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Search Results: 1 - 10 of 104279 matches for " Yufen Zhang "
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Influence Factor Analysis on Strength of Lime-Fly Ash Loess  [PDF]
Yufen Zhang, Zhiquan Zhang
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.56068
Abstract: Lime-fly ash loess is composed of fly ash, lime and loess. It is a new material in subgrade backfill. Main factors to influence the strength of lime-fly ash loess are age, amount of fly ash and lime, ratio of fly ash to lime (1:K), and moisture content. In order to observe the effect of each factor influencing the strength of lime-fly ash loess and find out the relationship between each other, this paper adopted orthogonal test design to conduct unconfined compression tests. The result shows that 90d strength can be considered to calculate the strength of lime-fly ash loess in practice. And the most important factor to influence the 90d strength of lime-fly ash loess is the amount of fly ash and lime, the second is moisture content, and then is the ratio of fly ash to lime (1:K). These achievements are significant to the design and application of lime-fly ash loess in subgrade construction of loess areas.
Smoothed ANOVA with spatial effects as a competitor to MCAR in multivariate spatial smoothing
Yufen Zhang,James S. Hodges,Sudipto Banerjee
Statistics , 2010, DOI: 10.1214/09-AOAS267
Abstract: Rapid developments in geographical information systems (GIS) continue to generate interest in analyzing complex spatial datasets. One area of activity is in creating smoothed disease maps to describe the geographic variation of disease and generate hypotheses for apparent differences in risk. With multiple diseases, a multivariate conditionally autoregressive (MCAR) model is often used to smooth across space while accounting for associations between the diseases. The MCAR, however, imposes complex covariance structures that are difficult to interpret and estimate. This article develops a much simpler alternative approach building upon the techniques of smoothed ANOVA (SANOVA). Instead of simply shrinking effects without any structure, here we use SANOVA to smooth spatial random effects by taking advantage of the spatial structure. We extend SANOVA to cases in which one factor is a spatial lattice, which is smoothed using a CAR model, and a second factor is, for example, type of cancer. Datasets routinely lack enough information to identify the additional structure of MCAR. SANOVA offers a simpler and more intelligible structure than the MCAR while performing as well. We demonstrate our approach with simulation studies designed to compare SANOVA with different design matrices versus MCAR with different priors. Subsequently a cancer-surveillance dataset, describing incidence of 3-cancers in Minnesota's 87 counties, is analyzed using both approaches, showing the competitiveness of the SANOVA approach.
Impairment of Di(2-Ethylhexyl) Phthalate on Cellular Immunity in Kunming Mice  [PDF]
Yufen Tian, Deli Xu, Shengqun Zhang, Jinyan Zhang, Zhicun Sun, Xiangfang Liu, Xin Wang, Xia Wang, Daqian Meng
Open Journal of Animal Sciences (OJAS) , 2015, DOI: 10.4236/ojas.2015.53031
Abstract: Immunity is crucial to the health of animals and it can determine their survival and fitness. Di(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer and hence is the most abundant phthalate in the environment. Exposure to DEHP is of great concern for human health. In the present study, we tested the hypothesis that exposure to DEHP would suppress T cell-mediated immunity in mice. Twenty adult male Kunming mice were randomly assigned into the control (n = 10) and the DEHP treatment (n = 10) groups. Both groups have free access to food and water, while the mice in the latter group drank DEHP solution (2000 mg/L) for 42 days. T cell-mediated immunity assessed by phytohaemagglutinin (PHA) response was depressed in the DEHP treated mice compared with the controls, however, wet thymus and spleen mass, white blood cells were not influenced by DEHP treatment. Taken together, different immunological parameters responded differently to DEHP treatment in Kunming mice.
