OALib Journal期刊

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匹配条件: “YU Xian-feng” ,找到相关结果约90158条。
An Energy-Efficient Instruction Scheduler Design with Two-Level Shelving and Adaptive Banking
Yu-Lai Zhao,Xian-Feng Li,Dong Tong,Xu Cheng,
Yu-Lai Zhao
,Xian-Feng Li,Dong Tong,and Xu Cheng

计算机科学技术学报 , 2007,
Abstract: Mainstream processors implement the instruction scheduler using a monolithic CAM-based issue queue (IQ), which consumes increasingly high energy as its size scales. In particular, its instruction wakeup logic accounts for a major portion of the consumed energy. Our study shows that instructions with 2 non-ready operands (called 2OP instructions) are in small percentage, but tend to spend long latencies in the IQ. They can be effectively shelved in a small RAM-based waiting instruction buffer (WIB) and steered into the IQ at appropriate time. With this two-level shelving ability, half of the CAM tag comparators are eliminated in the IQ, which significantly reduces the energy of wakeup operation. In addition, we propose an adaptive banking scheme to downsize the IQ and reduce the bit-width of tag comparators. Experiments indicate that for an 8-wide issue superscalar or SMT processor, the energy consumption of the instruction scheduler can be reduced by 67%. Furthermore, the new design has potentially faster scheduler clock speed while maintaining close IPC to the monolithic scheduler design. Compared with the previous work on eliminating tags through prediction, our design is superior in terms of both energy reduction and SMT support.
Serological and molecular study of hepatitis E virus among illegal blood donors
Xian-Feng Cheng,Yu-Feng Wen,Ming Zhu,Sheng-Wei Zhan
World Journal of Gastroenterology , 2012, DOI: 10.3748/wjg.v18.i9.986
Abstract: AIM: To investigate the seroprevalence and molecular characteristics of hepatitis E virus (HEV) in the illegal blood donors (IBDs) of central China in the early 1990s. METHODS: A total of 546 blood samples were collected from the IBDs in Maanshan city, a questionnaire was completed by each subject, detailing the age, sex, and periods of blood or plasma donation. Anhui Province and tested for the anti-HEV antibodies. The seropositive samples were subjected to nested reverse transcription-polymerase chain reaction and sequencing to analyze HEV partial genome. RESULTS: The prevalence of IgG and IgM HEV antibody in IBDs was 22.7% and 1.8%, and genotype 4 was the dominant circulating HEV type in IBDs. The prevalence of anti-HEV IgG was significantly related to sex (OR = 4.905, P = 0.004) and increased with age (OR = 2.78, P = 0.022), which ranged from 13.0% in those < 40 years old to 30.6% among older persons aged > 60 years. Moreover, frequency of blood donation was significantly associated with HEV seropositivity (OR = 2.06, P = 0.006). HEV partial sequences of ORF2 and obtained 3 sequences in serum samples of 10 IBDs which developed HEV specific IgM. CONCLUSION: This study helps define one of the possible routes of transmission of sporadic HEV infection and provides guidance to screen HEV in the blood donors so as to guarantee safe blood banks in China.
Effects of elevated atmospheric CO2 concentration and shading onleaf light utilization and yield of wheat

YU Xian-Feng,ZHANG Xu-Cheng,

中国生态农业学报 , 2012,
Abstract: CO2和光能是植物光合作用的动力和底物, 它们的变化必然引起植物光合特性和生长的变化。研究大气CO2浓度和光强变化对植物光合生理的影响, 有利于认识作物对全球生态变化的生理响应机制。试验以高大气CO2浓度和遮荫为处理手段, 通过测定小麦(Triticum aestivum)旗叶的光合气体交换参数、光强 光合速率响应曲线和产量构成因子, 分析光强 光能利用效率之间的关系, 研究高大气CO2浓度(760 μmol·mol-1)和遮荫对小麦叶片光合特性及产量构成因子的影响。结果表明, 高大气CO2浓度下, 小麦叶片的净光合速率(Pn)增加; 同时最大净光合速率(Pnmax)、光饱和点(LSP)、光补偿点(LCP)显著升高; 遮荫处理使小麦叶片的Pnmax、LSP、LCP降低。正常光照下大气CO2浓度升高使小麦叶片呼吸速率(Rd)显著下降, 遮荫后大气CO2浓度升高对Rd无显著影响。大气CO2浓度升高能显著提高小麦叶片表观量子效率(AQY), 而遮荫对AQY的影响因大气CO2浓度而异, 高大气CO2浓度下遮荫使AQY显著提高, 正常大气CO2浓度下遮荫则使AQY明显下降。高大气CO2浓度下遮荫使小麦株高、穗长增加, 而穗粒数、单株穗粒重、千粒重减小。受光合特性的变化和光强限制, 高大气CO2浓度下遮荫使小麦叶片呼吸增强, 导致Pn下降, 不利于干物质积累和籽粒产量的形成。
Optimized Second Harmonic Generation of Femtosecond Pulse by Phase-Blanking Effect in Aperiodically Optical Superlattice

