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381篇 您的检索式:作者名="DI Feng"
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1Anisotropic coding metamaterials and their powerful manipulation of differently polarized terahertz waves显示文摘Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.Shuo Liu Tie Jun Cui Quan Xu Di Bao Liangliang Du Xiang Wan Wen Xuan Tang Chunmei Ouyang Xiao Yang Zhou Hao Yuan Hui Feng Ma Wei Xiang Jiang Jiaguang Han Weili Zhang Qiang Cheng 2016Light(Science & Applications)2016,5,1:36
2Biological properties of neural progenitor cells isolated from the hippocampus of adult cynomolgus monkeys显示文摘Background The existence of neurogenesis in the hippocampus of adult nonhuman primates has been confirmed in recent years, however, the biological properties of adult neural stem cells or neural progenitor cells (NPCs) from this region remain to be extensively explored. The present work was to investigate on the expansion of NSCs/NPCs from the hippocampus of adult cynomolgus monkeys and the examination of their characteristics in vitro. Methods NPCs isolated from the hippocampus of adult cynomolgus monkeys were expanded in vitro in serum-free media containing growth factors, and were then allowed to differentiate by removing mitotic factors. The expansion capacity of NPCs and their differentiation potential were assayed by immunohistochemical and immunocytochemical analysis. Results During primary culture, NPCs underwent cell division, proliferation and aggregation to form neurospheres that were growing in suspension. Without mitotic stimulation, most neurospheres adhered to the culture dish and started to differentiate. Eventually, nearly 12% of the differentiated cells expressed neuron specific marker-βIII-tubulin (Tuj1) and 84% expressed astrocyte specific marker-fibrillary acidic protein (GFAP). In addition, the expression of a neural stem cell marker, nestin, was found both in NPCs and in the subgranular zone of adult monkey hippocampus, where NPCs were originally derived. Conclusions NPCs from the hippocampus of adult cynomolgus monkeys can be expanded to some extent in vitro and are capable of differentiating into neurons and astrocytes. Further experiments to promote the in vitro proliferation capacity of NPCs will be required before adult NPCs can be used as a useful cell model for studying adult neurogenesis and cell replacement therapy using adult stem cells.YUE Feng CHEN Biao WU Di DONG Kai ZENG Si-en ZHANG Yu 2006Chinese Medical Journal2006,,2:16
3Molecular Epidemiological Characteristics of Streptococcus pyogenes Strains Involved in an Outbreak of Scarlet Fever in China,2011显示文摘Objective To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011.Methods Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011.Emm genotyping,pulsed-field gel electrophoresis (PFGE),superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates.Results A total of 4 different emm types were identified.Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles.Emm12 (79.7%) and emml (14.9%) accounted for approximately 94%of all the isolates.The speA gene was all negative in emm12 isolates and positive in emml isolates.All strains were resistant to erythromycin,and 89.4%of them were resistant to erythromycin,tracycline,and clindamycin simultaneously.Conclusion Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains,though no new emm type was found in this outbreak.The data provide a baseline for further surveillance of scarlet fever,which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.YOU Yuan Hai SONG Yan Yan YAN Xiao Mei WANG Hai Bin ZHANG Meng Han TAO Xiao Xia Li Lei Lei ZHANG Yu Xin JIANG Xi Hong ZHANG Bing Hua ZHOU Hao XIAO Di JIN Lian Mei FENG Zi Jian LUO Feng Ji ZHANG Jian Zhong 2013Biomedical and Environmental Sciences2013,26,11:15
