882 resultados para 1.95 GeV Kr ions


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A facile and efficient synthetic route towards; highly substituted isothiazol-3(2H)-ones 2 from readily available U.-carbamoyl ketene-S,S-acetals 1 is presented. The key step features the formation of an N-acylnitrenium ion, generated from the oxidization of substituted amides with the hypervalent iodine reagent phenyliodine(III) bis(trifluoroacetate) (PIFA), and its succeeding intramolecular amidation to form a new N-S bond affording the title compounds.

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A method is developed to estimate the coverage of an electropolymerizable aniline-analogue monolayer (mixture of 2- and 3-aminophenols, 2/3-ATP) by measuring the charge capacitance of the electrode (theta = 81%). The technique of filling the uncovered area (defect sites) of the aniline-analogue monolayer with alkanethiols with long alkane chains (1-decanethiol, 1-DT) has been used to determine the coverage. The dielectric constant (permittivity) of the PANI-analogue monolayer was determined to 8.4. Adsorption kinetics of 1-DT was also studied, and the value of the rate constant of the secondary adsorption was measured to 0.9 mol(-1) dm(3) s(-1).

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聚丙烯和三元乙丙橡胶(EPDM)的γ辐射效应及辐射后的聚丙烯熔体流动速率的测定表明,在限 定空气中聚丙烯随着辐照剂量的增加,熔体流动速率急剧下降,而三元乙丙橡胶随辐射剂量的增加,凝胶含量 逐渐增加。在20kGy的剂量辐照下,凝胶含量为22.7%,加入2%的三聚异氰酸三烯丙酯,在相同的剂量辐 照下,凝胶含量达到68%。在低剂量下辐照对共混物的拉伸强度影响不大,对冲击强度有很大的影响。在20 kGy的剂量辐照下,加入50%EPDM的聚丙烯的缺口冲击强度由1.95 kJ/m2提高到30 kJ/m2,维卡软化温度 由85.9℃提高到97.0℃。

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用反应挤出法在聚丙烯 (PP)分子链上接枝甲基丙烯酸环氧丙酯 (GMA) ,制备功能化聚丙烯 .重点讨论了单体浓度、引发剂浓度、反应温度及物料在螺杆中的停留时间等对接枝产物 PP-g-GMA的接枝率、接枝效率和熔体流动速率的影响 .结果表明 ,PP-g-GMA接枝率与加入的单体浓度成正比 ,与引发剂浓度无关 ,反应挤出的适宜温度窗口在 1 95~ 2 3 0℃之间 ,停留时间超过 1 min后接枝率与停留时间无关 ;PP-g-GMA的熔体流动速率与单体浓度成反比 ,与引发剂的用量成正比 ,在反应温度窗口内与反应挤出温度和物料停留时间关系不大 ;单体和引发剂的浓度、反应挤出温度及物料停留时间对 PP-g-GMA的接枝效率无显著影响 .

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The conformational transition of horse heart cytochrome c induced by bromopyrogal red (BPR) in very low concentration has been firstly investigated by dynamic spectroelectrochemical technique, both at the BPR adsorbed platinum gauze electrode and at a bare platinum gauze electrode in a solution containing BPR. The effect of BPR on the structure of cytochrome c was studied by UV-visible and Fourier transform IR spectroscopy. The unfolded cytochrome c behaves simply as an electron transfer protein with a formal potential of -142 mV vs. a normal hydrogen electrode. The difference between the formal potentials of the native and unfolded cytochrome c is coupled to a difference in conformational energy of the two states of about 40 kJ mol(-1), which agrees well with the result reported. The stability and slow refolding of the unfolded cytochrome c are discussed.

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用ESR定量法研究了聚乙烯醇胺肟螯合纤维吸附铜(Ⅱ)离子的吸附反应动力学.为研究吸附反应动力学提供了新方法.并证实该螯合纤维的吸附性能较好.

