Direct Determination of Manganese in Seawater by Leucomalachite Green-sodium Periodate Catalytic Kinetic Spectrophotometry

海洋中溶解态锰是海洋生物必需的微量营养元素,也可作为很多海洋生物地球化学过程的示踪剂.催化动力学光度法具有灵敏度高、操作简单、分析成本低、可以在船上现场测定等优点.本文采用锰催化高碘酸钠氧化隐色孔雀绿的方法,以氨三乙酸为活化剂,用南大洋低锰海水定容制作工作曲线,测定海水中溶解态锰.方法检测限为2.72 nMOl/l,线性范围0--25.00 nMOl/l,加标回收率在92.36%--99.68%之间.Dissolved manganese in seawater is not only one of the essential trace nutrient elements,but also can serve as a tracer in various marine biogeochemical processes.Catalytic kinetic spectrophotometric method is sensitive,simple,low cost and can be used on ship.The new method was based on the catalytic effect of trace manganese on the oxidation of leucomalachite green by sodium periodate,the nitrilotriacetic acid as an activator,and used the low Mn Southern Ocean surface water as the reaction medium of the standard working curve.The absorbance was measured at 615 nm.The linear range is 0--25.00 nmol/L and the detection limit is 2.72 nmol/L.The recovery of standard addition ranges from 92.36% to 99.68%.国家自然科学基金青年项目(40706033);中国大洋协会国际海底区域研究开发“十一五”项目(DYXM-115-02-1-12);厦门大学第五届“海洋学生科研奖励计划”项目资

Estimation of genetic parameters of growth traits and genetic gain of F5 generation of scallop Hongmo No. 1

Argopecten irradians concentricus, natively distributed along the Atlantic coast of the United States, has advantages of fast growth, short growth cycle, and high meat yield. It was introduced into China mainland in 1991 and in 2001 its large-scale aquaculture began in the Beibu Gulf area. More than 20 years since the introduction of A. irradians concentricus, as the number of breeding generations increased, the characteristics of the breeding population deteriorated seriously reflected in small individuals, low survival rates, and low meat yields. To solve the problem of germplasm degradation of A. irradians concentricus, this research team hybridized A. irradians concentricus with the scallop Bohai Red in 2016, and successfully obtained hybrid offspring. After four generations of breeding, a new strain of scallop Hongmo No. 1 was obtained. Hongmo No. 1 has the characteristics of a fast growth rate, high survival rate, and high temperature resistance, and has completely adapted to the environment of Beibu Gulf in the south of China, so it has a good prospect of popularization and breeding. Although Hongmo No. 1 has been bred for multiple generations, the genetic parameters of its growth-related traits are unknown and whether it still has breeding potential is unclear. As a result of successive selection in a closed population, genetic parameters varied between different generations of selected strains. Obtaining estimates of genetic parameters and genetic gain of growth-related traits of scallop Hongmo No. 1, which has experienced numerous generations of selection, is of great significance for subsequent breeding. To evaluate the breeding effect of the new scallop strain Hongmo No. 1, this study compared the selected line and a non-selected line in the F4 generation of Hongmo No. 1 and evaluated the genetic parameters and genetic gain of F5 growth-related traits. The results indicated that in the F5 generation of Hongmo No. 1 there was no significant difference in the survival rate between the selected line and the non-selected line (P>0.05), but the growth traits of the selected line were significantly better than those of the non-selected line (P<0.05). The coefficients of variation of quality traits of the two populations of Hongmo No. 1 F5 were 14.60%-28.30%, showing potential for successive selective breeding. The genetic gain of shell length, shell height, shell width, body weight, adductor muscle weight, soft tissue weight, and shell weight in the F5 generation were 7.25%, 7.13%, 4.86%, 25.42%, 31.60%, 27.70%, and 21.29%, respectively. The realized heritability of shell length, shell height, shell width, body weight, adductor muscle weight, soft tissue weight, and shell weight in the F5 generation were 0.37, 0.36, 0.25, 0.36, 0.32, 0.38, and 0.32, respectively, which are moderate levels of heritability. The results of this study showed that the growth traits of the selected line were better than those of the non-selected line, both of which showed a large coefficient of variation for quality traits, moderate mean genetic gain, and medium realized heritability. These results indicate that the genetic improvement of A. irradians concentricus, using first hybridization and then sub-breeding, has achieved good results. These results provide a basis for further breeding of growth traits in scallop Hongmo No. 1