KONG Yan,CHEN Xian-Feng,XIA Yu-Xing,

中国物理快报 , 2008,
Abstract: In order to minimize the effect of the unconsidered frequency components on the generated compression pulse, the phasing-blanking effect is taken into account of designing the one-dimensional aperiodic domain reversal structure. Hierarchic genetic algorithm for the design of a domain reversal grating tomodulate the spectrum and phase of the generated SH pulse simultaneously are presented. Our simulation shows that the quality of an output pulse is fairly improved.
Calculation Model of Satisfaction Degree Based on Intuitionistic Fuzzy

YU Xian-feng,LI Yong-ming,

计算机科学 , 2013,
Abstract: Satisfaction degree theory is widely used in optimization, system control, management, decision-making, re- source allocation, task Scheduling, and other fields. But most of them based on background of the problem define and calculate satisfaction, which lack a universally applicable formalized satisfaction calculation model. Based on intuition fuzzy set theory, a universal multilevel intuitionistic fuzzy satisfaction degree calculation model was established. It effec- lively induces intuitionistic fuzzy satisfaction degree by using intuitionistic fuzzy filter operator. Combining qualitative and quantitative methods to calculate satisfaction degree, it makes the results more informative, scientific, reasonable and has a high automated degree. This paper analyzed the model's calculation complexity, and combining with a practical ex- ample computed the intuitionistic fuzzy satisfaction degree of shangluo tourism, and the result shows that the model is effective and practical.
Ethyl (2E,4Z)-5-diethylamino-2-(phenylsulfonyl)penta-2,4-dienoate
Guo-Qiang Song,Pei-Pei Yu,Xian-Feng Huang
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812023483
Abstract: In the title compound, C17H23NO4S, the pentadiene group adopts a planar conformation, with an r.m.s. deviation of 0.0410 (14) . The phenyl ring makes a dihedral angle of 85.73 (11)° with the pentadiene group, while the pentadiene group makes dihedral angles of 11.38 (11) and 14.08 (10)°, respectively, with the amino and ester groups. In the crystal, molecules are linked via pairs of C—H...O interactions, forming inversion dimers.
DNA microarray technique for detecting food-borne pathogens
Xing GAO,Xian-feng QU,Wei SUN,Hua-yu LI
Medical Journal of Chinese People's Liberation Army , 2012,
Abstract: Objective To study the application of DNA microarray technique for screening and identifying multiple food-borne pathogens. Methods The oligonucleotide probes were designed by Clustal X and Oligo 6.0 at the conserved regions of specific genes of multiple food-borne pathogens, and then were validated by bioinformatic analyses. The 5' end of each probe was modified by amino-group and 10 Poly-T, and the optimized probes were synthesized and spotted on aldehyde-coated slides. The bacteria DNA template incubated with Klenow enzyme was amplified by arbitrarily primed PCR, and PCR products incorporated into Aminoallyl-dUTP were coupled with fluorescent dye. After hybridization of the purified PCR products with DNA microarray, the hybridization image and fluorescence intensity analysis was acquired by ScanArray and GenePix Pro 5.1 software. A series of detection conditions such as arbitrarily primed PCR and microarray hybridization were optimized. The specificity of this approach was evaluated by 16 different bacteria DNA, and the sensitivity and reproducibility were verified by 4 food-borne pathogens DNA. The samples of multiple bacteria DNA and simulated water samples of Shigella dysenteriae were detected. Results Nine different food-borne bacteria were successfully discriminated under the same condition. The sensitivity of genomic DNA was 102 -103pg/ μl, and the coefficient of variation (CV) of the reproducibility of assay was less than 15%. The corresponding specific hybridization maps of the multiple bacteria DNA samples were obtained, and the detection limit of simulated water sample of Shigella dysenteriae was 3.54×105cfu/ml. Conclusions The DNA microarray detection system based on arbitrarily primed PCR can be employed for effective detection of multiple food-borne pathogens, and this assay may offer a new method for high-throughput platform for detecting bacteria.
Enhanced Kerr electro-optic nonlinearity through cascaded Pockels effects
Guang-Zhen Li,Yu-Ping Chen,Hao-Wei Jiang,Xian-Feng Chen
Physics , 2015,
Abstract: We demonstrated a large enhancement of Kerr electro-optic nonlinearity through cascaded Pockels effects in a domain inversion ferroelectric crystal. We designed a structure that can implement the cascaded Pockels effects and second-harmonic generation simultaneously. The energy coupling between the fundamental lights of different polarizations led to a large nonlinear phase shift, and thus an effective electro-optic nonlinear refractive index. The effective nonlinearity can be either positive or negative, causing the second-harmonic spectra to move towards the coupling center, which in turn, offered us a way to measure the effective electro-optic nonlinear refractive index. The corresponding enhanced Kerr electro-optic nonlinearity is more than three orders of magnitude higher than the intrinsic value. These results open a door to manipulate the nonlinear phase by applying external electric field instead of light intensity in noncentrosymmetric crystals.
Xian-Feng Huang
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809038045
Abstract: In the title complex, [Cu(C12H15Cl2N2O)2], the CuII ion is coordinated by one N,O-bidentate and one N,N′,O-tridentate Schiff base ligand, resulting in a distorted CuN3O2 square-based pyramidal coordination for the metal ion, with the O atoms lying trans to each other in the basal plane.
The Surface Gravitational Redshift of a Proto Neutron Star

ZHAO Xian-Feng,

中国物理快报 , 2010,

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