Evolved gas analysis of coal-derived pyrite/marcasite

The products evolved during the thermal decomposition of the coal-derived pyrite/marcasite were studied using simultaneous thermogravimetry coupled with Fourier-transform infrared spectroscopy and mass spectrometry (TG-FTIR–MS) technique. The main gases and volatile products released during the thermal decomposition of the coal-derived pyrite/marcasite are water (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂). The results showed that the evolved products obtained were mainly divided into two processes: (1) the main evolved product H₂O is mainly released at below 300 °C; (2) under the temperature of 450–650 °C, the main evolved products are SO₂ and small amount of CO₂. It is worth mentioning that SO₃ was not observed as a product as no peak was observed in the m/z = 80 curve. The chemical substance SO₂ is present as the main gaseous product in the thermal decomposition for the sample. The coal-derived pyrite/marcasite is different from mineral pyrite in thermal decomposition temperature. The mass spectrometric analysis results are in good agreement with the infrared spectroscopic analysis of the evolved gases. These results give the evidence on the thermal decomposition products and make all explanations have the sufficient evidence. Therefore, TG–MS–IR is a powerful tool for the investigation of gas evolution from the thermal decomposition of materials.     

醋酸碘苯介导的α-重氮羰基化合物的去重氮双氧合反应

报道了一类新颖的醋酸碘苯介导的α-重氮羰基化合物的去重氮双氧合反应.该反应利用醋酸碘苯与N-羟基邻苯二甲酰亚胺(或N-羟基丁二甲酰亚胺)反应能产生氧中心自由基的特性实现了氧中心自由基诱导的α-重氮羰基化合物的双氧合反应,合成了一系列α,α-双氧代芳酮和α,α-双氧代羧酸酯衍生物,产率中等到良好.基于实验结果及文献报道,提出了可能的反应机理,其涉及氧中心自由基加成、C-N键的均裂和自由基交叉偶联等.此外,该反应具有无需金属催化剂、条件温和、操作简便等优点.     

Numerical-experimental method for elastic parameters identification of a composite panel

A hybrid numerical-experimental approach to identify elastic modulus of a textile composite panel using vibration test data is proposed and investigated. Homogenization method is adopted to predict the initial values of elastic parameters of the composite, and parameter identification is transformed to an optimization problem in which the objective function is the minimization of the discrepancies between the experimental and numerical modal data. Case study is conducted employing a woven fabric reinforced composite panel. Three parameters (E₁₁, E₂₂, G₁₂) with higher sensitivities are selected to be identified. It is shown that the elastic parameters can be accurately identified from experimental modal data.     

一步CVD法制备WS2-MoS2垂直异质结及其表征

本文主要研究了WS₂-MoS₂垂直异质结的制备及其光电性能。以氧化钼(MoO₃)、氧化钨(WO₃)、硫粉(S)作为反应物,采用改良的一步化学气相沉积法(CVD)实现高质量的WS₂-MoS₂垂直异质结的制备。使用拉曼光谱仪(Raman)、光致发光光谱仪(PL)、光学显微镜(OM)、原子力显微镜(AFM)、透射电子显微镜(TEM)、X射线光电子能谱仪(XPS)等设备,对异质结的形貌、元素组成等进行了表征。最后制备了基于WS₂-MoS₂异质结的光电探测器,测量了包括输出特性曲线、转移特性曲线、光电流曲线等光电特性。经测试,WS₂-MoS₂异质结光电探测器在532 nm激光模式下展现了良好的光响应特性,使其能应用于高效率的光电子器件的制备,在微电子学领域具有广阔的应用前景。     

Molecularly imprinted electrochemical sensor based on the synergic effect of nanoporous gold and copper nanoparticles for the determination of cysteine

Journal of Solid State Electrochemistry - A sensitive molecularly imprinted sensor for L-cysteine (Cys) determination was designed and fabricated by electrodeposition method. The molecularly...     

