Transport properties of acetone aqueous solutions: molecular dynamics simulation and NMR studies

Two quantities η_rel and are applied to study the nonideal acetone–water association mixture. An all-atom acetone model and a TIP5P water model have been adopted for molecular dynamics simulation. We study the transport properties of the system comparing the 's of strong hydrogen bond and weak contact based on transport properties, MD simulations together with NMR experimental data and find good agreement of concentration dependence, which exhibits the cooperation effect.     

Status of heavy element research using a gas-filled recoil separator at RIKEN

A gas-filled type of recoil separator for heavy element research was installed at an experimental hall of RIKEN Linear Accelerator facility to realize getting higher intensity of primary beam and long beam time. Performance of the separator was studied using target recoils and various nuclear reactions. The results show the high performance of the separator for heave element research. As an application of the GARIS, production and identification of an isotope of the 110th element ²⁷¹[110] have been performed using the ²⁰⁸Pb(⁶⁴Ni,1n)²⁷¹[110] reaction. Three decay chains coincide well both in decay times and energies with the ones reported by the group of SHIP experiment at GSI, Germany. Our results provide a confirmation of the synthesis of an isotope ²⁷¹[110] of element 110.     

Concentrations of hazardous heavy metals in environmental samples collected in Xiamen, China, as determined by vapor generation non-dispersive atomic fluorescence spectrometry.

Non-dispersive atomic fluorescence spectrometry (NDAFS) coupled with vapor generation (VG) sample introduction was applied to the determination of the concentrations of hazardous heavy metals, such as arsenic, cadmium, lead and mercury, in seawater, soils and total airborne particulate matter (PM) collected around the Xiamen area in China. Almost 100% sample introduction efficiency was achieved by using thiourea and ascorbic acid for the pre-reduction of As(V) to As(III), K3Fe(CN)6 and tartaric acid for pre-oxidation of Pb(II) to Pb(IV), and masking the interferences arising from the co-existing transition metals to As, Cd, Hg and Pb during their vapor generation process. Moreover, a novel sample pretreatment device was developed to avoid the loss of mercury, lead, cadmium and arsenic during sample pretreatment. With such methods, the detection limit (DL) of arsenic, cadmium, lead and mercury was down to 0.08, 0.03, 0.05, 0.01 ng mL(-1) (3sigma), respectively. The relative standard deviations (RSD, n = 11) for arsenic, cadmium, lead and mercury at 10 ng mL(-1) were 0.9%, 1.6%, 1.3% and 2.0%, respectively. The concentrations of hazardous heavy metals in the environmental samples collected in Xiamen, China are in the range from 0.02 +/- 0.001 ng mL(-1) in seawater to 15.3 +/- 0.2 microg g(-1) in soils. Besides flame/GF-AAS and ICP-AES/MS, VG-NDAFS should be another choice for the determination of hazardous heavy metals in environmental samples.     

掺杂偶氮苯聚合物光致异构Z扫描测量及其理论解释

用He_Ne激光对掺有偶氮苯聚合物DR 13的PMMA薄膜样品进行Z扫描研究 ,发现其折射率改变量与光强的关系存在着饱和效应 ,且线偏振光引起的折射率改变明显大于圆偏振光引起的折射率改变 .对于这些现象 ,用光致异构的角烧孔机理进行解释     

