CircFoxo3调节miR-130a-5p/TEAD1轴对心力衰竭大鼠心肌细胞凋亡影响的实验研究

目的探讨环状RNA叉头框蛋白O3(CircFoxo3)调节miR-130a-5p/TEA域转录因子1(TEAD1)轴对心力衰竭(HF)大鼠心肌细胞凋亡的影响。方法将SD大鼠分为对照组、HF组、si-NC组、si-CircFoxo3组、agomir NC组、miR-130a-5p agomir组、si-CircFoxo3+antagomir NC组、si-CircFoxo3+miR-130a-5p antagomir组,每组18只。除对照组外,其他组大鼠均通过腹腔注射盐酸阿霉素的方法构建HF大鼠模型。建模成功后进行药物处理,每3 d给药一次,持续3周。应用反转录实时荧光定量聚合酶链式反应(qRT-PCR)法检测心肌组织中CircFoxo3、miR-130a-5p表达水平。应用彩色多普勒超声仪检测大鼠左室收缩末期内径(LVESD)、左室舒张末期内径(LVEDD)、左室射血分数(LVEF)水平。采用酶联免疫吸附试验(ELISA)法检测大鼠血清人基质裂解素2(ST_(2))、N端脑钠肽前体(NT-pro BNP)水平。应用HE染色、Masson染色检测大鼠心肌组织病理变化和心肌纤维化情况。通过TUNEL染色检测心肌细胞凋亡水平。应用Western blot法检测大鼠心肌组织TEA域转录因子1(TEAD1)、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、裂解的天冬氨酸特异性半胱氨酸蛋白酶-3(cleaved caspase-3)蛋白表达水平。通过双荧光素酶报告基因实验验证CircFoxo3与miR-130a-5p、miR-130a-5p与TEAD1的关系。结果与对照组比较,HF组大鼠心肌组织病理损伤、心肌纤维化严重,LVESD、LVEDD水平上升,心肌组织CircFoxo3及TEAD1、Bax、cleaved caspase-3蛋白表达水平升高,血清ST_(2)、NT-pro BNP水平升高,心肌细胞凋亡率升高,LVEF、miR-130a-5p和Bcl-2蛋白水平降低,差异有统计学意义(P<0.05)。与HF组、si-NC组比较,si-CircFoxo3组大鼠心肌组织病理损伤减轻,LVESD、LVEDD水平降低,心肌组织CircFoxo3及TEAD1、Bax、cleaved caspase-3蛋白表达水平降低,血清ST_(2)、NT-pro BNP水平降低,心肌细胞凋亡率降低,LVEF、miR-130a-5p及Bcl-2蛋白水平升高,差异有统计学意义(P<0.05)。与HF组、agomir NC组比较,miR-130a-5p agomir组大鼠心肌组织病理损伤、心肌纤维化有所改善,LVESD、LVEDD水平降低,心肌组织TEAD1、Bax、cleaved caspase-3蛋白表达水平降低,血清ST_(2)、NT-pro BNP水平降低,心肌细胞凋亡率降低,LVEF、miR-130a-5p及Bcl-2蛋白水平升高,差异有统计学意义(P<0.05)。与si-CircFoxo3组、si-CircFoxo3+antagomir NC组比较,si-CircFoxo3+miR-130a-5p antagomir组大鼠心肌组织病理损伤、心肌纤维化加剧,LVESD、LVEDD水平升高,心肌组织TEAD1、Bax、cleaved caspase-3蛋白表达水平升高,血清ST_(2)、NT-pro BNP水平升高,心肌细胞凋亡率升高,LVEF、miR-130a-5p、Bcl-2蛋白水平降低,差异有统计学意义(P<0.05)。CircFoxo3与miR-130a-5p、miR-130a-5p与TEAD1存在靶向关系。结论沉默CircFoxo3可能通过海绵化上调miR-130a-5p来抑制TEAD1表达,进而抑制HF大鼠心肌细胞凋亡。

miR-223-3p和FOXO3在结直肠癌中的研究进展

近年来,结直肠癌的发病率和死亡率一直居高不下,且出现年轻化趋势。结直肠癌具有异质性和隐匿性,且其在放化疗过程中可能出现药物耐受,导致结直肠癌的诊断和治疗结果一直不令人满意,患者预后较差。研究发现微RNA(microRNA,miRNA)在肿瘤的发生发展中发挥调控作用,miRNA可作为结直肠癌诊疗的生物靶点。本文就miR-223-3p和叉头框O3在结直肠癌中的研究进展作一综述。

Designing ultrastable P2/O3-type layered oxides for sodium ion batteries by regulating Na distribution and oxygen redox chemistry

P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.