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80年代出现的光活性高聚物—聚甲基丙烯酸三苯甲酯(PTrMA)是由非手性单体经不对称阴离子聚合得到的。近年来,PTrMA作为手性固定相在分离手性化合物方面得到了越来越多的实际应用。由于聚合物侧基上的三个苯基产生的大位阻,使它具

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本文研究了HPMBP与伯胺N_(1923)的二甲苯溶液,从盐酸介质中协同萃取希土(Ⅲ)的机理。用斜率法、恒摩尔法确定了协萃配合物的组成为:RNH_3Ln(PMBP)_4。求得关于Pr(Ⅲ)协萃反应的平衡常数及协萃配合物的生成常数分别为:logK_(12)=-1.95;logβ_(12)=3.94。实验发现,协萃系数(R)随希土元素的原子序数(Z)递变而呈现“双峰效应”。还研究了协萃配合物的IR,NMR谱。

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稀土体系三种元素同时分离的工艺最近已有发表,但非稀土方面的工作尚未见报导.对Cu、Co、Ni三种元素,通常是将Cu、Co作为一个组份与Ni分离.本工作对组成为Cu:Co:Ni=1:1:1的水相合成料液设计了两种工艺,进行了串级实验,实现了该三种元素的同时分离, 串级实验以HEH(EHP)作萃取剂,煤油为稀释剂,其它试剂均用分析纯.

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为了进一步完善裙带菜单倍体克隆(简称单克隆,以下同)育苗技术,实现该技术的产业化,本文对单克隆的快速扩增以及育苗条件进行了优化研究。获得如下结果:一、光对裙带菜排卵的干扰现象:一般附苗后4-5天雌雄配子即已形成。接近成熟的卵囊细胞翘起,长度达到50-55μm,直径为19-20μm,一到两天后即可排卵。精子囊略透明,颜色微绿。在11:13(L:D)的光周期下,排卵一般在黑暗开始后5分钟即已开始,5-15分钟后达到高峰。排卵的过程只有几秒钟。卵排出后停留在卵囊开口处,仍与卵囊牢固相连。虽然排卵过程只有几秒钟,一旦这个过程受到光的干扰,就会诱导卵脱离卵囊。实验证实,5-6μmol m~(-2)s~(-1)的微弱光强(显微镜下镜检的光强)即能引起95%的卵从卵囊脱落。根据我们的观察,一旦卵已排出并与卵囊相连,将不再受光的干扰而脱落。脱落的卵很快死亡分解。将配子已经形成但尚未释放的培养转移至连续光下以后,卵仍能排放,但排出的卵大部分脱落(75%),进一步说明了光对排卵的干扰作用。在育苗实践中,为了方便工作,育苗车间内在天黑后的2-3小时内仍有照明,而在第二天早晨取样观察,就会发现许多空的卵囊。我们的实验证实了这是由于排卵过程受到光的干扰引起的。因此,在育苗实践中,为了提高出苗率,在出苗期间,天黑后2-3小时内育苗车间内应避免照明,以降低光导卵的脱落。二、单克隆快速扩增以及育苗条件的优化:(一)、单克隆快速扩增的优化。实验结果表明:1、单克隆快速生长的适宜光照强度为80-120μmol m~(-2)s~(-1)。单克隆的培养密度宜控制在1-10g/L。接种密度以1g/L为宜。2、单克隆藻体内能贮藏氮,因此在单克隆快速扩增过程中,可采用间歇施肥法补充氮源。实验证明,培养液中氨态氮的适宜浓度为20μmol/L,可维持单克隆6天的生长之用(单克隆培养密度1-10g/L)。3、实验证明,在65天内,“老水”对单克隆的生长没有明显的抑制作用。而且,PES培养基除氮的其它成分也可满足单克隆65天的生长需求。4、单克隆快速生长的适宜温度为22 ℃。另外,单克隆密度与消光值之间存在着线形关系,可以通过测量消光值来计算单克隆的培养密度和鲜重,以代替称量法测鲜重。综上,可提出如下单克隆快速扩增的模式:温度为22 ℃;初始光强控制在80-120 μmol m~(-2)s~(-1);单克隆的接种密度为1g/L;PES培养基(除去氮的成分)可供单克隆65天的培养之用,在这65天内,每隔六天左右将初始氨态氮补充至20 μmol/L;单克隆的培养密度控制在1-10g/L;单克隆培养密度和鲜重可通过测量消光值计算得到。依以上模式,并及时进行扩养,单克隆的鲜重平均日增长率可达25%,以此增长率计算,10g单克隆经一个月培养后鲜重可达8070克,可培育苗帘2000多个,实现海面养殖1000多亩,达到了生产性育苗的要求。(二)、单克隆育苗条件的优化 根据实验结果,可采取如下的育苗优化措施:1、光对排卵有干扰作用。因此,在出苗期间,在天黑后2-3小时内,育苗车间内应避免照明,以降低光导的卵子脱落。2、1μmol/L磷(PO_4~(3-) -P)和70 μmolm/L氮(NH_4~+-N)有利于加速出苗。3、铁对配子体的发育有明显的促进作用。2.5μmolm/L的Fe(III)能使出苗时间提前1-2天,出苗率增加15%左右。4、单克隆育苗较适宜的温度为17 ℃。依以上条件,4-5天左右即可出苗,比一般出苗时间提前1-2天。出苗率也有所增加,例如在实验室条件下,出苗率由原来的50-60%增至80-90%,增加了30%左右。本项研究进一步完善了裙带菜单克隆育苗技术,将大大有利于该技术的进一步推广。

