飞行时间质谱中的空间电荷效应研究

在分子多光子电离实验中, 发现母体离子的飞行时间(TOF)质谱峰随激光强度的提高而展宽, 此现象归因于离子团内离子间库仑排斥作用的空间电荷效应. 为从理论上解释此现象, 尝试了从一个简单的理论模型进行推演, 得到飞行时间质谱峰的半高全宽(FWHM)与激光能量、样品气体的分压比、电极板的总电压、离子质量及所采用的透镜聚焦焦距之间关系的解析表达式, 所得的结果能够很好地说明实验现象.     

A New Asterosaponin from the Starfish Culcita novaeguineae

A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.     

Thermodynamic and Equilibrium Composition Analysis of Using Iron Oxide as an Oxygen Carrier in Nonflame Combustion Technology

1. Introduction The utilization of fossil fuels causes serious neg- ative impacts on the environment and human life. There are many pollutants such as SOx, NOx and CO2 emission produced from the combustion of coal, oil and natural gas. It has been known for more than 100 years that CO2 is a greenhouse gas and that the release of CO2 from fossil fuel combustion may affect the climate of the earth. In the last years the concern over the aspects of an increased release of greenhouse gases has…     

工业原料铁制备浆态床FT合成用的Fe-Cu-K-Si催化剂的探索

费托合成技术是公认的将煤基合成气转化为液体燃料和化工原料的重要技术途径。虽然固定床费托合成技术从五十年代起已经工业运转，但是浆态床费托合成技术由于其传热性能好，可直接使用第二代气化炉生产的富CO合成气，反应器结构简单，单台反应器生产能力大，开工率高，产品结构合理，     

Scalable synthesis of multi-shelled hollow N-doped carbon nanosheet arrays with confined Co/CoP heterostructures from MOFs for pH-universal hydrogen evolution reaction

Developing low-cost but efficient hydrogen evolution reaction(HER)electrocatalysts over whole pH values is a significant but daunting task for the large-scale application of electrochemical hydrogen production.Herein,we develop,for the first time,a scalable MOF-assisted strategy for the fabrication and microstructural optimization of multi-shelled hollow N-doped carbon nanosheet arrays with confined Co/CoP heterostructures on carbon cloth(Co/CoP@NC/CC)for boosting HER performances.The key to this strategy is the step-by-step epitaxial growth of unprecedented multilayer ZIF-L arrays on carbon cloth,which are subsequently pyrolyzed and controllably phosphorized to achieve the precise control over the shell number and nanoarchitectures of the Co/CoP@NC/CC.Impressively,the HER performances can be significantly enhanced by increasing hollow shell number,and the optimal triple-shelled hollow Co/CoP@NC/CC exhibits low overpotentials of 86,78 and 145 mV in acidic,alkaline and neutral media to deliver a current density of 10 mA cm^-2,respectively,ranking as one of the best Co-based HER electrocatalysts over whole pH values.Further DFT calculations suggest that the Co/CoP heterostructures can effectively boost the cleavage of H–OH to generate protons and optimize the adsorption energy of hydrogen(ΔG_H*),which,together with the large electrode/electrolyte interface and accelerated charge/mass transfer of multi-shelled hollow array structure as well as the good conductivity and dispersity,are responsible for the remarkably improved HER performances.This study not only provides a new toolbox for enriching the family of multi-shelled nanoarchitecture materials,but also points out a general and effective route to develop highly efficient self-supported electrode materials for energy-related applications and beyond.     

胶束溶液中高氯酸二水(四胺)合钴(Ⅲ)配合物催化磷酸二酯水解的研究

本文合成了疏水性高氯酸二水（四胺）合钴（Ⅲ）配合物，研究了它与非离子表面活性剂Brij35形成的金属2胶束催化二（对硝基苯酚）磷酸二酯水解的动力学及其机理。结果表明此金属胶束对磷酸二酯水解的速率大约提高10^4倍，这主要是由于表面活性剂胶束的pH效应和浓聚效应所致，暗示着顺式二水类配合物形成的金属胶束是一个潜在的磷酸二酯水解剪切的催化剂。     

Synthesis of Obyanamide, a Marine Cytotoxic Cyclic Depsipeptide

Obyanamide 1 is a cyclic depsipeptide that was recently isolated from the marine cyanobacterium Lyngbya confervoides by Moore and co-workers1. This compound displayed a potent inhibitory effect on both KB and LoVo cells in vitro. Several structural analog…     

芳香族热致液晶聚（对羟基苯甲酸－对苯二甲酸双酚A酯）的流变性能

用Ｉｎｓｔｒｏｎ３２１１型毛细管流变仪研究了以对羟基苯甲酸（ＰＨＢ）、对苯二甲酸（ＴＰＡ）和双酚Ａ（ＢＰＡ）为单体合成的共聚芳酯液晶熔体的流变性能。结果表明，切变速率、熔体温度及ＰＨＢ链节含量对切粘度和结构粘度有很大的影响。切变速率在１０～１０３／Ｓ、温度２９５～３３０℃范围内，共聚酯粘流活化能△Ｅη为７４．５～２０５．１（ｋＪ／ｍｏｌ）。液晶熔体在剪切流中存在屈服应力τｏ，随温度升高τｏ值降低。在低温、低切变速率下，共聚酯熔体的弹性很小，甚至呈现挤出收缩现象。     

乙醇酸和DL─乳酸交替共聚物的合成和表征

乙醇酸和ＤＬ－乳酸交替共聚物具有不同于其无规共聚物的理化性能和生物降解性。以ＤＬ－３－甲基－１，４－二烷－２，５－二酮为单体，通过在辛酸亚锡引发下的本体开环聚合，合成了该交替共聚物，并进行了结构表征。