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1.
Nowadays outdoor location systems have been used extensively in all fields of human life from military applications to daily life. However, these systems cannot operate in indoor applications. Hence, this paper considers a novel indoor location system that aims to locate an object within an accuracy of about 2 cm using ordinary and inexpensive off-the-shelf devices and that was designed and tested in an office room to evaluate its performance.In order to compute the distance between the transducers (speakers) and object to be localized (microphone), time-of-arrival measurements of acoustic signals consisting of Binary Phase Shift Keying modulated Gold sequences are performed. This DS-CDMA scheme assures accurate distance measurements and provides immunity to noise and interference.Two methods have been proposed for location estimation. The first method takes the average of four location estimates obtained by trilateration technique. In the second method, only a single robust position estimate is obtained using three distances while the least reliable fourth distance measurement is not taken into account.The system?s performance is evaluated at positions from two height levels using system parameters determined by preliminary experiments. The precision distributions in the work area and the precision versus accuracy plots depict the system performance. The proposed system provides location estimates of better than 2 cm accuracy with 99% precision.  相似文献   
2.
In this study, the entrance surface dose rates received by a phantom during cineangiography and fluoroscopy were compared. The X-ray conditions used in the measurements were those normally used in facilities performing percutaneous coronary intervention. Although, today, the entrance surface doses (cineangiography and fluoroscopy) of X-ray equipment used for cardiac interventional radiology (IVR) tends to be lower than they were previously, some equipment produces a high radiation dose. Therefore, the X-ray equipment used for cardiac IVR procedures must be maintained in good repair and must be carefully calibrated. In addition, periodic measurement of the radiation dose from the X-ray equipment used for both cineangiography and fluoroscopy for cardiac IVR is necessary. If the radiation dose of the X-ray system in use is too high, the IVR staff should determine the reason and make an effort to reduce it. Hence, the IVR staff must be adequately trained in radiation protection.  相似文献   
3.
Volatile concentrates were prepared from whole soybeans, roasted at 200°C for 10, 20 and 30 min, by steam distillation under reduced pressure followed by ether extraction, and analysed by gas chromatography and gas chromatography-mass spectrometry, in comparison with the volatile concentrate from raw soybean flour.Major flavour components of raw soybean, such as n-hexanol, 1-octen-3-ol and n-hexanal, decreased during the course of roasting, but the rate of this decrease was not rapid, especially between 10 and 20 minutes' roasting. During the roasting period, alkylated pyrazines, oxygenated furans, oxygenated pyrroles and phenols were formed or increased markedly. On the other hand, sensory evaluation showed that a flavour change to ‘desirable’ from ‘beany’ or ‘objectionable’ occurred between 10 and 20 minutes' roasting. These results suggest that roast flavour masks the ‘beany’ flavour in soybean.  相似文献   
4.
Metastases of breast cancer are a major cause of treatment failure. To evaluate the therapeutic efficacy of suicide gene therapy in metastatic breast cancer, we used the herpes simplex virus thymidine kinase (HSV-tk) gene followed by ganciclovir (GCV) administration to treat breast cancer, generated by an adenocarcinoma cell line MOD in syngeneic mice. The bystander effect of HSV-tk + GCV on tumor cell killing was illustrated by demonstrating complete regression of subcutaneous tumors consisting of 90% parental tumor cells and 10% HSV-tk transformed tumor cells. To establish a model of breast cancer metastases in the liver, tumors were generated by intra-hepatic implantation of MOD cells in syngeneic animals. Two weeks after tumor cell implantation, replication defective adenoviral vectors expressing HSV-tk (ADV.tk), or beta-galactosidease (ADV. beta-Gal) were injected intratumorally, followed by buffer or GCV administration. Treatment with ADV.tk + GCV resulted in significant regression of tumor (P < .001), as assessed by computerized morphometric analysis of residual tumor. This was reflected as a significant prolongation of survival in treated animals (P < .001). These results demonstrate that ADV-mediated suicide gene therapy in vivo can be incorporated in a comprehensive treatment strategy for liver metastases of breast cancer.  相似文献   
5.
