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DFT Studies on Hydrogen Overfall Mechanism for Catalyzed Hydroisomerization of Pentane

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Chinese Journal of Structural Chemistry 2007年第2期26卷 239-247页

作者： AI Chun-Zhi SUN Ren-An wang chang-sheng College of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 China Dalian Institute of Chemical Physics The Chinese Academy of Sciences Dalian 116021 China

The mechanism and related reaction paths in the hydroisomerization of n-pentane were studied by DFT calculations at the B3LYP/6-311＋＋G^＊＊ level. Two possible transition states were theoretically predicted and verified by the vibration frequency analysis as well as the calculations of intrinsic reaction coordinates （IRC）. Furthermore, the related reaction barriers were evaluated by single point energy at the MP2/6-311＋＋G^＊＊ level with zero point vibration correction of DFT method. Thus, it is concluded that the isomerization might go through two pathways.

关键词： catalyzed isomerization of n-pentane hydrogen overfall mechanism i-pentane DFT

Absorption and Fluorescence Emission Spectra of Molecules Containing Azo and/or Oxadiazole Units

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Chemical Research in Chinese Universities 2013年第4期29卷 776-781页

作者： wang chang-sheng YU Nan LIU Peng School of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 P. R. China

The ground state structures of a series of organic molecules containing azo and/or oxadiazole units were obtained by means of density functional theory B3LYP/6-3IG（d） method. The first singlet excited state structures were optimized by virtue of singlet-excitation configuration interaction CIS/6-31G（d） method. The absorption and fluorescence emission spectra were then evaluated via the time-dependent density functional theory B3LYP and PBE1PBE methods with 6-31 l＋＋G（3df,2p） basis set. The calculation results show that compared with those of their parent molecules A-H, B-H, C-H, D-H, the absorption and emission wavelength values of all the derivatives show red shifts. The derivatives containing both the oxadiazole and methoxyl units are good candidates for longer absorption wavelength materials. The effects of azo, oxadiazole, and methoxyl units on the absorption and emission wavelength were discussed.

关键词： Azo Azobenzene Oxadiazole Absorption spectrum Fluorescence emission spectrum Excited state

MXene Hybridized Polymer with Enhanced Electromagnetic Energy Harvest for Sensitized Microwave Actuation and Self‑Powered Motion Sensing

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Nano-Micro Letters 2025年第3期17卷 265-279页

作者： Yu‑Ze wang Yu‑chang wang Ting‑Ting Liu Quan‑Liang Zhao Chen‑Sha Li Mao‑sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of Materials Science and Engineering Peking UniversityBeijing 100871People’s Republic of China School of Mechanical and Material Engineering North China University of TechnologyBeijing 100144People’s Republic of China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080People’s Republic of China

Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.

关键词： Microwave absorption Electromagnetic response Energy harvest Self-sensing Soft actuator

Magnetostrictions and Magnetic Properties of Nd-Fe-B and SrFe_(12)O_(19)

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Chinese Physics Letters 2011年第7期28卷 271-274页

作者： CHEN Hai-Ying ZHANG Yan YANG Yun-Bo CHEN Xue-Gang LIU Shun-Quan wang chang-sheng YANG Ying-chang YANG Jin-Bo School of Physics Peking UniversityBeijing 100871 State Key Laboratory for Mesoscopic Physics Department of PhysicsPeking UniversityBeijing 100871

The magnetostrictions of polycrystalline Nd-Fe-B and Sr-ferrite at different temperatures are reinvestigated using a strain gauge rotating-sample *** is found that the magnetostrictionλs of Nd−Fe-B is+52×10^(−6),and that of Sr-ferrite is−25×10^(-6) under a magnetic field of 8 T at room *** maximum energy product(BH)max of the Nd-Fe-B magnet is improved when the powders are magnetically aligned perpendicular to the pressing direction,whereas that of the Sr-ferrite magnet is better when the powders are aligned parallel to the pressing *** experimental results suggest that the magnetostriction can generate compressive strain anisotropy resulting from the inverse effect of the ***,the magnetization of materials with a negative coefficient of magnetostriction are easier to be aligned normal to the stress direction,while for the materials with a positive coefficient of magnetostriction,the magnetization is easier to be aligned along the stress ***,the magnetostriction anisotropy can be used to improve the alignment of the magnetic powders as well as the performance of the magnets.

