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Microwave peak absorption frequency of liquid

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science china(Physics,Mechanics & Astronomy) 2008年第9期51卷 1254-1263页

作者： HAN GuangZe1 & CHEN MingDong2 1 Department of Physics,South china university of technology,guangzhou 510640,china 2 guangzhou Auto college,South china university of technology,guangzhou 510800,china 1. Department of Physics South China University of Technology Guangzhou 510640 China 2. guangzhou Auto college South China University of Technology Guangzhou 510800 China

Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

关键词： microwave-assisted extraction microwave heating relaxation time liquid viscosity peak absorption fre-quency

Investigation on the Surface Coating of Grinding Balls

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Rare Metals 2001年第4期20卷 259-264页

作者： Chengguo Wang1 Yujun Bai1.2 1) college of Materials science and Engineering, Shandong university, jinan 250061, china 2) Mechanical Department. Shandong university of science and technology. jinan 25003), china Shandong Univ Coll Mat Sci & Engn Jinan 250061 Peoples R China Shanghai Univ Sci & Technol Dept Mech Jinan 250031 Peoples R China

The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of interface.

关键词： coating ball grinding plastic deformation

Effects of temperature and organic and inorganic nutrients on the growth of Chattonella marina (Raphidophyceae)from the Daya Bay,South china Sea

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Acta Oceanologica Sinica 2011年第3期30卷 124-131页

作者： WANG Zhaohui YUAN Meiling LIANG Yu LU Sollghui college of life science and technology Jinan University Guangzhou 510632 China Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering Ministry of Education Guangzhou 510632 China

The effects of temperature and different forms of nutrients on Chattonella marina growth have been investigated in strains isolated from the Daya Bay, the South china Sea. The strain of C. marina preferred high temperatures, with an optimal temperature of 25℃, and 18℃ was the minimum for its survival. Higher cell number and growth rate were obtained in high nitrogen and phosphorus concentrations （500 μg/L, 74μg/L） than under nutrient limitation. Nitrogen influenced the growth most, as the specific growth rate and maximum cell density were lower in nitrogen- limited cultures than noted under phosphorus limitation or under limitation from both. C. marina was capable of using many kinds of organic nitrogen sources including L-serine （L-Ser）, glycine （Gly）, alanine （Ala）, L-threonine （L-Thr）, glutamic acid （Glu） and urea, but could not utilize uric acid. Various forms of organic phosphorus compound such as glucose-6-phosphate （G6P）, sodium glycerophosphate （GYP）, adenosine triphosphate （ATP）, adenosine monophosphate （AMP）, cyti- dine monophosphate （CMP）, guanosine monophosphate （GMP）, uridine monophosphate （UMP）, 4-nitrophenylphosphate （NPP） and triethyl phosphate （TEP） supported the growth as well. Algal cells had the ability to sustain growth under nitrogenand/or phosphorus-free conditions particularly under phosphorus depleted condition. These results led to the hypothesis that high loading of nitrogen has played an important role in frequent C. marina blooms in the past decade, and its capability for utilization of diverse forms of organic nutrients and growth in low nutrient conditions make this species a likely recurrent dominant in the Daya Bay phytoplankton assemblages, visible as more frequent blooms.

关键词： Chattonella marina growth inorganic and organic nutrients salinity temperature

pH-Dependent Stability of EGX, A Multi-functional Cellulase from Mollusca, Ampullaria crossean

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Acta Biochimica et Biophysica Sinica 2004年第9期36卷 603-608页

作者： Wen-Ying LI2, Ji WANG1, Yan-Hong LI1, Ming DING1, Gen-Jun XU1,3, Lan-Ying LIU2, and Fu-Kun ZHAO1,3* 1Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, the Chinese Academy of sciences,Graduate School of the Chinese Academy of sciences, Shanghai 200031, china 2college of life science, Jilin university, Changchun 130023, china college of life science, Zhejiang university of science and technology, Hangzhou 310018, china Key Laboratory ofProteomics Institute of Biochemistry and Cell BiologyShanghai Institutes for Biological Sciencesthe Chinese Academy of SciencesGraduate School of the Chinese Academy of SciencesShanghai 200031China

