种鸭大肠杆茵性生殖器官病的研究——6.氢氧化铝甲醛灭活菌苗免疫原性的研究

本文对大肠杆菌灭活菌苗的免疫原性、免疫鸭的外周血液免疫动态及卵黄凝集抗体的测定进行了研究。结果表明,菌苗对小白鼠、可疑感染鸭和健康鸭具有良好免疫原性,鸭的免疫期达4—5个月,可提高种鸭产蛋率和种蛋孵化率。鸭只免疫后45天平均凝集抗体滴度达270.4和313.6,免疫后5个月仍有62.5％鸭只的凝集抗体滴度≥40。免疫鸭血清r-球蛋白含量显著(P<0.05)或极显著(P<0.01),高于非免疫鸭。

基于分子结构矩阵的脂肪酸酯类化合物的QSRR研究

建立了脂肪酸酯类化合物的分子结构矩阵,以结构矩阵行列向量的1-范数为独立参变量,通过回归方法建立数学模型,预测了89种脂肪酸酯类化合物的色谱保留指数.研究结果表明,模型参数物理意义明确,计算容易,方法可靠实用,便于推广.预测值与实验值吻合良好,LOO方法交叉验证和随机抽样预测结果表明,模型具有良好的稳定性和较强的预测能力.

Microstructure evolution and grain growth behavior of Ti14 alloy during semi-solid isothermal process

Microstructure evolution of Ti14 （α＋Ti2Cu） alloy during semi-solid isothermal process at different temperatures was investigated. The results reveal that both the temperature and holding time have effect on the grain growth behavior. The grains grow obviously and the degree of globularity increases with the increase of holding time. According to the statistic analysis of experimental data, the grain growth indices are 0.88 and 0.97 at 1 000 ℃ and 1 050 ℃, respectively, which indicates that increasing isothermal temperature would accelerate microstructural evolution.

Hybrid particle swarm optimization with chaotic search for solving integer and mixed integer programming problems

A novel chaotic search method is proposed,and a hybrid algorithm combining particle swarm optimization(PSO) with this new method,called CLSPSO,is put forward to solve 14 integer and mixed integer programming problems.The performances of CLSPSO are compared with those of other five hybrid algorithms combining PSO with chaotic search methods.Experimental results indicate that in terms of robustness and final convergence speed,CLSPSO is better than other five algorithms in solving many of these problems.Furthermore,CLSPSO exhibits good performance in solving two high-dimensional problems,and it finds better solutions than the known ones.A performance index(PI) is introduced to fairly compare the above six algorithms,and the obtained values of(PI) in three cases demonstrate that CLSPSO is superior to all the other five algorithms under the same conditions.

Characterization of spherical AlSi10Mg powder produced by double-nozzle gas atomization using different parameters

A self-developed double-nozzle gas atomization technique was used to produce AlSi10Mg powder.Effects of delivery tube diameter,gas pressure,and melt superheat on powder characteristics were investigated.The concepts of bluntness and outgrowth were introduced to analyze powder sphericity and satellite index quantitatively.The results showed that the median diameters of all atomized powders ranged from 25 to 33μm.The highest yield rate(72.13%)of fine powder(<50μm)was obtained at a superheat of 350 K.The powder size decreased with increasing melt superheat but increased with increasing delivery tube diameter.Powders with bluntness values between 96%and 98%accounted for over 60%.The outgrowth values demonstrated that 70%-85%of all powders did not contain satellite particles,with few powders adhered two or three particles.Not only Al and Si phases were present but also a metastable Al9Si phase was detected.

Radial Non-uniformity Index Research on High-density,High-flux CFB Riser with Stratified Injection

A high-density, high-flux circulating fluidized bed （CFB） riser （100 mm in ID and 10.614 m in height） was ap- plied in a wide range of operating conditions （with solid fluxes up to 400 kg/m2s and superficial gas velocities up to 12 m/s） to examine its radial non-uniformity dynamics. The solids holdup was determined through the use of a fiber-optic probe at 11 axial levels. The results indicated that under all operating conditions, the high superficial gas velocity and low solid flux- es maintained a low radial non-uniformity index （RNI）. The high-density/flux CFB riser had several unique characteristics, so that the peak of the radial solids holdup profile occurred at a position with r/R=0.8. The RNI and solids holdup at the cross-sectional position had a good logarithmic relationship at the low-density condition （with a mean solids holdup of 〈0.2）, and the RNI decreased when the mean solids holdup exceeded 0.2. Investigation of the dynamics of stratified injec- tion revealed that the feed ratio had an important effect on G, and on solids holdup distribution. A novel ＂〈＂ shaped axial solids holdup profile was found. Gs decreased sharply when the up-flow feed ratio exceeded 0.5, and RNI was lowest when the up-flow feed ratio was 1.

