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Rheological properties of magnetorheological fluid prepared by gelatincarbonyl iron composite particles

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Journal of Central South University of Technology 2005年第4期12卷 411-415页

作者：潘华锦黄红军张灵振齐建英曹少坤 section of Physics and chemistry Shijiazhuang Mechanical Engineering College Shijiazhuang 050003 China section

Gelatincarbonyl iron composite particle was prepared by micro emulsion method. The analysis of scanning electron microscope(SEM) shows that the ultrafine particles are spheroids coated by gelatin, and the average sizes of particles are 310μm. The specific saturation magnetization σ_s is 130.9A·m2/kg, coercivity H_c is 0.823A/m, and residual magnetism r is 4.98Am2/kg for the composite particles. It is shown that the particles possess properties of soft magnetic. The yield stress of magnetorheological fluid(MRF) with composite particle reaches 70kPa at 0.5T magnetic induction. Magnetorheological effects are superior in lower magnetic field intensity and the subsidence stability of the MRF is excellent compared with pure carbonyl iron powder.

关键词： micro emulsion composite particle gelatin, carbonyl iron yield stress

A modified method for evaluation of materials containing volatile corrosion inhibitor

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Journal of Central South University of Technology 2005年第4期12卷 406-410页

作者：万红敬黄红军张敏李志广 section of Physics and chemistry Shijiazhuang Mechanical Engineering College Shijiazhuang 050003 China section

A systematic research on a modified method that was developed to evaluate the effectiveness of volatile corrosion inhibitor(VCI) materials was carried out. The metal specimen in size of 50mm×25mm×2mm was level mounted on the top of a beaker by transparent adhesive tape and the assembly was placed in a constant temperature water bath and kept at approximately 40℃ to accelerate the vaporization of VCI and distilled water, which was placed at the bottom of the beaker at the same time. The experimental results show that the reproducibility of rust appearance and corrosion rate calculated by specimen’s mass loss is perfect. The outstanding characteristic of the rust appearance based on different VCI formula is discovered that is very important in studying the mechanism of VCI and the synergism of chemical reagent. The accelerated ratio is increased greatly as compared with the traditional method and the value is approximately 15 as compared with Shijiazhuang atmospheric environment corrosion test. The modified method is suitable for formula screening test and quick effectiveness evaluation of VCI materials.

关键词： volatile corrosion inhibitor effectiveness evaluation rust appearance

Bed planting of wheat(Triticum aestivum L.)improves nitrogen use efficiency and grain yield compared to flat planting

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The Crop Journal 2015年第2期3卷 118-124页

作者： Abdul Majeed Atif Muhmood Abid Niaz Shahid Javid Zahid Ashfaq Ahmad Syed Shahid Hussain Shah Asrar Hussain Shah Soil chemistry section Institute of Soil Chemistry and Environmental Sciences Ayub Agricultural Research Institute

Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and volatilization losses. The practice also results in greater crop lodging, lower water use efficiency, and crusting of the soil surface. In contrast, bed planting of wheat not only saves water but improves fertilizer use efficiency and grain yield. Three years of pooled data from the present study showed that wheat planting on beds and nitrogen application at 120 kg ha-1produced 15.06% higher grain yield than flat planting at the same nitrogen rate. Similarly, 25.04%, 15.02%, 14.59%, and 29.83% higher nitrogen uptake, nitrogen use, and agronomic and recovery efficiencies, respectively, were recorded for bed compared to flat planting. Wheat planting on beds with a nitrogen application of80 kg ha-1gave a yield similar to that of flat planting with 120 kg ha-1nitrogen. However,the economic return was 29% higher in bed planting as compared to flat planting, when nitrogen was applied at 120 kg ha-1.

关键词： Bed and flat planting N uptake N use efficiency Grain yield

Energy-related catalysis

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National Science Review 2015年第2期2卷 143-145页

作者： Salvatore Abate Gabriele Centi Siglinda Perathoner Department DIECII Section Industrial ChemistryUniversity of Messina

Availability of energy is a vital element of our current society,but energy must be converted to usable forms,either when stemming from fossil fuel sources or from renewable(perennial)*** plays a central role to enabl... 详细信息

关键词： Energy-related catalysis GTL

Studies on The Adsorption Capacity for Bilirubin of The Adsorbent Chitosan-β-Cyclodextrin

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Chinese Chemical Letters 2001年第4期12卷 359-362页

作者： Wei Liang XU, Chun Ling FU, Jun LI Department of chemistry, Zhejiang University, Hua jia chi section, Hangzhou 310029 Department of chemistry Zhejiang University Hua Jia Chi Section Hangzhou 310029 China

The adsorbent crosslinked chitosan-β-cyclodextrin (β-CD) was prepared by the reaction of glutaraldehyde with chitosan and β-cyclodextrin. This type of adsorbent has high adsorption capacity for unconjugated bilirubin. The adsorption capacity was related to the β-CD content of the adsorbent; phosphate buffer concentration; temperature; pH value; ionic strength and the adsorbent beads. The results indicated that the chitosan-β-CD was a good adsorbent for unconjugated bilirubin with high capacity.

关键词： Chitosan-β-CD adsorption bilirubin.

