115 research outputs found

    Demonstrating the News by Talking ——Theory Study of the Communication Way with the TV News Talk show

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    本文以央视《新闻会客厅》、《面对面》和《央视论坛》三个栏目为主要个案对象,同时关注凤凰卫视的相关节目,在此基础上从理论范畴深入探讨新闻谈话节目传播方式的相关问题。论文首先探讨了大众传媒上涌现人际传播方式的时代背景,主要归纳了四个因素的推动作用:民主步伐不可遏抑、社会的后现代与平民化、社会变革、市场经济与媒体改革。论文接下来分析了大众传媒引入人际传播方式的媒介基础,并分析了电视谈话节目相比于广播谈话节目的优势。第三章就目前涌现的主要新闻谈话节目进行细分,主要分为三类:聊天座谈式、人物专访式和分析辩论式。文章关注人际交流方式对于电视新闻的价值:深入挖掘新闻信息,改变新闻传播面貌,提升新闻传播效果。...With News reception room , Face-to-face and CCTV forum of CCTV three main case target, pay close attention to the relevant programs of Phoenix Satellite TV at the same time, this thesis probe into the relevant problems of the communication way of the news talk show from the theory category thoroughly. The thesis probe into the era background of the way of interpersonal communication eme...学位:文学硕士院系专业:人文学院新闻传播系_新闻学学号:20023204

    供给侧结构性改革背景下我国劳动力市场改革研究

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    供给侧结构性改革背景下我国劳动力市场改革面临的困境(一)现行《劳动合同法》因保护企业不够而降低国内产业竞争力1.对企业权益保护缺位,增加企业劳动力成本。第一,从国际比较看,企业权益保护不足。根据OECD对全球72个国家的测算,我国对非临时职工的保护排名第二,仅次于委内瑞拉。第二,从立法层面看,企业权益保护不足。《劳动合同法》第37条将提前通知作为劳动者主动解除合同的充分条件,使关于劳动者责任的内容丧失约束

    Preparation and permeation characteristics of PVA/PEG/TEOS hybrid membranes

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    以聚乙烯醇(PVA)与聚乙二醇(PEG)共混,并与正硅酸乙酯(TEOS)进行交联反应制备杂化膜。FTIR证实杂化溶胶液发生交联反应形成共价键Si—O—C,WXRD观察表明加入TEOS改变了膜结晶度,加入PEG提高了PVA膜对乙醇/水溶液的渗透通量,但分离因子下降,随着TEOS的加入,膜的分离因子提高。在TEOS质量分数为10%时,杂化膜的分离因子达到最大。提高退火温度可以提高膜的分离因子,但通量下降。在100℃下退火12 h的杂化膜对乙醇质量分数为85%的乙醇/水溶液的分离性能最佳。Poly(vinyl alcohol)(PVA) was mixed with poly(ethylene glycol)(PEG) and then cross-linked by tetraethoxysilane (TEOS) to prepare organic-inorganic hybrid membranes.Fourier transform infrared spectroscopy(FTIR) proved that covalent bond Si—O—C was formed in the hybrid membranes.Wide-angle X-ray diffraction(WAXD) was used to observe the effect of TEOS and annealing on crystallinity.The hybrid membranes were tested in separation ethanol/water mixture by pervaporation.The effect of PEG,TEOS content and annealing temperature on the PVA hybrid membrane performance was discussed.The addition of PEG increased the PVA membrane flux,but its selectivity decreased.Water permselectivity increased with the addition of TEOS into the PVA/PEG membrane.The hybrid membrane exhibited the highest water permselectivity when TEOS mass fraction was 10%.Water permselectivity increased by increasing the annealing temperature,but permeation flux decreased at the same time.The hybrid membrane separation performance was best for pervaporation of water/ethanol(85%mass fraction of ethanol) mixture when annealing at 100 ℃ for 12 h.国家自然科学基金资助项目(50573063);; 高等学校博士点专项基金资助项目(20050384013

    香溪河小水电的梯级开发对浮游藻类的影响

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    以香溪河干流上5个连续的小水电站为对象,于2005年10月20—22日分别对其浮游藻类和主要理化指标进行研究.结果表明:硅藻占绝对优势(95.54%),其中,线性曲壳藻(Achnanthes linearis)、披针曲壳藻椭圆变种(A.lanceolatavar.elliptica)、扁圆卵形藻(Cocconeisplacentula)为绝对优势种,其平均相对丰富度分别为23.96%、18.62%和12.48%;所有样点的平均藻类密度为6.29×105ind.L-1,最高为1.81×106ind.L-1

