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Heavy metal concentrations in edible bivalves and gastropods available in major markets of the Pearl River Delta

Journal of Environmental Sciences 2001年第2期13卷 210-217页

作者： FANG zhan-qiang CHEUNG R.y.H. WONG M.H. Department of Biology South China Normal UniversityGuangzhou 510631China Department of Biology and Chemistry City University of Hong Kong83 Tat Chee AvenueKowloonHong Kong Institute for Natural Resources and Waste Management and Department of BiologyHong Kong Bapt ist UniversityKowloon TongHong Kong

Molluscs are able to accumulate heavy metals and impose health hazard to consumers. The main objective of the present study is to investigate the heavy metal concentrations in edible bivalves and gastropods available in major markets of the Pearl River Delta. Fourteen species of edible molluscs were purchased from six markets in Hong Kong and Guangdong Province. The fresh of these biota were tested for their cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn) concentrations (based on wet weight). The results indicated that amongst the 14 edible molluscs, only Cd, Pb, Ni, Cr, Sb and Sn concentrations in three species (Ruditapes philippinarum, Perna viridis and Hemifusus tuba) were within the local regulatory limits. Over 60% of bivalve species exceeded maximum permitted levels of Cd (2 mug/g) and Cr (1 mug/g), while over 40% of gastropod species exceeded the maximum levels of Sb (1 mug/g) and Cr (1 mug/g). Most of the samples collected from Hong Kong had significantly higher contents of Pb and Sb, but similar levels of Cd, Cu and Zn when compared with samples collected across the border ( p y). In general, the molluscs purchased in Guangdong markets had higher metal contents than those purchased from the Hong Kong markets. When compared with the Provisional Tolerable Weekly Intake or Maximum Acceptable Daily Load recommended by FAO/WHO Expert Committee on Food Additives, Cd levels of five species (Anadara ferruginea, Pinna pectinata, Chlamys nobilis, Babylonia lutosa and Hemifusus terntanus) and Cr levels of seven species ( Anadara ferruginea, Paphia undulata, Pinna pectinata, Babylonia lutosa, Hemifusus terntanus, Cymbium melo and Cipangopaludina chinensis) were higher than both the human daily acceptable limits (for Cd and Cr respectively) and the local regulatory levels (for Cd and Cr respectively).

关键词： heavy metals edible molluscs human health Pearl River Delta

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Islet separation and islet cell culture in vitro from human embryo-pancreas

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World Journal of Gastroenterology 1999年第5期5卷 458-460页

作者： yuan Z Wu Gy He yS Shao CM zhan y Kunming Med Coll Dept Histol & Embryol Kunming 650031 Yunnan Province Peoples R China First Affiliated Hosp Kunming Med Coll Dept Nucl Med Kunming 650032 Yunnan Province Peoples R China Kunming Med Coll Dept Biol Kunming 650031 Yunnan Province Peoples R China

INTRODUCTIONDiabetes mellitus is the most common disease and its death rate ranks the 8th in the world. Up to now, its incidence has a tendency to increase[1]. Since disorder of sugar metabolism might result in microvascular degeneration and injury of important human organs, it will endanger human health seriously. In 1969, younszai first reported the method that could decrease diabetes symptoms by islet tissue transplantation. In 1981, our country began to treat diabetes type Ⅰ by transplanting cultured islet tissues. In our study, we digested the pieces of pancreas with collagenase and made morphological observation on islet cells cultured for 3d, 5d, 7d, 9d and 13d respectively, and the contents of insulin and C-peptide in the supernatant were detected by radioimmunoassay. The experimental model of rabbit diabetes was established, and certain curative effect was achieved in the treatment of experimental diabetes in rats.

关键词： cell culture islet cell islets of langerhans transplantetion pancreas/ embryology

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OXIDATION RESISTANCE OF NANOCRySTAL ODS ALUMINIDE COATINGS PRODUCED By PACK ALUMINIZING PROCESS ASSISTED By BALL PEENING

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Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 215-222页

作者： Z.L. zhan y.D. He W. Gao Kunming University of Science and Technology Kunming 650093 China Beijing Key Laboratory for Corrosion Erosion and Surface Technology University of Science and Technology Beijing Beijing 100083 China Engineering School The University of Auckland Auckland 1020 New Zealand