The cellulase activity and stability of EGX, a multi-functional cellulase previously purified from the mollusca Ampullaria crossean, was systematically studied under different pH. The pH induced con- formation and stability change of EGX have been investigated by using the intrinsic fluorescence, ANS fluorescence and CD spectrum. It has been found that the conformation and activity of this cellulase were strongly dependent on the pH. EGX was stable for both the enzyme activity and the conformation from pH 5.6 to pH 7.4. As shown by intrinsic and ANS fluorescence, no red shift of emission maximum occurred and a negligible intensity change was observed at pH 5.6–7.4. The activity of EGX remained about 80% in pH 5.6–7.4 and obviously decreased out of side the pH range. Urea-induced changes in EGX at pH 5.4 and pH 8.0 were measured by intrinsic fluorescence and CD spectrum. At pH 5.4, a significantly red shift of emission maximum occurred when the concentration of urea was 5 M compared to the concentration was 3 M at pH 8.0. The α-helix at pH 5.4 was 40.51% in the absence of urea and 31.04% in the presence of 4 M urea. At pH 8.0 the α-helix was 7.23% in the presence of 4 M urea. The data indicated that EGX was much susceptible to urea-induced unfolding at pH 8.0 and much stable at pH 5.4. The greater pH dependent stability of EGX may allow the enzyme to adequately catalyze the hydrolysis of cellulosic materials under natural or industrial extreme conditions.

关键词： multi-functional cellulase stability Ampullaria crossean fluorescence spectroscopy pH-dependent structural change CD spectrum

Microstructure and formation mechanism of twins of laths of austenite with high nitrogen

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science china(Technological sciences) 2007年第6期50卷 755-764页

作者： WU CuiLan1,2 & LUO ChengPing2 1 Center for High Resolution Electron Microscopy, college of Materials science and Engineering, Hunan university, Changsha 410082, china 2 college of Mechanical Engineering, South china university of technology, guangzhou 510641, china 1. Center for High Resolution Electron Microscopy College of Materials Science and Engineering Hunan University Changsha 410082 China 2. college of Mechanical Engineering South China University of Technology Guangzhou 510641 China

The microstructure of composite diffusion layer of the nitrided and chromized 0.2% carbon steel is investigated using TEM and EDS. It is found that laths of austenite with high nitrogen (γ N) precipitate from α-ferrite matrix in the deeper zone of the diffusion layer. These γ N laths are all twins, with their {111} twinning planes parallel to the lath axis, thus forming a characteristic "back-to-back" morphology. There are two types of γN lath. The first is a genuinely {111} twin, and γ N and α keep the accurate K-S relationship, and each γ N and α form a sharp and smooth γ N/α inter- face of {335}γN//{341}α, namely habit plane {335}fcc. The second is a pseudo-twin, with micro-twins {111} or faults formed within the two twin components. Localized lattice deformation (relaxation) seems to have occurred at the interfaces of the second type of γ N due to the formation of micro-twins or faults within the twin components. These micro-twins or faults make the orientation relationship (OR) between each of the γN and the α-matrix deviate from the accurate K-S OR, and the OR between two γ N twin components deviate from the genuine {111} twin relation- ship. In addition, the γ N/α interface of the second type of γ N is not as sharp or smooth as that of the first one.

关键词： austenite containing nitrogen, twins, steel 20, nitriding, composite chromizing

Impact of EnKF assimilating Himawari-8 all-sky infrared radiance on the forecasting of a warm-sector rainstorm event

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science china Earth sciences 2024年第10期67卷 3110-3127页

作者： Shanshan LOU Lei ZHU Xuexing QIU guangzhou CHEN Song YUAN Shengnan ZHOU Anhui Meteorological Observatory Hefei 230031China Key Laboratory of Meteorological Disaster Ministry of Education(KLME)Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Joint International Research Laboratory of Climate and Environment Change(ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044China Huaihe River Basin Meteorological Center Hefei 230031China Shouxian National Climatology Observatory Huaihe River Basin Typical Farm Eco-Meteorological Experiment Field of CMAShouxian National Comprehensive Meteorological Observation Special Experimental OutfieldShouxian 232200China Anhui Province Key Laboratory of Atmospheric science and Satellite Remote Sensing Hefei 230031China

Warm-sector rainstorms are highly localized events, with weather systems and triggering mechanisms are not obvious,leading to limited forecasting capabilities in numerical models. Based on the ensemble Kalman filter(PSU-En KF) assimilation system and the regional mesoscale model WRF, this study conducted a simulation experiment assimilating all-sky infrared(IR)radiance for a warm-sector rainstorm in East china and investigated the positive impact of assimilating the Himawari-8 moisture channel all-sky IR radiance on the forecast of the rainstorm. Results indicate that hourly cycling assimilation of all-sky IR radiance can significantly improve the forecast accuracy of this warm-sector rainstorm. There is a notable increase in the Threat Score(TS), with the simulated location and intensity of the 3-hour precipitation aligning more closely with observations. These improvements result from the assimilation of cloud-affected radiance, which introduces more mesoscale convective information into the model's initial fields. The adjustments include enhancements to the moisture field, such as increased humidity and moisture transport, and modifications to the wind field, including the intrusion of mid-level cold air and the strengthening of lowlevel convergent shear. These factors are critical in improving the forecast of this warm-sector rainstorm event.

