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The compact radio structure of radio-loud narrow line Seyfert 1 galaxies
Minfeng Gu,Yongjun Chen
Physics , 2010, DOI: 10.1088/0004-6256/139/6/2612
Abstract: We present the compact radio structure of three radio-loud narrow line Seyfert 1 galaxies from VLBA archive data at 2.3, 5 and 8.4 GHz. In RXS J16290+4007, the radio structure is mostly unresolved. The combination of compact radio structure, high brightness temperature and inverted spectrum between simultaneous 2.3 and 8.4 GHz, strongly favors jet relativistic beaming. Combining with the VLBI data at 1.6 and 8.4 GHz from literatures, we argued that RXS J16333+4718 may also harbor a relativistic jet, with resolved core-jet structure in 5 GHz. B3 1702+457 is clearly resolved with well defined jet component. The overall radio steep spectrum indicates that B3 1702+457 is likely a source optically defined as NLS1 with radio definition of compact steep spectrum sources. From these three sources, we found that radio loud NLS1s can be either intrinsically radio loud (e.g. B3 1702+457), or apparently radio loud due to jet beaming effect (e.g. RXS J16290+4007 and RXS J16333+4718).
A New Strategy for BLDC Sensorless Control System and Its Application in Horizontal Well Tractor  [PDF]
Shuhan Yu, Yongjun Chen
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103844
Abstract:
The positionless brushless DC motor has the advantages of simple structure, good speed performance and high efficiency. It has become the best choice for horizontal well tractor. This paper introduces a set of brushless DC motor control system, gives the hardware structure of the system and brushless DC motor without Hall sensor control flow chart and the host computer communication interface protocol which solves the problem of phase lag in the case of high speed motor. Aiming at the problem that the parameters of the motor can not be monitored, the host computer monitoring program based on c# can be designed to monitor the parameters of the motor in real time. The experimental results show that the control system can make the motor run smoothly at different speeds, and can monitor the parameters of the motor in real time, suitable for the horizontal well logging and so on the motor control system requires relatively high industrial environment.
Experimental and Numerical Study of the Effect of Surround Protection Technique on the Strain Measurement for Offshore Jacket Platform  [PDF]
Yongjun Xu
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.35056
Abstract: For strain measurement on offshore jacket platform in deep water, waterproof of strain foil is always an important issue, especially, due to the high pressure in deep water. The waterproof is difficult in two places, one is between the matrix structure and the protection structure, and another is between the lead wires and the protection structure. The surround protection technique discussed in this paper is conventional and ideal, and can be operative for a long time, up to five years. In this method, a metal case and tube is added on the local position, which increases the local rigidity, but the effect on the measurement of strain is not well studied. In this paper, the effect of the surround protection technique on the strain measurement is studied by using numerical and experimental methods, and the results show that the measurement error is well in the range permitted by engineering practice.
Review and prospect of transgenic rice research
Hao Chen,YongJun Lin,QiFa Zhang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0645-x
Abstract: Rice is one of the most important crops as the staple food for more than half of the world’s population. Rice improvement has achieved remarkable success in the past half-century, with the yield doubled in most parts of the world and even tripled in certain regions, which has contributed greatly to food security globally. Rapid population growth and economic development pose a constantly increased food requirement. However, rice yield has been hovering in the past decade, which is mainly caused by the absence of novel breeding technologies, reduction of genetic diversity of rice cultivars, and serious yield loss due to increasingly severe occurrences of insects, diseases, and abiotic stresses. To address these challenges, Chinese scientists proposed a novel rice breeding goal of developing Green Super Rice to improve rice varieties and realize the sustainable development of agriculture, by focusing on the following 5 classes of traits: insect and disease resistance, drought-tolerance, nutrient-use efficiency, quality and yield potential. As a modern breeding approach, transgenic strategy will play an important role in realizing the goal of Green Super Rice. Presently, many transgenic studies of rice have been conducted, and most of target traits are consistent with the goal of Green Super Rice. In this paper, we firstly review technical advances of rice transformation, and then outline the main progress in transgenic rice research with respect to the most important traits: insect and disease-resistance, drought-tolerance, nutrient-use efficiency, quality, yield potential and herbicide-tolerance. The prospects of developing transgenic rice are also discussed.
A Smart Substation Field Secondary Device Testing Technique Based on Recurrence Principle  [PDF]
Kanjun Zhang, Lei Chen, Yongjun Xia, Yang Lei, Xin Shu, Hengxuan Li, Ting Wang, Zhenan Du
Journal of Power and Energy Engineering (JPEE) , 2014, DOI: 10.4236/jpee.2014.24035
Abstract: According to the demand of substation secondary device dynamic performance testing, a smart substation field testing technique based on recurrence principle is proposed in the paper, and the characteristics of smart substation secondary device digitization and information sharing are used by the technique. The principle of testing technique is as follow: the digital simulation model is constructed on the basis of the substation’s actual construction, then the simulating data highly similar to substation’s actual electric quantity transient process is generated, at last, the substation digital secondary device can be tested by using data “recurrence” technique. The testing technique is verified and applied by constructing testing system, the application results show that the technique can effectively perform field test on the dynamic performance of digital secondary device, and the technique has good engineering implementation and application value.