蜂窝遮弹层抗弹丸侵彻实验研究

为研究蜂窝遮弹层的抗弹丸侵彻性能,采用15 mm弹体对六边形单元蜂窝遮弹层结构进行了侵彻实验研究。实验结果表明,同钢筋混凝土遮弹层相比,蜂窝遮弹层的破坏仅发生在弹靶接触的六边形单元内,且破坏面积较小,同时弹体在侵彻蜂窝遮弹层过程中易发生偏航现象。应用应力波传播理论分析了实验结果,主要是六边形单元对其内的混凝土约束作用及其自身阻隔作用,使混凝土抗压强度和弹体在侵彻过程中受到的阻力增大,从而减小了弹体的破坏效应。     

SD大鼠亚慢性镉中毒试验模型的构建

为建立一种可靠、安全、方便的清洁级雄性SD大鼠亚慢性镉中毒模型,选取32只SD雄性大鼠随机分组,每天分别用含0,0.3,0.6和1.2mg·kg^-1剂量的CdCl₂溶液腹腔注射大鼠,研究镉离子在对清洁级雄性SD大鼠肝脏组织和性腺组织的损伤情况。结果显示,试验组大鼠的体重增长速度慢于对照组,两者之间具有显著性差异（P<0.05）。大鼠性腺组织和肝脏组织中的镉含量与镉离子呈剂量效应关系。氯化镉溶液处理大鼠28d后,试验组性腺组织中富积镉含量分别为0.022,0.84,1.17和1.94mg·kg^-1,肝脏组织富积镉含量分别为0.012,14.35,26.28和59.9mg·kg^-1。试验组性腺和肝脏组织富积镉的量均显著高于对照组。病理组织切片结果显示,试验组大鼠肝脏和性腺组织均出现不同程度的损伤。大鼠经过7d适应性饲养之后,每天腹腔注射浓度为0.3¹.2mg·kg^-1镉溶液,且连续处理28d,可以建立大鼠亚慢性镉中毒模型。 更多还原     

野生稻优良基因资源的发掘、种质创新及利用

种质资源是作物育种的物质基础,也是研究水稻起源、进化、发育和基因功能的基本材料.本文以野生稻为对象,系统总结、分析了近年来世界范围内水稻遗传育种界对野生稻有利基因资源发掘和利用所取得的成就,以及该领域在研究技术和手段方面的最新进展.     

Hydrogen production from coke oven gas over LiNi/γ-Al2O3 catalyst modified by rare earth metal oxide in a membrane reactor

The performance of LiNi/r-Al2O3 catalysts modified by rare earth metal oxide (La2O3 or CeO2) packed on BCFNO membrane reactor was discussed for the partial oxidation of methane (POM) in coke oven gas (COG) at 875 ◦C. The NiO/r-Al2O3 catalysts with different amounts of La2O3 and CeO2 were prepared with the same preparation method and under the same condition in order to compare the reaction performance (oxygen permeation, CH4 conversion, H2 and CO selectivity) on the membrane reactor. The results show that the oxygen permeation flux increased significantly with LiNiREOx/r-Al2O3 (RE = La or Ce) catalysts by adding the element of rare earth especially the Ce during the POM in COG. Such as, the Li15wt%CeO29wt%NiO/ -Al2O3 catalyst with an oxygen permeation flux of 24.71 ml·cm−2·min−1 and a high CH4 conversion was obtained in 875 ◦C. The resulted high oxygen permeation flux may be due to the added Ce that inhibited the strong interaction between Ni and Al2O3 to form the NiAl2O4 phase. In addition, the introduction of Ce leads up to an important property of storing and releasing oxygen.     

Radiation-induced catalytic degradation of p-nitrophenol (PNP) in the presence of TiO2 nanoparticles

The gamma radiation induced catalytic degradation of p-nitrophenol (PNP) in the presence of titanium dioxide (TiO₂) nanoparticles in aqueous solution was investigated. The initial concentration of PNP solution was 50 mg/L, and the additional TiO₂ doses were 0, 0.5, 1.0, and 2.0 g/L. The experimental results indicated that the PNP decomposition kinetics conformed to the modified pseudo-first order reaction equation under all applied conditions. When the TiO₂ dose was in the range of 0–2.0 g/L, the effect of additional TiO₂ on PNP decomposition rate was not obvious because PNP could be removed quite well by irradiation even in the absence of TiO₂ nanoparticles; however, the removal of total organic carbon (TOC) and total nitrogen (TN) was significantly accelerated in the presence of TiO₂ nanoparticles, the TOC removal efficiency increased from about 16% to 42%, and therefore the mineralization of PNP could be enhanced by TiO₂ nanoparticles. The inorganic nitrogen products were quantitatively measured to estimate the decomposition degree of PNP. The major aromatic intermediates, as well as carboxylic acids were identified by LCMS and IC. Possible reactions involved in radiation induced catalytic decomposition of PNP in aqueous solutions were proposed.