4The wonders of BMP9:From mesenchymal stem cell differentiation,angiogenesis,neurogenesis,tumorigenesis,and metabolism to regenerative medicine显示文摘Although bone morphogenetic proteins(BMPs)initially showed effective induction of ectopic bone growth in muscle,it has since been determined that these proteins,as members of the TGF-b superfamily,play a diverse and critical array of biological roles.These roles include regulating skeletal and bone formation,angiogenesis,and development and homeostasis of multiple organ systems.Disruptions of the members of the TGF-b/BMP superfamily result in severe skeletal and extra-skeletal irregularities,suggesting high therapeutic potential from understanding this family of BMP proteins.Although it was once one of the least characterized BMPs,BMP9 has revealed itself to have the highest osteogenic potential across numerous experiments both in vitro and in vivo,with recent studies suggesting that the exceptional potency of BMP9 may result from unique signaling pathways that differentiate it from other BMPs.The effectiveness of BMP9 in inducing bone formation was recently revealed in promising experiments that demonstrated efficacy in the repair of critical sized cranial defects as well as compatibility with bone-inducing bio-implants,revealing the great translational promise of BMP9.Furthermore,emerging evidence indicates that,besides its osteogenic activity,BMP9 exerts a broad range of biological functions,including stem cell differentiation,angiogenesis,neurogenesis,tumorigenesis,and metabolism.This review aims to summarize our current understanding of BMP9 across biology and the body.Sami Mostafa Mikhail Pakvasa Elam Coalson Allen Zhu Alex Alverdy Hector Castillo Jiaming Fan Alex Li Yixiao Feng Di Wu Elliott Bishop Scott Du Mia Spezia Alissa Li Ofir Hagag Alison Deng Winny Liu Mingyang Li Sherwin S·Ho Aravind Athiviraham Michael J·Lee Jennifer Moriatis Wolf Guillermo A·Ameer Hue H·Luu Rex C·Haydon Jason Strelzow Kelly Hynes Tong-Chuan He Russell R·Reid 2019Genes & Diseases2019,6,3:15
5Dihydromyricetin improves type 2 diabetes- induced cognitive impairment via suppressing oxidative stress and enhancing brain-derived neurotrophic factor-mediated neuroprotection in mice显示文摘类型 2 糖尿病 mellitus (T2DM ) 导致认知缺陷(CI ) ,但是为在 T2DM 的认知机能障碍没有有效 pharmacotherapies 或药。Dihydromyricetin (DHM ) 是从白蔹属 grossedentata 的叶子提取的自然 flavonoid 混合物并且包括抗氧化剂和反糖尿病有各种各样的药理学效果。因此,我们在 T2DM 老鼠模型和它的可能的机制在 CI 上调查了 DHM 的效果。导致 T2DM,老鼠用高糖、高脂肪的饮食被喂 8 个星期,由低剂量 streptozotocin (STZ ) 列在后面管理。在 T2DM 鼠标模型的成功的正式就职以后,鼠标与相等的体积分别地被对待盐(T2DM 组) , 125 mg/kg/d DHM (L-DHM 组) ,或 250 mg/kg/d DHM (H-DHM 组) 。在 16 星期 DHM 管理以后,身体重量(BW ) , fasting 血葡萄糖,血类脂化合物, intraperitoneal 葡萄糖忍耐(IPGT ) ,和认知功能是坚定的。然后,在在马头鱼尾的怪兽的氧化压力标记和导出大脑的神经营养的因素(BDNF ) 的表情的改变被调查。我们的调查结果证明 DHM 能显著地改善在 T2DM 老鼠的 CI 和反向的异常葡萄糖和类脂化合物新陈代谢,通过调停 BDNF 的 neuroprotection 的氧化应力和改进的抑制可能。在结论,我们的结果建议 DHM 是导致 T2DM 的认知机能障碍的处理的一个有希望的候选人。Hongyan Ling Zemei Zhu Jihua Yang Jianqin He Sisi Yang Di Wu Shuidong Feng Duanfang Liao 2018Acta Biochimica et Biophysica Sinica2018,50,3:14
6Eleven COVID-19 Outbreaks with Local Transmissions Caused by the Imported SARS-CoV-2 Delta VOC-China,July-August,2021显示文摘Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Lei Zhou Kai Nie Hongting Zhao Xiang Zhao Bixiong Ye Ji Wang Cao Chen Hong Wang Jiangli Di Jinsong Li Chao Li Zhixiao Chen Ruiqi Ren Peihua Niu Hui Chen Tao Chen Yali Wang Lili Li Bingxue Han Ruhan A Si Chen Dan Li Dan Li Chunxia Jin Xin Zhang Jiangmei Liu Chunyu Xu Yecheng Yao Yenan Feng Zhili Li Bike Zhang Yang Song Peter Hao Yanping Zhang Hao Li Qun Li George F.Gao Guoqing Shi Wenbo Xu 2021China CDC weekly2021,3,41:13
