• Title/Summary/Keyword: Hebei Province

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$\bar{WT}$-Classes of Differential Forms on Riemannian Manifolds

  • Hongya, Gao;Zhihua, Gu;Yuming, Chu
    • Kyungpook Mathematical Journal
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    • v.48 no.1
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    • pp.73-79
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    • 2008
  • The purpose of this paper is to study the relations between quasilinear elliptic equations on Riemannian manifolds and differential forms. Two classes of differential forms are introduced and it is shown that some differential expressions are connected in a natural way to quasilinear elliptic equations.

Morphological Characteristics of Normal and Gynandromorphic Hyalomma asiaticum Schulze and Schlottke, 1930

  • Chen, Ze;Li, You-quan;Ren, Qiao-Yun;Luo, Jin;Hu, Yonghong;Li, Kai;Liu, Guang-Yuan;Luo, Jian-xun;Liu, Jingze;Yin, Hong
    • Parasites, Hosts and Diseases
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    • v.53 no.3
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    • pp.361-364
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    • 2015
  • Gynandromorphic ticks are extremely rare, and often attract parasitologists' attention. During our examination of tick specimens, an engorged gynandromorph of Hyalomma asiaticum was noticed. This is the first record of gynandromorphic ticks from China. In this study, several important morphological structures of normal and gynandromorphic H. asiaticum were analyzed. Comparing to the normal H. asiaticum, the gynandromorphic specimen was a typical bipartite protogynander. Its right side showed normal female characteristics, whereas the left side had normal male traits. Different from other gynandromorphic ticks containing 1 anus, this tick reported here had 2 complete anuses, and the anus of the male part had a single adanal plate.

Infection of Oligochaetes, Limnodrilus hoffmeisteri (Annelida: Oligochaeta), in the Nasal Cavity of a Chinese Man

  • Liu, Hongbin;Zhang, Zhenming;Huang, Guangping;Gu, Xiaolong;Wang, Chunmiao;Wang, Yan;Lu, Zhimin
    • Parasites, Hosts and Diseases
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    • v.55 no.1
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    • pp.77-79
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    • 2017
  • The infection by Limnodrilus hoffmeisteri $Clapar{\grave{e}}de$, 1862 (Oligochaeta: Tubificinae) in humans is relatively uncommon. The present report is to describe an incidental human infection with oligochaetes in the nasal cavity of a Chinese man, a 25-year-old man residing in Zhangjiakou city, Hebei province, China presenting with nose bleed, severe itching, continuous sneezing, and rhinorrhea. A lot of oligochaete worms were found in the nasal discharge of the patient. The detected worms were identified as Limnodrilus hoffmeisteri (Annelida: Oligochaeta) based on morphological and molecular characteristics. This incidental L. hoffmeisteri nasal infection is the first case in China and indicates that oligochaete worms can be encountered in humans.

A Novel Recombinant BCG Vaccine Encoding Eimeria tenella Rhomboid and Chicken IL-2 Induces Protective Immunity Against Coccidiosis

  • Wang, Qiuyue;Chen, Lifeng;Li, Jianhua;Zheng, Jun;Cai, Ning;Gong, Pengtao;Li, Shuhong;Li, He;Zhang, Xichen
    • Parasites, Hosts and Diseases
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    • v.52 no.3
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    • pp.251-256
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    • 2014
  • A novel recombinant Bacille Calmette-Guerin (rBCG) vaccine co-expressed Eimeria tenella rhomboid and cytokine chicken IL-2 (chIL-2) was constructed, and its efficacy against E. tenella challenge was observed. The rhomboid gene of E. tenella and chIL-2 gene were subcloned into integrative expression vector pMV361, producing vaccines rBCG pMV361-rho and pMV361-rho-IL2. Animal experiment via intranasal and subcutaneous route in chickens was carried out to evaluate the immune efficacy of the vaccines. The results indicated that these rBCG vaccines could obviously alleviate cacal lesions and oocyst output. Intranasal immunization with pMV361-rho and pMV361-rho-IL2 elicited better protective immunity against E. tenella than subcutaneous immunization. Splenocytes from chickens immunized with either rBCG pMV361-rho and pMV361-rho-IL2 had increased $CD4^+$ and $CD8^+$ cell production. Our data indicate recombinant BCG is able to impart partial protection against E. tenella challenge and co-expression of cytokine with antigen was an effective strategy to improve vaccine immunity.

Analysis of orthotropic plates by the two-dimensional generalized FIT method

  • Zhang, Jinghui;Ullah, Salamat;Gao, Yuanyuan;Avcar, Mehmet;Civalek, Omer
    • Computers and Concrete
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    • v.26 no.5
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    • pp.421-427
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    • 2020
  • In this study, the two-dimensional generalized finite integral transform(FIT) approach was extended for new accurate thermal buckling analysis of fully clamped orthotropic thin plates. Clamped-clamped beam functions, which can automatically satisfy boundary conditions of the plate and orthogonality as an integral kernel to construct generalized integral transform pairs, are adopted. Through performing the transformation, the governing thermal buckling equation can be directly changed into solving linear algebraic equations, which reduces the complexity of the encountered mathematical problems and provides a more efficient solution. The obtained analytical thermal buckling solutions, including critical temperatures and mode shapes, match well with the finite element method (FEM) results, which verifies the precision and validity of the employed approach.