Difficulties, strategies, and recent research and development of layered sodium transition metal oxide cathode materials for high-energy sodium-ion batteries

Energy-storage systems and their production have attracted significant interest for practical applications.Batteries are the foundation of sustainable energy sources for electric vehicles(EVs),portable electronic devices(PEDs),etc.In recent decades,Lithium-ion batteries(LIBs) have been extensively utilized in largescale energy storage devices owing to their long cycle life and high energy density.However,the high cost and limited availability of Li are the two main obstacles for LIBs.In this regard,sodium-ion batteries(SIBs) are attractive alternatives to LIBs for large-scale energy storage systems because of the abundance and low cost of sodium materials.Cathode is one of the most important components in the battery,which limits cost and performance of a battery.Among the classified cathode structures,layered structure materials have attracted attention because of their high ionic conductivity,fast diffusion rate,and high specific capacity.Here,we present a comprehensive review of the classification of layered structures and the preparation of layered materials.Furthermore,the review article discusses extensively about the issues of the layered materials,namely(1) electrochemical degradation,(2) irreversible structural changes,and(3) structural instability,and also it provides strategies to overcome the issues such as elemental phase composition,a small amount of elemental doping,structural design,and surface alteration for emerging SIBs.In addition,the article discusses about the recent research development on layered unary,binary,ternary,quaternary,quinary,and senary-based O3-and P2-type cathode materials for high-energy SIBs.This review article provides useful information for the development of high-energy layered sodium transition metal oxide P2 and O3-cathode materials for practical SIBs.

O型口蹄疫病毒和塞内卡病毒双重荧光定量RT-PCR检测方法的建立

为建立O型口蹄疫病毒(FMDV-O)和塞内卡病毒(SVV)快速鉴别检测方法,本实验根据FMDV-O VP2基因序列和SVV P3基因序列,采用Primer Express3.0软件分别设计引物与探针,并经各反应条件的优化初步建立了可同时鉴别检测FMDV-O和SVV的双重荧光定量RT-PCR方法。利用该方法检测临床常见猪病毒,结果显示可同时检测出FMDV-O和SVV核酸,且与猪水泡性口炎病毒(VSV)、猪水疱病毒(SVDV)、猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪细小病毒(PPV)、A型口蹄疫病毒(FMDV-A)、A-1型口蹄疫病毒(FMDVA-1)核酸均无交叉反应,并可检测到FMDV-O PanAsia株、cathay株、Ind-2001株和Mya-98株等主要流行株,特异性强;该方法对含FMDV-O和SVV拼接质粒标准品的最低检测限为7.17×10^(2)拷贝/μL,敏感性高;利用该方法检测了同一时间和不同时间提取的3种不同浓度的质粒标准品,结果显示批内和批间重复性试验Ct值的变异系数均小于3%,重复性好。利用本实验所建立的方法对30份临床样品进行检测,结果与各病毒单一荧光定量RT-PCR检测结果一致。本研究建立的FMDV-O和SVV双重荧光定量RT-PCR方法能够快速准确的鉴别检测FMDV-O和SVV,为口岸检疫的快速通关提供了技术手段。

Comparative structural and electrochemical properties of mixed P2/O′3-layered sodium nickel manganese oxide prepared by sol-gel and electrospinning methods:Effect of Na-excess content

The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.

