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Magnetic Behavior of Ferri-ferromagnetic Alloy in Presence of External Magnetic Field

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Communications in Theoretical Physics 2008年第4期49卷 1059-1063页

作者： HU Hong-Liang XIN Zi-hua liu wei-Jie Department of Physics Shanghai University Shanghai 200444~ China

The magnetic behavior of the mixed ferro-ferrimagnetie alloy with （Aa Bb Cc）y D structure composed of Ising spins SA=1, SB = 5/2, SC= 2, and SD = 3/2 in the presence of the external magnetic field is investigated by the use of the effective field theory. The role of concentration b is discussed in this system in detail. Results show that for a =0.4, only when the concentration b is in the region 0.60 ≥b 〉 0.34 can the ferrimagnetic behavior be seen. Otherwise, the alloy shows ferromagnetic behavior.

关键词： magnetic susceptibility magnetization Prussian blue analogs effective field theory

Novel method for the determination of five carbamate pesticides in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography

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Chinese Chemical Letters 2009年第2期20卷 213-216页

作者： Zhi Mei liu Xiao huan Zang wei hua liu Chun Wang Zhi Wang Key Laboratory of Bioinorganic Chemistry College of Sciences Agricultural University of Hebei Baoding 071001 China

A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs）（S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.

关键词： Carbamate pesticides High performance liquid chromatography Diode array detection Dispersive liquid-liquid microextraction Water samples

Zinc finger protein rotund deficiency affects development of the thoracic leg in Bombyx mori

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Insect Science 2017年第3期24卷 385-396页

作者： Chun-Yan Zhou Xing-Fu Zha hua-wei liu Qing-You Xia State Key Laboratory of Silkworm Genome Biology College of Biotechnology Southwest University Chongqing China

The insect limb develops from the imaginal disc or larval leg during metamor- phosis. The molecular mechanisms involved in the development from the larval to the adult leg are poorly understood. Herein, we cloned the full length of a zinc finger gene rotund from Bombyx mori （Bmrn）, which contained a 1419 bp open reading frame, and encoded a 473 amino acid protein. Reverse transcription polymerase chain reaction and Western blot analyses demonstrated that Bmrn was expressed at higher levels in the epidermis than in other tissues tested, and it showed a very high expression level during metamorphosis. Knock-down of Bmrn produced defects in the tarsus and pretarsus, including the fusion and reduction of tarsomeres, and the developmental arrest of pretarsus. Our data showed that Bmrn is involved in the formation of the tarsus and pretarsus, whereas its homologous gene in Drosophila has been shown to affect three tarsal segments （t2-t4）, suggesting that the remodeling of the leg has involved changes in the patterning of gene regulation during evolution.

关键词： Bombyx mori limb / leg development pretarsus RNAi rotund/rn tarsus

Remediation of Ni^(2+)-contaminated water using iron powder and steel manufacturing byproducts

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Journal of Environmental Sciences 2006年第3期18卷 464-467页

作者： JIN Jian ZHAO wei-rong XU Xin-hua HAO Zhi-wei liu Yong HE Ping ZHOU Mi Department of Environment Engineering Zhejiang University Hangzhou 310027 China

Steel manufacturing byproducts and commercial iron powders were tested in the treatment of Ni^2＋-contaminated water. Ni^2＋ is a priority pollutant of some soils and groundwater. The use of zero-valent iron, which can reduce Ni^2＋ to its neural form appears to be an alternative approach for the remediation of Ni^2＋-contaminated sites. Our experimental data show that the removal efficiencies of Ni^2＋ were 95.15% and 94.68% at a metal to solution ratio of 20 g/L for commercial iron powders and the steel manufacturing byproducts in 60 min at room temperature, respectively. The removal efficiency reached 98.20% when the metal to solution ratio was 40 g/L for commercial iron powders. Furthermore, we found that the removal efficiency was also largely affected by other factors such as the pHs of the treated water, the length of time for the metal to be in contact with the Ni^2＋-contaminated water, initial concentrations of metal solutions, particle sizes and the amount of iron powders. Surprisingly, the reaction temperature appeared to have little effect on the removal efficiency. Our study opens the way to further optimize the reaction conditions of in situ remediation of Ni^2＋ or other heavy metals on contaminated sites.

关键词： zero-valent iron reduction remediation Ni^2+

Modification of inorganic binder used for sand core-making in foundry practice

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China Foundry 2020年第5期17卷 341-346页

作者： Fang-hai Xin wei-hua liu Lai Song Ying-min Li Shenyang University of Technology Shenyang 110870China

With modified water glass as binder and the introduction of micro silicon powders into the coremaking process,an improvement was made to the tensile strength and collapsibility of the sand *** potassium hydroxide,sodium hexametaphosphate and white sugar were applied as the modifiers of water *** optimum proportion of the modifiers was determined through the combination of single factor test and orthogonal *** optimum proportion of water glass,potassium hydroxide,sodium hexametaphosphate and white sugar is 1000:40:5:5(wt.).In terms of weight,modified binder and micro silicon powders accounted for 2%and 0.6%of sand,*** sand core was hardened by going through a warm core box process,in which the temperature of core box was 150°C,and the compressed hot air was blown at 120°C for 40 s under a pressure of 0.2 *** for the sand core bonded with modified water glass,the tensile strength is 2.46 MPa at room temperature(σ0)and 2.49 MPa at 25°C and 40%RH for 24 h(σ24),which are 2 times more than that with unmodified *** bonded strengths of sand core are increased as a result of the reaction between-OH groups from addition of potassium hydroxide and SiO2 particles widely distributed in the sand *** with the sand core bonded with unmodified water glass,the high temperature residual tensile strength(σr)of sand core bonded with modified water glass under 600°C for 5 min,is sharply reduced from 0.20 MPa to 0.01 *** the comparison with unmodified water glass,the dynamic viscosity of the modified water glass and the flowability of molding sand using modified water glass are increased from 74 mPa·s and 2.15 g to 80 mPa·s and 2.21 g,*** revealed by FT-IR analysis,new groups including PO3-,PO43-,and Si-O-C appear in the molecular structure of modified water glass,which are beneficial to the collapsibility of sand core.