Effect of Electroplating Waste water on Immune Function in Kunming Mice  [PDF]
Zongqi Ma, Guirong Wang, Yufen Tian, Deli Xu, Xiaofeng Miao, Ying Zhang, Jiao Meng, Hong Ni, Weiwei Sun
Natural Science (NS) , 2016, DOI: 10.4236/ns.2016.87036
Abstract: Electroplating waste water is considered to be harmful to health of animals. In the present study, we tested the hypothesis that electroplating waste water would suppress immune functions in Kunming mice. Twenty-six mice were randomly divided into the control group (n = 13) and the experimental group (n = 13), in which the latter drank electroplating waste water. We found that body mass and most organ wet masses (heart, lungs, liver, kidneys, stomach, caecum, colon, testes, epididymis, seminal vesicals) were not influenced by electroplating waste water. However, stomach with its content, small intestine, small intestine with its contents and colon with its contents were higher in the experimental group than in the control group. As expected, phytohaemagglutinin (PHA) response indicative of cellular immunity was suppressed by electroplating waste water. White blood cells, thymus and spleen mass were all not response to electroplating waste water. Taken together, electroplating waste water had different effects on distinct components of immune system in Kunming mice.
ApplicationofADERSchemeinMHDSimulation
ZHANG,Yanyan,FENG,Xueshang,JIANG,Chaowei,ZHOU,Yufen
空间科学学报 , 2012,
Abstract: TheArbitraryaccuracyDerivativesRiemannproblemmethod(ADER)schemeisanewhighordernumericalschemebasedontheconceptoffinitevolumeintegration,anditisveryeasytobeextendeduptoanyorderofspaceandtimeaccuracybyusingaTaylortimeexpansionatthecellinterfaceposition.Sofartheapproachhasbeenappliedsuccessfullytoflowmechanicsproblems.OurobjectivehereistocarryouttheextensionofmultidimensionalADERschemestomultidimensionalMHDsystemsofconservationlawsbycalculatingseveralMHDproblemsinoneandtwodimensions:(ⅰ)Brio-Wushocktubeproblem,(ⅱ)Dai-Woodwardshocktubeproblem,(ⅲ)Orszag-TangMHDvortexproblem.ThenumericalresultsprovethattheADERschemepossessestheabilitytosolveMHDproblem,remainshighorderaccuracybothinspaceandtime,keepspreciseincapturingtheshock.Meanwhile,thecomparedtestsshowthattheADERschemecanrestraintheoscillationandobtainthehighordernon-oscillatoryresult.
Triality and Quantization of Singularities in Massive Fermion
Liu Yufen
Physics , 2000,
Abstract: It is proved that fermions can acquire the mass through the additional non-integrable exponential factor. For this propose the special vector potential associated with the spinor field was introduced. Such a vector potential has close relation with the triality property in Dirac spinors and plays crucial role in the construction of massive term. It is shown that the change in phase of a wavefunction round any closed curve with the possibility of there being singularities in our vector potential will lead to the law of quantization of physical constants including the mass. The triality properties of Dirac's spinors are studied and it leads to a double covering vector representation of Dirac spinor field. It is proved that massive Dirac equation in the bosonic representation is self-dual.
Genome wide exploration of the origin and evolution of amino acids
Xiaoxia Liu, Jingxian Zhang, Feng Ni, Xu Dong, Bucong Han, Daxiong Han, Zhiliang Ji, Yufen Zhao
BMC Evolutionary Biology , 2010, DOI: 10.1186/1471-2148-10-77
Abstract: In this study, we statistically monitored the frequencies of 20 alpha-amino acids in 549 taxa from three kingdoms of life: archaebacteria, eubacteria, and eukaryotes. We found that the amino acids evolved independently in these three kingdoms; but, conserved linkages were observed in two groups of amino acids, (A, G, H, L, P, Q, R, and W) and (F, I, K, N, S, and Y). Moreover, the amino acids encoded by GC-poor codons (F, Y, N, K, I, and M) were found to "lose" their usage in the development from single cell eukaryotic organisms like S. cerevisiae to H. sapiens, while the amino acids encoded by GC-rich codons (P, A, G, and W) were found to gain usage. These findings further support the co-evolution hypothesis of amino acids and genetic codes.We proposed a new chronological order of the appearance of amino acids (L, A, V/E/G, S, I, K, T, R/D, P, N, F, Q, Y, M, H, W, C). Two conserved evolutionary paths of amino acids were also suggested: A→G→R→P and K→Y.The origin of life arising from either proteins or nucleic acids has been argued for nearly half century. Putting the "Chicken or Egg" question aside, there exist some unsolved problems. Which amino acid(s) appeared first in the prebiotic environment? What cause the different