复发性阿弗他口腔溃疡患者唾液外泌体miR⁃142⁃5p、FOXO3表达的相关性研究

目的分析复发性阿弗他口腔溃疡(RAU)患者唾液外泌体miR⁃142⁃5p、叉头转录蛋白O亚族3(FOXO3)表达与免疫功能的相关性。方法收集2019年12月—2021年12月三亚中心医院/海南省第三人民医院口腔科收治RAU患者134例作为观察组,另选取同期健康志愿者134例作为健康对照组。收集受试者唾液后提取唾液外泌体,qRT⁃PCR分析样本中miR⁃142⁃5p、FOXO3 mRNA表达水平,流式细胞仪测定外周血CD3^(+)CD4^(+)、CD3^(+)CD8^(+)细胞比例,并计算CD4^(+)/CD8^(+)比值;比较miR⁃142⁃5p、FOXO3高、低表达亚组间RAU患者的疼痛指数、溃疡面积;Pearson法分析患者唾液外泌体miR⁃142⁃5p、FOXO3 mRNA水平之间及二者与CD3^(+)CD4^(+)、CD3^(+)CD8^(+)、CD4^(+)/CD8^(+)的相关性;绘制受试者工作特征曲线(ROC)评估miR⁃142⁃5p、FOXO3 mRNA表达水平预测RAU的诊断价值。结果与健康对照组比较,观察组患者唾液外泌体miR⁃142⁃5p表达水平、外周血CD3^(+)CD8^(+)细胞比例升高[t(χ^(2))/P=34.580/<0.001、6.889/<0.001],FOXO3 mRNA及蛋白表达水平、外周血CD3^(+)CD4^(+)、CD4^(+)/CD8^(+)细胞比值降低[t(χ^(2)/P=43.121/<0.001、37.692/<0.001、10.219/0.001、26.091/<0.001)]。与miR⁃142⁃5p低表达亚组比较,miR⁃142⁃5p高表达亚组患者疼痛指数升高、溃疡面积增大(t/P=3.880/<0.001、5.027/<0.001);与FOXO3高表达亚组比较,FOXO3低表达亚组患者疼痛指数升高、溃疡面积增大(t/P=4.711/<0.001、5.382/<0.001)。观察组患者唾液外泌体miR⁃142⁃5p与CD3^(+)CD4^(+)、CD4^(+)/CD8^(+)细胞比值呈负相关(P均<0.001),FOXO3 mRNA与CD3^(+)CD4^(+)、CD4^(+)/CD8^(+)细胞比值呈正相关(P均<0.001),miR⁃142⁃5p、FOXO3与CD3^(+)CD8^(+)细胞比值均无相关性(P>0.05)。绘制ROC曲线结果提示,miR⁃142⁃5p、FOXO3 mRNA及二者联合预测RAU复发的曲线下面积(AUC)分别为0.810、0.809、0.947,二者联合检测优于各自单独预测效能(Z=6.528、8.573,P均<0.001)。结论RAU患者唾液外泌体miR⁃142⁃5p处于高表达状态,FOXO3处于低表达状态,二者共同参与复发性口腔溃疡的免疫调控。

miR-125a-3p对骨关节炎大鼠软骨细胞活性、氧化应激反应及SIRT1/Foxo1蛋白表达的影响

目的 探讨miR-125a-3p对骨关节炎大鼠软骨细胞活性、氧化应激反应及细胞沉默信息调节因子1/叉头框转录因子o1(SIRT1/Foxo1)蛋白表达的影响。方法 将40只大鼠随机分为对照组(健康大鼠)、模型组(骨关节炎大鼠,造模后不做其他处理及干预)、miR-125a-3p组(骨关节炎大鼠,造模成功7 d后于大鼠左膝关节关节腔内注射miR-125a-3p抑制剂)、阿利吉仑组(骨关节炎大鼠,造模成功7 d后给予大鼠50 mg/kg阿利吉仑灌胃),每组10只。通过氧化应激反应检测超氧物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽(GSH)、乳酸脱氢酶(LDH),HE、番红O、Masson染色检查大鼠软骨损伤情况,TUNEL检测软骨细胞凋亡,RT-PCR与免疫印迹检测SIRT1、Foxo1基因及蛋白水平。结果 软骨细胞凋亡率模型组高于miR-125a-3p组与阿利吉仑组(P<0.05),miR-125a-3p组与阿利吉仑组比较差异无统计学意义(P>0.05)。HE、番红O、Masson染色显示,模型组大鼠关节软骨面骨裂隙形成;miR-125a-3p组与阿利吉仑组大鼠关节软骨表面变得光滑,无明显裂隙。RT-PCR与免疫印迹检测显示,与模型组相比,miR-125a-3p组与阿利吉仑组SOD、GSH、SIRT1水平均升高(P<0.05), MDA、LDH、Foxo1水平均降低(P<0.05)。结论 miR-125a-3p通过调控SIRT1/Foxo1信号通路,可降低氧化应激反应,抑制软骨细胞凋亡,改善骨关节炎病情。

