The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite

The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.     

纳米颗粒透明分散体及其高性能有机无机复合材料

纳米颗粒分散是无机纳米材料在有机体系中应用的关键.本文提出了采用纳米颗粒液相分散体制备高度分散纳米透明有机无机复合材料的新方法,发明了超重力反应-萃取相转移方法制备纳米颗粒液相透明分散体技术,介绍了其制备原理和实施效果,以及其在纳米复合节能膜、纳米润滑油脂和高固含量光学材料等有机无机纳米复合材料中的最新研究进展.     

Two-flavor quark matter in the perturbation theory with full thermodynamic consistency

Direct extrapolation of the strong interaction between quarks in pure perturbative calculation has a problem of thermodynamic inconsistency.A new term determined by thermodynamic consistency requirement could resolve it.This new term plays an important role at lower density in describing the equation of state of quark matter,while it is negligible at high density.Accordingly,the density behavior of the sound velocity becomes more reasonable,and the maximum mass of quark stars can be as large as two times the solar mass.     

Synthesis of o-phenylphenol from cyclohexanone over platinum supported on calcined Mg/Al hydrotalcite

A kinetic model is proposed to account for the effect of oxygen during catalyst premodification on the rate and enantioselectivity in hydrogenation of methyl pyruvate over cinchonidine modified platinum catalysts.This revised version was published online in December 2005 with corrections to the Cover Date.     

Acyclic edge coloring of graphs with large girths

A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic chromatic index of G, denoted by χ’a(G), is the least number of colors such that G has an acyclic edge k-coloring. Let G be a graph with maximum degree Δ and girth g(G), and let 1≤r≤2Δ be an integer. In this paper, it is shown that there exists a constant c > 0 such that if g(G)≥cΔ r log(Δ2/r) then χa(G)≤Δ + r + 1, which generalizes the result of Alon et al. in 2001. When G is restricted to series-parallel graphs, it is proved that χ’a(G) = Δ if Δ≥4 and g(G)≥4; or Δ≥3 and g(G)≥5.     

苯乙烯基噻吩单体及对应的聚脲烷的合成 及其非线性光学性能

一种新型的反式-7-［4-N,N-二(β-羟基乙基胺基苯)］-3,5-二硝基乙烯基-噻吩（HBDT）单体分子及对应的预聚物和聚脲烷被合成和表征.由于噻吩环的电子去局域化能量低于苯环,在受授有机共轭化合物中噻吩环比苯环表现出更有效的共轭和更高的非线性,同时也能使目标分子保持好的光、热稳定性.该单体分子及其对应的聚脲烷在普通有机溶剂中具有良好的可溶性,聚脲烷膜具有好的热稳定性.制备了高质量的聚脲烷膜并进行了电晕极化.单体在甲醇中的紫外可见吸收峰（530nm）与对应未经电晕极化聚脲烷膜的吸收峰基本上没有改变.通过溶剂变色法及简并四波混频（DFWM）法测试了单体的二阶和三阶非线性极化率,其β     

Synthesis and structural studies of some titanium and zirconium complexes with chiral bis(amide), amidinate or bis(amidinate) ligands

Reaction of bis(amide) sodium Na₂[(1R,2R)-(−)-1,2-(NSiMe₃)₂-C₆H₁₀] (Na₂[L¹]) with Ti(OiPr)₂Cl₂ in different conditions gave mixed-ligand complexes [Ti(OiPr)Cl][L¹] (1) or [Ti(OiPr)₂Cl]₂[L¹] (2); 2 is a dinuclear titanium example in which Ti atoms are bridged by nitrogen and oxygen atoms simultaneously forming a distorted rhombic core. Reaction of the amine-amidinate ligand (1R,2R)-(−)-1-Li[NC(Ph)N(SiMe₃)]-2-(NHSiMe₃)-C₆H₁₀(Li[L²]) or rarely linked bis(amidinate) ligand Li₂[(1R,2R)-(−)-1,2-{NC(Ph)N(SiMe₃)}₂-C₆H₁₀](Li₂[L³]) with ZrCl₄ yielded the unbridged and bridged bis(amidinate) complexes ZrCl₂[L²]₂ (3) and [ZrCl₂(THF)][L³] (4), respectively; Moreover, the reaction of (1R,2R)-(−)-1-Li[NC(Ph)N(SiMe₃)]-2-Li(NSiMe₃)C₆H₁₀(Li₂[L²]) with Ti(OiPr)₂Cl₂ gave a new type of tridentate amido-amidinate product [Ti(OiPr)₂][L²] (6), which is a distinct model compared to [Ti(OiPr)₂Cl][L²] (5) yielded from Li[L²]. All the products have been characterized by X-ray crystallography and the structural studies are presented detailedly comparing with relevant compounds.     

Engineering of drug nanoparticles by HGCP for pharmaceutical applications

This paper reviews our work on the fundamental principles of high gravity controlled precipitation (HGCP) technology, and its applications in the production of drug nenoparticles, which was carded out in a rotating packed bed (RPB). Several kinds of drug nanoparticles with narrow particle size distributions (PSDs) were successfully prepared via HGCP, including the 300-nm Cefuroxirne Axetil (CFA) particles, 200-400-nm cephradine particles, 500-nm salbutamol sulfate (SS) particles (100 nm in width), end 850-nm beclomethasone dipropionate (BDP) particles, etc. Compared to drugs available in the current market, all the drug nanoparticles produced by HGCP exhibited advantages in both formulation end drug delivery, thus improving the bioavailability of drugs. HGCP is essentially a platform technology for the preparation of poorly water-soluble drug nanoparticles for oral and injection delivery, and of inhalable drugs for pulmonary delivery. Consequently, HGCP offers potential applications in the pharmaceutical industry due to its cost-effectiveness, efficient processing end the ease of scaling-up.     

RIBLL粒子鉴别气体电离室

描述了一种用于兰州放射性束流线粒子鉴别的阳极分别在x,y方向分条共阴极纵向场双叠层电离室.对其性能进行初步测试,得到了坪曲线和能量分辨.在10kPa的P10工作气体(10%CH₄+90%Ar)时,阴极电压为–650V,阳极电压为+120V是较佳的工作点.当工作气压为25kPa时,阴极电压为–1650V,阳极电压为+240V的工作条件较好,此时,对²³⁹Pu α源相对能量分辨约为4.7%.