Sediment recycling and indication of weathering proxies

As a result of recycling, the mineralogical and chemical compositions of riverine sediments may reflect the combined effects of the present-day weathering regime as well as previous weathering and diagenetic alteration history. River sediments can be interpreted as a mixture of non-weathered bedrock—of igneous, metamorphic, or sedimentary origin—and solids formed by the modern weathering system. The correlation between the weathering proxies chemical index of alteration and weathering index of Parker offers an approach to distinguish fine suspended particles, coarse bedload sediments, and recycled sediments under the influence of quartz dilution. Recycling of cation-depleted source rocks formed during past geological weathering episodes may have great impacts on the weathering indices of sediments from the Changjiang(Yangzte) and Zhuoshui Rivers. Special caution is required when using chemical weathering indices to investigate the intensity of chemical weathering registered in fluvial sediments. To minimize the effect of hydrodynamic sorting or sediment recycling, we suggest that the fine sediments(e.g.suspended particles and ﹤2 lm fractions of bedload sediments) in rivers better reflect the average of weatheredcrust in catchments and the terrigenous end-member in marginal seas.

Spatial Density Distributions and Correlations in a Quasi-one-Dimensional Polydisperse Granular Gas

By Monte Carlo simulations, the effect of the dispersion of particle size distribution on the spatial density distributions and correlations of a quasi one-dimensional polydisperse granular gas with fractal size distribution is investigated in the same inelasticity. The dispersive degree of the particle size distribution can be measured by a fractal dimension dr, and the smooth particles are constrained to move along a circle of length L, colliding inelastically with each other and thermalized by a viscosity heat bath. When the typical relaxation time τ of the driving Brownian process is longer than the mean collision time To, the system can reach a nonequilibrium steady state. The average energy of the system decays exponentially with time towards a stable asymptotic value, and the energy relaxation time τB to the steady state becomes shorter with increasing values of df. In the steady state, the spatial density distribution becomes more clusterized as df increases, which can be quantitatively characterized by statistical entropy of the system. Furthermore, the spatial correlation functions of density and velocities are found to be a power-law form for small separation distance of particles, and both of the correlations become stronger with the increase of df. Also, tile density clusterization is explained from the correlations.

Influence of sulfur content in raw materials on oxidized pellets

The influence of sulfur content in raw materials on oxidized pellets was studied. The results show that most sulfur exists in the form of elementary sulfur in pyrite cinder, and over 95% sulfur is removed in producing pyrite cinder oxidized pellets. The compressive strength of fired pellets drops from 3 186 N to 2 405 N when the ratio of pyrite cinder increases from 40% to 70% under the conditions of preheating at 900℃ for 9 min and firing at 1 230 ℃ for 15 min. The porosity and microstructures of fired pellets prove that the higher ratio of pyrite cinder is given, and the more holes and cracks are achieved, leading to the better reducibility index （RI） and reduction swelling index （RSI）, and the lower compressive strength of fired pellets and the worse reduction degradation index （RDI）.

An experimental research of Weining granule in treating gastric precancerous lesions

Objective： To investigate potential therapeutic effects and mechanism of Weining granule in the treatment of gastric precancerous lesions. Methods： Sixty rats were randomly assigned to a blank group or a model group or to receive retinoic acid or high-, medium- or low- dose of Weining granule. General conditions of the animals were observed before and after treatment. Changes in gastric mucosal pathohistology, telomerase activity, proliferation index （PI） and apoptosis index （AI） were measured. Results： General conditions, including activity and eating, were improved in all Weining-granule-treated groups with the numbers of rats having intestinal metaplasia （IM）, atypical hyperplasia （ATP） or positive telomerase activity being significantly lower than those in the model group （P 〈 0.05 or P 〈 0.01）. Compared with the model group, all doses of Weining granule significantly decreased PI （P 〈 0.01） and increased AI （P 〈 0.05）. Conclusion： Weining granule may provide a therapeutic benefit for the treatment of gastric precancerous lesions by inhibiting telomerase activity and proliferation of gastric cancer cells and by accelerating their apoptosis.