关键词： temperature method powders

Combined biochar and wheat-derived endophytic bacteria reduces cadmium uptake in wheat grains in a metal-polluted soil

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Journal of Environmental Sciences 2025年第1期147卷 165-178页

作者： Zhihui Xiong Yaping wang Linyan He Qi sheng Xiafang sheng College of Life Sciences Key Laboratory of Agricultural and Environmental MicrobiologyMinistry of AgricultureNanjing Agricultural UniversityNanjing 210095China

In this study,two wheat-derived cadmium(Cd)-immobilizing endophytic Pseudomonas paralactis M14 and Priestia megaterium R27 were evaluated for their effects on wheat tissue Cd uptake under hydroponic ***,the impacts of the biochar(BC),M14+R27(MR),and BC+MR treatments on wheat Cd uptake and the mechanisms involved were investigated at the jointing,heading,and mature stages of wheat plants under field-plot conditions.A hydroponic experiment showed that the MR treatment significantly decreased the above-ground tissue Cd content compared with theM14 or R27 *** BC+MRtreatment reduced the grain Cd content by 51.5%-67.7%and Cd translocation factor at the mature stage of wheat plants and increased the organic matter-bound Cd content by 31%-75%in the rhizosphere soils compared with the BC or MR *** with the BC or MR treatment,the relative abundances of the biomarkers associated with Gemmatimonas,Altererythrobacter,Gammaproteobacteria,Xanthomonadaceae,Phenylobacterium,and Nocardioides in the BC+MR-treated rhizosphere microbiome decreased and negatively correlated with the organic matter-bound Cd *** the BC+MR-treated root interior microbiome,the relative abundance of the biomarker belonging to Exiguobacterium increased and negatively correlated with the Cd translocation factor,while the relative abundance of the biomarker belonging to Pseudonocardiaceae decreased and positively correlated with the Cd translocation *** findings suggested that the BC+MR treatment reduced Cd availability and Cd transfer through affecting the abundances of these specific biomarkers in the rhizosphere soil and root interior microbiomes,leading to decreased wheat grain Cd uptake in the contaminated soil.

关键词： Cd-immobilizing endophytic bacteria Cd-contaminated soil Biochar+endophytic bacteria Grain Cd uptake Specific biomarkers

Culprit vessel only versus ＂one-week＂ staged percutaneous coronary intervention for multivessel disease in patients presenting with ST-segment elevation myocardial infarction

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Journal of Geriatric Cardiology 2015年第3期12卷 226-231页

作者： Li-Xiang MA Zhen-Hua LU Le wang Xin DU chang-sheng MA Department of Cardiology Beijing Anzhen Hospital Capital Medical University Beo'ing China

Objective To explore the impact of a ＂one-week＂ staged muhivessel percutaneous coronary intervention （PCI） versus culprit-only PCI on deaths and major adverse cardiac events （MACE）. Methods We retrospectively analyzed 447 patients with multivessel disease who experienced a ST-segment elevation myocardial infarction （STEMI） within 12 h before undergoing PCI between July 26, 2008 and Septem- ber 25, 201 l. After completion of PCI in the infarct artery, 201 patients still in the hospital agreed to undergo PCI in non-infarct arteries with more than 70% stenosis for a ＂one-week＂ staged multivessel PCI. A total of 246 patients only received intervention for the culprit vessel. Follow-up ended on September 9, 2014. This study examined the differences in deaths from any cause （i.e., cardiac and noncardiac） and MACE between the two treatment groups. Results Compared to a culprit-only PCI treatment approach, the ＂one-week＂ staged multivessel PCI was strongly associated with greater benefits for 55-month all cause death [41 （16.7%） vs. 13 （6.5%）, P = 0.004] and MACE [82 （33.3%） vs. 40 （19.9%）, P = 0.002] rates. In addition, there were significant differences in the number of myocardial infarctions [43 （17.5%） vs. 20 （10.0%）, P = 0.023], coronary-artery bypass grafting [CABG; 20 （8.1%） vs. 6 （3.0%）, P = 0.021], and PCI [31 （12.6%） vs. 12 （6.0%）, P - 0.018]. Patients undergoing culprit-only PCI compared to ＂one-week＂ PCI had the same number of stent thrombosis events [7 （2.8%） vs. 3 （1.5%）, P - 0.522]. Conclusions Compared to a culprit-only PCI treatment approach, ＂one-week＂ staged multi-vessel PCI was a safe and effective selection for STEMI and multi-vessel PCL

关键词： ST-segment elevation myocardial infarction Percutaneous coronary intervention Multivessel revascularization