Abstract

Robots composed of hydraulic actuators have been utilized in various fields and at disaster sites. However, the hydraulic control system for multiple-degree-of-freedom mechanisms is large because such systems require many control components. The purpose of this research was to develop a small hydraulic flow control valve. This paper describes the fabrication and evaluation of a small three-way valve by particle excitation using a piezoelectric transducer. This valve consists of two transducers and can switch the inlet and outlet ports by applying an AC voltage of different driving frequencies to each transducer because each transducer has different resonant frequencies. The flow rate was controlled by applying a voltage to the piezoelectric transducer. We evaluated the vibration characteristics of the fabricated three-way valve. The vibration velocity exhibited peaks at 120 and 155 kHz for the inlet and outlet port, respectively, and that of each transducer increased with the applied voltage. Therefore, this three-way valve can switch the opening port by changing the driving frequencies and continuously controlling the flow rate. As a result, we have succeeded in driving the novel small three-way valve.  相似文献   
6.
In this article, device modeling refers to numerical simulation of semiconductor device physics to predict electrical behavior. The silicon integrated circuit industry provides the example for the use of technology computer-aided design to simulate wafer fabrication processes, and the electrical performance of devices and circuits. This paper first reviews semiconductor device modeling in general, then as applied in work supporting the development and analysis of HgCdTe infrared detectors. Example applications of one- and two-dimensional device modeling are simulation of a bias-selectable, integrated two-color detector, and two-dimensional effects on the spectral response of a HgCdTe detector with composition grading.  相似文献   
7.
We have witnessed 3D shape models abundant in many application fields including 3D CAD/CAM, augmented/mixed reality (AR/MR), and entertainment. Creating 3D shape models from scratch is still very expensive. Efficient and accurate methods for shape retrieval is essential for 3D shape models to be reused. To retrieve similar 3D shape models, one must provide an arbitrary 3D shape as a query. Most of the research on 3D shape retrieval has been conducted with a “whole” shape as a query (aka whole-to-whole shape retrieval), while a “part” shape (aka part-to-whole shape retrieval) is more practically requested as a query especially by mechanical engineering with 3D CAD/CAM applications. A “part” shape is naturally constructed by a 3D range scanner as an input device. In this paper, we focus on the efficient method for part-to-whole shape retrieval where the “part” shape is assumed to be given by a 3D range scanner. Specifically, we propose a Super-Vector coding feature with SURF local features extracted from the View-Normal-Angle image, or the image synthesized by taking account of the angle between the view vector and the surface normal vector, together with the depth-buffered image, for part-to-whole shape retrieval. In addition, we propose a weighted whole-to-whole re-ranking method taking advantage of global information based on the result of part-to-whole shape retrieval. Through experiments we demonstrate that our proposed method outperforms the previous methods with or without re-ranking.  相似文献   
8.
9.
Metastases of lung cancer are a major cause of treatment failure. To evaluate the therapeutic efficacy of gene therapy in metastatic lung cancer, we used adenoviral (ADV) mediated transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene and the cytokine gene interleukin-2 (IL-2) to treat a murine model of metastatic lung cancer in the liver. Hepatic metastases were established by intrahepatic implantation of LL2 cells in syngeneic recipient mice. One week after tumor implantation, various replication defective ADV vectors were injected intratumorally. Treatment with a vector expressing the HSV-tk followed by ganciclovir administration with ADV.tk resulted in significant regression of tumor (p<0.01) as well as prolongation of survival (p<0.001). While a vector expressing mouse IL-2 ADV.IL-2 alone was ineffective, combination therapy with HSV-tk resulted in further tumor regression and improvement of animal survival (p<0.05). These results demonstrate that suicide and cytokine genes can be utilized in combination to treat metastatic lung cancer in vivo.  相似文献   
10.
Wireless sensor networks (WSNs) are composed of sensor nodes generally powered by batteries, for which recharging or replacement is difficult. Since battery technology has not progressed as rapidly as semiconductor technology, energy efficiency has become increasingly important in WSN. On the other hand, data exchanged between nodes are vulnerable to corruption by errors induced by random noise, signal fading and other factors. Therefore, improving link reliability and reducing energy consumption are prime concerns in the design of wireless sensor networks. In this context, performing optimal modulation schemes with suitable channel coding process is a crucial task at the physical layer of this class of networks. This paper investigates the best modulation strategy to minimize the total energy consumption required to send a given number of bits. Energy consumption with both uncoded and coded modulation techniques including M-ary QAM (MQAM), M-ary PSK (MPSK), M-ary FSK (MFSK) and MSK is analytically analyzed and simulated over transmission time, modulation rate and transmission distance. A comparative analysis in terms of energy consumption and probability of Bit Error Rate (BER) referring to MSK modulation with proper Error Control Codes (ECC) approach is presented in this paper. We show that the gain achieved with coded MSK scheme is very promising for obtaining optimal energy network consumption.  相似文献   
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