miR-29b-3p和FOXO3A在结肠癌组织中的表达及临床意义

目的:通过检测结肠癌组织微小RNA-29b-3p(miR-29b-3p)和叉头框O3A(FOXO3A)的表达水平,讨论其在结肠癌组织中的临床意义。方法:选取本院2015年1月至2017年1月期间收治的结肠癌患者82例,术中收集患者结肠癌组织及距离肿瘤边缘≥5cm的癌旁正常组织。采用实时荧光定量(qRT-PCR)检测各组织中miR-29b-3p和FOXO3A mRNA的表达水平,同时使用免疫印迹试验(Western blot)检测各组织中FOXO3A蛋白的表达水平;Pearson法分析结肠癌组织中miR-29b-3p与FOXO3A mRNA表达水平的相关性;采用Kaplan-Meier法分析miR-29b-3p、FOXO3A mRNA表达与患者生存率的关系;影响结肠癌患者5年死亡的因素用COX回归分析。结果:miR-29b-3p在结肠癌组织(1.55±0.40)中的表达水平高于癌旁正常组织(1.01±0.23),FOXO3A mRNA及蛋白表达水平在结肠癌组织[(0.48±0.13)、(0.72±0.19)]中的表达水平低于癌旁正常组织[(0.99±0.25)、(1.43±0.37)],差异具有统计学意义(t=23.87、35.501、33.318,P<0.05)。结肠癌组织中miR-29b-3p和FOXO3A mRNA的表达均与结肠癌患者TNM分期和淋巴结转移相关(P<0.05)。结肠癌组织中miR-29b-3p与FOXO3A mRNA的表达水平呈负相关(r=-0.479,P<0.05)。miR-29b-3p低表达组患者5年总生存率(83.33%)高于高表达组患者(55.00%),差异具有统计学意义(χ^(2)=6.820,P<0.05);FOXO3A mRNA高表达组患者5年总生存率(88.64%)高于低表达组患者(47.37%),差异具有统计学意义(χ^(2)=16.005,P<0.05)。结肠癌TNMⅢ期及结肠癌组织中miR-29b-3p高表达及FOXO3A mRNA低表达是影响结肠癌患者5年死亡的危险因素(P<0.05)。结论:结肠癌组织miR-29b-3p高表达,FOXO3A mRNA及其蛋白低表达,miR-29b-3p、FOXO3A mRNA与TNM分期、淋巴结转移及预后均具有相关性。

MiR-148 b-3 p/FOXO 4轴对乳腺癌细胞自噬及生长的影响

目的:MiR-148b-3p通过调节叉头框蛋白O4(forkhead box O4,FOXO4)在乳腺癌(breast cancer,BC)进展中的作用还未完全阐明。本研究探究miR-148b-3p调节FOXO4表达对BC细胞增殖、凋亡和自噬的影响。方法:采用实时反转录聚合酶链反应(real-time reverse transcription polymerase chain reaction,real-time RT-PCR)检测BC患者的癌组织标本(BC组织)和邻近的非肿瘤组织标本(正常组织)、人正常乳腺上皮细胞MCF-10A和人BC细胞(MCF7、SKBR3、MDA-MB-231细胞)中miR-148b-3p和FOXO4的表达情况。对MDA-MB-231细胞进行转染并将其分为对照组(Ctrl组)、inhibitor-NC组、miR-148b-3p inhibitor组、si-NC组、si-FOXO4组、miR-148b-3p inhibitor+si-NC组、miR-148b-3p inhibitor+si-FOXO4组。采用细胞计数试剂盒8(cell counting kit 8,CCK-8)法检测细胞增殖;流式细胞术检测细胞凋亡;透射电镜观察细胞自噬;蛋白质印迹法检测细胞FOXO4、增殖、凋亡和自噬相关蛋白表达;双荧光素酶报告基因检测(double luciferase reporter gene assay,DLR)和miRNA下拉实验验证miR-148b-3p与FOXO4的靶向作用关系。结果:与正常组织比较,BC组织中miR-148b-3p表达升高,FOXO4 mRNA表达降低(P<0.05);Pearson相关性分析结果显示BC患者癌组织中miR-148b-3p的表达水平与FOXO4 mRNA的水平呈负相关(r=−0.774,P<0.01)。与MCF-10A细胞比较,MCF-7细胞、SKBR3细胞和MDA-MB-231细胞中miR-148b-3p表达均升高,FOXO4蛋白和mRNA表达均降低(均P<0.05),且MDA-MB-231细胞中升高或降低更多。miR-148b-3p靶向负调控FOXO4的表达。敲减miR-148b-3p后MDA-MB-231细胞活力、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)蛋白水平降低,凋亡率、自噬小体数量、FOXO4蛋白和mRNA水平、cleaved-caspase-3、cleaved-PARP-1、LC3-II/LC3-I、Beclin-1蛋白水平均升高(均P<0.05),而敲减FOXO4后与之相反;敲减FOXO4可减弱敲减miR-148b-3p对MDA-MB-231细胞增殖、凋亡和自噬的影响。结论:miR-148b-3p可能通过靶向FOXO4促进MDA-MB-231细胞增殖,抑制其凋亡和自噬。