7Type I IFN augments IL-27-dependent TRIM25 expression to inhibit HBV replication显示文摘Hepatitis B virus(HBV)can cause chronic hepatitis B,which may lead to cirrhosis and liver cancer.Type I interferon(IFN)is an approved drug for the treatment of chronic hepatitis B.However,the fundamental mechanisms of antiviral action by type I IFN and the downstream signaling pathway are unclear.TRIM25 is an IFN-stimulated gene(ISG)that has an important role in RIG-I ubiquitination and activation.Whether TRIM25 is induced in liver cells by type I IFN to mediate anti-HBV function remains unclear.Here we report that interleukin-27(IL-27)has a critical role in IFN-induced TRIM25 upregulation.TRIM25 induction requires both STAT1 and STAT3.In TRIM25 knockout HepG2 cells,type I IFN production was consistently attenuated and HBV replication was increased,whereas overexpression of TRIM25 in HepG2 cells resulted in elevated IFN production and reduced HBV replication.More interestingly,we found that TRIM25 expression was downregulated in HBV patients and the addition of serum samples from HBV patients could inhibit TRIM25 expression in HepG2 cells,suggesting that HBV might have involved a mechanism to inhibit antiviral ISG expression and induce IFN resistance.Collectively,our results demonstrate that type I IFN-induced TRIM25 is an important factor in inhibiting HBV replication,and the IFN-IL-27-TRIM25 axis may represent a new target for treating HBV infection.Guangyun Tan Qingfei Xiao Hongxiao Song Feng Ma Fengchao Xu Di Peng Na Li Xiaosong Wang Junqi Niu Pujun Gao F Xiao-Feng Qin Genhong Cheng 2018Cellular & Molecular Immunology2018,15,3:13
8Progress in Joining Ceramics to Metals显示文摘The research and development of joining methods of ceramics to metals, especially brazing, diffusion bonding and partial transition liquid phase bonding, were introduced. Some opinions were put forward. For new composites emerging, it is necessary to develop new joining methods, particularly in the field of high temperature technique for joining ceramics to superalloys.ZHANG Yong FENG Di HE Zhi-yong CHEN Xi-chun 2006Journal of Iron and Steel Research(International)2006,13,2:12
9Evaluation on Tourism Ecological Security in Nature Heritage Sites——Case of Kanas Nature Reserve of Xinjiang,China显示文摘The nature heritages are the precious legacy of nature with outstanding scientific and aesthetic value. They are quite different from other common ecotourism areas, because of its original and unique system, sensitive and vulnerable landscape, and peripheral cultural features. Therefore, the tourism development in the nature heritage sites should be on the premise of ecological security. The evaluation index system of tourism ecological security in nature heritage sites was constructed in this article by AHP and Delphi methods, including nature ecological security, landscape visual security and local culture ecological security, and the security thresholds of indices were also established. In the indices' weights of the evaluation model, the nature ecological security ranked the highest, followed by tourist landscape visual security and culture ecological security, which reflected the influence degree of the limited factor to tourism ecological security. Then, this paper carried out an empirical study of Kanas of Xinjiang Uygur Autonomous Region, China, which has the potential to be the World Nature Heritage. On the basis of the data attained from survey and observation on the spot, as well as questionnaire answered by tourists and local communities, the ecological security status in Kanas was evaluated. The result showed that the status of Kanas tourism ecological security was better, but there had some limiting factors. Lastly, effective measures were put forward to ensure its ecological security.LIU Xuling YANG Zhaoping DI Feng CHEN Xuegang 2009Chinese Geographical Science2009,19,3:12
10The enhanced X-ray Timing and Polarimetry mission—eXTP显示文摘In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources.The paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment.ShuangNan Zhang Andrea Santangelo Marco Feroci YuPeng Xu FangJun Lu Yong Chen Hua Feng Shu Zhang Sφren Brandt Margarita Hernanz Luca Baldini Enrico Bozzo Riccardo Campana Alessandra De Rosa YongWei Dong Yuri Evangelista Vladimir Karas Norbert Meidinger Aline Meuris Kirpal Nandra Teng Pan Giovanni Pareschi Piotr Orleanski QiuShi Huang Stephane Schanne Giorgia Sironi Daniele Spiga Jiri Svoboda Gianpiero Tagliaferri Christoph Tenzer Andrea Vacchi Silvia Zane Dave Walton ZhanShan Wang Berend Winter