Reaction of Crossed Diperoxidation Between Cyclic Ketones and Alkyl Ketones

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Chemical Research in Chinese Universities 2002年第4期18卷 412-413页

作者： XU Wei-liang FU Cheng-ling Organic chemistry Group Huajiachi SectionZhejiang UniversityHangzhou 310029P.R.China

The reaction of crossed diperoxidation between the cyclic ketones and the alkyl ketones was investigated. The reaction is a competing in different ketones. It is slightly favorable to resulting in crossed ketone diper... 详细信息

关键词： Synthesis Crossed diperoxidation Crossed ketone diperoxide

Variability in the Content of 25α- and 25β-Steroidal Sapogenins among Thirty Morphologically Different Sudanese Seed Accessions of Fenugreek

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Journal of Life Sciences 2014年第9期8卷 744-757页

作者： Nour Ahmed Osman Salah Ahmed Elhussein Marzougah Aziz Dager Albalawi Department of chemistry University College at Alwajh University ofTabuk Tabuk 71491 Saudi Arabia oilseed chemistry section National Oilseed Proc. Res. Inst. University of Gezira Wad-Medani Pb 020 Sudan

Seeds of Fenugreek （Trigonellafoenum-graecum L.）, an international spice commodity, are much consumed in Sudan as a food, for flavoring and as a folk-remedy for several ailments, together with local beliefs in nutraceutical benefits. The authors have noted an immense variability in colour and other morphological characters of Fenugreek seeds offered in local Sudanese markets and wondered whether this variability is extended to their chemical composition. Steroidal sapogenins are important chemical constituents of Fenugreek seeds in view of their potential as precursors for the commercial synthesis of steroid drugs and their continually revealed beneficial biological activities. In this study, thirty Sudanese Fenugreek seed accessions collected from different geographical regions in Sudan were analyzed for their 25α-, 25β- and total sapogenin content using a simple and specific infra-red spectroscopic method. The seed accessions exhibited much morphological variability particularly in outer seed coat color and size. Preparative TLC followed by gravimetric analysis showed that steroidal sapogenins, mostly diosgenin and yamogenin, represented more than 70% of the steroids of Fenugreek seeds. Infra-red spectroscopic analysis showed that total 25α-sapogenins （calculated as diosgenin） varied from 0.65% to 1.68%. Total 25β-sapogenin （calculated as yamogenin） varied from 0.38% to 2.03%. The content of total sapogenins （α ＋ β epimeric forms） varied between 1.24% and 3.0% of the oven-dry weight of seeds. β-sapogenins （mostly yamogenin） were dominant over α-sapogenins （diosgenin） in most Sudanese Fenugreek seed accessions.

关键词： Fenugreek seeds Trigonellafoenum-graecum steroidal sapogenins seed morphology variability.

Biogenetic Pathways for Marine Terpenoids

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Science China chemistry 1994年第8期37卷 897-905页

作者：郑其煌苏镜娱黄起鹏王植材刘璇高碧曾陇梅郑德炫 Department of chemistry Zhongshan UniversityGuangzhou 510275PRC Teaching and Research section of chemistry First Military Medical UniversityGuangzhou 510515PRC

A reasonable theoretical elucidation of biogenetic pathways is given for marine ter-penoids——halogenated terpenoids,cernbranolides and tetracyclic tetraterpenoids in marine organisms ac-cording to biogenesis,and the... 详细信息

关键词： marine terpenoids biogenetic pathways biogenesis chemical synthesis molecular probe

Comparison of PBDE congener profiles and concentration levels in human specimens from China and the US and identification of human exposure sources

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Science China chemistry 2010年第5期53卷 995-1002页

作者： SHE JianWen 1,SHE YiFan 2 &SONG WenLu 2 1 Biochemistry section,Environmental Health Laboratory Branch,California Department of Public Health,Richmond,CA 94804,USA 2chemistry section,Food and Drug Laboratory Branch,California Department of Public Health,Richmond,CA 94804,USA Environmental Health Laboratory Branch California Department of Public Health Biochemistry Section Richmond USA Food and Drug Laboratory Branch California Department of Public Health Chemistry Section Richmond USA

In an effort to investigate the status of human exposure to PBDEs in China,available monitoring data in human specimens(including breast milk,serums,and blood) was collected from the general population as well as specific groups that are occupationally *** exposure profiles and concentration levels were compared with their counterparts in the United States of *** was found that PBDE burdens in general Chinese population are one order lower and have different congener profiles from that in the US,showing higher percentages of BDE-28 or BDE-153 in human specimens from *** and residents in electronic wastes recycling regions or areas of commercial PBDE manufacturing have the highest PBDE exposure levels reported worldwide,which are close or higher than the exposure levels of the general population in the US. Highly brominated congeners,such as BDE-207 and 209,are among the major PBDE congeners,and BDE-209 has the highest percentage(above 50%) for all occupational populations *** components analysis(PCA) demonstrates that the exposure of the general population in the US is closely related to penta-BDE while the human burden in China is *** PBDE in indoor air(gas phase) in the US is highly correlated with the PBDE burden in the general population in the US,indicating a major exposure *** the occupationally exposed populations in China,the congener profiles are closely related to the commercial deca-BDE *** of exposure profiles for general and occupational populations in China suggests that it is essential to include more highly brominated congeners,such as BDE-207 and 209,in future human exposure studies,in order to assess the real burdens and profiles of PBDEs exposure in *** pollution prevention and occupational protection procedures are in need in China to avoid the PBDE contamination problem that has occurred in the US.

关键词： human exposure PBDEs congener profiles concentration levels source source identification China and USA