检索结果-南通市图书馆

Effects of Lactobacillus acidophilus on the growth performance and intestinal health of broilers challenged with Clostridium perfringens

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2018年第3期9卷 689-698页

作者： Zhui Li Weiwei Wang Dan Liu Yuming guo State Key Laboratory of Animal Nutrition College of Animal Science and Technology China Agricultural University

Background: Clostridium perfringens is the main etiological agent of necrotic enteritis. Lactobacil i show beneficial effects on intestinal health in infectious disease, but the protective functions of lactobacil i in C. perfringens-infected chickens are scarcely described. This study examined the effects of Lactobacil us acidophilus(L. acidophilus) on the growth performance and intestinal health of broiler chickens chal enged with Clostridium perfringens(C. perfringens) over a 28-day period. Using a 2 × 2 factorial arrangement of treatments, a total of 308 1-day-old male Arbor Acres broiler chicks were included to investigate the effects of Lactobacil us acidophilus(L. acidophilus) on the growth performance and intestinal health of broiler chickens chal enged with Clostridium perfringens(C. perfringens) during a 28-day ***: During infection(d 14–21), C. perfringens challenge decreased the average daily gain(P < 0.05), and increased feed conversion ratio and the mortality rate(P < 0.05). However, dietary supplementation with L. acidophilus increased the body weight of C. perfringens-infected broilers on d 21(P < 0.05), and tended to decrease the mortality(P = 0.061).C. perfringens challenge decreased the villus height(P < 0.05), the ratio of villus height to crypt depth(P < 0.05) and OCLN(occludin) m RNA expression(P < 0.05), and increased the pro-inflammatory cytokine expression in the spleen and jejunum, the intestinal populations of C. perfringens and Escherichia(P < 0.05), and the serum content of endotoxin(P < 0.05), regardless of L. acidophilus supplementation. In contrast, dietary L. acidophilus reducedthe intestinal lesion score of challenged broilers(P < 0.05), the m RNA expression of pro-inflammatory cytokines, ileal populations of Escherichia and serum endotoxin content(P < 0.05), but increased the intestinal Lactobacillus populations(P < 0.05),irrespective of C. perfringens ***: Dietary addition of L. acidophilus could improve

关键词： Broiler Clostridium perfringens Intestine Lactobacillus acidophilus Necrotic enteritis

NUMERICAL STUDY ON THE FLOW AROUND A CIRCULAR CYLINDER WITH SURFACE SUCTION OR BLOWING USING VORTICITY-VELOCITY METHOD

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2002年第9期23卷 1089-1096页

作者： LING guo-ping(凌国平) FANG Jian-wen(方健雯) Department of Mathematics Suzhou University Suzhou215006 P R China Department of Mathematics Suzhou University Suzhou215006 P R China

A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LU decomposition conjugate gradient scheme ( MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too.

关键词： circular cylinder with surface suction or blowing separated vortex flow around bluff body and its control vorticity-velocity method preconditioned conjugate gradient method

The effect of symmetry potential on the balance energy of light particles emitted from mass symmetric heavy-ion collisions with isotopes,isobars and isotones

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2407-2413页

作者： WANG YongJia guo ChenChen LI QingFeng ZHANG HongFei School of Science Huzhou Teachers CollegeHuzhou 513000China School of Nuclear Science and Technology Lanzhou University Lanzhou 730000China College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China

Using the Ultrarelativistic Quantum Molecular Dynamics(UrQMD) model,the balance energies of free neutrons,free protons and Z=1 particles(including free protons,deuterons and tritons) from mass symmetric heavy-ion collisions with isotopes,isobars and isotones are *** influence of nuclear symmetry potential energy on the balance energy is *** is found that the balance energy of free neutrons is sensitive to the nuclear symmetry energy,while that of free protons is ***,the initial neutron/proton ratio dependence of the balance energy of free neutrons from Sn isotopes can be taken as a useful probe to constrain the stiffness of the nuclear symmetry energy.

关键词： symmetry energy directed flow balance energy

Some Properties for the Largest Component of Random Geometric Graphs with Applications in Sensor Networks

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2009年第4期25卷 579-592页

作者： Ge Chen Tian-de guo Chang-long Yao School of Mathematical Science Graduate University of Chinese Academy of Sciences Beijing 100049 China

In this paper we consider the standard Poisson Boolean model of random geometric graphs G（Hλ,s; 1） in Rd and study the properties of the order of the largest component L1 （G（Hλ,s; 1）） . We prove that ElL1 （G（Hλ,s; 1））] is smooth with respect to A, and is derivable with respect to s. Also, we give the expression of these derivatives. These studies provide some new methods for the theory of the largest component of finite random geometric graphs （not asymptotic graphs as s - co） in the high dimensional space （d 〉 2）. Moreover, we investigate the convergence rate of E[L1（G（Hλ,s; 1））]. These results have significance for theory development of random geometric graphs and its practical application. Using our theories, we construct and solve a new optimal energy-efficient topology control model of wireless sensor networks, which has the significance of theoretical foundation and guidance for the design of network layout.

