金配合物[Au（C=C-4-LNO2）（PPh3）二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au（C≡C-4-LNO2）（PPh3），L=-C6H4（1），-C5H3N（2）]和自行设计的金配合物[Au（C≡C-4-CdH：N2NO2）（PPh3）L=-C4H2N2]（3）的非线性光学性质．计算结果表明，3个配合物的二阶非线性性质变化规律为β1〈β2〈β3，与芳香性的变化规律正好相反．3个配合物的频率色散理论计算结果与实验观测值不符，暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一．     

具有生物活性的金属配合物的研究 IV: 3,6-二(二甲氨基)-二苯并碘六环稀土二(氨三乙酸)配合物的合成、性质及抗肿瘤活性

合成了十五种3,6-(二甲氨基)-二苯并碘六环稀土二(氨三乙酸)配合物,[C17H20N2I]3{RE[N(CH2CO2)3]2}.nH2O(RE=La, Eu, Er. n=3; RE=Ce-Nd, b-Ho, Tm,Yb. Y. n=4; RE=Sm, Gd, Lu. n=5). 利用X射线粉末衍射, 热重-差热分析、红外光谱、紫外光谱、^1H-NMR及摩尔电导等对这些配合物进行了表征. 实验表明, 镧配合物对体外L1210癌细胞生长有较好的抑制效果, 对小鼠S180肿瘤生长的抑制效果高于其前体.     

由对羟基苯乙酸与乙酰丙酮共同构筑的稀土三元配合物的合成及荧光性质

以对羟基苯乙酸(H2PPA,C8H8O3)和乙酰丙酮(Hacac,C5H8O2)为配体,稀土硝酸盐为金属源,用溶液法合成了4个稀土配合物[Ln2(HPPA) (acac)4(NO3)(H2O)2]n(Ln=Sm,(1);Eu,(2);Tb,(3);Dy,(4)).产物为异质同晶,铕配合物为单晶样,其余为多晶粉末.通过元...     

2-苯亚胺官能化吲哚基铕胺基配合物与芳基取代甲脒的反应性（英文）

2-(苯亚胺基次甲基)吲哚铕胺基配合物[η1∶η1-2-(C6H5NH=CH)C8H5N]2Eu[N(Si Me3)2](1)与二芳基取代甲脒(2,6-R2C6H3N=CHNH(C6H3R2-2,6)(R=iPr(2),Me(3))经过配体交换反应,分别得到了含吲哚基脒基铕配合物[η1∶η1-2-(C6H5NH=CH)C8H5N]Eu[(η3-2,6-iPr2C6H3)N=CHN(C6H3iPr2-2,6)][N(Si Me3)2](4)和含脒基的稀土铕配合物[(η3-2,6-Me2C6H3)N=CHN(C6H3Me2-2,6)]2Eu[N(Si Me3)2](5)。结果表明,脒基的位阻显著影响了吲哚基稀土金属胺基配合物与二芳基取代甲脒的配体交换反应。配合物4和5通过IR、元素分析和X射线单晶衍射分析进行了表征。     

金配合物[Au(C≡C-4-LNO2)(PPh3)二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au(C≡C-4-LNO2)(PPh3),L=—C6H4(1),—C5H3N(2)]和自行设计的金配合物[Au(C≡C-4-C4H2N2NO2)(PPh3)L=—C4H2N2](3)的非线性光学性质.计算结果表明,3个配合物的二阶非线性性质变化规律为β1<β2<β3,与芳香性的变化规律正好相反.3个配合物的频率色散理论计算结果与实验观测值不符,暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一.     

含吡咯基亚胺配体稀土铕配合物催化合成胍

以2-(2,4,6-Me3C6H2N=CH)C4H3NH为配体与铕配合物[(Me3Si)2N]3Eu(μ-Cl)Li(THF)3反应,合成了三价铕金属配合物[2-(2,4,6-Me3C6H2N=CH)C4H3N]3Eu(THF),以此配合物为催化剂催化芳胺与N,N’-二异丙基碳二亚胺反应,得到一系列胍产物,研究了反应时间、温度、催化剂用量和溶剂对催化反应的影响。结果表明:铕配合物具有良好的催化活性,以2%mol的催化剂用量、在THF中加热60℃反应8 h,得到高于80%产率的相应胍产物。     

具有生物活性的金属配合物的研究 III: 3-6(二(二甲氨基)-二苯并碘六环稀土二柠檬酸配合物的合成, 性质及抗肿瘤活性

合成了十五种新的3,6-二(二甲氨基)-二苯并碘六环稀土二柠檬酸配合物, 其化学式为: [C17H20N2I]3[RE(C6H5O7)2].xH2O(RE=La-Nd, x=5; Sm-Tb, x=4; Dy-Lu, Y,x=3). 利用X射线粉末衍射、热重-差热, 红外光谱、紫外光谱、摩尔电导等对这些配合物进行了表征. 试验表明, 镧配合物对L7712癌细胞DNA合成的抑制率(97.3%)明显高于其前体(C17H20N2I^+.HCOO^-, 72.5%; Na3[La(C6H5O7)2], -16.5%.     