    Advances in inorganic particle filled polymeric membranes

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    [中文文摘]根据有机、无机组分间相互作用类型对有机-无机杂化膜进行了分类,重点论述了无机粒子填充型有机-无机杂化膜的最新研究进展,归纳了此类杂化膜的优异性能,总结了无机粒子的物理化学性能、含量、尺寸及其与聚合物的相容性等因素对此类杂化膜结构和性能的主要影响。最后提出了目前研究中存在的一些问题,并对其发展做出了简要的述评。[英文文摘]Hybrid organic-inorganic membranes are being classified according to the links between the organic and inorganic components ,the advances in inorganic particles filled polymeric membranes are reviewed emphatically. The superior properties of this kind of hybrid membranes are briefly discussed and some influencing factors such as physical and chemical properties ,content ,size of inorganic particles and its compatibility with polymers on the morphology and characteristics of the hybrid membranes are illustrated. Finally , some problems which existed in the present research are pointed out and a brief comment on their development is given.国家自然科学基金项目(50573063);高等学校博士点专项基金项目(20050384013

    An Electrochemical Study of DDTC Adsorption Jamesonite

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     通过循环伏安法、交流阻抗法研究了二乙基二硫代氨基甲酸钠(以D表示)与脆硫锑铅矿的相互作用.在不同的电位条件下呈现出不同的电极过程.从-178~472mV(相对于标准氢电极),脆硫锑铅矿表面主要是DDTC,PbD2,S0等疏水性物质的吸附,界面电容也比较小.当电极电位高于472mV时,由于PbD2,S0等疏水性物质被氧化成Pb2+,SO32-,SO42-,PbSO4等亲水性产物,脆硫锑铅矿表面是亲水的.由此推测用DDTC做捕收剂浮选脆硫锑铅矿的电位范围为-178~472mV,最佳电位范围为60~222mV.The interactions of jamesonite with diethyl dithiocarbamate (DDTC) were studied by AC impedance measurement and cyclic voltammetry. Several electrode processes under different potential conditions were observed. There mainly is the absorption of hydrophobic DDTC. PbD_2, S~0 etc on the surface of jamesonite mineral from -178 mV to 472 mV (vs. SHE) and the interfacial capacitance also is small. When the electrode potential is over 472 mV, the surface of jamesonite mineral is of hydrophilicity due to the fact that hydrophobic PbD_2,S~0 etc are oxidized into hydrophilic products such as Pb~(2+), SO_3~(2-) ,SO_4~(2-), PbSO_4. So it was deduced that the potential range of jamesonite flotation using diethyl dithiocarbmate as a collector is from -178 mV to 472 mV, and its optimum potential range is between 122 mV and 222 mv due to the passive action by the hydrophobic species.作者联系地址:中南大学资源加工与生物工程学院,中南大学资源加工与生物工程学院,中南大学资源加工与生物工程学院,中南大学资源加工与生物工程学院 湖南长沙410083 衡阳师范学院化学与材料科学系湖南衡阳421008 ,湖南长沙410083 ,湖南长沙410083 ,湖南长沙410083Author's Address: *1,2, HU Yue-hua~1, QIU Guan-zhou~1, QIN Wen-qing~1 1.School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China 2.Department of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, Chin

    暴露测年样品中26Al和10Be分离及其加速器质谱测定

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    在已有实验流程基础上,建立并优化了石英样品中Be和Al提取、纯化等实验流程,设计的流程条件实验包括实验试剂、器皿和离子交换柱选择、离子交换树脂分离Be和Al时酸浓度选择等。结果表明,选择钢铁研究总院研制的~9Be标准溶液作为~(10)Be样品制备的载体;使用一次性实验器皿;选用4 cm规格的离子交换柱;用0.05 mol/L草酸和0.75 mol/L盐酸混合溶液洗脱吸附于阴离子树脂上的Al,可有效提取、纯化样品中的Be和Al。加速器质谱(AMS)测量结果显示,13组化学空白的~(10)Be/~9Be和~(26)Al/~(27)Al比值平均值分别为7.48×10~(-15)和1.96×10~(-15),与国内已有宇宙成因核素实验室的结果(5×10~(-15)~8×10~(-15))具有可比性。电感耦合等离子体发射光谱(ICP-AES)的测量结果表明,Be、Al回收率分别达90%和60%。基于新建立的实验流程分析了祁连山北侧金佛寺的一个岩石样品,获得了~(10)Be和~(26)Al的暴露年代分别为(10.7±1.0)ka和(10.0±1.2)ka,与前人研究结果一致