Relationship of Post-Stroke Aphasic Types with Sex, Age and Stroke Types  [PDF]
Jingfan Yao, Zaizhu Han, Yanli Song, Lei Li, Yun Zhou, Weikang Chen, Chunxue Wang, Yongjun Wang, Yumei Zhang
World Journal of Neuroscience (WJNS) , 2015, DOI: 10.4236/wjns.2015.51004
Abstract: Aim:To explore what is the relationship of the types of post-stroke aphasia with sex, age andstroke types.Methods:Retrospective analysis was administrated on data of 421 patients with acutestroke. Western battery aphasia was used to measure aphasiac type and aphasia quotient (AQ)score. The patients were divided into three age groups: young, middle-aged and elderly. The stroketypes were classified into cerebral infraction (CI) and intracerebral hemorrhage (ICH). Results: All subjects were right-handed, which males and females accounted for 69.60% and 30.40%, respectively. There were 116 cases of Broca’s aphasia (85 males), 35 cases of Wernicke’s aphasia (20 males),15 cases of conductive aphasia (10 males), 63 cases of transcortical motor aphasia (50 males), 11 cases of transcortical sensory aphasia (8 males), 27 cases of transcortical combined aphasia (13 males), 73 cases of anomic aphasia (47 males) and 81 cases of global aphasia (60 males). Male patients (69.60%) have a significantly higher morbidity of aphasia than that of females (30.40%) after stroke (χ2
Relationship of Post-Stroke Aphasic Types with Sex, Age and Stroke Types  [PDF]
Jingfan Yao, Zaizhu Han, Yanli Song, Lei Li, Yun Zhou, Weikang Chen, Yongmei Deng, Yongjun Wang, Yumei Zhang
World Journal of Neuroscience (WJNS) , 2015, DOI: 10.4236/wjns.2015.51004
Abstract: Aim: To explore what is the relationship of the types of post-stroke aphasia with sex, age and stroke types. Methods: Retrospective analysis was administrated on data of 421 patients with acute stroke. Western battery aphasia was used to measure aphasiac type and aphasia quotient (AQ) score. The patients were divided into three age groups: young, middle-aged and elderly. The stroke types were classified into cerebral infraction (CI) and intracerebral hemorrhage (ICH). Results: All subjects were right-handed, which males and females accounted for 69.60% and 30.40%, respectively. There were 116 cases of Broca’s aphasia (85 males), 35 cases of Wernicke’s aphasia (20 males), 15 cases of conductive aphasia (10 males), 63 cases of transcortical motor aphasia (50 males), 11 cases of transcortical sensory aphasia (8 males), 27 cases of transcortical combined aphasia (13 males), 73 cases of anomic aphasia (47 males) and 81 cases of global aphasia (60 males). Male patients (69.60%) have a significantly higher morbidity of aphasia than that of females (30.40%) after stroke (χ2 = 11.57
Electrodeposition and Low-Temperature Post-Treatment of Nanocrystalline Films for Flexible Dye-Sensitized Solar Cells
Shengjun Li,Yongjun Li,Zeng Chen,Junhui Liu,Weifeng Zhang
Journal of Nanomaterials , 2012, DOI: 10.1155/2012/536810
Abstract: SnO2 porous films were electrodeposited on Ti substrate using pulse-potential technique. These deposited films were dealt with different post-treatments. The effects of the post treatments were investigated through X-ray diffraction, FE-SEM, and Raman spectra. These investigations showed that crystal nanoporous SnO2 films were obtained through low-temperature post-treatment process. The photoelectric conversion efficiency of the SnO2 film treated with both the water vapour treatment and ultraviolet illumination was improved to be 0.35% which was comparable with the conversion efficiency of the film sintered at 550°C.
Determination of color centers in CaF2 crystals by multiple gamma-ray irradiations
Wei Chen,PingXin Song,YongJun Dong,YingJiu Zhang,Wei Hua
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5615-z
Abstract: Color centers of CaF2 crystals subjected to three high-dose gamma-ray irradiation treatments were studied. Three absorption bands at 349, 409 and 478 nm are ascribed to the F interstitials through the variation in difference additional absorption values. The transformation of interstitial F atoms to F ions (Fi ) is demonstrated using data with increasing radiation dose. The decrease in the 600 nm absorption band and the occurrence of the 580 nm band correspond to F2 + center conversion to F center. The complex (F -Fi 0) might be associated with the 962 and 1196 nm bands.
Thermoluminescence of Al2O3 crystals grown by temperature gradient techniques
Wei Chen,PingXin Song,YongJun Dong,YingJiu Zhang,Wei Hua
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5614-0
Abstract: Color center concentrations of the Al2O3 crystal grown by temperature gradient techniques were calculated from Gaussian fits to absorption spectra. The concentrations for F- and F +-centers at 204, 232, and 255 nm were determined to be 1.361×1017, 0.098×1017, and 0.325×1017cm 3, respectively. Studies have shown that the thermoluminescence (TL) glow curve exhibits a prominent 450 K peak that matches well the first-order fitting curve. The thermal activation energy E and frequency factor s of the trap were determined to be 0.94456±0.00545 eV and 5.8703×1011 s 1. With this theoretical analysis, a simple one-trap/one-center TL model is presented to provide a theoretical explanation of the TL process.
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