检索结果-南通市图书馆

Coupled Band Gap Solitons in One-Dimensional Alternating Heisenberg Ferromagnetic Chains

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2001年第10期 477-482页

作者： ZHU shan-hua huaNG Guo-Xiang Key Laboratory for Optical and Magnetic Resonance Spectroscopy and Department of Physics East China Normal University Shanghai 200062 China Physics Group Zhuzhou Institute of Technology Zhuzhou 412008 Hunan Province China Key Laboratory for Optical and Magnetic Resonance Spectroscopy and Department of Physics East China Normal University Shanghai 200062 China

The dynamics of coupled band gap solitons in one-dimensional Heisenberg ferromagnetic chains with bond alternation is considered analytically. Using the method of multiple scales the nonlinear coupled-mode equations (*** equations) for the upper cutoff mode of acoustic band and the lower cutoff mode of optical band are derived under the quasi-discreteness approximation. Due to the cross-phase modulation the type of soliton excitations may be changed and the vibrating frequencies of these soliton excitations may locate within or outside the gap of magnon frequency bands.

关键词： gap solitons, Heisenberg ferromagnetic chains

Ingredients-based Methodology and Fuzzy Logic Combined Short-Duration Heavy Rainfall Short-Range Forecasting:An Improved Scheme

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

Journal of Tropical Meteorology 2024年第3期30卷 241-256页

作者： TIAN Fu-you XIA Kun SUN Jian-hua ZHENG Yong-guang hua shan National Meteorological Center Beijing100081 China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of Sciences(IAP/CAS)Beijing 100029 China Key Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) Institute of Atmospheric PhysicsChinese Academy of Sciences(IAP/CAS)Beijing 100029 China

Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 *** is one of the most common convective weather phenomena that can cause severe ***-range forecasting of SHR is an important part of operational severe weather *** the present study,an improved objective SHR forecasting scheme was developed by adopting the ingredients-based methodology and using the fuzzy logic *** 1.0°×1.0°National Centers for Environmental Prediction(NCEP)final analysis data and the ordinary rainfall(0.1-19.9 mm h-1)and SHR observational data from 411 stations were used in the improved *** best lifted index,the total precipitable water,the 925 hPa specific humidity(Q 925),and the 925 hPa divergence(DIV 925)were selected as predictors based on objective *** distributed membership functions of predictors were obtained based on relative frequency *** weights of predictors were also objectively *** with a typhoon SHR case and a spring SHR case show that the main possible areas could be captured by the improved *** of SHR forecasts within 96 hours with NCEP global forecasts 1.0°×1.0°data initiated at 08:00 Beijing Time during the warm seasons in 2015 show the results were improved from both deterministic and probabilistic *** study provides an objectively feasible choice for short-range guidance forecasts of *** scheme can be applied to other convective phenomena.

关键词： ingredients-based methodology fuzzy logic approach probability of short-duration heavy rainfall(SHR) improved forecasting scheme objectively obtained membership functions

Classification of underwater still objects based on multi-field features and SVM

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2007年第1期6卷 36-40页

作者： TIAN Jie XUE shan-hua huaNG Hai-ning ZHANG Chun-hua Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China

A Support Vector Machine is used as a classifier to the automatic detection and recognition of underwater still objects. Discrimination between the objects can be transferred into different projection spaces by the process of multi-field feature extraction. The multi-field feature vector includes time-domain, spectral, time-frequency distribution and bi-spectral features. Underwater target recognition can be considered as a problem of small sample recognition. SVM algorithm is appropriate to this kind of problems because of its outstanding generalizability. The SVM is contrasted with a Gaussian classifier and a k-nearest classifier in some experiments using real data of lake or sea trial. The experimental results indicate that SVM is better than the others two.

关键词： underwater still objects classification feature support vector machine (SVM)

Study on Triplex DNA by Use of Molecular“hight Switch”Complex of Ru(phen)_(2)(dppx)^(2+)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第3期14卷 300-303页

作者： Lian Sheng LING Zhi Ke HE Fang CHEN hua shan ZHANG Yun E ZENG Department of Chemistry Wuhan UniversityWuhan 430072 Institute of Chemistry the Chinese Academy of SciencesBeijing 100080

A new method for the study of triplex DNA is established according the fluorescence enhancement of molecular 揕ight Switch?complex of Ru(phen)2(dppx)2+ when it intercalate into triplex DNA. Because the fluorescence intensity of Ru(phen)2(dppx)2+ bonded to triplex DNA is in the case higher than that bonded to duplex DNA in certain range of DNA concentration, the method is much more sensitive than other methods reported previously.