关键词： Ensemble Kalman filter WRF model Himawari-8 All-sky radiance Warm-sector rainstorm

Investigation of 'chazi'(damaged-enamels)on Chenghua doucai Porcelains

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science china(Technological sciences) 2009年第6期52卷 1722-1729页

作者： DU Feng1 & SU BaoRu2 1 Institute of Chemistry & Molecular Engineering,Qingdao university of science & technology,Qingdao,china 2 college of Information science & technology,Qingdao university of science & technology,Qingdao,china Institute of Chemistry & Molecular Engineering Qingdao University of Science & Technology Qingdao China college of Information science & technology Qingdao University of Science & Technology Qingdao China

At the end of the 1950s,Sun Yingzhou considered that the 'chazi'(damaged colour)on Chenghua doucai imperial porcelain as a defect was originally produced in firing process during Chenghua period(1465―1487).Researchers in china have accepted his *** any fragment with the 'chazi' has never been found in several tons of Chenghua imperial sherds excavated from Ming imperial kiln site in *** china,few scholars have questioned the formation of 'chazi',and further investigated *** researchers at the Research Laboratory in the British Museum,employing unde-structive EDXRF,have analyzed the chemical composition of the 'chazi'(damaged colour)on a Chen-ghua doucai stem cup in the museum,and they have confirmed that the 'chazi'(damaged colour)was caused by the fire of the Jianfu palace in the Forbidden City in *** on their research,the authors studied the colour chemical principle of the 'chazi's' formation *** to the ceramic technology principle,scientific reasoning for the 'chazi' was carried *** the help of the history of Qing court,the brainteaser of the 'chazi' was totally uncovered,the misunderstanding for the 'chazi' has also been *** research also suggests that employing modern science and technology is a direction to study Chinese ancient ceramic further.

关键词： Chenghua doucai porcelains court eunuchs the set on fire at the Jianfu palace ’chazi’(damaged-enamels) the British Museum colour chemical principle archaeology using science and technology

Langmuir-Blodgett Films and Calcium Ion Coordination of Biliverdin and Its Amphiphilic Derivatives

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Chinese Chemical Letters 2001年第5期12卷 457-460页

作者： Jian Ming OUYANG Department of Chemistry, jinan university, guangzhou 510632 jinan Univ Dept Chem Guangzhou 510632 Peoples R China

Monolayer formation and LB film fabrication of amphiphilic derivative of biliverdin 1, diododecyl biliverdinamide [B(CONHC12H25)(2), 2] at an air-water interface on pure water subphase and subphase containing calcium ion were investigated and compared with 1. The coordination in ordered molecular films is much different from that in bulk solution. The formation of ligand-calcium complex was confirmed by X-ray photoelectron spectroscopy.

关键词： monolayer Langmuir-Blodgett films biliverdin calcium ion

Theoretical analysis of alloy multiplying factor by the empirical electron theory of solids and molecules

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science china(Technological sciences) 2007年第6期50卷 807-814页

作者： SONG YuePeng1,2, LIU GuoQuan2, LI ZhiLin3, FENG ChengMing1 1 Mechanical and Electronic Engineering college, Shandong Agricultural university, Tai’an 271018, china 2 college of Materials science and Engineering, university of science and technology, Beijing 100083, china 3 college of Material science and Engineering, Beijing university of Chemical technology, Beijing 100029, china Mechanical Electronic Engineering college Shandong Agricultural University Tai’an 271018 China college of Materials science Engineering University of Science technology Beijing 100083 China college of Material science Engineering Beijing University of Chemical Technology Beijing 100029 China

By introducing the distribution probability of structural units in austenite contain- ing alloying elements and considering its effects on phase transformation, this paper establishes a calculation model of distribution probability of structural units. A new valence electron structure (VES) parameter-transformation effect coefficient of alloying elements (HL), is defined and then studied both theoretically and ex- perimentally. The relationship between the parameter HL and the multiplying factor (the quenching capability factor) of alloying elements is studied. The results indi- cate that the two parameters (HL and the quenching capability factor) have the same variation characteristic and substance feature. Therefore, the multiplying factor virtually expresses the relative quantity of structural units in the alloying elements-containing austenite.

关键词： multiplying factor (the quenching capability factor), empirical electron theory of solids and molecules, transformation effect coefficient of alloying elements, structural units in austenite containing alloying elements