关键词： Random geometric graph the largest component wireless sensor networks topology control

Current patterns of plant diversity and phylogenetic structure on the Kunlun Mountains

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2022年第1期44卷 30-38页

作者： Wei-Bo Du Peng Jia guo-Zhen Du State Key Laboratory of Grassland and Agro-Ecosystems School of Life SciencesLanzhou UniversityLanzhouGansu Province730000P.R.China

Large-scale patterns of biodiversity and the underlying mechanisms that regulate these patterns are central topics in biogeography and *** Qinghai-Tibet Plateau serves as a natural laboratory for studying these ***,most previous studies have focused on the entire Qinghai-Tibet Plateau,leaving independent physical geographic subunits in the region less well *** studied the current plant diversity of the Kunlun Mountains,an independent physical geographic subunit located in northwestern China on the northern edge of the Qinghai-Tibet *** integrated measures of species distribution,geological history,and phylogeography,and analyzed the taxonomic richness,phylogenetic diversity,and community phylogenetic structure of the current plant diversity in the *** distribution patterns of 1911 seed plants showed that species were distributed mainly in the eastern regions of the Kunlun *** taxonomic richness,phylogenetic diversity,and genera richness showed that the eastern regions of the Kunlun Mountains should be the priority area of biodiversity conservation,particularly the southeastern *** proportion of Chinese endemic species inhabiting the Kunlun Mountains and their floristic similarity may indicate that the current patterns of species diversity were favored via species *** Hengduan Mountains,a biodiversity hotspot,is likely the largest source of species colonization of the Kunlun Mountains after the *** net relatedness index indicated that 20 of the 28 communities examined were phylo-genetically dispersed,while the remaining communities were phylogenetically *** nearest taxon index indicated that 27 of the 28 communities were phylogenetically *** results suggest that species colonization and habitat filtering may have contributed to the current plant diversity of the Kunlun Mountains via ecological and evolutionary processes,and habitat filtering may play an impor

关键词： Biodiversity Plant community Kunlun mountains Phylogenetic structure Seed plants

Accurate stress analysis on rigid central buckle of long-span suspension bridges based on submodel method

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第4期52卷 1019-1026页

作者： WANG Hao LI AiQun guo Tong MA Shuang College of Civil Engineering Southeast UniversityNanjing 210096China

Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is in- troduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the ac- curate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working be- havior and mechanical characteristics of the central buckle of the RSB under vehicle loads were ana- lyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.

关键词： suspension bridge central buckle accurate stress submodel method field measurements

Feedback control design with vibration suppression for flexible air-breathing hypersonic vehicles

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2014年第3期57卷 249-262页

作者： GAO Yan WU HuaiNing WANG JunWei guo Lei Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical EngineeringBeihang University

This paper investigates the problem of feedback control design with vibration suppression for a flexible air-breathing hypersonic vehicle(FAHV).FAHV includes intricate coupling between the engine and flight dynamics,as well as complex interplay between flexible and rigid modes,which results in an intractable system for the control *** this paper,a longitudinal model,which is described by a coupled system of ordinary diferential equations(ODEs)and partial diferential equations(PDEs),is ***,a linearized ODE model for the rigid part is established around the trim condition,while vibration of the fuselage is described by ***,based on the Lyapunov direct method,a control law via ODE state feedback and PDE boundary output feedback is designed for the system such that the closed-loop exponential stability is ***,simulation results are given to illustrate the efectiveness of the proposed design method.

关键词： flexible air-breathing hypersonic vehicle(FAHV) Euler-Bernoulli beam vibration suppression Lyapunov direct method boundary control

Modified technique in treating recurrent priapism： a technique report

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2015年第2期17卷 329-331页

作者： Wei Chen Shu-Ben Sun Li-An Sun Jian-Ming guo guo-Min Wang Department of Urology Zhongshan Hospital of Fudan University Shanghai China Department of Urology The Affiliated Hospital of School of Medicine of Ningbo University Ningbo China.

Recurrent ischemic priapism is a problem in clinical treatment. Most of the cases require more invasive surgery to shunt the blood stasis. We introduce a modified technique in treating recurrent ischemic priapism. The technique described is applied to acute ischaemic priapic episodes in patients with a history of stuttering priapism. It was carried out by a Winter＇s shunt combined with a continuous cavernosal irrigation system. Priapism was effectively resolved on the patients without recurrence. ]he four patients who received this treatment recovered most sexual function after 6 months follow-up.

关键词： @@

Characterizations of Sobolev spaces in Euclidean spaces and Heisenberg groups

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 531-547页

作者： CUI Xiao-yue LAM Nguyen LU guo-zhen Department of Mathematics Wayne State UniversityDetroit MI 48202 USA

Recently, many new features of Sobolev spaces W k,p ？RN ？ were studied in [4-6, 32]. This paper is devoted to giving a brief review of some known characterizations of Sobolev spaces in Euclidean spaces and describing our recent study of new characterizations of Sobolev spaces on both Heisenberg groups and Euclidean spaces obtained in [12] and [13] and outlining their proofs. Our results extend those characterizations of first order Sobolev spaces in [32] to the Heisenberg group setting. Moreover, our theorems also provide diff erent characterizations for the second order Sobolev spaces in Euclidean spaces from those in [4, 5].

关键词： characterization of Sobelev spaces Folland-Stein space Poincar′e inequalities Heisenberg group second order Sobolev space