全文获取类型
收费全文 | 174篇 |
免费 | 25篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 22篇 |
金属工艺 | 7篇 |
机械仪表 | 14篇 |
建筑科学 | 3篇 |
能源动力 | 9篇 |
轻工业 | 39篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 17篇 |
冶金工业 | 19篇 |
原子能技术 | 1篇 |
自动化技术 | 55篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 12篇 |
2012年 | 11篇 |
2011年 | 11篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有199条查询结果,搜索用时 15 毫秒
41.
Belen Larumbe Jaime Laviada Asier Ibáñez-Loinaz Jorge Teniente 《Journal of Infrared, Millimeter and Terahertz Waves》2018,39(1):45-63
A real-time imaging system based on a frequency scanning antenna for conveyor belt setups is presented in this paper. The frequency scanning antenna together with an inexpensive parabolic reflector operates at the W band enabling the detection of details with dimensions in the order of 2 mm. In addition, a low level of sidelobes is achieved by optimizing unequal dividers to window the power distribution for sidelobe reduction. Furthermore, the quality of the images is enhanced by the radiation pattern properties. The performance of the system is validated by showing simulation as well as experimental results obtained in real time, proving the feasibility of these kinds of frequency scanning antennas for cost-effective imaging applications. 相似文献
42.
The Journal of Supercomputing - Virtualization technology is important for servers that compose cloud data centers. The current trend is to consolidate servers to manage them easily and reduce... 相似文献
43.
44.
OBJECTIVE: The aim of the present study was to determine the extent to which mother-child interactional patterns in high- and low-risk (for child physical abuse) mothers were similar to patterns observed in physically abusive parents. METHOD: Ten high-risk and 10 demographically similar low-risk mother-child dyads were studied. Trained observers coded maternal-child interaction patterns in the home during five 1-hour periods using the Standardized Observation Codes system. RESULTS: As expected, high-risk mothers made fewer neutral approaches to their children, displayed more negative behaviors toward their children, and made more indiscriminant responses to their children's prosocial behavior. Expected risk group differences were not found in the number of neutral instructions or positive responses, albeit the proportion of positive responses out of the total number of positive and negative responses was higher for low-risk mothers. After control for educational differences, risk group differences remained in the rates of neutral approaches and the number of indiscriminant behaviors made in response to children's prosocial behaviors. CONCLUSIONS: The observational data indicated that high-risk mothers display some behaviors similar to those observed in physically abusive mothers. The finding that high-risk mothers made more indiscriminate or noncontingent responses when reacting to their children's prosocial behavior is consistent with a coercive model of child physical abuse. 相似文献
45.
MarÍ A Victoria Margarit In S Carmen Rodrí guez Antonio Cerezo 《Drug development and industrial pharmacy》1992,18(1):79-92
The importance of the spreading capacity of the suppository base in the rectal ampulla makes it important to determine dynamic viscosity of lipophilic excipients and to characterize the changes in their rheological properties caused by the addition of other components. We evaluated the influence of colloidal silica (Aerosil R 972), Span 80 and sodium valproate on the excipients Witepsol H-15 and Suppocire AS2. Subsequent analyses in rabbits established the correlation between viscosity of the suppository mass after melting and the release and absorption of drugs administered rectally. The results show that excipients with initially dilating flow subsequently showed plastic flow characteristics, with marked thixotropy and increased viscosity which delayed release and absorption. 相似文献
46.
This paper examines the institutional pursuit of the technological fix in a particular case concerning forestry management in northern Spain. Scholars in Science, Technology, and Society (STS) studies have devoted much attention to the criticism of technological determinism, as well as to uncovering the social underpinnings of technological artifacts, disputes, and disasters. But the political role of technical expertise in the closure of social controversies has not been the object of similar historical or case-study STS research. In many instances, transformation of social issues into technical ones by means of “neutral” legal measures and administrative practice lets a form of technocracy in through the back door. 相似文献
47.