Xin Wu Jean J.M.in't Zand Mahdi Ahangarianabhari Giovanni Ambrosi Filippo Ambrosino Marco Barbera Stefano Basso Jörg Bayer Ronaldo Bellazzini Pierluigi Bellutti Bruna Bertucci Giuseppe Bertuccio Giacomo Borghi XueLei Cao Franck Cadoux Francesco Ceraudo TianXiang Chen Yu Peng Chen Jerome Chevenez Marta Civitani Wei Cui WeiWei Cui Thomas Dauser Ettore Del Monte Sergio Di Cosimo Sebastian Diebold Victor Doroshenko Michal Dovciak YuanYuan Du Lorenzo Ducci QingMei Fan Yannick Favre Fabio Fuschino JoséLuis Ga'lvez Min Gao MingYu Ge Olivier Gevin Marco Grassi QuanYing Gu YuDong Gu DaWei Han Bin Hong Wei Hu Long Ji ShuMei Jia WeiChun Jiang Thomas Kennedy Ingo Kreykenbohm Irfan Kuvvetli Claudio Labanti Luca Latronico Gang Li MaoShun Li Xian Li Wei Li ZhengWei Li Olivier Limousin HongWei Liu XiaoJing Liu Bo Lu Tao Luo Daniele Macera Piero Malcovati Adrian Martindale Malgorzata Michalska Bin Meng Massimo Minuti Alfredo Morbidini Fabio Muleri Stephane Paltani Emanuele Perinati Antonino Picciotto Claudio Piemonte JinLu Qu Alexandre Rachevski Irina Rashevskaya Jerome Rodriguez Thomas Schanz ZhengXiang Shen LiZhi Sheng JiangBo Song LiMing Song Carmelo Sgro Liang Sun Ying Tan Phil Uttley Bo Wang DianLong Wang GuoFeng Wang Juan Wang LangPing Wang YuSa Wang Anna L.Watts XiangYang Wen Jörn Wilms ShaoLin Xiong JiaWei Yang Sheng Yang YanJi Yang Nian Yu WenDa Zhang Gianluigi Zampa Nicola Zampa Andrzej A.Zdziarski AiMei Zhang ChengMo Zhang Fan Zhang Long Zhang Tong Zhang Yi Zhang XiaoLi Zhang ZiLiang Zhang BaoSheng Zhao ShiJie Zheng Yu Peng Zhou Nicola Zorzi J.Frans Zwart 2019Science China(Physics,Mechanics & Astronomy)2019,62,2:11
11Estimation on Aesthetic Value of Tourist Landscapes in a Natural Heritage Site:Kanas National Nature Reserve,Xinjiang,China显示文摘Most world natural heritage sites are designated partly by reason of their prominent aesthetic values in accordance with Article Ⅶ of World Natural Heritage Convention.In this paper, the aesthetic values of Kanas National Nature Reserve, which has potential for such designation, was analyzed quantitatively using scenic beauty estimation(SBE).The landscapes of 19 representative scenic spots in the Kanas National Nature Reserve in summer and autumn were selected as the objects of evaluation.The contributions of different landscape factors to the aesthetic value of the Kanas National Nature Reserve were revealed using a multivariate quantitative model.The main factors affecting the aesthetic value were waterscapes, vegetation, mountains, folk culture and the tourist environment.The t-test and F-test results are extremely significant.According to the results, some suggestions were given for conserving the landscapes in the Kanas National Nature Reserve.DI Feng YANG Zhaoping LIU Xuling WU Jingrui MA Zhongguo 2010Chinese Geographical Science2010,20,1:11
12A de novo Genome of a Chinese Radish Cultivar显示文摘Here, we report a high-quality draft genome of a Chinese radish(Raphanus sativus) cultivar. This draft contains 387.73 Mb of assembled scaffolds, 83.93% of the scaffolds were anchored onto nine pseudochromosomes and 95.09% of 43 240 protein-coding genes were functionally annotated. 184.75 Mb(47.65%) of repeat sequences was identified in the assembled genome. By comparative analyses of the radish genome against 10 other plant genomes, 2 275 genes in 780 gene families were found unique to R. sativus. This genome is a good reference for genomic study and of great value for genetic improvement of radish.ZHANG Xiaohui YUE Zhen MEI Shiyong QIU Yang YANG Xinhua CHEN Xiaohua CHENG Feng WU Zhangyan SUN Yuyan JING Yi LIU Bo SHEN Di WANG Haiping CUI Na DUAN Yundan WU Jian WANG Jinglei GAN Caixia WANG Jun WANG Xiaowu LI Xixiang 2015Horticultural Plant Journal2015,1,3:10
