检索结果-南通市图书馆

Structure and Electrical Properties of(Na_(0.5)Bi_(0.5))_(0.94)Ba_(0.06)TiO_3 Ceramic with 0.5 wt% of MnO

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 499-502页

作者： LIU Weihua XU Qing chen Wen chen min KIM Bokhee School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Faculty of Advanced Materials Engineering Chonbuk National University Chonju 561756 Korea

The structure and electrical properties of （Na0.5Bi0.5）0.94Ba0.06TiO3 ceramic doped with 0.5 wt% of MnO were investigated in comparison with those of （Na0.5Bi0.5）0.94Ba0.06TiO3 ceramic. It was ascertained that the MnO addition did not cause remarkable change in crystal structure and microstructure. The MnO addition mainly displayed a hard effect on the electrical properties, an increase of coercive field （E） and mechanical quality factor （Qm） together with a decrease of dielectric constant （εr） and piezoelectric constant （d33）. An enhancement of electromechanical coupling factor （kp） with the MnO addition was obtained too. An essential relation between the piezoelectric properties and ferroelectric nature of the ceramics was detected. It was found that the piezoelectric properties of the ceramics highly depended on the corporative contribution of remanent polarization （Pt） and coercive field.

关键词： ceramics oxides crystal structure piezoelectricity ferroelectricity

SiO_(2)-Supported Ni(II)and Fe(II)Catalysts Bearing Sodium-Sulfonate Group for Olefin Polymerization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第23期40卷 2773-2779页

作者： Yao Sun Quan Wang Yao Pan Wenmin Pang chen Zou min chen CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefeiAnhui 230026China Institutes of Physical Science and Information Technology Anhui UniversityHefeiAnhui 230601China

Heterogeneous catalysts have been dominant for industrial polyolefin production,offering many distinct advantages,such as controlling the morphology of the polymer and preventing reactor *** this contribution,we designed several types of imine ligands bearing sodium-sulfonate ionic groups and the corresponding nickel/iron *** catalysts could be immobilized on SiO_(2)with strong affinity and high catalyst *** SiO_(2)-supported catalysts behaved better than their homogeneous counterparts during ethylene polymerization with extremely high activity(2.6×10^(4)kg·mol^(−1)·h^(−1))and high thermal *** addition,the supported nickel catalysts generated free-flowing polyethylene with high molecular weight(Mn up to 2.65×10^(3)kg·mol^(–1))and excellent morphology control,indicating no reactor fouling due to the leaching of ***,for copolymerization,immobilized nickel catalysts showed a higher tolerance of polar monomers,and the efficient copolymerization of ethylene with undecylenic acid was achieved with high activity(450 kg·mol^(−1)·h^(−1))and a high incorporation ratio(up to 12.3%).

关键词： Heterogeneous catalysis Nickel iron catalysts Sodium-sulfonate group Polymerization Copolymerization

A novel phycocyanin-Chla/c_2-protein complex isolated from chloroplasts of Chroomonas placoidea

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

Chinese Chemical Letters 2007年第11期18卷 1374-1378页

作者： min chen Si Hui Li Li Sun College of Chemical and Biological Science and Engineering Yantai University Shandong 264005 China

Nine pigment-protein complexes were separated and characterized from intact Chroomonasplacoidea chloroplasts by IEF. The bands Ⅰ-Ⅵ with their isoelectric points （pI） values from 4 to 6 were phycocyanin components; bands Ⅷ and Ⅸ （pI = 2.8-3.6） were chlorophyll-protein complexes. According to absorption and fluorescence spectra, band VII was designated as a novel phycocyanin-Chla/c2-protein complex （pI ≈ 3.4-3.7）. These results indicated that phycocyanin is structurally and functionally coupled with chlorophyll-protein complex in C. placoidea, and probably interacted with electrostatic force in combination.

