Three-dimensional five-connected coordination polymer [M2(C3H2O4)2(H2O)2(μ2-hmt)]n with 46 topologies (M=Zn, Cu; hmt=hexamethylenetetramine)

Two novel three-dimensional five-connected coordination polymers [M₂(C₃H₂O₄)₂(H₂O)₂(μ₂-hmt)]_n with 4⁴6⁶ topologies (M=Zn, Cu; hmt=hexamethylenetetramine) were synthesized and characterized by elemental analysis, crystal structure, IR, thermal gravimetric analyses. Both [Zn₂(C₃H₂O₄)₂(H₂O)₂(μ₂-hmt)]_n and [Cu₂(C₃H₂O₄)₂(H₂O)₂(μ₂-hmt)]_n all crystallize in the orthorhombic system, space group Imm2, and with Z=2. Metal ions have all octahedral geometry coordinated by four oxygen atoms from three malonates, one oxygen atom from a water molecule and one nitrogen atom of hmt ligand. Each malonate binds a metal ion with its two oxygen atoms in a chelating mode and connects to adjacent two metal ions with another two oxygen atoms to form an infinite wavy layer. The layers are bridged by μ₂-hmt molecules to form a three-dimensional framework with channels. The magnetic susceptibility data show there is a weak antiferromagnetic exchange interaction in the complex [Cu₂(C₃H₂O₄)₂(H₂O)₂(μ₂-hmt)]_n.     

A fiber coupling system based on the GRIN lens for use in all-fiber lidars

The all-fiber lidar shows exciting prospects in space-borne applications, but the coupling efficiency between the telescope and a single-mode fiber is an important problem in the lidar design. We employ the mode-matching theory to analyze theoretically the coupling efficiency. In practical coupling system design, three position deviations, which are the off-axis deviation, defocus deviation, and angle deviation, exert a substantial influence on the coupling efficiency and must be considered and discussed. Generally it is very difficult for a fiber coupling system based on a single lens to adjust the fiber position deviations and obtain the maximum coupling efficiency. Therefore, a coupling system, based on the GRIN lens combined with the lenses, is designed and employed to decrease the influence of these position deviations. We perform some numerical simulations to verify the feasibility of a coupling system based on the GRIN lens. Our results show that a coupling system based on the GRIN lens can overcome the off-axis deviation and defocus deviation and decrease the adjustment difficulty.     

自动固相萃取-液相色谱-飞行时间质谱法快速筛查与确证血液中抗抑郁类药物

建立了血液中抗抑郁类药物快速筛查的自动固相萃取-液相色谱-飞行时间质谱（ASPE-LC-Q-TOF/MS）方法。样品经HLB固相萃取柱提取后,采用LC-Q-TOF/MS进行测定,外标法定量。结果表明：目标物的线性范围为1~500 μg/L,相关系数为0.9976~0.9997,检出限为0.01~0.5 μg/L。在10、100和500 μg/L 3个添加水平的平均回收率为79.6%~96.4%,相对标准偏差为4.1%~6.4%。利用Agilent MassHunter PCDL Manager软件建立了抗抑郁类药物数据库,并应用于加标样品的筛查分析,本方法能够全部筛查出样品中添加的抗抑郁类药物,鉴定准确度达到100%,且保留时间偏差均小于0.1 min,质量偏差均小于1 mDa,同位素丰度匹配得分、同位素间距得分和MS匹配得分均大于95,MS/MS图谱匹配得分均大于70。利用本方法对实际案例进行筛查分析,检出阿米替林、卡马西平和多虑平,说明该方法可用于法庭与临床毒物分析。     

长江三峡花岗岩林地坡面降雨渗流与水土流失关系研究

在大量的野外观测试验的基础上,根据土壤水分的形态和能态,对长江三峡花岗岩林地坡面降雨渗流机制进行了分析研究,研究发现在试验区当降雨强度大于表层土壤入渗率,即地表产生积水的情况下,长江三峡花岗岩林地坡面优先流在土壤含水量未达到最大毛管持水量时开始产流,早于土壤渗流产流的时间;在降雨强度小于表层土壤入渗率,即地表不产生积水的情况下,土壤渗流产流早于优先流产流;从壤中流产流过程来看,在地表不产生积水的条件下,土壤渗流先于优先流产生;在地表产生积水而土壤水分含量未达到最大毛管持水量的条件下,优先流先于土壤渗流产生。在两种情况下,优先流的峰值都先于土壤渗流。     

二苯乙烯衍生物的合成与抗癌活性的初步研究

以对硝基甲苯和3,4,5-三甲氧基苯甲醛或3,4-二甲氧基苯甲醛为起始原料,经过缩合、还原和酰化反应,合成了(E)-3,4,5-三甲氧基-4'-乙酰氨基二苯乙烯等4种二苯乙烯衍生物.4种化合物对HepG2和BGC-823两种细胞模型的体外抗癌活性测试结果表明,这些化合物具有良好的抗肿瘤活性且对正常细胞毒性较小.     