The Crystal Structure of N-Benzoyl-N''-(2-hydroxyethyl)-thiourea

Thiourea compounds are excellent agents of bioactive substance. A number of biological activities are associated with substituted thiourea derivatives. A survey of literature reveals that some work has been reported on benzoylthiourea, which has found plenty of applications as a facile and simple ligand in determination of trances of the transition metal and as an available starting material in preparation of a wide variety of metal complexes. In recent years,N-benzoyl-N'-(2-hydroxyethyl)-thiourea has attracted considerable attention as selective reagents for the liquid-liquid extraction and preconcentration of platinum group metals and its antifungle activity.As a part of our works in studying coordination behaviours of N-benzoyl-N'-(2-hydroxyethyl)-thiourea and its bioactivity, in view of these observations and in continuation of our previous works on it, the present work was reported on the crystal structure of N-benzoyl-N'-( 2-hydroxyethyl)-thiourea.The crystals structure in the monoclinic system and space group of P21/c of N-benzoyl-N'-(2-hydroxyethyl)- thiourea (C10H12N2O2S) was determined from single-crystal X-ray diffraction analysis, a = 17.083 (3) A, b = 4.5490 (10) A, c = 14.279 (3)A, a = 90.00°, a = 102.44(3)°, a = 90.00 °, Ⅴ = 1083.6 (4)A3, Z = 4, Dc = 1.375 Mg/m3, i (Mo Ka)= 0.280 mm-1, F(000) =472. The final R and u R are 0.0399 and 0.0881 for 783 observed reflections [Ⅰ＞26(Ⅰ)].Fig. 1 shows the molecular crystal structure of N-benzoyl-N'-(2-hydroxyethyl)thiourea indicating that the carbonyl and thiocarbonyl moieties are pointing in approximate opposite directions. The six atoms in the ring structure hydrogen bonded are almost in one plane. The N(2)-H proton pendant arm extends to the carbonyl oxygen atom, forms hydrogen bond between them.The existence of hydrogen bond in benzoyl-thiourea molecular six-membered ring structure has significant implications on coordination properties, suggest the possibility of intramolecular hydrogen bond controlled coordination behaviors of these potentially bidentate ligands. In the coordination compound reported by Bourne et al.,cis-bis(N-benzoyl-N'-propylthiourea)dichloroplatinum(Ⅱ), the two ligand molecules bind to Pt(Ⅱ)via the sulfur atoms only, the carbonyl oxygen atom being locked into hydrogen bond similar to that in the free ligands.     

Crystal Structures of Two Potential Tumor Imaging Agents and Therapeutic Agents Copper（Ⅱ） Ternary Complexes with Salicylidene-tyrosinato Schiff Base and Nitrogen-donor Chelating Lewis Base

The crystal structures of two potential tumor imaging agents and therapeutic agents -copper(Ⅱ) complexes with salicylidene-tyrosinato Schiff base and nitrogen-donor chelating Lewis base, [Cu(sal-tyr)(bipy)] 1 and [Cu(sal-tyr)(phen)]2CH3OH 2 are presented. Our work is helpful to get deep understanding of novel 64Cu tumor imaging agents and therapeutic agents.     

The structure of students' emotions experienced during a mathematical achievement test

Several models have been developed in order to categorize the numerous expressions that people use in order to describe their emotional experiences. The focus of the present study is on one of these theoretical classifications proposed by Pekrun (1992) specifically concerning emotions which are directly related to learning and achievement in mathematics. In his model, emotions are classified according to their valence (positive vs. negative) and their level of activation. In testing the assumptions of this model, we investigated students' enjoyment, anxiety, anger and boredom experienced before, during, and after the completion of a math test. Correspondence analyses which were used to generate a graphical illustration of structural interrelationships between these emotions provide empirical support for the theoretical classification.     

Appropriate problems for learning and for performing—an issue for teacher training

Selecting, modifying or creating appropriate problems for mathematics class has become an activity of increaing importance in the professional development of German mathematics teachers. But rather than asking in general: “What is a good problem?” there should be a stronger emphasis on considering the specific goal of a problem, e.g.: “What are the ingredients that make a problem appropriate for initiating a learning process” or “What are the characteristics that make a problem appropriate for its use in a central test?” We propose a guiding scheme for teachers that turns out to be especially helpful, since the newly introduced orientation on outcome standards a) leads to a critical predominance of test items and b) expects teachers to design adequate problems for specific learning processes (e.g. problem solving, reasoning and modelling activities).     

}MSo浸种对大麦种子萌发及若干性状的影响

本文报道二甲亚矾(DMSO)浸种影响大麦“早熟3号”种子的萌发以及浸种后种子的渗漏和呼吸强度等的变化.结果表明:在24℃条件干浸种，。.1%和5芳的DMSO明显促进种子的萌发，5劣DMSO浸种的促进作用尤为明显.然而这种影响效应在zs c条件下浸种则完全相反，对种子萌发有抑制作用，表现明显的温度效应.     

黄酮类天然产物13C NMR数据的计算机检索和辅助解析(Ⅱ)黄酮类天然产物的13C NMR数据规律及其在智能解析中的应用

本文通过对大量的黄酮类化合物¹³C NMR图谱的分析和研究,总结了不同类型的黄酮类化合物的¹³C NMR图谱特征及化学位移规律.对影响黄酮类化合物结构骨架上不同位置碳原子化学位移的因素进行了分析,建立了用于黄酮类天然产物¹³C NMR图谱智能解析的知识库.