M. D. Salmer n P. J. Hern ndez A. Cerezo 《Drug development and industrial pharmacy》1997,23(2):133-136
The search for new pharmaceutical forms that provide greater security and efficiency is one of the main research activities of pharmaceutical technology. This paper concerns a detailed study of the encapsulation of a glucoconicoid with anti-inflammatory action (6-methylprednisolone) in lipid microspheres, one of the systems used for the transport and delivery of lipid-soluble-type drugs. The method used, in common with previous experiments, was that of the solubilization of the constituents of the oil phase (refined soybean oil, soybean lecithin, cholesterol, and the active agent) and, separately, of the aqueous phase of the emulsion (Tween 80, glycerol, and distilled water). The two phases were then mixed by mechanical shaking, and the micelles were homogenized and filtered through membranes of 1.20-μm pore diameter. To determine the percentage encapsulated of the active agent, the first step was the separation of the encapsulated fraction from the free fraction in the medium by molecular exclusion chromatography or filtration in gel. A dextrose (Sephadex G-50 fine) gel was used for the absorbent or stationary phase, and distilled water was used for the eland, or mobile phase. me determination of the free glucocorticoid in the hydroethanol solution by ultraviolet spectrophotometry at 243 nm permits us to calculate the percentage taken by the microspheres. The formula composed of soybean oil and lecithin in the ratio 1:1.1 (w/w), cholesterol (0.50 g/100 ml), Tween 80 (0.25 g/100 ml), and glycerol (0.63 g/100 ml) produced the greatest quantity of encapsulated active agent: 84.91 ± 4.45%. 相似文献
48.
M. T. Marí n Bosc Ismail I. Salem S nchez J. Morcillo Cerezo A. Gal n 《Drug development and industrial pharmacy》1995,21(13):1557-1562
This study presents the results of “in vitro” dissolution of prolonged release morphine tablets using hydroxypropylmethylcellulose. Tablets with four different doses were elaborated and the liberation from these formulated tablets was compared with that of the only commercial pharmaceutical preparation of this type registered in the Spanish Pharmaceutical Market.
The results of the dissolution tests show that the drug was gradually released in all cases and tablets had released from 60 to 90% of its contents after 8 hours.
In the comparative study, the commercial tablets showed the fastest release. In both cases the release rate was lower when artificial intestinal fluids were used as the dissolution medium. 相似文献
The results of the dissolution tests show that the drug was gradually released in all cases and tablets had released from 60 to 90% of its contents after 8 hours.
In the comparative study, the commercial tablets showed the fastest release. In both cases the release rate was lower when artificial intestinal fluids were used as the dissolution medium. 相似文献
49.
Herein, design, development, and analysis of ultra‐low power sensing energy harvesting modules and their subcomponents for ISM band applications have been studied with a holistic approach in an effort to achieve a feasible and high efficient RF energy harvesting performance. The complete harvester system designed and developed here consists of a zero‐bias RF energy rectifying antenna (rectenna), DC boost converters and energy storage super‐capacitors. Compared with the counterpart energy sources, the surrounding or transmitted wireless energy has low intensity which requires designs with high efficiency. To achieve a successful harvester performance, rectifier circuits with high sensitivity Schottky diodes and proper impedance matching circuits are designed. Dedicated RF signals at various levels from nanowatts to miliwatts are applied at the input of the rectenna and the measured input power versus the scavenged DC output voltage are tabulated. Furthermore, by connecting the rectifier to a high gain antenna and using a RF signal transmitter, the wireless RF power harvesting performance at 2.4 GHz was tested up to 5 m. The performance of the rectenna is analyzed for both low‐power detection and efficiencies. Impedance matching network is implemented to reduce the reflected input RF power, DC to DC converters are evaluated for their compatibility to the rectifiers, and super‐capacitor behaviors are investigated for their charging and storage capabilities. The measured results indicate that a wide operating power range with an ultra‐low power sensing and conversion performance have been achieved by optimizing the efficiency of the Schottky rectifier as low as ?50 dBm. The system can be used for battery free applications or expanding battery life for ultra‐low power electronics, such as; RFID, LoRa, Bluetooth, ZigBee, and low power remote sensor systems. 相似文献
50.
Adrian Jarabo Belen Masia Andreas Velten Christopher Barsi Ramesh Raskar Diego Gutierrez 《Computer Graphics Forum》2015,34(8):1-12
We present a real‐time framework which allows interactive visualization of relativistic effects for time‐resolved light transport. We leverage data from two different sources: real‐world data acquired with an effective exposure time of less than 2 picoseconds, using an ultra‐fast imaging technique termed femto‐photography, and a transient renderer based on ray‐tracing. We explore the effects of time dilation, light aberration, frequency shift and radiance accumulation by modifying existing models of these relativistic effects to take into account the time‐resolved nature of light propagation. Unlike previous works, we do not impose limiting constraints in the visualization, allowing the virtual camera to explore freely a reconstructed 3D scene depicting dynamic illumination. Moreover, we consider not only linear motion, but also acceleration and rotation of the camera. We further introduce, for the first time, a pinhole camera model into our relativistic rendering framework, and account for subsequent changes in focal length and field of view as the camera moves through the scene. 相似文献