关键词： Molecular "Light Switch" Ru(phen)2(dppx)2+ Triplex DNA

Changes with aging in gastric biomarkers levels and in biochemical factors associated with Helicobacter pylori infection in asymptomatic Chinese population

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第32期23卷 5945-5953页

作者： Jin-hua shan Xiao-Juan Bai Lu-Lu Han Yuan Yuan Xue-Feng Sun Department of Gerontology and Geriatrics the First Affiliated Hospital of China Medical University Department of Gerontology and Geriatrics Shengjing Hospital of China Medical University Department of Tumor Research the First Affiliated Hospital of China Medical University Department of Kidney General Hospital of Chinese People’s Liberation Army

AIM To observe changes in gastric biomarker levels with age and effects of Helicobacter pylori(H. pylori) infection in a healthy population, and explore factors associated with gastric *** Three hundred and ninety-five subjects were selected and underwent physical examinations, biochemical tests, and measurement of serum pepsinogen(PG)Ⅰ and Ⅱ, gastrin-17(G-17) and H. pylori antibody levels. Analyses were made by Student's t-test, ANOVA, Pearson's correlation and multiple linear *** PGII levels were higher in the ≥ 65-years-old age group(P < 0.05) and PGI/PGII were lower in the ≥ 75-years-old age group(P = 0.035) compared to the 35-44-years-old age group. Levels of low-density lipoprotein cholesterol(LDL-C) were higher(P = 0.009) in H. pylori-infected subjects that were male. LDL-C levels were higher in 55-74-years-old age group(P < 0.05) for H. pylori-infected subjects and 45-64-yearsold age group(P < 0.05) for non-infected subjects compared to 35-44-years-old age group. Hp-Ig G level positively correlated with PGⅠ, PGⅡ and G-17(P < 0.001, P < 0.001, P = 0.006), and negatively correlated with PGI/PGII(P < 0.001). Creatinine positively correlated with PGⅠ, PGⅡ and G-17(P < 0.001, P < 0.001, P < 0.001). Fasting blood glucose(FBG) positively correlated with PGⅠ/PGⅡ and G-17(P < 0.001, P = 0.037). Age positively correlated with PGII and G-17(P = 0.005, P = 0.026).CONCLUSION PGII levels increased while PGI/PGII declined with age in a healthy population. H. pylori infection had an effect on raising LDL-C levels to increase the risk of atherosclerosis in males, especially those of elderly age. Age, H. pylori infection, levels of renal function and FBG were associated with levels of pepsinogens and gastrin.

关键词： Helicobacter pylori antibody Pepsinogen Gastrin Gastric ageing

Effect of thioredoxin-interacting protein on Wnt/β-catenin signaling pathway and diabetic myocardial infarction

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

Asian Pacific Journal of Tropical Medicine 2015年第11期8卷 951-956页

作者： Hui Yu Xian-Xian Zhao Xing-hua shan Pan Li Tao Chen Cardiovascular Department Changhai Hospital Affiliated to Second Military Medical University

Objective:To explore the regulatory role of thioredoxin-interacting protein(TXNIP) in Wnt/β-catenin signaling pathway and therefore to elucidate its function in diabetic myocardial ***:Diabetic myocardial infarction models were generated in *** expression levels of TXNIP and β-catenin and level of reactive oxygen species(ROS) were determined and compared with those in control *** umbilical vein endothelial cells were treated with high-eoncentration glucose and/or silencing TXNIP and/or H_2O_*** 24 h,expression levels of TXNIP、β-catenin and its downstream protein Cyclin D1,and C-myc gene were determined by real-time PCR,Western blot and immunofluorescence *** cell proliferation and ROS production capability in different groups were determined by methyl thiazolyl tetrazolium ***:Compared with control group,hyperglycemia significantly up-regulated TXNIP expression and ROS level in the myocardium and endothelial cells of myocardial infarction area,whereas the β-catenin expression was down-regulated,and the difference was statistically significant(P<0.05).In comparison with Human umbilical vein endothelial cells in the control group,high glucose level increased the levels of TXNIP expression and ROS level in cells,but reduced cell proliferation as well as migration capability and expression levels of β-catenin,Cyclin D1 and C-myc;the difference was statistically significant(P<0.05).However,this trend can be partially reversed by silencing ***:Diabetic myocardial ischemia could up-regulate levels of TXNIP expression and ROS production in endothelial cells of myocardial infarction *** regulation effect of TXNIP on β-catenin was partially achieved by changing ROS levels.