关键词： inorganic binder modified water glass tensile strength collapsibility warm box core-making process

Protease inhibitors in Bombyx mori silk might participate in protecting the pupating larva from microbial infection

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Insect Science 2016年第6期23卷 835-842页

作者： You-Shan Li hua-wei liu Rui Zhu Qing-You Xia Ping Zhao State Key Laboratory of Silkworm Genome Biology Southwest University Chongqing Vitamin D Research Institute Shaanxi University of Technology Hanzhong Shaanxi Province School of Management Shaanxi University of Technology Hanzhong Shaanxi Province China

Pupae inside cocoons rarely suffer from disease. It is apparent that some factors in the cocoon exert antimicrobial effects whereby the pupae inside can be protected from microbial infection. In the present study, we investigated the expression of cocoon protease inhibitors using immunoblotting and activity staining. Enzymatic hydrolysis of cocoon proteins in vitro was performed to characterize their roles in protecting the cocoon from microbial proteases. We found that some protease inhibitors, particularly trypsin inhibitor-like （TIL）-type protease inhibitors, can be secreted into the cocoon layer during the spinning process, thereby providing effective protection to the cocoon and pupa by inhibiting the extracellular proteases that can be secreted by pathogens.

关键词： Bombyx mori cocoon enzymatic hydrolysis microbial proteases protease inhibitors pupating larva

Free-radical evolution and decay in cross-linked polytetrafluoroethylene irradiated by gamma-rays

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Nuclear Science and Techniques 2022年第5期33卷 113-125页

作者： Fei-Xiang Sha Guo-Jun Cheng Zi-Yue Xuan Yang liu wei-hua liu Xiao-Dong Zhang Zhong-Feng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232000China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environment Harbin Institute of TechnologyHarbin 150001China University of Chinese Academy of Sciences Beijing 100049China

Electron spin resonance techniques were employed to investigate the effects of the absorbed dose and post-irradiation conditions on the evolution and decay of free-radicals in cross-linked polytetrafluoroethylene(XPTFE),induced byγ-ray ***-end free-radicals,chain alkyl free-radicals,and tertiary alkyl free-radicals were detected when XPTFE was irradiated under Ar *** corresponding peroxy free-radicals were formed upon exposure of irradiated XPTFE to air;the freeradicals concentration first increased linearly with increasing absorbed dose and then gradually *** free-radicals yield under air atmosphere was greater than that under Ar,and the peroxy free-radicals were preserved for a relatively long time when irradiated XPTFE was stored under air *** chain alkyl free-radicals may be converted to chain end free-radicals byβ-scission,while chain end free-radicals are more sensitive to oxygen than chain alkyl *** the annealing temperature was raised above the a-transition temperature of XPTFE,the decay of the free-radicals was greatly affected and accelerated by the motion of the molecules over the long range.

关键词： Polytetrafluoroethylene Cross-linked polytetrafluoroethylene Electron spinresonance Decay Radiation c-ray

Palladium-catalyzed highly regioselective Heck reaction of aryl nonaflates with electron-rich olefins

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Chinese Chemical Letters 2008年第9期19卷 1017-1020页

作者： Dan Xu Zhi hua liu wei Jun Tang Jun Mo Li Jin Xu Department of Chemistry Renmin University of China Beijing 100872 China

Highly efficient palladium-catalyzed Heck coupling of aryl nonaflates with electron-rich vinyl ethers, and enamides is described. These reactions afforded exclusively the branched products in good yields. The results ... 详细信息

关键词： Aryl nonaflates Electron-rich Palladium Heck reaction Regioselectivity

Humidity-resistant inorganic binder for sand core making in foundry practice

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China Foundry 2019年第4期16卷 267-271页

作者： Lai Song wei-hua liu Ying-min Li Fang-hai Xin Shenyang University of Technology

The performance of sand core was improved by using the modified water glass as a binder and adding powder additives in the sand hardening process. The optimal proportion of the compound additives was determined by an orthogonal test, with a ratio of microsilica: polyvinyl alcohol solution: borax: B agent = 25: 20: 2: 1. The binder accounted for 2% of the sand by weight, and the compound additives accounted for 0.96%. The core box was heated to 175 °C, and the compressed hot air of 120 °C kept blowing for 40 s. Tensile strength was used as the main indicator to evaluate the humidity-resistance of the sand core. For the sand core, the instant tensile strength reached 0.73 MPa, the tensile strength at room temperature was 1.81 MPa, and that of sand core holding at the condition of 35 °C and 90% RH for 2 h and for 4 h reached 1.61 MPa and 1.19 MPa, respectively. The gas evolution was 7.5 mL·g-1 at 850 °C for 3 min. The residual tensile strength was 0 MPa at 750 °C for 5 min. Fourier-transform infrared spectroscopy analysis showed that the humidity-resistance of the core was greatly improved by the powder additives.

关键词： water glass inorganic binder compound additives humidity-resistance