Electrocatalytic Oxidation of Methanol on Polythionine Film ModiFied with Pt Microparticles

利用电化学循环伏安和现场fTIr反射光谱等技术研究了甲醇在铂微粒修饰的聚硫堇电极上的电催化氧化.结果表明，循环伏安法制备的铂微粒均匀分散于聚合物膜上，其粒径大小约为30-130uM；复合修饰电极对甲醇电化学氧化呈现了较高的假化活性，其催化活性的大小依赖于PT载量现场fTIr光谱实验揭示了线性吸附的CO物种是甲醇在复合电极上氧化的唯一中间体，这种吸附的CO物种在复合修饰电极上更容易被氧化为最终产物CO2，增强的电催化活性可归属于PT微粒在聚合物膜中的高度分散和金属微粒与聚合物的协同效应.依据实验结果，提出了甲醇在复合电极上电化学氧化可能的反应机理.The electrocatalytic oxidation of methanol on polythionine(PTn) Film modiFied with Pt ndcroparticles has been studied by means of cyclic voltammetry and in-situ FTIR spectroscopy The Pt microparticles produced by cyclic voltammetry were highly dispersed in and on the PTn Film.The modiFied electrodes exhibit signiFicant electrocatalytic artivity For the oxidation of methanol and the catalytic activity was Found in dependence on the Pt loading.The linearly adsorbed CO species is the only intermediate in the okidation of methanol and the abnormal IR spectra For adsorbed CO were observed.On such modiFied electrodes, adsorbed CO species derived From methanol can be readily oxidized.The enhanced electrocatalytic activity may be ascribed to the high dispersion of Pt microparticles in and on the PTn Film and the synergestic eFFect between Pt microparticles and the polymer.Frtom the above results, a possible reaction mechanism was proposed.国家自然科学基金;厦门大学固体表面物理化学国家重点实验室基

Studies of Electrocatalytic Properties of Electrode of Dispersed Pt on GC Support in Ethylene Glycol Oxidation

运用电化学循环伏安、阶跃电位、以及Ｘ－光衍射（ＸＲＤ）和扫描电镜（ＳＥＭ）等方法，研究了玻碳表面高分散铂电催化剂在不同条件下的结构与性能．结果指出，玻碳表面沉积的高分散铂黑经高温处理后具有一定的择优取向，晶粒尺寸变大，具有更好的稳定性和对乙二醇的电催化活性．The structures and properties of electrocatalyst of dispersed Plutinum(Pt) on glassy carbon(GC) support under different conditions were studied using cyclic voltammetry,potential step technique,x ray diffraction(XRD) and scanning Electron microscopy(SEM). The results indicated that after having been treated in high temperature,the dispersed Pt on GC support was recrystallised with preferented orientation,and the grain of Pt microcrystal become large and regular.It was illustrated that the dispersed Pt on GC support after high temperature treatment exhibited better stability and high activity for ethylene glycol oxidation.作者联系地址：厦门大学化学系固体表面物理化学国家重点实验室物化所,张掖师专化生系Author's Address: Dept. of chem., State Key Lab. for Phy. Chem. of the Solid Surf., Inst. of Phy. Chem., Xiamen Univ., Xiamen 361005 Xue Guoqing Dept. of Chem. and Biochem., teachers col

双维位置灵敏探测器性能测试

对用于放射性次级束测量的大面积双维位置灵敏探测器 (PSD)的性能进行了测试。通过选择实验中电子线路的脉冲成形时间 ,并改进数据处理方法 ,即主放大器的成形时间常数要大于6 μs,而位置路的时间常数约为 0 .5— 1μs ,且在位置公式中使用能量信号作为分母 ,测试得到了较好的位置分辨和能量分辨及线性。结果表明 ,这一类型的PSD探测器可以用于低能放射性束流的测

中能核反应的余核测量与分布性质

报道了 30 Me V/u4 0 Ar+112 ,12 4 Sn反应中余核的测量方法和结果。对反应中的余核、裂变碎片以及类弹粒子在平行板雪崩计数器中的不同响应以及各自的几何探测效率进行了 Monte- Carlo模拟。利用平行板雪崩计数器 ,通过 TOF-ΔE的关联成功地鉴别了余核 ,并得到了反应的线性动量分布 ,余核的分布与模拟计算的结果基本一