具有生物活性的金属配合物的研究 III: 3-6(二(二甲氨基)-二苯并碘六环稀土二柠檬酸配合物的合成, 性质及抗肿瘤活性

合成了十五种新的3,6-二(二甲氨基)-二苯并碘六环稀土二柠檬酸配合物, 其化学式为: [C17H20N2I]3[RE(C6H5O7)2].xH2O(RE=La-Nd, x=5; Sm-Tb, x=4; Dy-Lu, Y,x=3). 利用X射线粉末衍射、热重-差热, 红外光谱、紫外光谱、摩尔电导等对这些配合物进行了表征. 试验表明, 镧配合物对L7712癌细胞DNA合成的抑制率(97.3%)明显高于其前体(C17H20N2I^+.HCOO^-, 72.5%; Na3[La(C6H5O7)2], -16.5%.     

钛钨杂多配合物的合成与表征

首次合成了杂多配合物K2[(C2H5)4N]2[TiW5O19].5H2O和K2[(C2H5)4N]2[(TiO2)W5O18].5H2O,配合物通过IR,UV,TG-DTA,摩尔电导,X射线粉末衍射进行了表征.结果表明[TiW5O19]4-具有L indqvist-Aronsson结构.     

水杨醛缩氨基硫脲合锑(Ⅲ)、铋(Ⅲ)配合物的固相合成

水杨醛缩氨基硫脲与三碘化锑、三碘化铋通过固相反应，合成了新的配合物[SbI3(C8H9N3OS)]，[BiI3(C8H9N3OS)]。经元素分析、X-射线粉末衍射，中红外、远红外光谱和差热一热重分析，确定了其组成和结构。对XRD谱进行指标化，确定了配合物的晶系和晶胞参数。     

Effect of partial substitution of Ca in LaMnO3 on coal catalytic combustion

Coal combustion catalysts of mesoporous perovskite-type La_1?xCa_xMnO₃ were prepared by sol–gel method. The resulting powder was characterized by scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction, dynamic light scattering and differential scanning calorimetry. After partially substituting La with Ca in LaMnO₃, Ca was found to occupy parts of La-site. As the substitution rate of Ca increased, the catalyst particle size distribution decreased and the pore size distribution of catalysts increased. Thermogravimetric measurements and combustion of coal in the presence of the La_1?xCa_xMnO₃ catalysis indicated that the presence of catalysts reduced the temperature for onset of coal combustion and increased the combustion rate. In fact, the addition of 1 % La_0.6Ca_0.4MnO₃ to coal made the combustion point decrease by 41.5 K compared with coal alone. On the other hand, addition of 1 % La_0.1Ca_0.9MnO₃ made the combustion rate increase by 22.2 % compared with combustion rate of organic coal.     

Thermal degradation and evolved gas analysis of thiourea-formaldehyde resin (TFR) during pyrolysis and combustion

Thiourea formaldehyde resin (TFR) has been synthesized by condensation of thiourea and formaldehyde in acidic medium and its thermal degradation has been investigated using TG-FTIR-MS technique during pyrolysis and combustion. The results revealed that the thermal decomposition of TFR occurs in three steps assigned to drying of the sample, fast thermal decomposition of polymers, and further cracking. The similar TG and DTG characteristics were found for the first two stages during pyrolysis and combustion. The combustion process was almost finished at 680?°C, while during pyrolysis a total mass loss of 93 wt% is found at 950?°C. The release of volatile products during pyrolysis are NH₃, CS₂, CO, HCN, HNCS, and NH₂CN. The main products in the second stage are NH₃ CO₂, CS₂, SO₂, and H₂O during combustion. In the next stage, the combustion products mentioned above keep on increasing, but some new volatiles such as HCN, COS etc., are identified. Among the above volatiles, CO₂ is the dominant gaseous product in the whole combustion process. It is found that the thermal degradation during pyrolysis of TFR produced more hazardous gases like HCN, NH₃, and CO when compared with combustion in similar conditions.     