usage of amino acids in modern organisms? To address these questions, a number of hypotheses and theories, e.g. mutation drifts and natural selection, have been proposed. Multiple factors, such as genetic codes, physicochemical properties, mutation-selection equilibrium, amino acid biosynthesis, etc, are likely related to the variation of amino acid usage in organisms [1,2]. Since there is no way to trace geological evidence in the way scientists normally use in chronicling the evolution of organisms, an alternative path is needed to seek a clue from current living organisms.Observation of amino acid composition in proteins was recently applied as a statistical approach in facilitating various investigations of the evolution of genetic codes [3],
Magnetism parameters characteristics of drilling deposits in Jianghan Plain and indication for forming of the Yangtze River Three Gorges
YuFen Zhang,Chang’an Li,QiuLiang Wang,Liang Chen,YongFa Ma,ChunGuo Kang
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0111-1
Abstract: The forming time of the Yangtze River Three Gorges is considered as one of keys in the research on the Yangtze River, also is one of the most disputed hotspots. In order to solve the difficult problem, the authors adopt the internationally recognized thoughts and methods of substance tracing from source to sink. The lithologic characteristics, magnetic parameters and magnetic mineral characteristics of deposits in 2 bores are analyzed, which are both sampled from the sedimentary center of the Jianghan Plain. The results are as follows: At about 110 m depth of the core, the contents of coarse materials and stable magnetic mineral both increase significantly. Meanwhile, the magnetic susceptibility of sediment, saturation isothermal remanent magnetization and magnetic susceptibility values of anhysteretic remanent magnetism increase suddenly, which all reflect that at about 110 m depth, the important adjustment has appeared in water system of the Jianghan Plain, and the sedimentary environment and material composition have changed greatly. And it may be the horizon where the Yangtze River Three Gorges formed, its forming time reflected by the paleomagnetic dating is between 1.17 and 1.12Ma B.P.
Temporal and spatial variations of chemical constituents in maize
玉米营养成分时空动态
CHEN Yuxiang,ZHOU Daowei,ZHANG Yufen,
陈玉香,周道玮,张玉芬
应用生态学报 , 2004,
Abstract: Study on the temporal and spatial variations of chemical constituents in maize showed that with the development of maize,the contents of total starch,crude protein and crude lipid in its kernel increased,while those of crude protein and crude lipid in its leaf and stem decreased.The content of fiber extracted by neutral agent and that of fiber and lignin in leaves and stems increased.The crude protein content of the top leaf was higher than that of the basal leaf,while the content of fiber extracted by neutral agent and that of fiber and lignin in the top leaf were lower than those of the basal leaf.The crude protein content of the top stem was higher than that of the basal stem,while the content of the fiber extracted by neutral agent and that of the fiber and lignin in the top stem were lower than those of the basal stem.
Allelopathic effects of Cymbopogon citratu volatile and its chemical components
香茅天然挥发物的化感作用及其化学成分分析
LI Huashou,HUANG Jinghua,ZHANG Xiuyu,CHEN Yufen,YANG Jun,HEI Liang,
黎华寿
应用生态学报 , 2005,
Abstract: This paper studied the allelopathic effects of Cymbopogon citratus volatile on the seed germination and seedling growth of corn and barnyard grass (Echinochloa crusgalli) in field and in obturator,and analyzed the chemical components of the volatile with SPME and GC-MS. The results of bio-assay indicated that the germination rate of corn or barnyard grass intercropped with C.citrate or enclosed in obturator with fresh C.citratus had no significant difference from the control,but the seedling growth of corn and barnyard grass was significantly inhibited.The volatile from C.citratus roots contained 10 components.The main component was longifolene-(V4),occupying 56.67% of the total,the second component was selina-6-en-4-ol (20.03%),while the others were under 10%.There were 12 components in the volatile from C.citratus shoots.The main component was citral (53.98%),the second was z-citral (34.40%),and the others were under 4%.There were 2 monoterpenes and 9 sesquiterpenes in the volatile from shoots,and all the terpenes in the volatile from roots were sesquiterpenes.Therefore,the allelopathy of C.citratus should not be ignored when planted it with other crops.
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