关键词： Thioredoxin-interacting protein Diabetes Myocardia

Separation and Determination of Cobalt, Rhodium,Nickel and Iridium with 2-(6-Methyl-2-Benzothiazolylazo)-5-Diethylamino Phenol by HPLC

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

Chemical Research in Chinese Universities 1993年第1期9卷 18-23页

作者： LIU Qi-ping, ZHANG hua-shan and CHENG Jie-ke (Department of Chemistry, Wuhan University, Wuhan, 430072)

The synthesis and spectrophotometric properties of 2-(6-methyl-2-benzothiazolylazo)-5-diethylamino phenol (MBTAE), and the use of it as a precolumn derivatizing reagent to separate Co(Ⅱ), Ni(Ⅱ), Rh(Ⅲ) and Ir( Ⅳ) complexes by HPLC are discussed. When the mobile phase consists of methanol/water(90/10 Ⅴ/Ⅴ), acetate buffer with pH 4. 0 and 5×10-5 mol/L EDTA solution, the four complexes Can be separated within 9 min on ODS column. The detection limits (20 μL sample size) are 0. 059 ppb, 0. 062 ppb, 0. 053 ppb and 0. 049 ppb for Co(Ⅱ) , Rh(Ⅲ), Ni(Ⅱ) and lr(Ⅳ) respectively at a signal-to-noise ratio of 3.

关键词： Cobalt Rhodium Nickel Iridium HPLC

Mapping of QTLs for Nitrogen Use Efficiency and Related Traits in Rice(Oryza sativa L.)

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2005年第10期4卷 721-727页

作者： shan Yu-hua WANG Yu-long PAN Xue-biao College of Environmental Sciences Yangzhou University Yangzhou 225009 P.R.China Rice Research Center Yangzhou University Yangzhou 225009 P.R.China

Current rice production is usually guaranteed by applying large amount of chemical nitrogen fertilizers to paddy soils. The improvement of nitrogen use efficiency is of great importance not only in rice production itself but in environmental protection as well. In this study we performed a molecular marker-based genetic analysis of nitrogen use efficiency for biomass production （NUEp） and several other related traits in a recombinant inbred line （RIL） population, derived from a cross of the parents of shanyou 63, the most widely cultivated indica hybrid in China. A total of 12 QTLs were detected using interval mapping with a LOD threshold of 2.0, among which one QTL controlling NUEp was located at the marker interval of Waxy-C1496 on chromosome 6, and the rest 11 QTLs associated nitrogen concentration and accumulation in rice plant were positioned on chromosomes 1, 2, 4 and 6, respectively. Correlation between NUEp and other traits was analyzed and the implications of the results with respect to the improvement of the hybrid rice were discussed.

关键词： Rice Nitrogen use efficiency QTL mapping

Spectrofluorimetric Determination of Magnesium (Ⅱ) with 7-(8-Hydroxy-3, 6-Disulfonaphthylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2001年第4期6卷 831-835页

作者： Zhang Xian, Wang Hong, Zhang hua shan College of Chemisitry and Molecular Science, Wuhan University, Wuhan 430072, China Wuhan University College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

A new fluorescent reagent, 7 (8 hydroxy 3, 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1∶1 fluorescent complex with λ ex / λ em =356/495 nm immediately at room temperature in ammonia ammonium chloride buffer (pH 10.7). A linear relationship was obtained in the magnesium concentration range of 0 160 ng·mL -1 with the detection limit of 0.04 ng·mL -1 . The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103.75% and 98.16%, respectively.

关键词： Hydroxy 3 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid magnesium spectrofluorimetry blood serum