Aggregation Processes with Catalysis-Driven Decomposition

We propose a three-species aggregation model with catalysis-driven decomposition. Based on the mean-field rate equations, we investigate the evoIution behavior of the system with the size-dependent catalysis-driven decomposition rate J（i; j; k） = Jijk^v and the constant aggregation rates. The results show that the cluster size distribution of the species without decomposition can always obey the conventional scaling law in the case of 0 ≤v ≤ 1, while the kinetic evolution of the decomposed species depends crucially on the index v. Moreover, the total size of the species without decomposition can keep a nonzero value at large times, while the total size of the decomposed species decreases exponentially with time and vanishes finally.     

IR光谱分析PEO/V2O5纳米复合材料结构

聚合物溶液直接嵌入法制备 PEO/ V2 O5纳米复合材料。由红外光谱 (IR)表征了 PEO与氧化物层之间的相互作用。V2 O5干凝胶的钒氧双键 (V=O)主要与层间聚合物 PEO中的醚氧键 (Oet)发生作用 ,以Oet…V=O形式存在     

Determining the η−η′ mixing by the newly measured \mathit{BR}(D(D_{s})\to\eta(\eta')+\bar{l}+\nu_{l}

The mixing of η?η′ or η?η′?G is of a great theoretical interest, because it concerns many aspects of the underlying dynamics and hadronic structure of pseudoscalar mesons and glueball. Determining the mixing parameters by fitting data is by no means trivial. In order to extract the mixing parameters from the available processes where hadrons are involved, theoretical evaluation of hadronic matrix elements is necessary. Therefore model dependence is somehow unavoidable. In fact, it is impossible to extract the mixing angle from a unique experiment because the model parameters must be obtained by fitting other experiments. Recently $\mathit{BR}(D\to\eta+\bar{l}+\nu_{l})$ and $\mathit{BR}(D_{s}\to\eta(\eta')+\bar{l}+\nu_{l})$ have been measured, thus we are able to determine the η?η′ mixing solely from the semileptonic decays of D-mesons where contamination from the final state interactions is absent. Thus we hope that the model dependence of the extraction can be somehow alleviated. Once $\mathit{BR}(D\to\eta'+\bar{l}+\nu_{l})$ is measured, we can further determine all the mixing parameters for η?η′?G. As more data are accumulated, the determination will be more accurate. In this work, we obtain the transition matrix elements of D _(s)→η ^(′) using the light-front quark model whose feasibility and reasonability for such processes have been tested.     

Synthesis,Spectroscopic Properties,and Photodynamic Anticancer Activities of Novel Arginine-modified Silicon(Ⅳ) Phthalocyanines

We design and synthesize a series of novel silicon(IV) phthalocyanines(SiPcs, 1 a, 2 a, 1 b, and 2 b) axially conjugated with arginine or arginine-containing oligopeptides(Arg-Arg, Cys-Arg, Cys-Arg-Arg) through ester or ether linkers to demonstrate the effects of substituents and coupling ways on the spectral behaviors and photodynamic activities. The ester-linked SiPcs(1 a and 2 a) show slight red-shift, higher fluorescence emission and singlet oxygen generation compared to the ether-linked analogues(1 b and 2 b) due to the stronger electron-withdrawing ability of the ester group, suggesting that electronic effect of the linkers plays an important role in their spectral properties. The introduction of arginine could effectively reduce the aggregation of phthalocyanine in aqueous solutions. With higher cellular uptake and plasma membrane localization ability, 1 b and 2 b exhibit significantly higher photocytotoxicity against both HepG2 and Hela cells. Moreover, the in vivo fluorescence imaging suggests that 2 b is the most specific toward H22 tumor-bearing ICR mice, and it shows efficient tumor growth inhibition with the tumor inhibition rate up to 93%. Thus, this work would provide a new reference for the development of phthalocyanine-based photosensitizers.     