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The inventories of nutrients in the surface water and large phytoplankton( > 69 pm) were analyzed from the data set of JERS ecological database about a typical coastal waters, the Jiaozhou Bay, China, from 1960s for N, P and from 1980s; for Si. By examining long-term changes of nutrient concentration, calculating stoichiometric balance, and comparing diatom composition, Si limitation of diatom production was found to be more possible. The possibility of Si limitation was from 37% in 1980s to 50% in 1990s. Jiaozhou Bay ecosystem is becoming serious eutrophication, with notable increase of NO2-N, NO3-N and NH4-N from 0.1417 mumol/L, 0.5414 mumol/L, 1.7222 mumol/L in 1960s to 0.9551 mumol/L, 3.001 mumol/L, 8.0359 mumol/L in late 1990s respectively and prominent decrease of Si from 4.2614 mumol/L in 1980s to 1.5861 mumol/L in late 1990s; the nutrient structure is controlled by nitrogen; the main limiting nutrient is probably silicon; because of the Si limitation the phytoplankton community structure has changed drastically.

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墨江金矿床厂组中下段硅质岩具有典型的沉积构造,岩石富集∑Fe和As 、Sb、Bi、Ga等微量元素(相对于地壳克拉克值),而相对贫AI2O3;稀土元素以总量(∑REE)低,负铈异常为特征,与热水沉积的硅质岩特征相似。在判别硅质岩形成与作用的一系列主量和微量元素图解上,本区的硅质岩位于热水沉积作用范围,但四十八两山段硅质岩有趋近于正常化学沉积作用。利用硅质岩的氧同位素计算出它的形成温度为128-146℃。地质、地球化学特征表明本区硅质岩的形成与热水沉积作用有关,但四十八两山段硅质岩受到正常化学沉积作用的影响。

