吹扫/捕集-热脱附气质联用法对荷叶挥发油成分的对比分析

采用同时蒸馏萃取提取得到荷叶挥发油, 通过吹扫/捕集-热脱附法(P&T-TD)对上述提取物中挥发性成分进行富集, 以气质联用(GC/MS)进行定性检测, 同时与直接进样GC/MS法分析的成分进行比较. 两种方法成功分离分析出有机酸、酯、醛、醇、酚、烷烃、芳香烃、烯烃以及含氮、硫、氧杂原子的化合物等共计84种成分, 其中P&T-TD GC/MS鉴定出63种有机化合物, GC/MS鉴定出41种有机化合物, 有20种成分共同检出. 对比分析表明: P&T-TD GC/MS的吹扫/捕集-热脱附过程能富集各种组分, 相比GC/MS分析, 可以鉴定出微量成分及更多挥发性和半挥发性成分, 在精油等挥发性成分的分析检测中使用优势明显.     

Cationic IrIII Emitters with Near-Infrared Emission Beyond 800 nm and Their Use in Light-Emitting Electrochemical Cells

Solid-state near-infrared (NIR) light-emitting devices have recently received considerable attention as NIR light sources that can penetrate deep into human tissue and are suitable for bioimaging and labeling. In addition, solid-state NIR light-emitting electrochemical cells (LECs) have shown several promising advantages over NIR organic light-emitting devices (OLEDs). However, among the reported NIR LECs based on ionic transition-metal complexes (iTMCs), there is currently no iridium-based LEC that displays NIR electroluminescence (EL) peaks near to or above 800 nm. In this report we demonstrate a simple method for adjusting the energy gap between the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO) of iridium-based iTMCs to generate NIR emission. We describe a series of novel ionic iridium complexes with very small energy gaps, namely NIR1 – NIR6 , in which 2,3-diphenylbenzo[g]quinoxaline moieties mainly take charge of the HOMO energy levels and 2,2′-biquinoline, 2-(quinolin-2-yl)quinazoline, and 2,2′-bibenzo[d]thiazole moieties mainly control the LUMO energy levels. All the complexes exhibited NIR phosphorescence, with emission maxima up to 850 nm, and have been applied as components in LECs, showing a maximum external quantum efficiency (EQE) of 0.05 % in the EL devices. By using a host–guest emissive system, with the iridium complex RED as the host and the complex NIR3 or NIR6 as guest, the highest EQE of the LECs can be further enhanced to above 0.1 %.     

Neuroprotective effects of exogenous activin A on oxygen-glucose deprivation in PC12 cells

Ischemic cerebrovascular disease is one of the most common causes of death in the World. Exogenous activin A (ActA) protects neurons against toxicity and plays a central role in regulating the brain's response to injury. In the present study, we investigated the mechanisms involved in the neuroprotective effects of ActA in a model of hypoxic-ischemic brain disease. We found that ActA could effectively increase the survival rate of PC12 cells and relieve oxygen-glucose deprivation (OGD) damage. To clarify the neuroprotective mechanisms of ActA, the effects of ActA on the ActA/Smad pathway and on the up-regulation of inducible nitric oxide synthase (NOS) and superoxide dismutase (SOD) were investigated using OGD in PC12 cells. The results showed that ActA could increase the expression of activin receptor IIA (ActRIIA), Smad3 and Smad4 and that 50 ng/mL and 100 ng/mL of ActA could reduce NO levels and increase SOD activity by 78.9% and 79.9%, respectively. These results suggested that the neuroprotective effects of ActA in ischemia could be related to the activation of the ActA/Smad signaling pathway and to its anti-oxidant activities.     

较高当量比氢气空气预混合气的燃烧特性研究

利用纹影法,在定容燃烧弹中研究了较高当量比和不同初始压力下氢气空气预混合气的燃烧特性,分析了两参数对其燃烧特性的影响。试验结果表明,本实验条件下的氢气空气预混合物燃烧过程中,主火焰两侧出现挤流火焰,且挤流火焰的传播明显快于主火焰;根据出现挤流火焰与否、两侧挤流火焰相遇与否、实验时的热力参数、燃料浓度等条件,燃烧过程可分为四个阶段;在本文的实验条件下随着当量比增加,挤流火焰燃烧速度加快,其倾向于自燃时的多点燃烧;随着初始压力降低,挤流火焰逐渐出现在主火焰层流燃烧阶段。     

Development of a family of explicit algorithms for structural dynamics with unconditional stability

A new family of explicit integration algorithms is developed based on discrete control theory for solving the dynamic equations of motion. The proposed algorithms are explicit for both displacement and velocity and require no factorisation of the damping matrix and the stiffness matrix. Therefore, for a system with nonlinear damping and stiffness, the proposed algorithms are more efficient than the common explicit algorithms that provide only explicit displacement. Accuracy and stability properties of the proposed algorithms are analysed theoretically and verified numerically. Certain subfamilies are found to be unconditionally stable for any system state (linear elastic, stiffness softening or stiffness hardening) that may occur in earthquake engineering of a practical structure. With dual explicit expression and excellent stability property, the proposed family of algorithms can potentially solve complicated nonlinear dynamic problems.     