聚醚醚酮链结构与反应的模型化合物的量子化学研究

利用ＡＭ１方法对聚醚醚酮模型化合物全优化，结果为：芳环平均相互扭转角为３３．０度，桥键角１１７．０－１１８．０度，其分子结构拓扑图形表明：所有苯环（核）为平面构型，但其内角扭曲；其氢原子对苯环构型无实质性贡献，在更长链的计算中，冻结苯核与氢原子也得出满意结果，根据Ｍｕｌｌｉｋｅｎ键序与电荷讨论了醚交换与磺化反应。     

芳香聚醚酮酮晶体结构及其晶型变化的研究（Ⅰ）

利用Ｘ射线及热分析技术研究了聚醚酮酮（ＰＥＫＫ）的溶剂诱导结晶及从玻璃态结晶和从熔融态结晶的行为。发现ＰＥＫＫ有两种晶型结构（Ⅰ和Ⅱ），晶型Ⅱ的形成与热历史和溶剂诱导有关，其熔点始终低于Ⅰ型１０℃左右。ＰＥＫＫ的低温熔融峰与其分子链极化有关，而与热历史无关，此低温熔融峰热焓占总热焓２％～１０％，其平衡熔点为４０９℃。     

FTIR study of hydrogen bonding of stearic acid with ethanol, dimethyl sulfoxide,and acetonitrile in supercritical CO_2

FTIR spectroscopy was used to study the hydrogen bonding of stearic acid with ethanol, dimethyl sulfoxide (DMSO),and acetonitrile in supercritical CO_2 at 318.15 K, and 12.5 and 16.5 MPa. The concentrations of the cosolvents range from 0—0.6 mol·L~(-1). The area percentage of absorption bands for hydrogen-bonded and nonhydrogen-bonded species was obtained from the IR spectra. The acid and the cosolvents can form hydrogen bond even when their concentrations are very low. At fixed solute concentration, the extent of hydrogenbonding increases with cosolvent concentration. At higher ethanol concentrations, it seems that one stearic acid molecule can hydrogen bond with more than one ethanol molecules simultaneously. It is seen that the strength of the hydrogen bond formed by the acid and the cosolvents is in the order: DMSO>ethanol>acetonitrile.     

蜂产品中蛋白质测定方法的改进

蜂产品中蛋白质的测定主要采用凯氏定氮法,其测定结果稳定可靠,被广泛采用.但其操作较繁杂,消化时间长,需蒸馏滴定,费时费力.本法通过改进消化条件,即采用过氧化氢-浓硫酸混合液为消化液,消化过程中滴加硝酸-高氯酸混合酸,缩短了消化时间.样品中的蛋白质与硫酸和催化剂一同加热分解,生成的氨与硫酸反应生成硫酸铵,硫酸铵在碱性溶液中与次氯酸盐生成-氯胺,在亚硝基铁氰化钠催化作用下与水杨酸生成蓝色化合物,可在655 nm波长下比色定量.     

磷酸硼固体酸催化合成邻苯二甲酸二乙酯的性能研究

以邻苯二甲酸酐和无水乙醇为原料,固体磷酸硼为催化剂,在醇酐比为4：1,催化剂用量为苯酐用量的20．3％,反应时间8h,反应温度80℃条件下合成邻苯二甲酸二乙酯（DEP）,探讨了影响催化剂催化效果的各个因素。实验表明,催化剂最佳的制备条件为：磷酸、硼酸和硫酸的摩尔比为1：1：1,焙烧温度为300℃,焙烧时间为3．5h。DEP最高产率可达75％。     

高效液相色谱-电喷雾串联质谱法快速测定纺织品中苯氧羧酸类除草剂残留量

建立了纺织品中7种苯氧羧酸类除草剂的高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)快速检测方法.样品经甲酸酸化的丙酮溶液超声提取两次,无需其它净化过程.液相色谱使用C18反相色谱柱,流动相为醋酸铵水溶液和甲醇,在梯度条件下分析.在选择反应检测(SRM)负离子模式下进行质谱信号采集,采用两对同位素离子对进行定性和定量分析.选取3种有代表性的纺织品进行方法检出限(LOD)、定量限(LOQ)、线性、回收率和精密度的验证.方法的LOQ为 0.9～2.4 μg/kg; 回收率为85%～106%; 相对标准偏差为2%～11%.本方法简便、有效、可靠、灵敏,能够满足国际生态纺织品标准(Oeko-Tex Standard 100)的限量要求,适用于纺织品中苯氧羧酸类除草剂的日常检测及确证.