构建一维铜基配位聚合物作为锂离子电池正极材料

合成了一种新型的一维(1D)羰基配位聚合物[Cu (BGPD)(DMA)(H₂O)]·DMA (记为Cu-BD,H₂BGPD=N,N′-双(甘氨酰)均苯四甲酸二酰亚胺,DMA=二甲基乙酰胺),并考察了其用作锂离子电池正极材料的电化学性能。电化学测试结果表明,Cu-BD正极在50 mA·g^-1的电流密度下循环100圈后仍然保留50 mAh·g^-1的比容量,具有较好的循环稳定性。Cu-BD电极反应机理研究表明,BGPD^2-配体和Cu (Ⅱ)离子在充放电过程中都可能参与了电子转移过程。     

An energy decomposition analysis for intramolecular non-covalent interaction in solvated environment

In this work, the intra-EDA method, which is a recently developed energy decomposition analysis scheme for intramolecular non-covalent interaction is extended from gas phase to solvated environment. It is the first analysis scheme that performs analysis for intramolecular interaction in solution. By fragmentation scheme, a molecule is divided into intramolecular interacting fragments and environmental fragments via single bond homolysis breaking. The solvent effect is taken into account by implicit solvation model. Intramolecular interaction free energy is estimated as the separated treatment of inter-fragment interactions in dielectric environment. The analysis results highlight the importance of solvent effects to intramolecular non-covalent interaction.     

Particle Size Distributions Based on a Multipopulation Genetic Algorithm Used in Multiwavelength Lidar

Aerosols influence the radiation budget of the Earth’s atmospheric system. Aerosol particle size distribution is one of the major parameters used for characterizing aerosol influence on radiative forcing. The optical and microphysical properties of aerosol particles over Yinchuan, China, were measured with a multiwavelength lidar developed at Beifang University of Nationalities using backscatter and extinction coefficients at wavelengths of 1064, 532, and 355 nm. These data were used to retrieve particle size distributions. Given the disadvantages of the traditional regularization method, the innovative multipopulation genetic algorithm (MPGA) was used to retrieve the particle size distribution from the lidar data. To verify the feasibility of using the MPGA on multiwavelength lidar data, experiments were carried out under different atmospheric conditions, including a background sunny day, a cloudy day, and a foggy day. The particle size distributions obtained from the multiwavelength lidar data were compared with results retrieved from direct irradiance data from a sun photometer. Results showed that the MPGA is suitable for retrieving particle size distributions from multiwavelength lidar data.     

Asymmetric Dearomatization of Indoles through a Michael/Friedel–Crafts‐Type Cascade To Construct Polycyclic Spiroindolines

A highly efficient asymmetric dearomatization of indoles was realized through a cascade reaction between 2‐isocyanoethylindole and alkylidene malonates catalyzed by a chiral N,N′‐dioxide/Mg^II catalyst. Fused polycyclic indolines containing three stereocenters were afforded in good yields with excellent diastereo‐ and enantioselectivities through a Michael/Friedel–Crafts/Mannich cascade. When 2‐substituted 2‐isocyanoethylindoles were used, spiroindoline derivatives were obtained through a Michael/Friedel–Crafts reaction.     

Comparative pharmacokinetic study of six lignans in normal and diabetic rats after oral administration of Saururus chinensis extract by LC–MS/MS

Saururus chinensis (SC) possesses significant anti-diabetic activity and lignans were its major bioactive compounds. In this study, a rapid and sensitive ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was established for simultaneous quantification of six lignans, namely (-)-(7R,8R)-machilin D ( 1 ), verrucesin ( 2 ), rel-(7S,8S,7′R,8′R)-3,3′,4,4′,5,5′-hexamethoxy-7.O.7′,8.8′-lignan ( 3 ), manassantin A ( 4 ), manassantin B ( 5 ), and saucerneol F ( 6 ) in rat’s plasma. It was validated with acceptable linearity (r ≥ 0.9922), accuracy (80.42–95.17%), precision (RSD ≤ 12.08%), and extraction recovery (80.36–93.45%). The method was successfully applied to the comparative pharmacokinetic study of the six lignans in normal and diabetic rats after oral administration of SC extract. Results showed that the areas under the plasma concentration-time curve (AUC_{0 → t} and AUC_{0 → ∞}) of (-)-(7R,8R)-machilin D, rel-(7S,8S,7′R,8′R)-3,3′,4,4′,5,5′-hexamethoxy-7.O.7′,8.8′-lignan, manassantin B, and saucerneol F in diabetic rats were significantly increased, and the plasma clearance (CL) of (-)-(7R,8R)-machilin D in diabetic rats was significantly decreased. However, the AUC_{0 → t} and AUC_{0 → ∞} of verrucesin were significantly decreased, and its CL was significantly increased in diabetic rats compared with those in normal rats. These results indicated that there were remarkable differences in the pharmacokinetic parameters between the normal and diabetic rats. The pharmacokinetic studies might be beneficial for the clinical use of SC as hypoglycemic agent.