凹凸棒黏土对燃煤PM2.5排放及团聚捕集特性影响

在固定床反应系统上考察凹凸棒黏土对燃煤可吸入颗粒物PM_2.5的排放及团聚捕集特性影响,分析凹凸棒黏土添加量以及添加凹凸棒黏土情况下燃烧气氛、燃烧温度和钙硫物质的量比等参数对燃煤PM_2.5的数量浓度、质量浓度以及团聚捕集率的影响规律。结果表明,煤燃烧过程中添加凹凸棒黏土可以显著降低PM_2.5排放浓度,凹凸棒黏土的添加量不宜超过3%(质量分数);空气气氛下燃烧产生的PM_2.5多于O₂/CO₂气氛;随着钙硫物质的量比的增大,PM₁的质量浓度减小,但PM_1~2.5的质量浓度增大,颗粒物的粒径有向更大粒径转移的趋势;燃烧温度的升高会促进PM_2.5各粒径范围颗粒物的生成,降低了凹凸棒黏土对PM_2.5团聚捕集率。     

Diesel Soot Combustion over Mn2O3 Catalysts with Different Morphologies: Elucidating the Role of Active Oxygen Species in Soot Combustion

Catalytic diesel soot combustion was examined using a series of Mn₂O₃ catalysts with different morphologies, including plate, prism, hollow spheres and powders. The plate‐shaped Mn₂O₃ (Mn₂O₃‐plate) exhibited superior carbon soot combustion activity compared to the prism‐shaped, hollow‐structured and powdery Mn₂O₃ under both tight and loose contact modes at soot combustion temperatures (T₅₀) of 327 °C and 457 °C, respectively. Comprehensive characterization studies using scanning electron microscopy, scanning transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, temperature‐programmed reduction and oxygen release measurements, revealed that the improved activity of Mn₂O₃‐plate was mainly attributed to the high oxygen release rate of surface‐adsorbed active oxygen species, which originated from oxygen vacancy sites introduced during the catalyst preparation, rather than specific surface‐exposed planes. The study provides new insights for the design and synthesis of efficient oxidation catalysts for carbon soot combustion as well as for other oxidation reactions of harmful hydrocarbon compounds.     

Effect of Bismuth Oxide Particles Size on the Thermal Excitation and Combustion Properties of Thermite Systems

The influence of Bi₂O₃ particles size at the sub-micron scale on the thermal excitation threshold and combustion performance of nano-thermite systems was investigated. Three formulas were designed and prepared, Al(100 nm)/Bi₂O₃(170 nm), Al(100 nm)/Bi₂O₃(370 nm) and Al(100 nm)/Bi₂O₃(740 nm). The samples were characterized and tested by SEM, XRD, and DSC techniques. Electrical ignition and combustion experiments were performed. The results showed that with the increase of the particle size of Bi₂O₃, in the case of slow linear heating, the exothermic heat decreased (1051.2 J g⁻¹, 527.3 J g⁻¹ and 243.6 J g⁻¹) and the thermal excitation threshold temperature increased (564.52 °C, 658.1 °C and 810.9 °C). Simultaneously, the state of the thermite reaction correspondingly changed to solid-solid, liquid-solid and liquid-liquid thermite reaction. In the case of rapid heating , the increase in particle size increased the excitation current (0.561A, 0.710A and 0.837A). During the combustion process, the thermite system with the smallest Bi₂O₃ particle size showed the largest combustion rate, and that with the largest particle size had the longest combustion duration.     

Influence of combustion reagent and microwave drying method on the characteristics of nano-sized Nd<Superscript>3+</Superscript>:YAG powders synthesized by the gel combustion method

Nanosized Nd³⁺ doped Y₃Al₅O₁₂ (Nd³⁺:YAG) powders have been synthesized by the gel combustion method using different combustion reagent such as citric acid, ethylene diamine tetraacetic acid (EDTA), glycine, glycol and the combination of citric acid and EDTA with different ratio. The pure YAG phase was obtained at relatively low temperature around 950 °C for citric acid or EDTA and 1,050 °C for glycine or glycol as combustion reagent, respectively by the gel combustion method. It was found that citric acid and EDTA are the better combustion reagents and yield rather homogeneous and well dispersed club-shape Nd³⁺:YAG samples, and the particle size synthesized by EDTA is larger than that by citric acid. Moreover, the particle size of Nd:YAG was enlarged when the ratio of EDTA was increased in the combination reagent, and the better dispersion of YAG was obtained when the ratio of citric acid to EDTA was 1:1 compared to that of other ratios and pure one as combustion reagent. On the other hand, the results showed that the microwave assisted in drying process of gel to xerogel produced more smaller Nd³⁺:YAG particles in size, and more homogeneous dispersion of the Nd³⁺:YAG particles than that of the traditional dry method.     