13Crystal structure of the swine-origin A (H1N1)- 2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus显示文摘Influenza virus is the causative agent of the seasonal and occasional pandemic flu.The current H1N1 influenza pandemic,announced by the WHO in June 2009,is highly contagious and responsible for global economic losses and fatalities.Although the H1N1 gene segments have three origins in terms of host species,the virus has been named swine-origin influenza virus(S-OIV)due to a predominant swine origin.2009 S-OIV has been shown to highly resemble the 1918 pandemic virus in many aspects.Hemagglutinin is responsible for the host range and receptor binding of the virus and is therefore a primary indicator for the potential of infection.Primary sequence analysis of the 2009 S-OIV hemagglutinin(HA)reveals its closest relationship to that of the 1918 pandemic influenza virus,however,analysis at the structural level is necessary to critically assess the functional significance.In this report,we report the crystal structure of soluble hemagglutinin H1(09H1)at 2.9Å,illustrating that the 09H1 is very similar to the 1918 pandemic HA(18H1)in overall structure and the structural modules,including the five defined antiboby(Ab)-binding epitopes.Our results provide an explanation as to why sera from the survivors of the 1918 pandemics can neutralize the 2009 S-OIV,and people born around the 1918 are resistant to the current pandemic,yet younger generations are more susceptible to the 2009 pandemic.Wei Zhang Jianxun Qi Yi Shi Qing Li Feng Gao Yeping Sun Xishan Lu Qiong Lu Christopher J.Vavricka Di Liu Jinghua Yan George F.Gao 2010Protein & Cell2010,1,5:10
14Epigenetic regulation in B-cell maturation and its dysregulation in autoimmunity显示文摘B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated byautoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreign antigens andsignals from helper T cells for differentiating into either memory B cells or antibody-producing plasma cells.Accumulating evidence has shown that epigenetic regulations modulate somatic hypermutation and class switchDNA recombination during B-cell activation and differentiation. Any abnormalities in these complex regulatoryprocesses may contribute to aberrant antibody production, resulting in autoimmune pathogenesis such as systemiclupus erythematosus. Newly generated knowledge from advanced modern technologies such as next-generationsequencing, single-cell sequencing and DNA methylation sequencing has enabled us to better understand B-cellbiology and its role in autoimmune development. Thus this review aims to summarize current research progress inepigenetic modifications contributing to B-cell activation and differentiation, especially under autoimmuneconditions such as lupus, rheumatoid arthritis and type 1 diabetes.Haijing Wu Yaxiong Deng Yu Feng Di Long Kongyang Ma Xiaohui Wang Ming Zhao Liwei Lu Qianjin Lu 2018Cellular & Molecular Immunology2018,15,7:10
15Hot workability characteristics of Rene88DT superalloy with directionally solidified microstructure显示文摘The hot deformation characteristics of Rene88 DT superalloy with directionally solidified microstructure produced by electroslag remelting continuous directionally solidification(ESR-CDSò) were studied in the temperature range of 1,040–1,140 °C and strain rate range of 0.001–1.000 s-1by hot compression tests. Flow curves for Rene88 DT alloy with initial directionally solidified(DS)microstructure exhibit pronounced peak stresses at the early stage of deformation followed by the occurrence of dynamic softening phenomenon. Rene88 DT alloy with DS microstructure shows higher flow peak stresses compared with HIPed P/M superalloy FGH4096, but the disparities in peak stresses between ESR-CDSed Rene88 DT and HIPed P/M superalloy FGH4096 reduce as temperature increases. The improvement of hot workability of DS alloy with columnar grains avoiding the maximum shear stress comes true. A hot deformation constitutive equation as a function of strain that describes the dependence of flow stress on strain rate and temperature is established. Hot deformation apparent activation energy(Q) varies not only with the strain rate and temperature but also with strain. The strain rate sensitivity exponent(m) map is established at the strain of 0.8, which reveals that global dynamic recrystallization(DRX) shows a relatively high m value in a large strain compression.Optimum parameters are predicted in two regions:T = 1,100–1,130 °C,_e = 0.100–1.000 s-1and T = 1,080–1,100 °C,_e = 0.010–0.100 s-1, which is based on processing maps and deformation microstructure observations.Fu-Lin Li Rui Fu Di Feng Zhi-Ling Tian 2015Rare Metals2015,34,1:9
