes of neural action potentials are punctuated by periodic episodes of inactivity, is ubiquitous in neural systems. Examples include components of the respiratory rhythm generating circuitry in the brain stem, spontaneous activity in the neonatal rat spinal cord, and developing neural networks in the retina of the immature ferret. Bursting can also manifest itself in single neurons. Bursting dynamics require one or more kinetic processes slower than the timescale of the action potentials. Such processes usually manifest themselves in intrinsic ion channel properties, such as slow voltage-dependent gating or calcium-dependent processes, or synaptic mechanisms, such as synaptic depression. In this note, we show rhythmic bursting in a simulated neural network where no such slow processes exist at the cellular or synaptic level. Rather, the existence of rhythmic bursting is critically dependent on the connectivity of the network and manifests itself only when connectivity is characterized as small world. The slow process underlying the timescale of bursting manifests itself as a progressive synchronization of the network within each burst. 相似文献
15.
Hong TH Rosenfeld A 《IEEE transactions on pattern analysis and machine intelligence》1984,(2):222-229
This correspondence describes a method of image segmentation based on a ``pyramid' of reduced-resolution versions of the image. It defines link strengths between pixels at adjacent levels of the pyramid, based on proximity and similarity, and iteratively recomputes the pixel values and adjusts the link strengths. After a few iterations, the strengths stabilize, and the links that remain strong define subtrees of the pyramid; the leaves of each tree are the pixels belonging to a compact (piece of a) homogeneous region in the image. 相似文献
16.
17.
18.
In this paper, the singular value decomposition (SVD) based identification and compensation of the hysteretic phenomenon in piezo actuators are addressed using a Preisach model. First, this paper presents an SVD-based least squares algorithm and a revision approach of the identification through updating the SVD. With the identified parameters and a log of the memory curve, a Preisach-based inversion compensator is constructed which is complemented with a feedback controller to address the inevitable and residual modeling errors. Experimental results are furnished for both the identification and compensation approaches. The Preisach-based feedforward controller significantly improves the tracking performance and reduces the root-mean-square (RMS) tracking error of a PID controller by 76.7% and 89% at 1 Hz and 25 Hz, respectively. With the proposed composite controller, the percent-RMS errors at 1 Hz and 25 Hz are reduced to 0.035% and 0.31%, respectively. 相似文献
19.
Tsai FC Tai LA Wang YJ Xiao JL Hsu TH Yang CS Lee CH 《Microscopy research and technique》2011,74(6):531-538
Gold nanoparticles (AuNPs) confined in liposomes of diameters around 200 nm produce strong scattering signal owing to surface plasmon resonance, and therefore bright-field optical tracking of the AuNP-encapsulating liposomes can be conducted in living cells. Using an optical profiling technique called noninterferometric wide-field optical profilometry and a bright-field tracking algorithm, the polynomial-fit Gaussian weight method, we analyze three-dimensional (3D) motion of such liposomes in living fibroblasts. The positioning accuracy in three dimensions is nearly 20 nm. We tag the liposome membranes with fibroblast growth factor-1 and reveal the intracellular transportation processes toward or away from the nucleus. On the basis of a temporal analysis of the intracellular 3D trajectories of AuNP-encapsulating liposomes, we identify directed and diffusive motions in the transportation processes. 相似文献
20.
A pilot-scale evaluation of magnetic ion exchange treatment for removal of natural organic material and inorganic anions 总被引:3,自引:0,他引:3
The objective of this research was to evaluate a magnetic ion exchange process (MIEX) for the removal of natural organic material (NOM) and bromide on a continuous-flow pilot-scale basis under different operating conditions and raw water characteristics. The most important operating variable was the effective resin dose (ERD), which is the product of the steady-state resin concentration in the contactor and the regeneration ratio. The raw water employed in this study had a moderate concentration of ultraviolet (UV)-absorbing substances and dissolved organic carbon (DOC), and a low turbidity, alkalinity, and concentration of competing anionic species. Experiments were conducted using the ambient raw water and raw water spiked with bromide, chloride, and sulfate. Substantial removal of UV-absorbing substances and DOC was achieved at ERDs as low as 0.16mL/L. Moderate bromide removal was achieved, depending on the ERD. Increasing the sulfate concentration resulted in decreased removal of UV-absorbing substances, DOC, and bromide. Consistent results were observed between the continuous-flow pilot plant tests and batch equilibrium studies. 相似文献