关键词： Chroomonas placoidea IEF Chlorophyll-protein complex Phycocyanin

Kinetics of phytohemaglutinin-induced IFN-γ and TNF-a expression in peripheral blood mononuclear cells from patients with chronic hepatitis B after liver transplantation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第29期11卷 4574-4578页

作者： Ying-Mei Tang min-Hu chen Gui-Hua chen Chang-Jie Cai Xiao-Shun He min-Giang Lu Wei-min Bao Department of Gastroenterology the First Affiliated Hospital of Sun-Yat Sen University Guangzhou 510080 Guangdong Province China Department of Liver Transplantation Center the Third Affiliated Hospital of Sun-Yat Sen University Guangzhou 510080 Guangdong Province China Department of Organ Transplantation the First Affiliated Hospital of Sun-Yat Sen University Guangzhou 510080 Guangdong Province China

AIM： To study the association between host immunity and hepatitis B virus （HBV） recurrence after liver transplantation. METHODS： Peripheral blood mononuclear cells （PBMC） were isolated from 40 patients with hepatitis B and underwent orthotopic liver transplantation （OLT） before and 2, 4, 8 wk after surgery. After being cultured in vitro for 72 h, the levels of INF-γ and TNF-α in culture supematants were detected with ELISA. At the same time, the quantities of HBV DNA in serum and PBMCs were measured by real time PCR. RESULTS： The levels of INF-γ and TNF-α in PBMC culture supernatants decreased before and 2, 4 wk after surgery in turns （INF-γ 155.52±72.32 ng/L vs 14.76±9.88 ng/L vs 13.22±10.35 ng/L, F= 6.946, P= 0.027〈0.05; TNF-α 80.839±46.75 ng/L vs18.59±17.29 ng/L vs9.758±7.96 ng/L, F= 22.61, P = 0.0001〈0.05）. The levels of INF-γ and TNF-α were higher in groups with phytohemagglutinin （PHA） than in those without PHA before surgery. However, the difference disappeared following OLT. Furthermore, INF-γ and TNF-α could not be detected in most patients at wk 4 and none at wk 8 after OLT. The HBV detection rate and virus load in PBMC before and 2, 4 wk after surgery were fluctuated （HBV detected rate： 51.4%, 13.3%, 50% respectively; HBV DNA： 3.55±0.674 log（10） copies/mL vs 3.00±0.329 log（10） copies/mL vs 4.608±1.344 log（10） copies/mL, F= 7.582, P= 0.002〈0.05）. HBV DNA in serum was 4.48±1.463 log（10） copies/mL before surgery and 〈 10^3 copies/mL after OLT except for one with 5.72×10^6 copies/mL 4 wk after OLT who was diagnosed as HBV recurrence. The levels of INF-γ and TNF-α were lower in patients with a high HBV load than in those with a low HBV load （HBV DNA detected/undetected in PBMCs： IFN-γ 138.08±72.44 ng/L vs 164.24±72.07 ng/L, t = 1.065, P= 0.297〉0.05, TNF-α 80.75±47.30 ng/L vs 74.10±49.70 ng/L, t= 0.407, P= 0.686〉 0.05; HBV DNA positive/negative： IFN-γ 136.77±70.04 ng/L vs 175.27±71.50 ng/L, t= 1.702, P= 0.097〉0.05; TNF-α 75.37±43.02 ng/L vs 81.53±52.46 ng/L, t

关键词： Liver transplantation HBV Recurrence PBMC

A new fluorescent particle prepared by chemical stabilized phycobilisome

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

Chinese Chemical Letters 2009年第6期20卷 724-728页

作者： min chen Guo Ping Ma Li Sun College of Chemical and Biological Sciences and Engineering Yantai University Shandong 264005 China The Clinic Naval Aeronautical Engineering Institute Shandong 264001 China

Natural phycobilisomes （PBSs） were isolated and purified from a red macroalga, Polysiphonia urceolata, by multi-step of sucrose gradient centrifugation, and were chemically stabilized by small molecule cross-linker formaldehyde. The stabilized PBSs showed similar absorption and fluorescent properties at room temperature compared to natural PBSs and kept a steady F672/F580 value during more than 3 months of storage in 0.45 mol/L phosphate buffer （pH 6.8） or at low temperature at 77 K. The stabilized PBS migrated as a single band at mild PAGE and in 14-18 h of sucrose gradient centrifugation. All these characters indicated that the stabilized PBSs were stable, soluble, homogenous fluorescent particles with favorable spectroscopic features prepared under present conditions.