Simulation of the screening process on a circularly vibrating screen using 3D-DEM

A numerical study of the motion particulates follow along a circularly vibrating screen deck was done using the three dimensional Discrete Element Method (DEM). The motion of the particles was analyzed. The effects of vibration amplitude, throwing index, and screen deck inclination angle on the screening process are discussed. The results show that the average velocity of the particles increases along the lon- gitudinal direction of the deck. The screening efficiency is highest when the vibration amplitude, throw- ing index, and screen deck inclination angle are 3-3.5 mm, 2.7 and 15°, respectively. This work is helpful for developing a deep understanding of particle motion and for optimizing screen separator designs.

Unusual presentations of eosinophilic gastroenteritis:Case series and review of literature

Eosinophilic gastroenteritis (EG) is an uncommon disease characterized by focal or diffuse eosinophilic infiltration of the gastrointestinal tract, and is usually associated with dyspepsia, diarrhea and peripheral eosinophilia. Diffuse gastrointestinal tract and colonic involvement are uncommon. The endoscopic appearance may vary from normal to mucosal nodularity and ulceration. Gastrointestinal obstruction is unusual and is associated with predominantly muscular disease. We present five unusual cases of EG associated with gastric outlet and duodenal obstruction. Two cases presented with acute pancreatitis and one had a history of pancreatitis. Four cases responded well to medical therapy and one had recurrent gastric outlet obstruction that required surgery. Four out of the five cases had endoscopic and histological evidence of esophagitis and two had colitis. Two patients had ascites. These cases reaffirm that EG is a disorder with protean manifestations and may involve the entire gastrointestinal tract. Gastric outlet and/or small bowel obstruction is an important though uncommon presentation of EG. It may also present as esophagitis, gastritis with polypoid lesions, ulcers or erosions, colitis and pancreatitis and may mimic malignancy.

Microphysical Structure of a Nimbostratus over Jilin Province Provided by Airborne Observations

Airborne measurements were collected during a stepwise ascent within a nimbostratus cloud associated with a cold vortex depression over the Jilin Province on 21 June 2005 to study cloud structure and ice particle spectra. The melting layer of the nimbostratus was clearly defined in the radar images. The microphysical structure of the nimbostratus was elucidated by a King liquid water probe and Particle Measuring Systems （PMS） probes aboard the research aircraft. The PMS 2-D images provided detailed information of ice crystal transformations. A thick layer of supercooled cloud was observed, and the high ice particle concentrations at temperatures ranging from -3℃ to -6℃ were consistent with Hallett-Mossop ice multiplication. The shape of ice crystals from near the cloud top to the melting layer were in the form of columns, needles, aggregations, and plates. In addition, significant horizontal variability was evident on the scale of few hundred meters. Particle spectra in this cloud were adequately described by exponential relationships. Relationship between the intercept （No） and slope （2） parameters of an exponential size distribution was well characterized by a power law.

Exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes

We find exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes.For particles with a zero angular momentum,the convergence range of the solution is r < 4M.One of the solutions describes an exponential enhancement of the density of particles in the vicinity of Schwarzschild black holes,which might be the mechanism of gamma-ray bursts.

Single and Joint Multifractal Analysis of Soil Particle Size Distributions

It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connections between volume-based and number-based PSDs by applying single and joint multifractal analysis. Twelve soil samples were taken from selected sites in Northwest China and their PSDs were analyzed using laser diffractometry. The results indicated that the volume-based PSDs of all 12 samples and the number-based PSDs of 4 samples had multifractal scalings for moment order -6 〈 q 〈： 6. Some empirical relationships were identified between the extreme probability values, maximum probability （Pmax）, minimum probability （Pmin）, and Pmax/Pmin, and the multifractal indices, the difference and the ratio of generalized dimensions at q = 0 and 1 （Do - D1 and D1/Do）, maximum and minimum singularity strength （αmax and OZmin） and their difference （αmax - αmin, spectrum width）, and asymmetric index （RD）. An increase in Pmax generally resulted in corresponding increases of Do - D1, αmax, αmax - αmin, and RD, which indicated that a large Pmax increased the multifractality of a distribution. Joint multifractal analysis showed that there was significant correlation between the scaling indices of volume-based and number-based PSDs. The multifractality indices indicated that for a given soil, the volume-based PSD was more homogeneous than the number-based PSD, and more likely to display monofractal rather than multifractal scaling.