Omnidirectional simulation analysis of thermomechanical coupling mechanism in inertia friction welding of Ni-based superalloy

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Chinese Journal of Aeronautics 2025年第1期38卷 202-216页

作者： chang-an LI Guoliang QIN Hao wang School of Materials Science and Engineering Shandong UniversityJinan 250061China

The coupling between heat and pressure is the kernel of inertia friction welding(IFW)and is still not fully understood.A novel 3D fully coupled finite element model based on a plastic friction pair was developed to simulate the IFW process of a Ni-based superalloy and reveal the omnidirectional thermo-mechanical coupling mechanism of the friction *** numerical model successfully simulated the deceleration,deformation processes,and peak torsional moments in IFW and captured the evolution of temperature,contact pressure,and *** simulated results were validated through measured thermal history,optical macrography,and axial *** results indicated that interfacial friction heat was the primary heat source,and plastic deformation energy only accounted for 4%of the *** increase in initial rotational speed and friction pressure elevated the peak temperature,reaching a maximum of 1525.5K at an initial rotational speed of 2000 r/min and friction pressure of 400 *** interface heat generation could form an axial temperature gradient exceeding 320K/*** radial inhomogeneities of heat generation and temperature were manifested in a concentric ring distribution with maximum heat flux and temperature ranging from 2/5 to 2/3 *** radial inhomogeneities were caused by increasing linear velocity along the radius and an opposite distribution of contact pressure,which could reach 1.7 times the set pressure at the *** circumferential inhomogeneity of thermomechanical distribution during rotary friction welding was revealed for the first time,benefiting from the 3D *** deflection and transformation of distribution in contact pressure and Mises stress were indicators of plastic deformation and transition of quasi-steady state *** critical Mises stress was 0.5 times the friction pressure in this *** presented modeling provides a reliable insight into the thermo-mechanical coupling mechanism of IFW and lays a solid found

关键词： Inertia friction welding Thermo-mechanical coupling Inhomogeneity Numerical simulation Ni-based superalloy

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2-磷酸甘油酸脱水反应机理的理论研究

化学学报 2010年第21期68卷 2186-2190页

作者：曲威王长生辽宁师范大学化学化工学院大连116029

采用密度泛函理论B3LYP方法研究了蛋白质和水环境下2-磷酸甘油酸脱水生成磷酸烯醇式丙酮酸的反应机理.优化得到了反应物、过渡态及产物的几何构型并计算了反应势垒.研究结果表明:没有H2O参与时,反应需要通过四元环过渡态完成,反应势垒高... 详细信息

采用密度泛函理论B3LYP方法研究了蛋白质和水环境下2-磷酸甘油酸脱水生成磷酸烯醇式丙酮酸的反应机理.优化得到了反应物、过渡态及产物的几何构型并计算了反应势垒.研究结果表明:没有H2O参与时,反应需要通过四元环过渡态完成,反应势垒高达287.7kJ/mol,常温下难以进行;有H2O参与时,反应可以通过六元环过渡态完成,反应势垒大为降低;Mg2+的参与可使反应势垒进一步降低;蛋白质环境下两个Mg2+和一个H2O的共同作用可使反应势垒降低至91.2kJ/mol,从而使反应在常温下容易进行.

关键词： 2-磷酸甘油酸磷酸烯醇式丙酮酸反应势垒

取代基对有机金属钽化合物中分子内α-H转移势垒的影响

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物理化学学报 2009年第2期25卷 360-364页

作者：赵威王长生辽宁师范大学化学化工学院辽宁大连116029

运用B3LYP方法研究了有机钽化合物中分子内α-氢转移反应,探讨了不同取代基对α-氢转移反应势垒的影响.确定了反应物、过渡态和产物的几何构型和反应势垒.结果表明,过渡金属钽有机化合物中,发生α-氢转移的碳原子在过渡态中采用sp2杂化... 详细信息

运用B3LYP方法研究了有机钽化合物中分子内α-氢转移反应,探讨了不同取代基对α-氢转移反应势垒的影响.确定了反应物、过渡态和产物的几何构型和反应势垒.结果表明,过渡金属钽有机化合物中,发生α-氢转移的碳原子在过渡态中采用sp2杂化.取代基对α-氢转移势垒的影响取决于取代基对过渡态中碳原子的未参与杂化的pz轨道上单电子的离域作用.Ta(CH3)4CH(SiMe3)2的α-氢转移反应势垒最低.

关键词：金属钽有机化合物 α-H转移反应势垒