关键词： Polysiphonia urceolata PBSs Chemical stabilization Formaldehyde

Isolation and Neuroprotective Activity of Phenolic Derivatives from the Marine-Derived Fungus Penicillium janthinellum

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2020年第3期19卷 700-706页

作者： ZHENG Yaoyao chen Xu chen Lumin SHEN Li FU Xiumei chen Qiuxia chen min WANG Changyun Marine Science&Technology Institute College of Environmental Science&EngineeringYangzhou UniversityYangzhou 225127China Key Laboratory of Marine Drugs of ministry of Education of China School of Medicine and PharmacyOcean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Institute of Translational Medicine Medical CollegeYangzhou UniversityYangzhou 225001China Institute of Evolution&Marine Biodiversity Ocean University of ChinaQingdao 266003China

A new phenolic compound, 6-(2-acetyl-3,5-dihydroxybenzyl)-4-hydroxy-3-methyl-2H-pyran-2-one(1), along with other six known phenolic derivatives(2-7), were isolated from the mangrove rhizosphere fungus Penicillium janthinellum HK1-6 cultured in potato dextrose broth medium containing 30 g L^(-1) of natural sea salt. The structure of the new compound(1) was elucidated by comprehensive analysis of spectroscopic data including 1D and 2D NMR spectra. The proposed biosynthetic pathway of compound 1 was also studied in this research. Interestingly, a brominated phenolic derivative, aryl bromide(compound 8), was obtained from this fungal strain cultured in medium containing 30 g L^-1 of NaBr instead of natural sea salt. Compound 8 is proposed as a new natural product and formed through bromination of compound 7 when the fungus was cultured with NaBr. The neuroprotective effect of compound 1 on oxygen-glucose deprivation(OGD)-induced injury was investigated in rat spinal cord astrocytes. MTT assay demonstrated that compound 1 can attenuate OGD-induced cell viability loss in rat spinal cord astrocytes.

关键词： marine fungus Penicillium janthinellum phenolic derivative neuroprotective activity

Monothetic and conductive network and mechanical stress releasing layer on micron-silicon anode enabling high-energy solid-state battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1017-1029页

作者： Xiang Han min Xu Lan-Hui Gu Chao-Fei Lan min-Feng chen Jun-Jie Lu Bi-Fu Sheng Peng Wang Song-Yan chen Ji-Zhang chen College of Materials Science and Engineering Co-Innovation Center of Efficient Processing and Utilization of Forestry ResourcesNanjing Forestry UniversityNanjing210037China Department of Physics Xiamen UniversityXiamen361005China Western Digital Corporation MilpitasCA95035USA

Silicon has ultrahigh capacity,dendrite-free alloy lithiation mechanism and low cost and has been regarded as a promising anode candidate for solid-state *** to the low infiltration of solid-state electrolyte(SSE),not the unstable solid-electrolyte interphase(SEI),but the huge stress during lithiation-and delithiation-induced particle fracture and conductivity lost tend to be the main *** this study,starting with micron-Si,a novel monothetic carbon conductive framework and a MgO coating layer are designed,which serve as electron pathway across the whole electrode and stress releasing layer,*** addition,the in situ reaction between Si and SSE helps to form a LiF-rich and mechanically stable SEI *** a result,the mechanical stability and charge transfer kinetics of the uniquely designed Si anode are significantly ***,high initial Coulombic efficiency,high capacity and durable cycling stability can be achieved by applying the Si@MgO@C anode in *** example,high specific capacity of 3224.6 mAh·g^(-1)and long cycling durability of 200 cycles are *** work provides a new concept for designing alloy-type anode that combines surface coating on particle and electrode structure design.

