Photopromoted Methoxycarbonylation of Olefins Under Ambient Conditions in DMF

Photopromoted methoxycarbonylation of olefins with carbon monoxide can be carded out under ambient conditions with non-precious transition metal complexes (such as cobalt complexes) catalysts in DME The isotope experiments show that DMF is decomposed under irradiation and is conveniently used as a carbon monoxide source for the reaction.     

Theoretical and Experimental Study on the Adsorption and Desorption of Methane by Granular Activated Carbon at 25 ℃

A theoretical and experimental study was conducted to accurately determine the amount of adsorption and desorption of methane by various Granular Activated Carbon(GAC)under different physical conditions.To carry out the experiments,the volumetric method was used up to 500 psia at constant temperature of 25℃.In these experiments,adsorption as well as desorption capacities of four different GAC in the adsorption of methane,the major constituent of natural gas,at various equilibrium pressures and a constant temperature were studied.Also,various adsorption isotherm models were used to model the experimental data collected from the experiments.The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported.The results shows that the physical characteristics of activated carbons such as BET surface area,micropore volume,packing density,and pore size distribution play an important role in the amount of methane to be adsorbed and desorbed.     

TOPICS IN POLYMER PHYSICS（With CD-Rom）

This important book emphasizes the basic derivation of many key equations used in polymer physics. Phrases such as “it can be easily shown that” and “it readily follows that”, seen in many textbooks, are seldom used here. The models, assumptions and key equations underlying concepts are presented in the text; details used in the derivations are given in the accompanying CD-Rom. The CD-Rom also contains problems （with solutions in many cases） which test the reader＇s grasp of the material, as well as a glossary of symbols.     

Studies on the Adsorption of Asymmetrical Triblock Copolymers by Scheutjens-Fleer Theory and Monte Carlo Simulation

The adsorption of asymmetrical triblock copolymers from a non-selective solvent on solid surface has been studied by using Scheutjens-Fleer mean-field theory and Monte Carlo simulation method on lattice model. The main aim of this paper is to provide detailed computer simulation data, taking A8-kB20Ak as a key example, to study the influence of the structure of copolymer on adsorption behavior and make a comparison between MC and SF results. The simulated results show that the size distribution of various configurations and density-profile are dependent on molecular structure and adsorption energy. The molecular structure will lead to diversity of adsorption behavior. This discrepancy between different structures would be enlarged for the surface coverage and adsorption amount with increasing of the adsorption energy. The surface coverage and the adsorption amount as well as the bound fraction will become larger as symmetry of the molecular structure becomes gradually worse. The adsorption layer becomes thicker with increasing of symmetry of the molecule when adsorption energy is smaller but it becomes thinner when adsorption energy is higher. It is shown that SF theory can reproduce the adsorption behavior of asymmetrical triblock copolymers. However, systematic discrepancy between the theory and simulation still exists.The approximations inherited in the mean-filed theory such as random mixing and the allowance of direct back folding may be responsible for those deviations.     

4D-proteomics-based breast cancer progressionEI北大核心CSCD

：The occurrence and development of breast cancer go through multiple processes，and the protein molecular information in its evolution is intricate and complex. The 4D-proteomics technique was used to investigate the tumor progression of MMTV-PyMT transgenic mice. The results of protein identification and differential expression analysis showed that a total of 5819 proteins were identified in 4D-proteomics analysis and 5667 proteins were quantifiable. Compared with 3-week-old tumors，a total of 270 differentially expressed proteins were found in the 5-week-old tumors，while 255 proteins in the 7-week-old tumors. We also detected 23 of proteins （such as，Srpk11 and Tinagl1）with gradual up-regulation and 35 of proteins （such as，Pdgfrb， Col1a2 and Col1a1）with gradual down-regulation during the tumor progression，including 3-，5-and 7-weeks. We also performed bioinformatics analysis，including subcellular localization，GO function analysis and pathway enrichment analysis. The results showed that the biological processes（immune regulation and lipid metabolism） and enrichment pathways （metabolic pathway）involved in differentially expressed proteins remained the same during the tumor progression，but some cellular components and molecular functions changed，such as，protein locations were extracellular region and membrane in 5-weeks-old tumors as well as cytoplasm in 7-weeks-old tumors. And important protein functions were protein binding functions in 5-weeks-old tumors as well as nucleotide binding in 7-weeks-old tumors. The acquired protein biomarkers and pathways could help with the accurate exploration of molecular mechanisms of tumor progression，screening of molecular targets of breast cancer，and evaluation of personalized treatment programs. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Two-photon spectroscopic behaviors and photodynamic effect on the BEL-7402 cancer cells of the new chlorophyll photosensitizer

