Porous sheet-like and sphere-like nano-architectures of SnO2 nanoparticles via a solvent-thermal approach and their gas-sensing performances

Porous sheet-like and sphere-like nano-architectures of SnO₂ nanoparticles have been prepared via a solvent-thermal approach in the absence of any surfactant or polymer templates by simply changing the volume ratio of DMF to water. The nano-materials have been characterized by FESEM, XRD, IR, TEM and BET. A mechanism for the formation of nano-architectures is also proposed based on the assembly behaviors of DMF in water. The gas sensors constructed with porous sphere-like SnO₂ nano-architectures exhibit much higher sensitivity to the reduce vapors tested, compared to those from porous sheet-like SnO₂ materials, while the sheet-like materials show better selectivity to ethanol. The nano-architectures fabricated with the facile method are promising candidates for building chemical sensors with tunable performances.     

三维配位聚合物[Cu_2(pda)_2(bpp)]的合成和结构

利用间苯二乙酸,1,3-二(4-吡啶)丙烷和硝酸铜在水热条件下反应制备了一种新型三维配位聚合物[Cu2(pda)2(bpp)](1)(H2pda=间苯二乙酸,bpp=1,3-二(4-吡啶基)丙烷)。通过X单晶衍射测定了晶体结构,并用元素分析、红外光谱、热重分析等技术对其进行表征。配合物属单斜晶系,空间群为P2(1)/c,a=24.412(1)nm,b=12.632(5)nmc,=10.076(4)nm,β=95.134(4)°,Z=4。晶体结构分析表明:在配合物1中,铜离子均形成六配位微扭曲八面体,较为特殊的是在双核结构单元中存在着轮浆[Cu2(CH2COO)4]次级单元。这些次级单元通过顺式桥连双齿间苯二已酸的连接形成(4,4)网格二维波浪面。毗邻的波浪网面又通过1,3-二(4-吡啶基)丙烷配体的连接支撑,拓展为复杂的三维网络结构。     

罗丹明B作为试踪剂在测试光生酸剂产酸中的应用

采用一种在树脂膜中测试光生酸剂产酸量的方法,测试了膜中光生酸剂的产酸率.以罗丹明B为试踪剂,在酸性条件下罗丹明B的紫外吸收随酸浓度而变化,通过其紫外吸光度的改变来反映酸度的变化.用紫外分光光度计分别测量盐酸、三氟甲磺酸在不同浓度时罗丹明B特征吸收的变化,选取酸浓度与罗丹明的特征吸收的变化量呈线性关系的线段部分作为标准工作曲线.根据标准工作曲线及推导出的公式,通过计算就可以得出光生酸剂曝光产生的酸量.     

Visualization of the ribosomal DNA (45S rDNA) of Indica rice with FISH on some phases of cell cycle and extended DNA fibers.

The ribosomal DNA (45S rDNA) behaviors during the cell cycle were analyzed on interphase nuclei, prophases, metaphases, pachytene chromosomes and extended DNA fibers in rice (Oryza, sativa ssp. indica cv. Guangluai No.4) by using high-resolution fluorescent in situ hybridization (FISH). The results show that 45S rDNA is located at the ends of short arms of chromosomes 9 and 10. But the signals are much more intense on chromosome 9 than on chromosome 10 in metaphase. Pachytene chromosome has rDNA signal arrays on chromosome 9. Different phases are described and discussed. These results indicate that the activity ofrDNA at individual loci may also vary through the cell cycle in rice. On extended DNA fibers, 45S rDNA signals appear as strings of numerous red spots, but some signals are missed in some regions, probably result from weak signals or intergenic spacers.     

微波消解-原子荧光光谱法同时测定香辛料中砷、汞含量

目的 建立微波消解-原子荧光光谱法同时测定香辛料中砷、汞含量的方法。方法 样品加入硝酸和双氧水, 微波消解后加热浓缩, 冷却后加入硫脲与抗环血酸混合溶液, 加水定容, 使用原子荧光光谱仪进行测定。结果 砷和汞分别在0~20.0 μg/L和0~2.0 μg/L浓度范围与荧光强度呈良好的线性关系, 相关系数均大于0.9997。砷和汞的方法检出限分别为0.0026和0.0006 mg/kg; 精密度和重复性实验的相对标准偏差(relative standard deviations, RSD)小于5%; 加标回收率分别为93.2%和103.0%; 对国家标准物质(GBW 10020柑橘叶)检测结果均在标准认定值范围。结论 该法操作简单、检出限低、准确度高, 适合香辛料中砷、汞含量的检测。     

Silencing of the Ortholog of DEFECTIVE IN ANTHER DEHISCENCE 1 Gene in the Woody Perennial Jatropha curcas Alters Flower and Fruit Development

DEFECTIVE IN ANTHER DEHISCENCE 1 (DAD1), a phospholipase A1, utilizes galactolipids (18:3) to generate α-linolenic acid (ALA) in the initial step of jasmonic acid (JA) biosynthesis in Arabidopsis thaliana. In this study, we isolated the JcDAD1 gene, an ortholog of Arabidopsis DAD1 in Jatropha curcas, and found that it is mainly expressed in the stems, roots, and male flowers of Jatropha. JcDAD1-RNAi transgenic plants with low endogenous jasmonate levels in inflorescences exhibited more and larger flowers, as well as a few abortive female flowers, although anther and pollen development were normal. In addition, fruit number was increased and the seed size, weight, and oil contents were reduced in the transgenic Jatropha plants. These results indicate that JcDAD1 regulates the development of flowers and fruits through the JA biosynthesis pathway, but does not alter androecium development in Jatropha. These findings strengthen our understanding of the roles of JA and DAD1 in the regulation of floral development in woody perennial plants.     

基于酶法制备的凉薯饮料配方优化及品质测定

;凉薯为主要原料,羧甲基纤维素钠、白砂糖、柠檬酸、木糖醇为辅料,凉薯经液化、糖化后,使用单因素及正交试验研究各辅料对凉薯饮料品质的影响,并对凉薯饮料总酸、总糖、可溶性固形物进行测定。凉薯饮料最优配方为：白砂糖添加量8%、柠檬酸添加量0.12%、木糖醇添加量1%、CMC-Na添加量0.18%。在此最优配方条件下,凉薯饮料感官评分为86.4分,总酸含量为0.55%,总糖含量为7.97%,可溶性固形物含量为11.0%,pH为4.3,饮料组织均匀、酸甜适中、回味清爽,呈淡黄色,具有凉薯的独特风味。     

时序Agent程序设计语言TAOPLID的离线解释器

AOPLID是一种面向agent程序设计语言。本文旨在对AOPLID语言进行时序扩充,使之能表达并处理带时间参数的并发行动,基于离线方式下AOPLID程序的语义,用Prolog语言实现时序AOPLID语言(TAOPLID)的离线解释嚣。首先,我们对经典情境演算进行适当改造,使之能描述合时间变元的行动,因为持续行动一般可认为是具有瞬时开始行动和瞬时终止行动的过程,所以可以将一个持续动作分解为两个时间上互不相交的瞬时动作,再引入一个新的关系流刻画这两个瞬时动作的执行情况,从而可在扩充后的情境演算中表达带时间参数的并发行动。其次,为使TAOPLID离线解释嚣方便处理以集合方式表示的TAOPLID程序,设计并实现了TAOPLID预处理嚣,它将TAO—PLID程序的集合形式转换成Prolog子句形式,然后通过TAPOLID离线解释嚣对其解释生成一可执行的原子行动序列。