    改良分子信标-双重实时荧光PCR快速检测SARS病毒

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    目的建立改良分子信标-双重实时荧光PCR检测SARS病毒的方法,用于SARS的早期诊断和动物溯源。方法利用改良分子信标技术、装甲RNA和双片段双色荧光技术,根据GenBank公布的SARS病毒聚合酶基因1b的阅读开放框架结构的保守序列,自行设计一对引物和探针,以部分临床标本的酶联吸附实验结果和传统细胞培养方法作为对照,建立分子信标检测SARS病毒的方法。对368份临床标本(咽漱液、血液、粪便、尿液)、52份细胞培养液和50份动物标本进行荧光PCR扩增。结果分子信标检测SARS病毒的方法灵敏度为10~100个拷贝ml,与流感病毒等呼吸道病毒无交叉反应。分子信标检测368份临床标本,20份阳性。其中确诊病例阳性率为21.27%(1047),确诊病例的咽漱液阳性率为43.48%,还分别从粪便和血清中检测到SARS病毒。52份细胞培养液,29份阳性,阳性率为55.77%。50份动物标本,23份阳性,阳性率为46%。结论改良分子信标-双重实时荧光PCR检测SARS病毒方法灵敏度高、特异性强,可用于SARS的临床早期诊断和动物溯源

    Constraint of a ruthenium-carbon triple bond to a five-membered ring

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    含过渡金属碳三键(M≡C)的金属卡拜化合物是许多有机反应的催化剂或关键中间体。对其合成及性质的研究是金属有机化学的热点之一。由于卡拜碳的sp杂化方式,大部分金属卡拜化合物均为链状结构(卡拜碳键角理想值为180 °),环内金属卡拜化合物因存在很大的环张力而难于合成。夏海平教授课题组发展了由链状多炔(称之为碳龙)构筑碳龙配合物的高效方法(Nature Communications, 2017, 8, 1912),实现了锇杂戊搭炔/烯及其衍生物的一锅法合成。现在,他们把该方法进一步拓展到了第二过渡系金属钌,通过碳龙与市售的RuCl2(PPh3)3反应一锅合成了钌杂戊搭炔I。本研究是碳龙化学的进一步延伸和发展,首次把碳龙化学的金属中心由锇拓展到了其它金属,展示了碳龙化学广阔的发展空间。该研究工作在夏海平教授指导下完成,能源材料化学协同创新中心(iChEM)博士后卓庆德和张弘副教授为共同第一作者。iChEM博士后周小茜、博士生陈志昕、林剑锋、卓凯玥、硕士康慧君、林鑫磊参与了部分实验工作。博士生华煜晖负责理论计算。【Abstract】The incorporation of a metal-carbon triple bond into a ring system is challenging because of the linear nature of triple bonds. To date, the synthesis of these complexes has been limited to those containing third-row transition metal centers, namely, osmium and rhenium. We report the synthesis and full characterization of the first cyclic metal carbyne complex with a second-row transition metal center, ruthenapentalyne. It shows a bond angle of 130.2(3)° around the sp-hybridized carbyne carbon, which represents the recorded smallest angle of second-row transition metal carbyne complexes, as it deviates nearly 50° from the original angle (180°). Density functional theory calculations suggest that the inherent aromatic nature of these metallacycles with bent Ru≡C–C moieties enhances their stability. Reactivity studies showed striking observations, such as ambiphilic reactivity, a metal-carbon triple bond shift, and a [2 + 2] cycloaddition reaction with alkyne and cascade cyclization reactions with ambident nucleophiles.This research was supported by the National Key R&D Program of China (2017YFA0204902) and the National Natural Science Foundation of China (nos. 21490573,21332002, and 21561162001). 研究工作得到国家自然科学基金项目(21490573、21332002 和21561162001)和国家重点研发计划(2017YFA0204902)的资助
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