The spectroscopic properties of a new chlorophyll derivate photosensitizer(CDP) are studied under the excitation wavelengths at 800 and 400 nm using femtosecond pulses from a Ti:sapphire laser.The damaging effect of CDP on the BEL-7402 cancer cells is also investigated upon two-photon illumination at 800 nm.The normalized fluorescence spectra of CDP in tetrahydrofuran(THF) show that two-photon and one-photon spectra have the same distributions and the same emission bands(675 nm).The life-times of two-and one-photon induced fluorescence of this molecule are of the order of 5.0 ns.By comparing the data it is shown that there is some difference between the two lifetimes,but the differ-ence is less than one nanosecond.The two-photon absorption cross section of the molecule is also measured at 800 nm and estimated as about σ′2 ≈ 31.5×10-50 cm4·s·photon-1.The results of two-photon photodynamic therapy(TPPDT) tests show that CDP can kill all of the tested cancer cells according to the usual Eosine assessment.Our results indicate that the two-photon-induced photophysical,photo-chemical and photosensitizing processes of CDP may be basically similar to those of one-photon ex-citation.These behaviors of the sample suggest that one may find other possible methods to estimate some photosensitizers' effects in details such as their distribution in cells and the reactive targets of the sub-cellular parts of some tumor cells via two-photon excitation techniques.     

Modeling the oxidative coupling of methane： Heterogeneous chemistry coupled with 3D flow field simulation

The oxidative coupling of methane (OCM) over titanate perovskite catalyst has been developed by three-dimensional numerical simulations of flow field coupled with heat transfer as well as heterogeneous kinetic model. The reaction was assumed to take place both in the gas phase and on the catalytic surface. Kinetic rate constants were experimentally obtained using a ten step kinetic model. The simulation results agree quite well with the data of OCM experiments, which were used to investigate the effect of temperature on the selectivity and conversion obtained in the methane oxidative coupling process. The conversion of methane linearly increased with temperature and the selectivity of C2 was practically constant in the temperature range of 973–1073 K. The study shows that CFD tools make it possible to implement the heterogeneous kinetic model even for high exothermic reaction such as OCM.     

常温预辐射聚合法物理包埋葡萄糖氧化酶的研究

Most of bioactive species such as enzyme and antibody will be damaged and lose part of their bioactivity when they are irradiated by ionizing radiation at room temperature. Low temperature could somewhat control the effect, so kaetsu and his co-workers developed an entrapping technique at low temperature ( - 78℃). On the other hand, some enzymes such as catalase and house radish peroxidase have so-called radiation-induced post-deactivation effect as well. In order to avoid the trouble in performance and loss of bioactivity, a physical ent-rapping of bioactive species via preirradiation polymerization at room temperature were deve-loped in the Authors'lab. In this work we developed this technique. The glucose oxidase was entrapped in polyacrylamide hydrogel ind uced by pre-irradiation. Experiments under several different conditions such as absorbed dose and concentrations of enzymes,monomer and crosslinking agent were carried out. The results showed that this technique can be used ex-tensively in various enzyme.     

Study on the Synthesis and Characterization of Novel Immobilized β-Cyclodextrin Polymer (Ⅰ)

A series of novel β-cyclodextrin polymers was synthesized by immobilization of β-cyclodextrin on the chloromethylated crosslinked polystyrene carriers. The synthetic conditions such as reaction time, temperature, molar feeding ratio of reactants, the degree of crosslinking of polystyrene and the catalysts used were studied in detail and the chemical and physical structures of the formed β-CDpolymers were characterized. Results show that the preparation method is simple and the amount of β-CD immobilized is high. As biomedical adsorbents, they were tested for removal of various endogenous and exogenous toxins such as phenols, aromatic amins, barbitals and unconjugated bilirubin. Results indicate that the adsorptión capacity for those toxins can be enhanced by the inclusion interaction among the β-CD, the substrate molecules and the β-CD polymers.     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