以5-甲基-3-吡唑甲酸为配体构建的具有六方孔道的钴(Ⅱ)、镍(Ⅱ)超分子化合物：合成、晶体结构和性质

利用5-甲基-3-吡唑甲酸,分别与CoCl2·6H2O和Ni(NO3)2·6H2O反应,得到了配合物[M(MPA)2(H2O)2](1:M=Co;2:M=Ni)(HMPA=5-甲基-3-吡唑甲酸)。用元素分析、红外光谱、X-单晶衍射结构分析对其进行了表征。配合物1和2的晶体结构参数如下:配合物1和2的晶体都属于六方晶系,空间群为R3c。配合物1的晶胞参数为a=1.483 94(4)nm,b=1.483 94(4)nm,c=3.207 66(6)nm,V=6.117 2(3)nm3,Z=18;配合物2的晶胞参数为a=1.466 53(14)nm,b=1.466 53(14)nm,c=3.243 0(6)nm,V=6.04 03(14)nm3,Z=18。金属离子与来自2个5-甲基-3-吡唑甲酸配体中的2个氮原子及2个氧原子,2个水分子中的2个氧原子配位,形成八面体配位构型。配合物中的独立结构单元[M(MPA)2(H2O)2]通过分子间氢键形成具有六方孔道的三维结构。热重分析表明配合物1和2具有较高的热稳定性。此外,考察了配合物1和2的荧光和电化学性质。CCDC:900677,1;900678,2。     

Synthesis,structure, and luminescent properties of two novel polynuclear complexes of 1,3-di(pyridin-2-yl)propane-1,3-dione

Two complexes, {[Cd₆(o-dppd)₂(μ²-Cl)₆(μ³-Cl)₂(DMF)₂(H₂O)₂Cl₂]·DMF·CH₃OH} _n (I) (DMF = N,N-dimethylformamide; o-dppdH = 1,3-di(pyridin-2-yl)propane-1,3-dione) and [Cu₄(o-dppd)₂(OAc)₄(OH)₂]·4H₂O (II), were synthesised and characterised by single-crystal X-ray diffraction, elemental analysis, IR, solid fluorescence and TGA. The results showed that complex I had a rodshaped polynuclear chain with hexacoordinating Cd atoms bridged by oxygen, μ²-Cl and μ³-Cl; complex II was a tetranuclear oligomer. In general, supramolecular architectures are constructed through hydrogen-bonding and π-π stacking interactions. I shows luminescence.     

CS+2离子(～C)2∑+g←(～B)2∑+u跃迁的Franck-Condon因子计算以及与光解离谱的比较

将线性三原子分子离子CS+2的对称伸缩振动简化为SC和S之间的简谐振动,用谐振子的势能曲线和波函数对CS+2分子离子(～C)2∑+g和(～B)2∑+u电子态(对称伸缩)振动能级间跃迁的Franck-Condon因子进行了计算,得到的结果与(～C)2∑+g←(～B)2∑+u跃迁的光解离谱实验强度进行了比较,对前人给出的分子数据(转动常数、分子平衡核间距)进行了验证和分析,讨论了经由(～C)2∑+g←(～B)2∑+g电子态振动能级间跃迁的光解离机理.     

Bi2212体系的层间耦合对临界电流密度的影响

通过对具有不同层间耦合强度的Bi2212单晶样品的磁滞回线的测量,得到了样品的临界电流密度Jc随层间耦合强度和磁场的变化关系．实验结果显示,样品的层间耦合减弱,Jc明显减小．同时发现Jc与磁场间存在Jc ∝ exp(-H^a)关系,进一步分析表明,Jc的这种磁场依赖关系是对数钉扎势垒模型的必然结果．     

Crystal and Molecular Structure of （μ—FcCO）（μ—t—BuS）Fe2（CO）6

ＣｒｙｓｔａｌａｎｄＭｏｌｅｃｕｌａｒＳｔｒｕｃｔｕｒｅｏｆ（μ－ＦｃＣＯ）（μ－ｔ－ＢｕＳ）Ｆｅ_２（ＣＯ）_６ＬｉｕＪｉｎ－Ｔｉｎｇ（ＣｏｌｌｅｇｅｏｆＣｈｅｍｉｓｔｒｙ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｊｉｎａｎ，２５０１００）Ｒｅｃｅｉｖ...