16Fluorescence regional integration and differential fluorescence spectroscopy for analysis of structural characteristics and proton binding properties of fulvic acid sub-fractions显示文摘Structural characteristics and proton binding properties of sub-fractions(FA3–FA13) of fulvic acid(FA), eluted stepwise by pyrophosphate buffer were examined by use of fluorescence titration combined with fluorescence regional integration(FRI) and differential fluorescence spectroscopy(DFS). Humic-like(H-L) and fulvic-like(F-L) materials, which accounted for more than 80% of fluorescence response, were dominant in five sub-fractions of FA. Based on FRI analysis, except the response of F-L materials in FA9 and FA13, maximum changes in percent fluorescence response were less than 10% as pH was increased from 2.5 to 11.5.Contents of carboxylic and phenolic groups were compared for fluorescence peaks of FA sub-fractions based on pH-dependent fluorescence derived from DFS. Static quenching was the dominant mechanism for binding of protons by FA sub-fractions. Dissociation constants(p Ka) were calculated by use of results of DFS and the modified Stern-Volmer relationship. The p Kaof H-L, F-L, tryptophan-like and tyrosine-like materials of FA subfractions exhibited ranges of 3.17–4.06, 3.12–3.97, 4.14–4.45 and 4.25–4.76, respectively, for acidic pHs. At basic pHs, values of p Ka for corresponding materials were in ranges of 9.71–10.24, 9.62–10.99, 9.67–10.31 and 9.33–10.28, respectively. At acidic pH, protein-like(P-L)materials had greater affinities for protons than did either H-L or F-L materials. The dicarboxylic and phenolic groups were likely predominant sites of protonation for both H-L and F-L materials at both acidic and basic pHs. Amino acid groups were significant factors during proton binding to protein-like materials of FA sub-fractions at basic pH.Fanhao Song Fengchang Wu Weiying Feng Zhi Tang John P.Giesy Fei Guo Di Shi Xiaofei Liu Ning Qin Baoshan Xing Yingchen Bai 2018Journal of Environmental Sciences2018,30,12:9
17Application of chemical fractionation and X-ray powder diffraction to study phosphorus speciation in sediments from Lake Hongfeng,China显示文摘Based on the techniques of sequential extraction and X-ray powder diffraction(XRD) ,the distribution characteristics of phosphorus speciation were investigated in 13 sediment samples from Lake Hongfeng,an important drinking water source for Guiyang with a typical karstic limestone environment.The total phosphorus(TP) concentrations in the sediments ranged from 973.36 to 2334.18 mg/kg with a mean concentration of 1635.87 mg/kg(dry weight) ,and it was evident that the phosphorus level in the sediments was high compared with other eutrophic lakes such as Lake Chaohu and Lake Xihu.The results of the two methods,sequential extraction and XRD,demonstrated the presence of different phosphorus species in the lake sediments.Being compatible with local geophysical characteristics,the results of sequential extraction techniques indicate that the average percentages of dissolved phosphorus(DP) ,aluminum-bound phosphorus(Al-P) ,iron-bound phosphorus(Fe-P) ,calcium-bound phosphorus(Ca-P) and organic phosphorus(OP) in the sediments were 0.40%,7.06%,5.07%,45.48%and 38.49%,respectively.Notably,the concentrations of inorganic phosphorus(IP) were higher than those of OP,and the IP consisted primarily of Ca-P.The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable,inert and non-bioavailable phosphorus fraction.The results of XRD analysis indicated that,among phosphorus species,AlPO4 was found in all