层状O2结构锂锰氧化物Li0.60[MgxCoyMn1-x-y]O2的制备及结构表征

本文采用离子交换法分别制备了双复合锂锰氧化物Li_0.60[Mg_xMn_1-x]O₂(0.05 ≤ x ≤ 0.15)和三复合锂锰氧化物Li_0.60[Mg_xCo_yMn_1-x-y]O₂(x=0.05，0.05 ≤      

直接Z型Zn2SnO4-xNx/ZnO1-yNy异质结光催化剂的制备及机理

采用微波溶剂热法成功制备直接Z型Zn_2SnO_(4-x)N_x/ZnO_(1-y)N_y核壳结构异质结光催化剂。2种物质不同的功函数改变了其表面电荷密度,并在界面处形成内建电场,导致其从传统的Ⅰ型镶嵌异质结转变为Ⅱ型异质结,再转变为Z型异质结构。N杂质原子替代O原子进入Zn_2SnO_4和ZnO的晶格,在两者的价带(VB)顶部形成双杂质能级。核壳结构的Z型异质结光催化剂对罗丹明B的降解速率为纯相Zn_2SnO_(4-x)N_x的1.40～1.43倍,同时具有良好的循环稳定性,且可以降解亚甲基蓝、甲基橙、水杨酸等污染物。Z型异质结的形成使其光生电子-空穴对具有较强的氧化还原能力,而双杂质能级的存在可以拓宽其光响应范围并提高载流子的分离效率。因此,Zn_2SnO_(4-x)N_x/ZnO_(1-y)N_y异质结光催化剂高的光催化活性归因于Z型异质结和双杂质能级的协同作用。     

用于NO_x低温下吸附还原的CoO_x/CeO_2二元氧化物的制备

研究了以多孔二氧化硅微球和活性炭为载体制备NOx吸附/还原催化剂的方法,摸索了最佳Ce/Co物质的量的比例。采用低温氮吸附方法测定了样品的BET比表面和孔容,利用XRD方法表征了样品中所掺杂的金属元素的晶型。研究发现:当nCe/nCo=75/25时,材料获得最佳NOx吸附能力,当以多孔二氧化硅微球作载体时,材料对于NOx的吸附主要来自CoOx和CeO2的二元氧化物;当以活性炭作为载体时,活性炭参与了NOx的吸附,因此其吸附容量大大提高。对NOx的吸附机理进行了探讨,并研究了样品的NH3还原性质。     

Synthesis, thermal stability and magnetic properties of the Lu1−xLaxMn2O5 solid solution

Polycrystalline samples of the Lu_1−xLa_xMn₂O₅ solid solution system were synthesized under moderate conditions for compositions with x up to 0.815. Due to the large difference in ionic size between Lu³⁺ and La³⁺, significant changes in lattice parameters and severe lattice strains are present in the solid solution. This in turn leads to the composition dependent thermal stability and magnetic properties. It is found that the solid solution samples with x≤0.487 decompose at a single well defined temperature, while those with x≥0.634 decompose over a temperature range with the formation of intermediate phases. For the samples with x≤0.487, the primary magnetic transition occurs below 40 K, similar to LuMn₂O₅ and other individual RMn₂O₅ (R=Bi, Y, and rare earth) compounds. In contrast, a magnetic phase with a 200 K onset transition temperature is dominant in the samples with x≥0.634.     

纳米钙钛矿LaxSr1-xFe1-yCoyO3复合氧化物的制备和表征

用甘氨酸-硝酸盐燃烧合成法，制备La_xSr_1-xFe_1-yCo_yO₃复合氧化物的陶瓷粉末，对该钙钛矿型氧化物进行了XRD、IR、紫外漫反射光谱及循环伏安曲线分析。结果表明：该复合氧化物粉体平均晶粒为15.3～29.8 nm,为立方和正交晶系。该氧电极具有双功能催化特性，但不完全可逆。对水溶液染料进行光解实验，利用紫外-可见、人工神经网络光度法研究La_xSr_1-xFe_1-yCo_yO₃的催化性能。结果表明：CO²⁺的加入可使La_xSr_1-xFeO₃的光催化活性有所提高，B位离子(Fe³⁺，CO²⁺)改变与加入，使La_xSr_1-xFe_1-yCo_yO₃(x=0.7，0.3；y=0.3，0.9，1)光催化活性高于La_xSr_1-xFeO₃。同时，对5种染料进行紫外光解，在0.75 h，脱色率大于91%，并为动力学一级反应。     