Influences of different oxidants on characteristics of La_2O_3/Al_2O_3 nanolaminates deposited by atomic layer deposition

A comparative study of two kinds of oxidants（H2O and O3） with the combination of two metal precursors（TMA and La（～iPrCp）3） for atomic layer deposition（ALD） La2O3/Al2O3 nanolaminates is carried out. The effects of different oxidants on the physical properties and electrical characteristics of La2O3/Al2O3 nanolaminates are studied. Initial testing results indicate that La2O3/Al2O3 nanolaminates could avoid moisture absorption in the air after thermal annealing. However, moisture absorption occurs in H2O-based La2O3/Al2O3 nanolaminates due to the residue hydroxyl/hydrogen groups during annealing. As a result, roughness enhancement, band offset variation, low dielectric constant and poor electrical characteristics are measured because the properties of H2O-based La2O3/Al2O3 nanolaminates are deteriorated. Addition thermal annealing effects on the properties of O3-based La2O3/Al2O3 nanolaminates indicate that O3 is a more appropriate oxidant to deposit La2O3/Al2O3 nanolaminates for electron devices application.

Density Functional Study of the C Atom Adsorption on the α-Fe_2O_3 (001) Surface

The adsorption of C atoms on the α-Fe2O3（001） surface was studied based on density function theory（DFT） ,in which the exchange-correlation potential was chosen as the PBE（Perdew,Burke and Ernzerhof） generalized gradient approximation（GGA） with a plane wave basis set. Upon the optimization on different adsorption sites with coverage of 1/20 and 1/5 ML,it was found that the adsorption of C atoms on the α-Fe2O3（001） surface was chemical adsorption. The coverage can affect the adsorption behavior greatly. Under low coverage,the most stable adsorption geometry lied on the bridged site with the adsorption energy of about 3.22 eV; however,under high coverage,it located at the top site with the energy change of 8.79 eV. Strong chemical reaction has occurred between the C and O atoms at this site. The density of states and population analysis showed that the s,p orbitals of C and p orbital of O give the most contribution to the adsorption bonding. During the adsorption process,O atom shares the electrons with C,and C can only affect the outermost and subsurface layers of α-Fe2O3; the third layer can not be affected obviously.

Influence of annealing temperature on passivation performance of thermal atomic layer deposition Al_2O_3 films

Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.

Surface termination effects on the electrical characteristics of La2O3/Al2O3 nanolaminates deposited by atomic layer deposition

Effects of initial surface termination on electrical characteristics of La2O3/Al2O3 nanolaminates deposited by atomic layer deposition are studied by conductive atomic force microscopy working in contact mode and standard electrical characterization methods.It is found that,compared with La2O3/Al2O3 nanolaminates with LaOx as termination,lower interface trap density,less current leakage spots,and higher breakdown voltage are obtained in the La2O3/Al2O3 nanolaminates with AlOx as termination after annealing.A clear promotion of interface silicate layer is observed for La2O3/Al2O3 nanolaminates with AlOx as termination compared with LaOx as termination under the same annealing condition.In addition,the current conduction mechanism in La2O3/Al2O3 nanolaminates is considered as the Poole-Frenkel conduction.All results indicate that the AlOx is a more appropriate termination to deposit La2O3/Al2O3 nanolaminates on Si substrate,which is useful for the high-κ process development.