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汞是一种有毒的人体非必需重金属元素,是一种全球性污染物。大气在全球汞生物地球化学循环中占极其重要的地位,20世纪80年代末和90年代初,在没有人为和自然汞污染源的北欧和北美偏远地区的大片湖泊中发现的鱼体高甲基汞负荷就是由人为排放的汞通过大气长距离迁移后的沉降造成的。我国被认为是全球汞排放最多的国家,大量的汞排放到大气中势必会造成不同形态大气汞浓度以及大气汞沉降通量的升高,然而就目前而言,国内关于长时间分辨率的大气汞分布规律及汞沉降通量的系统研究还比较缺乏。 2005年5月到2007年5月,采用高时间分辨率大气自动测汞仪、镀KCl石英扩散管和颗粒汞微型捕汞管对贡嘎山地区大气中的气态总汞(TGM)、活性气态汞(RGM)和颗粒汞(TPM)进行了为期2年的系统监测;同时,系统的采集分析了贡嘎山地区的大气降水、植物叶片和河流水体样品,对大气汞的干、湿沉降进行了研究,并初步探讨了贡嘎山地区汞的输入和输出。主要得到以下结论: (1) 贡嘎山大气本底站两年的大气气态总汞的几何平均浓度为3.94±1.16 ng m-3,显著高于欧洲和北美同类型地区的大气气态总汞浓度,但和亚洲一些同类型地区的监测结果较为一致;和国内城市等受人为污染区域的大气气态总汞浓度相比,贡嘎山的浓度明显偏低,但略高于长白山大气本底站的气态总汞年均浓度。以上说明,贡嘎山地区的监测结果基本上反映了亚洲特别是我国西南偏远地区的大气汞的含量水平,说明我国人为活动的汞排放,已经造成了一定程度的大气汞污染。 (2) 活性气态汞和颗粒汞表现出和气态总汞不一致的分布特征,贡嘎山地区的活性气态汞平均浓度为6.2±3.9 pg m-3,颗粒汞的平均浓度为30.7±32.1 pg m-3,分别占到大气总汞的0.2%和0.8%,和国外偏远地区的研究结果一致。而活性气态汞和颗粒汞较高的沉降速率和较短的大气迁移距离是导致活性气态汞和颗粒汞偏低的主要原因。 (3) 贡嘎山不同功能区(特别是取暖季节)的大气气态总汞浓度明显高于全球背景区的平均浓度,且具有显著的空间分布特征:城区(8.63~22.5 ng m-3)>乡镇(4.74 ng m-3)>村落(2.55~8.83 ng m-3)>区域参照点(1.65~3.57 ng m-3)。 (4) 西南地区较高的汞释放背景是贡嘎山地区大气气态总汞偏高的一个重要原因;另外,石棉地区的金属冶炼活动、城市等人口集中地区的汞释放是造成该地区大气气态总汞浓度升高的区域性污染源。 (5) 气态总汞和颗粒汞表现出冬季>秋季>春季>夏季的季节性分布规律,而活性气态汞的季节性分布规律为春季>秋季>夏季>冬季。影响气态总汞和颗粒汞季节性变化的因素有释放源强度、气象条件(特别是风向)、光化学反应和干沉降速率的季节性变化;而活性气态汞的季节性变化则可能与大气光化学反应速率以及湿沉降的季节性变化有关。 (6) 贡嘎山地区海拔1600米和3000米空旷处的大气降水的湿沉降通量分别为9.1和26.1 μg m-2 yr-1,而森林地区的湿沉降通量可达57.0 μg m-2 yr-1;贡嘎山地区大气汞的干沉降通量51.9 μg m-2 yr-1,其中约15.9 μg m-2 yr-1(31 %)来自于植物落叶的沉降。 (7) 贡嘎山地区是大气汞的汇,仅泸定县的年均大气汞净沉降量就达142 kg yr-1,且绝大部分(>95%)进入了森林生态系统,而非森林地区的大气汞输入和输出则基本平衡。

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A column method was developed to conveniently and reliably determine the soil organic partition coefficients (K-oc) of three insecticides (methiocarb, azinphos-methyl, fenthion), four fungicides (triadimenol, fuberidazole, tebuconazole, pencycuron), and one herbicide (atrazine), in which real soil acted as a stationary phase and the water solution of pesticide as an eluent. The processes of sorption equilibrium were directly shown through a breakthrough curve(BTC). The log K-oc values are 1.69, 1.95, 2.25, 2.55, 2.69, 2.67, 3.10, and 3.33 for atrazine, triadimenol, methiocarb, fuberidazole, azinphos-methyl, tebuconazole, fenthion and pencycuron, respectively.

