论新闻与公共关系

新闻与公共关系从一开始就是既相互依存又相互对立的。从实务界到学界,关于新闻与公共关系二者应该互斥还是合作的争论持续了多年。然而,从现实以及未来发展趋势看,随着现代社会组织化程度的不断加深,记者和媒体对作为消息源的组织依赖也日益加深,公共新闻学理论和现代公关理念的渐行渐近,使新闻与公共关系的合作成为必然。新闻与公共关系都是社会的润滑剂。告知真相、建构社会,正在成为新闻和公共关系的共同目标

我国上市公司股利政策与股市波动的实证研究

从实证的角度分析了中国上市公司的年度股利公告对股票价格的影响 ,运用的研究方法是事件研究法。研究结果表明 ,三种不同的股利分配形式都可以引起股价的异常反应 ,相对于现金股利而言 ,市场更加欢迎股票股利和混合股利 ,而股票股利和现金股利之间的差异并不显

中国股市季节效应实证分析

本文运用标准的K-S非参数检验和虚拟变量回归的方法 ,利用1993年至2003年的股指数据 ,从三个层次(月份 /季度 /半年度)对我国沪深股市的季节效应进行了较为全面的分析和检验。研究结果表明 ,上海市场存在着较为显著的季节效应 ,而深圳市场的季节效应并不明显。研究还发现 ,沪深两市均存在较为显著的“十二月份效应”,这与中国股市特殊的政策和市场背景是分不开的。季节效应的存在 ,从一个角度反映了我国股市运行的低效率 ,这在上海股市表现得更为明显

上市公司股利政策与股市波动的实证研究

运用事件研究法从实证的角度分析了中国上市公司的年度股利公告对股票价格的影响 ,研究结果表明 ,三种不同的股利分配形式都可以引起股价的异常反应 ,相对于现金股利而言 ,市场更加欢迎股票股利和混合股利 ,而股票股利和现金股利之间的差异并不显著

中国股市季节效应实证分析

运用 K- S非参数检验和虚拟变量回归的方法 ,利用 1993年至 2 0 0 3年的股指数据 ,对我国沪深股市的季节效应进行分析和检验。研究结果表明 ,上海市场存在着较为显著的季节效应 ,而深圳市场的季节效应并不明显。研究还发现 ,沪深两市均存在较为显著的“十二月份效应”,这与中国股市特殊的政策和市场背景是分不开的。季节效应的存在 ,从一个角度反映了我国股市运行的低效率 ,这在上海股市表现得更为明

湖泊底泥中微囊藻DNA的分子检测

通过改进裂解温度和延长裂解时间并增加苯酚/氯仿洗脱次数的DNA提取方法获得南京玄武湖底泥中的DNA,通过PCR法来扩增微囊藻的16SrRNA基因．结果表明在所有采样点中均得到微囊藻基因组DNA,并且纯度较高,OD_(260)/ OD_(280)均高于1．54,最高值达到1．89．PCR的扩增结果显示所有样点的DNA都得到212 bp大小的微囊藻16SrRNA基因片断,表明这种方法可以有效的从底泥中提取微囊藻的DNA,从而为研究底泥微囊藻生理生态及其越冬、上浮、形成水华的机理提供更有利的方法

An Analysis of Optimum Pulse Shaping Filter in Time-Discrete Multipath Rayleigh Fading Channels

This paper concerns with an optimal pulse shaping filter in time-discrete multipath Rayleigh fading environment. The shift orthogonal pulse shaping filter is proposed and proved to be the optimal envelope in the sense of least average bit error probability. It is suited to the Rayleigh fading channel with an arbitrary strength/delay profile of multiple time-discrete paths for BPSK and QPSK signaling etc. Numerical results show that shift orthogonal waveform based pulse shaping filter has lower bit error rate than general shaping waveforms such as square root raised cosine (SRRC) waveform