A novel PdNi/Al2O3 catalyst prepared by galvanic deposition for low temperature methane combustion

Galvanic deposition method was used to prepare the Pd/Ni-Al₂O₃-GD catalyst for the combustion of methane under lean conditions. The new catalyst and compared catalysts (Pd/Al₂O₃-IW, Pd-Ni/Al₂O₃-IW, Pd/Ni-Al₂O₃-IW) prepared by incipient wetness impregnation were characterized by N₂-physisorption, XRD and TEM to clarify particle size and size distribution of palladium species. Combined O₂-TPD and XPS results with the catalytic data, it shows that the surface palladium species with low valence exhibits better combustion performance due to their stronger interaction with support. The results indicate that the galvanic deposition method is an effective route to prepare efficient catalyst for methane combustion, and it also provides useful information for improving the present commercial catalyst.     

Improving effect of boron carbide on the combustion and thermal oxidation characteristics of amorphous boron

Boron carbide (B₄C) is one of the main products from the primary combustion of boron (B)-based propellants and has a significant influence on the secondary combustion of B. To systematically evaluate its effects on the secondary combustion of B, mixtures of B₄C and B in different mass ratios were prepared. To study the ignition temperatures and combustion flames of the samples, a xenon lamp ignition experimental system and a flame shape test system were designed, respectively. A thermogravimetry–differential scanning calorimetry–Fourier transform infrared spectroscopy combined thermal analysis system was used to study the thermal oxidation characteristics and analyze the gaseous products of the samples. The results indicate that B₄C reduces the heat absorption at the beginning of the ignition, but subsequently prevents the rapid rise of sample temperature. During the stable combustion stage, the maximum flame length under optical density 10⁻⁴ (OD4) filter was 20.4 mm, and the maximum flame length under 580 nm + OD4 filters (represents the combustion of B element) was 16.7 mm. The samples contained a small amount of HBO₂ and H₃BO₃, which led to slight mass loss during the low temperature section of the thermal oxidation process. During the high temperature section, the oxidation of B and B₄C caused considerable mass gain. The gaseous products of the thermal oxidation process include CO₂, CO, and H₂O. In general, the B content of 60% was the most beneficial to decrease the oxidation temperature, increase the combustion intensity, and improve the heat-releasing ability of the samples.

     

Combustion Derived Ultrafine γ-Fe2O3 Structure,morphology and thermal studies

A novel combustion method of employing poly(ethylene glycol) with the precursor in a fixed ratio for the synthesis of ultrafine γ-Fe₂O₃ through a self-propagating combustion synthesis is reported. Four different precursors viz. ferrous hydroxide, ferrous oxalate dihydrate, ferric 8-hydroxyquinoline and ferric acetylacetonate are employed in this study for the conversion of these precursors to ultrafine g-Fe₂O₃ particles. The as synthesized γ-Fe₂O₃ samples are characterized by XRD, SEM and thermal techniques. A case study for the synthesis of γ-Fe₂O₃ employing ferric acetyl acetonate as precursor is reported. The importance of employing thermal analysis techniques in understanding the combustion synthesis is envisaged. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sol–gel combustion synthesis of chromium doped yttrium aluminum perovskites

A water-based sol–gel combustion synthesis was optimized in order to achieve pure yttrium aluminium perovskite (YAlO₃, YAP). The method involved three main steps: xerogel formation, combustion treatment and calcination of the combusted precursors. TG DTA, FTIR and XRPD, used to investigate the precursor phase evolution, confirmed the strong influence of gel synthesis conditions, combustion temperature and calcination rate on YAP purity. Both stoichiometry and kinetics control during all the preparation steps are crucial in order to avoid the formation of undesired Y₃Al₅O₁₂ (YAG) and Y₄Al₂O₉ (YAM) stable phases. This method allowed to synthesize, for the first time from an aqueous sol–gel process, single phase samples of YAP. A series of samples with composition: YAl_(1−x)Cr_(x)O₃ where x is 0, 0.035, 0.135, 0.250, 0.500, 0.750 was obtained. A consistent decrease of calcination temperature, with respect to conventional solid state synthesis, was achieved by sol–gel combustion, avoiding polyphase materials even without the use of mineralizers. This is an important result in several applications like the synthesis of ceramic pigments.