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IQ Structure, Psycholinguistic and Visual-motor Abilities Study on Children Learning Disability TONG Fang Directed by professor Zhu Liqi (Developmental and educational psychology) ABSTRACT Objective To comprehensive analyze the IQ structures, and relationships among IQ, psychometric characteristics and visual-motor integration on children disability. At same time, to probe into the family factors that influenced IQ, psycholinguistic abilities and behavior of LD children. Method (1) Downloading the papers on children learning disability from www.cqvip.com and www.wanfangdata.com, in which, the articles were collected by key words from 1985 to 2005. To conduct meta-analysis on IQ construction, compare the case group and the control group, including full IQ, verbal and practice IQ. (2) Designed with model compared and self-compared, 59 diagnosed learning disability children, tested themes with WISC, ITPA and Berry’s VMI. WISC included 10 items, 5 of which subtotal to verbal and practice IQ respectively. IPTA included 10 items, too, 5 process of which subtotal to auditory and visual perception. The first 3 items shared representation level, the other 2 of that shared automatic level.VMI had one score. Analyzed factors and levels with description and Pearson Correlation. To probe to linguistic internal alternately functions of LD children, and compare the scores of groups in different IQ. (3) Analyzed the perspective questionnaire filled by parents. Early development facts compared with model groups. Factors relationships analyzed with Kendall correlation, KOM and Bartlett’s test of sphericity, Promax Rotation. Results: (1) There have been 319 papers related with LD, in which 36 with IQ and 14 valid reports have been analyzed by Meta. FIQ’s 95%CI (confidence interval) is 2.418 ~ 0.172, VIQ between the difficulty and non- difficulty group. C-WISC-R reports were 10 papers, of which, 95%CI of FIQ is 2.424 ~ 0.676, of VIQ is 2.314 ~ 1.196, of PIQ is 2.176 ~ 0.176. The VIQ comparing the PIQ, 95%CI is 1.1 ~ -0.07 in difficulty group and 0.5 ~ -0.0046 in non-difficult group. Nevertheless, in the other 4 tests, FIQ’s 95%CI is 2.00 ~ -0.818 between LD and NLD. (2) Children psycholinguistic abilities had strong relation with Berry’s VMI test excluding auditory reception, and with perceptive factor of intelligence excluding verbal expression. Auditory reception and visual closure had strong relation with FIQ and PIQ. Grammatic closure, visual association and manual expression had strong relation with concept factor. The representational and automatic levels are depended on integration of auditory and visual procession. Lower verbal expression (VE) let to lower expression process and low scores on representational level. Lower visual sequential memory (VSM) let to lower memory process and influenced automatic level. Groups compared by IQ 90 show that LD children with under IQ 90 had lower scores on items of IPTA than with up IQ 90 excluded verbal expression. It was proved that IQ administrated the linguistic ability. Nevertheless, general abilities deficiency didn’t show influencing on the types of the perceptive delay. There was mutual function among linguistic ability on LD children. Auditory and visual level are overlapped each other. Not only show higher Decoding and lower Encoding on Auditory perception, lower Decoding and higher Encoding on Visual perception, in representation, but also higher Sequential remember, lower Closure on Audition, and lower Sequential member, higher Closure on Vision, in Automation. Nevertheless, there was no different between Representational and Automatic level, which may be the relationship of parallel or evolution. (3) Major family factors were father’s education, occupation. Lower auditory perception related to unconcerned, lower visual perception related to premature delivery and written slowly. Threatened–abortion, childbirth-suffocated were known as influencing children’s IQ and later linguistic abilities. It wasn’t shown that dosage relationship with the types of perceptive delay. Conclusion: (1) The FIQ, VIQ and PIQ of Children with LD is lower than that of NLD group. There is no significantly different between VIQ and PIQ in LD and NLD groups. (2) The objectives of ITPA and WISC tests are differently. The psycholinguistic abilities had strong relation with perceptive factor and VMI. Some facts of IPTA related with FIQ. IQ had strong administration on linguistic abilities. There was mutual function among linguistic internal abilities. (3) Family facts on IQ and psycholinguistic abilities were Father’s education, abnormal pregnant and abortion. It would be pre-show development delay in early period.