Nanocrystal ODS （oxide dispersion strengthening） aluminide coatings were produced on a stainless steel and nickel-based superalloy by the pock aluminizing process assisted by ball peening, Pure Al powders and 1% of ultra-fine y2O3 powders were mixed by ball milling. The ultra-fine y2O3 powders were dispersed in Al particles. Ball peening welded the Al particles onto the substrate and accelerated the formation of aluminide coating. Nanocrystal ODS aluminide coatings were produced by the outward growth at a much low temperature （below 600℃） in a short treatment time. The effects of the operation temperature and treatment time on the formation of the coatings were analyzed. SEM （scanning electron microscope）, AFM （atomic force microscope）, EDS （energy dispersive X-ray spectroscopy）, XRF （X-ray fluorescence spectrometer） and XRD （X-ray diffraction） methods were applied to investigate the microstructure of the coatings. High-temperature oxidation tests were carried out to evaluate the oxidation resistance of the ODS aluminide coatings.

关键词： nano-coating ODS coating aluminide coating ball peening high-temperature oxidation

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Influence of inorganic salt on aerobic biodegradability of dyestuffs

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Journal of Environmental Sciences 2000年第4期12卷 416-421页

作者： zhan, X. Wang, J. Wen, X. Feng, y. Qian, y. Key Joint Lab. on Envl. Simulation Dept. of Envtl. Sciences and Eng. Tsinghua University Beijing 100084 China

In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi-continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl = 15 g/L; in the three NaCl conditions, biodegradability of tested dyestuffs followed the following order: NaCl = 0 g/L>NaCl = 30 g/L>NaCl = 15 g/L.

关键词： Biodegradation Positive ions Sludge disposal Sodium chloride Wastewater treatment

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Refractory high-entropy alloys:A focused review of preparation methods and properties

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Journal of Materials Science & Technology 2023年第11期142卷 196-215页

作者： Wei Xiong Amy X.y.Guo Shuai zhan Chain-Tsuan Liu Shan Cecilia Cao Materials Genome Institute Shanghai UniversityShanghai 200444China Hong Kong Institute of Advanced Study City University of Hong KongKowloonHong KongChina

In recent years,high-entropy alloys(HEAs)have become prominent metallic materials due to their unique design strategies and excellent mechanical *** HEAs-inherent high-entropy,lattice-distortion,sluggish-diffusion,and cocktail effects make HEAs maintain high strength,oxidation resistance,corrosion resistance,wear resistance,and other excellent comprehensive properties,showing stronger competitiveness relative to traditional *** high-entropy alloys(RHEAs)are considered as a new kind of high-temperature materials with great application prospects due to their excellent mechanical properties and have the potential to replace nickel-based superalloy as the next generation of high-temperature *** reviewed the research status and preparation methods of RHEAs in recent years,including the metallurgical smelting,powder metallurgy,magnetron sputtering,and additive manufacturing *** microstructure and phase-transformation process of RHEAs were *** mechan-ical properties and main strengthening and toughening mechanisms of RHEAs,such as solid-solution strengthening,precipitation strengthening,and the transformation-induced plasticity(TRIP),were discussed,and the deformation mechanism of RHEAs was *** properties of RHEAs,including high strength,oxidation resistance,corrosion and wear resistance were *** will meet the huge market demand in the engineering materials field,but there are still many challenges,such as the tradeoff between high strength and high ductility,structural design,and performance optimization of RHEAs with brittle BCC *** believe that this combination of knowledge may shape the future of RHEAs and break through the mutually exclusive conundrum of high strength and high toughness for RHEAs.

关键词： Refractory high-entropy alloy Preparation technology Phase transformation Mechanical properties Strengthening and toughening mechanisms Deformation mechanisms

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Learning real-time automata

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Science China(Information Sciences) 2021年第9期64卷 57-73页

作者： Jie AN Lingtai WANG Bohua zhan Naijun zhan Miaomiao zhanG School of Software Engineering Tongji University State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences University of Chinese Academy of Sciences

Real-time automata(RTAs) are a subclass of timed automata with only one clock which resets at each transition. In this paper, we present an active learning algorithm for deterministic real-time automata(DRTAs) in both continuous-time semantics and discrete-time semantics. For a target language recognized by a DRTA A, we convert the problem of learning DRTA A to the problem of learning a canonical real-time automaton A with the same recognized language, i.e., L(A) = L(A). The algorithm is inspired by existing learning algorithms for symbolic automata.