不同硅铝比Cu-ZSM-5纳米片上N2O催化分解

以双季铵盐表面活性剂为模板剂,水热条件下合成了硅铝比(nSi/nAl)为18、26和95的ZSM-5沸石纳米片,采用离子交换方法制备了铜改性的ZSM-5纳米片样品,并测试了其催化分解N_2O性能。结合X射线衍射(XRD)、N_2吸附/脱附、X射线荧光光谱(XRF)、扫描电镜(SEM)、透射电镜(TEM)、氢气程序升温还原(H_2-TPR)、氧气程序升温脱附(O_2-TPD)和原位红外漫反射光谱(CODRIFT)等表征结果 ,探讨了沸石硅铝比对于催化剂N_2O分解性能的影响及其原因。结果表明,ZSM-5纳米片硅铝比越低,CuZSM-5纳米片催化剂的活性越高。催化活性的提高归因于低硅铝比催化剂上Cu~+活性物种可还原性的增强和吸附氧脱附能力的提高。     

Chromium(III) Hydroxide Solubility in The Aqueous Na+-OH?-H2PO?4-HPO2?4-PO3?4-H2O System: A Thermodynamic Model

Chromium(III)-phosphate reactions are expected to be important in managing high-level radioactive wastes stored in tanks at many DOE sites. Extensive studies on the solubility of amorphous Cr(III) solids in a wide range of pH (2.8–14) and phosphate concentrations (10^–4 to 1.0 m) at room temperature (22±2)°C were carried out to obtain reliable thermodynamic data for important Cr(III)-phosphate reactions. A combination of techniques (XRD, XANES, EXAFS, Raman spectroscopy, total chemical composition, and thermodynamic analyses of solubility data) was used to characterize solid and aqueous species. Contrary to the data recently reported in the literature,⁽¹⁾ only a limited number of aqueous species [Cr(OH)₃H₂PO^–₄, Cr(OH)₃(H₂PO₄)^2–₂), and Cr(OH)₃HPO^2–₄] with up to about four orders of magnitude lower values for the formation constants of these species are required to explain Cr(III)-phosphate reactions in a wide range of pH and phosphate concentrations. The log K^o values of reactions involving these species [Cr(OH)₃(aq)+H₂PO^–₄⇌Cr(OH)₃H₂PO^–₄; Cr(OH)₃(aq)+2H₂PO^–₄⇌Cr(OH)₃(H₂PO₄)^2–₂; Cr(OH)₃(aq)+HPO^2–₄⇌Cr(OH)₃HPO^2–₄] were found to be 2.78±0.3, 3.48±0.3, and 1.97±0.3, respectively.     

CrOx-CeO2二元氧化物表面NO的NH3催化还原反应机理

利用原位漫反射红外光谱法研究了473 K下在CrOx-CeO₂二元氧化物表面NO的NH₃催化还原反应的机理。研究了CrO-CeO₂二元氧化物表面在反应过程中的表面吸附物种。为了更加清晰的了解反应过程, 在SCR反应过程中分别切断NH₃和NO的气流, 并采集了所生成的原位漫反射红外光谱图, 通过研究以上结果得出结论:当前状态下的SCR反应过程可能服从E-R机理。     

CrOx-CeO2二元氧化物表面NO的NH3催化还原反应机理

利用原位漫反射红外光谱法研究了473 K下在CrOx-CeO2二元氧化物表面NO的NH3催化还原反应的机理。研究了CrOx-CeO2二元氧化物表面在反应过程中的表面吸附物种。为了更加清晰的了解反应过程,在SCR反应过程中分别切断NH3和NO的气流,并采集了所生成的原位漫反射红外光谱图,通过研究以上结果得出结论:当前状态下的SCR反应过程可能服从ER机理。