Development and application of CK-MB specific monoclonal antibodies

本研究拟建立肌酸激酶同工酶MB(CK-MB)特异性单克隆抗体(mAb)的研制方法,对抗CK-MB单抗进行评价分类及性质鉴定,并初步建立CK-MB; 定量检测试剂。以CK-MB抗原免疫BALB/c小鼠,利用常规单抗制备技术,使用间接和捕获ELISA差异筛选法筛选单抗。利用肌酸激酶同工酶(CK-; MM/BB/MB)抗原对所制备单抗的抗原识别表位进行鉴定,另通过免疫印迹法及合成CK-MM、CK-BB差异性的线性表位肽鉴定对所制备的单抗进行评; 价分类。使用双抗体夹心ELISA方法筛选检测CK-MB抗原的配对mAb,并初步建立CK-MB定量检测试剂。使用74例临床标本初步评价该试剂与罗氏; 试剂的检测一致性。最终,我们成功筛选到22株稳定分泌抗CK-MB抗体的杂交瘤细胞株,这些单抗可以分为线性、偏构象的CK-MB和CK-MM或者CK; -BB交叉的单抗以及与CK-MB特异反应的偏构象型单抗,并使用偏构象型单抗研制出CK-MB定量检测试剂,该试剂与罗氏试剂相关系数r达到0.930; 9。综上所述,本研究建立了研制CK-MB偏构象型特异性单抗的筛选方法,通过对所筛选的单抗进行分析鉴定并建立了CK-MB定量检测试剂,与罗氏试剂检; 测结果符合率高。The aim of this study is to develop creatine kinase isoenzyme MB (CK-MB); specific monoclonal antibodies (mAb), and characterize the monoclonal; antibody and further development of quantitative detection assay for; CK-MB. The BALB/c mice were immunized with purchased CK-MB antigen, then; monoclonal antibodies were prepared according to conventional hybridoma; technique and screened by indirect and capture ELISA method. To identify; the epitopes and evaluate the classification, purchased creatine kinase; isoenzyme MB (CK-MM/BB/MB) antigen was used to identify the epitopes,; with immunoblotting and synthetic CK-MM and CK-BB in different linear; epitope. A double antibody sandwich ELISA was applied to screen the mAb; pairs for CK-MB detection, and the quantitative detection assay for; CK-MB was developed. We used 74 cases of clinical specimens for; comparison of our assay with Roche's CK-MB assay. We successfully; developed 22 strains of hybridoms against CK-MB, these mAbs can be; divided into linear, partial conformational CK-MB, CK-MM or CK-BB cross; monoclonal antibody and CK-MB specific reaction with partial; conformational monoclonal antibody, and CK-MB quantitative detection; assay was developed by using partial conformational monoclonal antibody.; The correlation coefficient factor r of our reagent and Roche's was; 0.930 9. This study established a screening method for CK-MB partial; conformational specific monoclonal antibody, and these monoclonal; antibodies were analyzed and an established quantitative detection assay; was developed. The new assay had a high concordance with Roche's.厦门市科技计

Preparation and Electrochemical Lithium Intercalation Performance of Segmented Carbon Nanofibers

以泡沫镍为催化剂 ,在 6 0 0和 70 0℃下 ,以CVD法热解乙炔气体制备大量的纳米碳纤维 .随着制备温度增加 ,纳米碳纤维直径变小 ,竹节状含量减少 ,d0 0 2 值减小 ,微晶片层平面Lc 和La 值增大 ,碳材料的可逆容量则下降 .分别用透射电镜、X射线衍射和拉曼光谱观察和测定了纳米碳纤维的形貌、微结构 ,发现在不同条件下生长的纳米碳纤维有不同的形貌和结构 .对纳米碳纤维的电化学嵌锂性能的研究表明 ,纳米碳纤维的结构对其电化学嵌锂容量和充放电循环寿命起重要影响 ,制备温度越低 ,纳米碳纤维的石墨化程度越差 ,可逆嵌锂容量相应要高一些Segmented carbon nanofibers were prepared by pyrolysis of acetylene on foam Ni at 600 and 700℃ in a fixed bed flowed-reactor. The morphology, microstructure and lithium insertion properties of these carbon nanofibers were investigated by TEM, XRD, Raman and electrochemical methods. Through TEM observations, it was found that this kind of carbon nanofibers was composed of lens-like segments with nearly equal separation stacking along the nanofiber axis. When the reaction temperature was 600℃, segmented carbon nanofibers were the major production. However, when the reaction temperature increased to 700 ℃, the content of segmented carbon filaments decreased and their diameter became smaller. The crystallite size d 002 and L c were determined by the 002 carbon Bragg peak of XRD patterns using the Bragg and Scherrer formulas. The intensity ratios of the 1350 cm -1 line and the 1580 cm -1 line (R=I D/I G) was used to evaluate the L a value, which was inversely proportional to the effective crystallite size in the direction of the graphite plane (L a). With the reaction temperature increased, the d 002 value decreased, L a and L c values increased, which indicated the degree of crystallinity increased. Segmented carbon nanofibers were used as positive electrodes of C/Li cells. The first charge capacities of C/Li cells were 480 and 300 mAh/g for samples produced at 600 and 700℃, respectively. The samples at 600℃ showed capacities higher than the theoretical value of graphite, which was attributed to accommodation of more lithium at the edge of graphene layers and on the surface of graphene layers according to the mechanisms of lithium insertion in carbons prepared by low-temperature pyrolysis of hydrocarbons. As confirmed by the XRD and Raman spectra, the samples at 700℃ had larger L a and L c, which led to the capacity decreasing.国家自然科学基金 (6 0 2 710 0 9);; 浙江省自然科学基金 (5 0 110 9,2 0 0 0 5 3)资助项

戊型肝炎病毒基因1型和基因4型中和表位区域分子差异研究

戊型肝炎病毒(HEV)根据易感宿主的差别可以分为两大类:一类只分离自人的H(Human)类,包括HEV-1和HEV-2;一类为人畜共患的Z(Zoonosis)类,包括HEV-3和HEV-4。本研究通过比较这两类HEV的ORF2aa368~606区段,发现存在4个类保守的差异位点,均位于HEV的主要中和表位区域aa459~606,分别是aa483、aa492、aa497和aa599;对这四个位点进行定点替换突变,以一组能够捕获HEV-1和/或HEV-4的单克隆抗体比较各种突变体的免疫反应性,结果表明仅aa497的差异造成了这两类HEV中和表位构象的部分差异,提示aa497及其相关的病毒表面结构差异在H类和Z类HEV宿主选择中可能扮演重要角色