Power Closed-loop Control of Switched Reluctance Generator for High Efficiency Operation

  • Li, Zhenguo;Gao, Dongdong;Ahn, Jin-Woo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.3
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    • pp.397-403
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    • 2012
  • This paper describes a control method of turn-on/off angles to improve the efficiency of the switched reluctance generator(SRG) with a power closed-loop control system, and the inner-loop of the system is current hysteresis control. The SRG control system is constituted by the PI power controller and the two-level current hysteresis controller. By measuring and analyzing the system losses of different reference powers, speeds and turn-on/off angles, selection strategy of optimal turn-on/off angles is discussed. The proposed method is simple, reliable, and easy to achieve.

Pancreatic Cancer Incidence and Mortality Patterns in China, 2009

  • Chen, Wan-Qing;Liang, Di;Zhang, Si-Wei;Zheng, Rou-Shou;He, Yu-Tong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7321-7324
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    • 2013
  • Objective: To estimate the incidence and mortality rates for pancreatic cancer in China. Methods: After checking and reviewing the cancer registry data in 2009 from 72 cancer registry centers, we divided cancer registry areas into urban and rural areas. Incidence/mortality rates, age-specific incidence/mortality rates, age-standardized incidence/mortality rates, proportions, and cumulative incidence/mortality rates for pancreatic cancer were calculated. Results: The total number of newly diagnosed pancreatic cancer cases and deaths in 2009 were 6,220 and 5,650, respectively. The crude incidence rate in all cancer registry areas was 7.28/100,000 (males 8.24, females 6.29). The age-standardized incidence rate by Chinese standard population (ASR) was 3.35/100,000, with ranking at 7th among all cancers. Pancreatic cancer incidence rate was 8.19/100,000 in urban areas whereas it was 5.41/100 000 in rural areas. Cancer mortality rate in all cancer registry areas was 6.61/100,000 (males 7.45; females 5.75), with ranking at 6th among all cancers, and 7.42/100 000 in urban but 4.94/100000 in rural areas. Conclusions: Pancreatic cancer incidence and mortality rates have shown a gradual increase in China. Owing to the difficulty of early diagnosis, identification of high-risk population and modification of risk factors are important to reduce the burden of pancreatic cancer.

Midinfrared Pulse Compression in a Dispersion-decreasing and Nonlinearity-increasing Tapered As2S3 Photonic Crystal Fiber

  • Shen, Jianping;Zhang, Siwei;Wang, Wei;Li, Shuguang;Zhang, Song;Wang, Yujun
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.250-260
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    • 2021
  • A tapered As2S3 photonic crystal fiber (PCF) with four layers of air holes in a hexagonal array around the core is designed in this paper. Numerical simulation shows that the dispersion D decreases and the nonlinearity coefficient γ increases from the thick to the thin end along the tapered PCF. We simulate the midinfrared pulse compression in the tapered As2S3 PCF using the adaptive split-step Fourier method. Initial Gaussian pulses of 4.4 ps and a central wavelength of 2.5 ㎛ propagating in the tapered PCF are located in the anomalous dispersion region. With an average power of assumed input pulses at 3 mW and a repetition frequency of 81.0 MHz, we theoretically obtain a pulse duration of 56 fs and a compression factor of 78 when the pulse propagates from the thick end to the thin end of the tapered PCF. When confinement loss in the tapered PCF is included in the simulation, the minimum pulse duration reaches 72 fs; correspondingly, the maximum compression factor reaches 61. The results show that in the anomalous-dispersion region, midinfrared pulses can be efficiently compressed in a dispersion-decreasing and nonlinearity-increasing tapered As2S3 PCF. Due to confinement loss in the tapered fiber, the efficiency of pulse compression is suppressed.

A Sensorless Switched Reluctance Drive System Based on the Improved Simplified Flux Method

  • Li, Zhenguo;Song, Andong;Ahn, Jin-Woo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.4
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    • pp.477-482
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    • 2012
  • This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.

Magnetic Field Gradient Optimization for Electronic Anti-Fouling Effect in Heat Exchanger

  • Han, Yong;Wang, Shu-Tao
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.1921-1927
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    • 2014
  • A new method for optimizing the magnetic field gradient in the exciting coil of electronic anti-fouling (EAF) system is presented based on changing exciting coil size. In the proposed method, two optimization expressions are deduced based on biot-savart law. The optimization expressions, which can describe the distribution of the magnetic field gradient in the coil, are the function of coil radius and coil length. These optimization expressions can be used to obtain an accurate coil size if the magnetic field gradient on a certain point on the coil's axis of symmetry is needed to be the maximum value. Comparing with the experimental results and the computation results using Finite Element Method simulation to the magnetic field gradient on the coil's axis of symmetry, the computation results obtained by the optimization expression in this article can fit the experimental results and the Finite Element Method results very well. This new method can optimize the EAF system's anti-fouling performance based on improving the magnetic field gradient distribution in the exciting coil.