关键词： automaton learning active learning real-time automata

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A Novel Humidity-Sensitive Material Based on PDEB with Nickel Complex Catalyst

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Chinese Chemical Letters 1998年第2期9卷 223-225页

作者： yang, MJ Li, y zhan, XW Sun, HM Ling, MF Zhu, yH Zhejiang Univ Dept Polymer Sci & Engn Hangzhou 310027 Peoples R China Zhejiang Univ Dept Elect & Informat Hangzhou 310027 Peoples R China

Poly(p-diethynylbenzene) (PDEB) with improved solubility was synthesized using a novel catalyst bis(triphenylphosphine)bis(p-diethynylbenzene) nickel complex (NI-C). A surface acoustic wave (SAW) delay line oscillator was covered by Langmuir-Blodgett (LB) films of resulting PDEB to prepare a humidity sensor, which was found to have high sensitivity and good repeatability. PDEB shows promise as a good humidity-sensitive material.

关键词： humidity-sensitive material bis(triphenylphosphine)bis(p-diethynylbenzene) nickel poly (p-diethynylbenzene) SAW humidity sensor LB membrane

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Initial Boundary Value Problem of an Equation from Mathematical Finance

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Chinese Annals of Mathematics,Series B 2016年第3期37卷 465-482页

作者： Huashui zhan School of Applied Mathematics Xiamen University of Technology

Consider the initial boundary value problem of the strong degenerate parabolic equation ?_(xx)u + u?_yu-?_tu = f(x, y, t, u),(x, y, t) ∈ Q_T = Ω×(0, T)with a homogeneous boundary condition. By introducing a new kind of entropy solution, according to Oleinik rules, the partial boundary condition is given to assure the well-posedness of the problem. By the parabolic regularization method, the uniform estimate of the gradient is obtained, and by using Kolmogoroff 's theorem, the solvability of the equation is obtained in BV(Q_T) sense. The stability of the solutions is obtained by Kruzkov's double variables method.

关键词： Mathematical finance Oleinik rules Partial boundary condition Entropy solution Kruzkov's double variables method

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SIMULATION OF THE CHANGE OF SINTERING NECK BETWEEN TWO GRAINS IN TWO DIMENSIONS

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Acta Metallurgica Sinica(English Letters) 2006年第6期19卷 397-404页

作者： y.y.Zhu S.H.Liang Z.J.zhan P.Xiao Z.K.Fan School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China

A modified two-sphere model of sintering neck has been proposed, wherein three diffusion mechanisms including surface diffusion, grain-boundary diffusion and coupled surface and grain-boundary diffusion are assumed. Sintering neck is appropriately simulated using the modified model. The dynamic change of sintering neck is presented using the simulation. The variational shape of sintering neck in surface diffusion mechanism is continuous, whereas in grain-boundary diffusion mechanism, besides the variational shape of sintering neck being continuous, the center distance between the particles is also assumed to contract. However, the variational shape of sintering neck in coupling diffusion mechanism is integrated using the two diffusion mechanisms mentioned above.

关键词： sintering simulation neck growth surface diffusion grain-boundary diffusion

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How to evaluate diagnosis and management of biliary atresia in the era of liver Transplantation in China

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World Journal of Pediatric Surgery 2018年第1期1卷 3-8页

作者： Jianghua zhan yajun Chen Kenneth K y Wong Department of Pediatric Surgery Tianjin Children’s HospitalTianjinChina Department of Pediatric Surgery Beijing Children’s HospitalBeijingChina Department of Pediatric Surgery Queen Mary HospitalHong KongChina

background Biliary atresia(BA)is one of the most challenging hepatobiliary diseases in *** the reasonable outcome of liver transplantation(LT),portoenteral anastomosis(Kasai operation)is still the first choice of treatment for patients with *** to improve the survival rate of the patients with BA in the era of LT is a new *** sources Based on recent original publications and the experience with the BA in China,we review many factors that influence BA survival situation,including early diagnosis and screen plan,defects of early treatment,Kasai operation,and LT and indicate present questions about BA diagnosis and treatment in *** BA diagnosis may also be delayed due to insufficient understanding of BA and lack of jaundice monitoring methods at different levels of the hospitals in *** education of the physicians at smaller city hospitals about BA,neonatal jaundice and cholestasis would be helpful in improving early diagnosis of *** surgical intervention is still the only guarantee to improve the survival rate of BA with native *** In the era of LT,especially in China,Kasai operation can provide waiting time for living donor LT and improve the success rate of LT and minimize the rapid deterioration of liver function of the children with BA and decrease the mortality in patients with BA.

关键词： diagnosis treatment guarantee

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