Theoretical Studies on the Abstraction Reaction of Atomic O(^3p) with Si2H6

ion reaction of O (3P) with Si2H6 has been studied theoretically. Two transition states of 3A and 3A symmetries have been located for this abstraction reaction. Geometries have been optimized at the UMP2 level with 6-311G+(d) basis set. G3MP2 has been used for the final single-point energy calculation. The rate constants have been calculated over a wide temperature range of 200~3000 K using canonical variational transition-state theory (CVT) with small curvature tunneling effect (SCT). The calculated CVT/SCT rate constants match well with the experimental value.

共沉淀法制备Y(P,V)O_4∶Tm^(3+)荧光粉及其光致发光

采用氨水、双氧水和磷酸氢二铵溶液作沉淀剂,通过共沉淀法制备出Y(P,V)O4∶Tm3+荧光粉,利用XRD、SEM、紫外以及真空紫外激发下的发射光谱对其进行研究。结果表明:共沉淀法制备的Y(P,V)O4∶Tm3+荧光粉的颗粒形貌好,在147nm真空紫外光和254nm紫外光激发下,荧光粉发射主峰位于476nm,色坐标范围为: 0. 167≤x≤0. 200; 0. 146≤y≤0. 183。从这些结果来看,Y(P,V)O4∶Tm3+体系还不能满足实际应用的要求,仍需进一步的深入研究以改善其性能。

P改性NiW/γ-Al_2O_3的低温焦油芳烃组分加氢性能研究

以γ-Al2O3为载体,采用浸渍法制备了不同P添加量的负载型NiW加氢催化剂,采用固定床加氢装置,对模型化合物萘和低温焦油富集的芳烃组分进行了催化加氢。催化剂采用N2吸附、XRD、H2-TPR、XPS以及NH3-TPD的方法进行表征,加氢产物采用GC-MS和GC×GC-TOFMS进行分析。结果表明,P助剂能够扩大催化剂的孔径并促进活性金属组分在载体表面的分散;当P含量为1.0%1.5%时,能够促进Ni-W-O混合相生成,并提高催化剂表面弱酸的含量;萘加氢反应的转化率和十氢萘的选择性也在添加1.0%的P时达到最高,分别为80%和50%左右;低温焦油芳烃组分的催化加氢结果显示,芳烃饱和加氢反应占优,绝大部分芳烃转化为环烷烃,且催化剂具有显著的脱除杂原子效果。

O（^3P）与CHBr2反应的理论研究

用量子化学从头算方法对O(3P)原子与CHBr2自由基的反应进行了理论研究.在UMP2/6-31G 的计算水平上优化了反应势能面上各驻点的几何结构,并在QCISD(T)/6-311G 水平上计算了各驻点的单点能量.通过内禀坐标(IRC)计算和振动分析,对反应过渡态进行了确认,并确定了反应机理.

亚微米Al_2O_3颗粒的微观结构及Al_2O_(3p)/1070Al复合材料的界面

利用透射电镜和高分辨电镜对直径为 0 .15 μm的球形Al2 O3 颗粒增强相及其增强 10 70Al复合材料的界面进行了观察 ,结果表明 :Al2 O3 颗粒是由一些角度相差较小的晶面构成的多面体 ,多面体的各晶面是由密排面沿着密排晶向形成的台阶式结构 ;0 .15 μm的Al2 O3 p/10 70Al复合材料界面结合良好 ,没有发现任何界面反应物 ;由于颗粒的台阶式结构导致铝基体与Al2 O3

O(~3P)原子与丙酮和3.3-2甲基-2-丁酮化学反应动力学研究

用流动微波放电—化学发光方法测定O(~3p)原子与CH_3COCH_3和CH_3COC(CH_3)_3的化学反应速率常数k=3.37±1.00×10^(-12)exp(-7.03±0.22kcal.mol^(-1)/RT) (丙酮+0(~3p),T=373-503K)和k=4.61±2.60×10^(-11)exp(-5.46±0.44kcal·mol^(-1)/RT) (3.3-2甲基-2-丁酮+O(~3p),T=303-503K)并就测定的O(~3p)原子与一系列酮分子反应速率常数进行了讨论,估算了O(~3p)原子与各类C—H键反应速率的Arrhenius参数。发现与羰基相邻的C—H键与O(~3p)反应的活化能要略大于非相邻的同类键反应的活化能。还根据Evans-Polanyi关系式,对这些键的键能进行了讨论。