sediment samples at relatively high concentrations.Moreover,the TP concentrations in the sediments were high;thus the release potential and bioavailability of phosphorus in the sediments was important.Further statistical analyses of the results revealed significant correlations between phosphorus species in the sediments with two extractable principal components and four selectable cluster levels allowing interpretation of possible origins of phosphorus loading and transformation mechanisms of phosphorus species.Furthermore,available remediation measures were briefly assessed for the lake while considering its distinct environmental features.JIANG CuiHong WU Di HU JiWei LIU Feng HUANG XianFei LI CunXiong JIN Mei 2011Chinese Science Bulletin2011,56,20:9
18Lattice-based key exchange on small integer solution problem显示文摘In this paper, we propose a new hard problem, called bilateral inhomogeneous small integer solution(Bi-ISIS), which can be seen as an extension of the small integer solution problem on lattices. The main idea is that, instead of choosing a rectangle matrix, we choose a square matrix with small rank to generate Bi-ISIS problem without affecting the hardness of the underlying SIS problem. Based on this new problem, we present two new hardness problems: computational Bi-ISIS and decisional problems. As a direct application of these problems, we construct a new lattice-based key exchange(KE) protocol, which is analogous to the classic DiffieHellman KE protocol. We prove the security of this protocol and show that it provides better security in case of worst-case hardness of lattice problems, relatively efficient implementations, and great simplicity.WANG ShanBiao ZHU Yan MA Di FENG RongQuan 2014Science China(Information Sciences)2014,57,11:9
19Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography显示文摘Objective The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography(OCTA) based on optical microangiography(OMAG) measurements of macular vessels in normal eyes. Methods In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA(Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density(VAD), vessel skeleton density(VSD), vessel diameter index(VDI), vessel perimeter index(VPI), vessel complexity index(VCI), flux, and foveal avascular zone(FAZ). Coefficient of variation(CV) and intraclass correlation coefficient(ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. Results The measurements showed high repeatability [CVs ≤ 4.2%(intravisit) and ≤ 4.6%(intervisit)] and interobserver reproducibility(ICCs ≥ 0.923) for all parameters. Conclusion This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.ZHAO Qi YANG Wen Li WANG Xiao Na Ruikang K Wang YOU Qi Sheng CHU Zhong Di XIN Chen ZHANG Meng Yu LI Dong Jun WANG Zi Yang CHEN Wei LI Yi Feng CUI Rui SHEN Lin WEI Wen Bin 2018Biomedical and Environmental Sciences2018,31,6:8
20Improving Damping Properties and Thermal Stability of Epoxy/Polyurethane Grafted Copolymer by Adding Glycidyl POSS显示文摘Modified castor oil-based epoxy resin (EP)/polyurethane (PU) grafted copolymer by glycidyl polyhedral oligomeric silsesquioxane (glycidyl POSS) was synthesized. The damping properties, thermal stability, mechanical properties and morphology of the grafted copolymer modified by glycidyl POSS were studied systematically. The results revealed that the incorporation of glycidyl POSS improved the damping performance evidently and broadened damping temperature range, especially when the glycidyl POSS content was0.2%–1%. At the same time, there was a slight increase in thermal stability with the increase of POSS content. The tensile properties changed with the change of the copolymer's Tg, decreased at low POSS contents and increased at high POSS contents. This modified copolymer has the potential to be used as film damping material or constrained damping layer.Ge-Liang Zhu Di Han Ye Yuan Feng Chen Qiang Fu 2018Chinese Journal of Polymer Science2018,36,11:8
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