Critical phenomena in head-on collisions of neutron stars

We find type I critical collapses of compact objects modeled by a polytropic equation of state (EOS) with a polytropic index Gamma=2 without the ultrarelativistic assumption. The object is formed in head-on collisions of neutron stars. Further, we show that the critical collapse can occur due to a change of the EOS, without fine-tuning of initial data. This opens the possibility that a neutron-star-like compact object, not just those formed in a collision, may undergo a critical collapse in processes which slowly change the EOS, such as cooling.     

结晶猪、牛B1色氨酸胰岛素的制备及性质

猪、牛胰岛素经与MSC·ONSu选择性反应.随后Edman降解,和与MSC·Trp·ONp缩合,去保护制备了二个种属的[Trp]^B₁胰岛素类似物. 经醋酸纤维素电泳.氨基酸组成分析,UV吸收光谱和N-端分析鉴定,确定它们是均一的[Trp]^B₁胰岛素.鼠惊厥分析显示猪、牛[Trp]^B₁胰岛素的生物活力分别为18国际单位/毫克和17国际单位/毫克.分别相当于天然胰岛素的70％.     

P3HT as hole transport material and assistant light absorber in CdS quantum dots-sensitized solid-state solar cells

Regioregular poly(3-hexylthiophene) (P3HT) was employed as a hole transport material and assistant light absorber for the fabrication of a CdS quantum dot-sensitized solid-state solar cell, by which a power-conversion efficiency of 1.42% was achieved under an AM1.5 G (100 mW cm(-2)) condition.     

四种5-氟尿嘧啶二肽衍生物的合成、晶体结构和抗癌活性

合成了四种新的5-氟尿嘧啶(5-Fu)二肽衍生物, 它们的结构经过元素分析、IR、1H NMR和13C NMR的表征, 比旋光度[a]D的测定结果表明了它们之间的对映异构关系, 用X射线衍射法测定了其中一对对映异构的晶体结构3a (S)和3b (R), 生物活性测试的结果表明这四种化合物都具有一定的抑制活性, 并且R型产物比S型产物抑制率高. 研究了2a和3a与DNA在Au电极上相互作用的伏安行为, 比较了它们跟5-氟尿嘧啶与双链DNA发生相互作用的差别.     

Effect of the phosphoryl substituent in the linear nitrone on the spin trapping of superoxide radical and the stability of the superoxide adduct: combined experimental and theoretical studies

A new phosphorylated linear nitrone N-(4-hydroxybenzyliene)-1-diethoxyphosphoryl-1-methylethylamine N-oxide (4-HOPPN) was synthesized, and its X-ray structure was determined. The spin trapping ability of various kinds of free radicals by 4-HOPPN was evaluated. Kinetic study of decay of the superoxide spin adduct (4-HOPPN-OOH) shows the half-life time of 8.8 min. On the basis of the X-ray structural coordinates, theoretical analyses using density functional theory (DFT) calculations at the B3LYP/6-31+G(d,p)//B3LYP/6-31G(d) level were performed on spin-trapping reactions of superoxide radical with 4-HOPPN and PBN and three possible decay routes for their corresponding superoxide adducts. The comparative calculations on the spin-trapping reactions with superoxide radical predicted that both spin traps share an identical reaction type and have comparable potency when spin trapping superoxide radical. Analysis of the optimized geometries of 4-HOPPN-OOH and PBN-OOH reveals that an introduction of the phosphoryl group can efficiently stabilize the spin adduct through the intramolecular H-bonds, the intramolecular nonbonding attractive interactions, as well as the bulky steric protection. Examination of the decomposition thermodynamics of 4-HOPPN-OOH and PBN-OOH further supports the stabilizing role of the phosphoryl group to a linear phosphorylated spin adduct.     

生物大分子纳米孔分析技术研究进展

脱氧核糖核酸穿越纳米孔动力学研究以及利用纳米孔开展新型DNA测序技术研究是后人类基因组计划的热点之一。本文对生物纳米孔、固态纳米孔以及纳米孔生物大分子识别技术的研究现状进行了归纳和总结,并对该领域的发展趋势进行展望。     

A novel ruthenium sensitizer with a hydrophobic 2-thiophen-2-yl-vinyl-conjugated bipyridyl ligand for effective dye sensitized TiO2 solar cells

A hydrophobic and 2-thiophen-2-yl-vinyl-conjugated ruthenium complex, cis-Ru(dhtbpy)(dcbpy)(NCS)2 [dhtbpy = 4,4'-di(hexylthienylvinyl)-2,2'-bipyridyl; dcbpy = 4,4'-dicarboxy-2,2'-bipyridyl], was newly designed, synthesized and applied successfully to sensitization of nanocrystalline TiO2-based solar cells, giving a conversion efficiency of 9.5% under irradiation with AM 1.5 solar light.     

二氰基二硫纶和4,4-二甲基2,2-联吡啶镍(Ⅱ)配合物的光谱和理论研究

报道了标题配合物Ni(mnt)(dmbpy)溶液的电子光谱、粉末样品部分IR光谱及量子化学理论研究结果.PM3方法的几何优化表明,该配合物分子为平面结构,其对称性属于C2v点群,基态为自旋三重态.结合ZINDO方法的CI计算,解释了实测电子光谱,发现该配合物在可见区450～550nm存在本质上属于配体dmbpy到配体mnt2-的荷移跃迁(LL′CT).建立了解析复杂分子振动光谱的一种新方法:根据理论计算所得三维动态图象,对于每一个正则模,先给出固定不动的点,再给出关键性的振动类型.在本方法中,用符号η(X)定义了一种新的沿给定方向起伏或跳动式的振动类型.     

Passively Q-switched laser performance of a composite Nd:YVO_{4}/Nd:YVO_{4}/Nd:YVO_{4} crystal with GaAs saturable absorber

By using GaAs wafer as the saturable absorber, the laser-diode pumped passively Q-switched composite Nd:YVO \(_{4}\) laser has been successfully demonstrated. For this passively Q-switched operation, the average output power obtained is as high as 846 mW at the incident pump power of 5.31 W, while the pulse duration is as short as 14.5 ns. The largest single-pulse energy of 2.49 \(\upmu \) J and the highest peak power of 166 W are obtained. The GaAs saturable absorber with thickness of 400 \(\upmu \) m has shown more excellent laser performance comparing with 700 \(\upmu \) m thick GaAs.     

原子对作用能与有机红外光谱的相关性研究

将有机分子中的Ｃ和Ｈ、Ｃ和Ｃ、Ｃ和Ｏ、Ｃ和Ｎ间化学键的红外伸缩振动吸收峰位与ＭＮＤＯ法计算的原子对作用能相比较，找到了很好的相关性，并用最小二乘法拟合得到各自的回归线和回归方程，其相关系数均达到０．９７以上。运用二者相关性规律定量地解释了有机分子中Ｃ－Ｈ、Ｃ－Ｃ、Ｃ＝Ｃ、Ｃ≡Ｃ、Ｃ－Ｏ、Ｃ＝Ｏ、Ｃ－Ｎ、Ｃ＝Ｎ、Ｃ≡Ｎ键的伸缩振动吸收峰移动的影响因素，如不饱和性、诱导、中介、共轭、环张力等。