关键词： Lithium-ion battery(LIB) Solid-state electrolyte(SSE) Silicon anode Stress relief Coating

Isolation and characterization of a new subunit of phycocyanin from Chroomonas placoidea

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第10期22卷 1229-1232页

作者： Yun Yun Zhang min chen Hong Cui College of Chemical and Biological Sciences and Engineering Yantai University Yantai 264005 China Yantai Traditional Chinese Medical-science Hospital Yantai 264002 China

A new phycocyanin（PC） fluorescent subunit namedβ_2（18kDa） was isolated and characterized by both SDS-PAGE and isoelectric focusing（IEF） from a species of cryptophytic alga Chroomonas *** was separated and purified by ammonium sulfate sedimentation followed by two steps of Sephadex G-100 *** denatured in 4 mol/L urea for 48 h,PC was divided into two fractions by passing through a Sephacryl S-100 chromatography column *** blue fraction（S-1） containedβsubunits with a maximal absorbance at 595 nm in visible light *** the green fraction（S-2） enriched inαsubunits showed a characteristic long wavelength absorbance at 680-700 nm region and exhibited a relatively low molecular weight of 9.4（α_1） and 8.5 kDa（α_2）.Fraction S-1 also consisted of two different fluorescent subunits with molecular weight of 20.1 kDa（β_1） and 18 kDa （β_2） and differed from each other on isoelectric points of pH 5.7（ft） and 6.0（ft）,*** investigation of peptide sequence will help a lot in elucidating the new subunit ft that was smaller in size and more neutral than the known ft subunit,and may provide an alternative explanation in structure of cryptophytic phycobiliproteins.

关键词： Chroomonas placoidea Phycocyanin subunit Sephacryl S-100 chromatography SDS-PAGE IEF

On the integrity of a commercial cassette ultrafiltration membrane: implications for marine colloidal biogeochemistry

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2014年第9期33卷 109-116页

作者： LIN Liangshi CAI Yihua SUN Xiuwu chen min State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Science Xiamen University Third Institute of Oceanography State Oceanic Administration

The performance and integrity of a cassette cross-flow ultrafilter （Pellicon 2, Millipore） are examined with a suite of macromolecules of different molecular masses. The retention coefficient during the cross-flow ultrafiltration experiments increases with increasing molecular mass and reaches 90% with 10 kDa dextran in both milli-Q water and ultrafiltered seawater media. Based on a 90% retention coefficient, the molecular mass cut-off for the ultrafiltration membrane is defined at 10 kDa, which is ten times （1 kDa） that rated by the manufacturer. To further validate the accuracy of the laboratory calibration, the samples from the lower Zhujiang River and the Jiulong River Estuary are ultrafiltered with the cassette ultrafiltration membrane and the colloidal organic carbon abundances in these samples are quantified with the ultrafiltration per- meation model based on time series permeation subsamples. The colloidal organic carbon abundances are 5.8%-21.1% in the Jiulong River Estuary and 5.6%-11.0% in the lower Zhujiang River. These are consistent with the reported values for both estuaries as well as with the colloidal organic carbon abundances in ma- rine environments over the coastal and open oceans with 10 kDa cut-off membranes. Therefore, these field data support the laboratory calibration result and indicate the validity of the experimental and quantification procedure adopted. The discrepancy between the nominal molecular mass cut-off and the actual pore size of the ultrafiltration membrane should be of great concern for research in colloidal and nanoparticle biogeochemistry. Careflfl examination of the membrane integrity should be taken during ultrafiltration ex- oeriments in order to avoid misleading molecular mass cut-off information.

关键词： cross-flow ultrafiltration membrane calibration colloidal organic carbon Iiulong RiverEstuary Zhujiang River Estuary