铈改善TP347H钢的高温持久性能研究

以超临界锅炉管用耐热奥氏体不锈钢TP347H为研究对象,加入0%~0.3%(质量分数)的Ce,用25 kg真空感应炉在氩气保护下熔炼,研究了Ce对TP347H钢高温持久性能等的影响。结果表明:当TP347H中加入Ce量为0.005%时,在750℃,120 MPa时持久寿命达到最大297 h,比未加Ce时提高48%,随着Ce添加量的进一步增加持久寿命逐渐下降,Ce添加量≥0.15%时开始趋于稳定;Ce的添加将导致TP347H钢在高温固溶处理时δ铁素体的形成,Ce的合适添加量约为0.005%~0.03%。     

平行共轴线圈的磁场特征研究与实验设计

通过计算机及相关的传感器和数据采集接口辅助,研究了平行共轴双线圈间距分别为0.5R,R,1.5R时,轴线方向磁场强度的分布规律及特征.从平行共轴双线圈间距为R的亥姆霍兹线圈所形成的均匀磁场出发,结合理论推导,自己设计并组装了三线圈实验装置,实现了平行共轴三线圈均匀磁场区域扩大、强度增强的实验设计,在一定程度上弥补了传统亥姆霍兹线圈磁场测量的不足并有助于对其深入的理解和研究.     

Layer-by-layer inkjet printing of fabricating reduced graphene-polyoxometalate composite film for chemical sensors

Graphene oxide (GO) nanosheets and polyoxometalate such as H(3)PW(12)O(40) (PTA) are prepared into a multilayer film via a layer-by-layer inkjet printing method. The GO/PTA composite thin film shows linear, uniform and regular layer-by-layer growth. Under UV-irradiation, a photoreduction reaction takes place in the film which converts GO to reduced GO (rGO) due to the photoreduction activity of polyoxometalate clusters. According to the cyclic voltammograms measurement, the rGO/PTA composite film displays good electrocatalytic activity for the oxidation of dopamine (DA). The oxidation peak current (I(pa)) increases gradually with increasing the dopamine concentration, which may be used in electrochemical biosensors.     

Growth of calcium oxalate crystals induced by complex films containing biomolecules

Nucleation and growth of calcium oxalate (CaC₂O₄) crystals induced by films composed of phosphatidylcholine (PC), cholesterol (CS) and human serum albumin (HSA), and of PC, CS and dextran have been carried out. The products obtained were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and ultraviolet‐visible spectroscopy. The results indicate that hexagonal calcium oxalate monohydrate (COM) and club‐shaped calcium oxalate trihydrate (COT) crystals are obtained on the PC/CH/HSA film, and the microstructure and properties of the PC/CH/HSA film depend on the weight ratio of PC to CS. With an increase in the PC‐to‐CS ratio, the number of COM crystals decreases gradually, and finally disappear, suggesting that PC inhibits the growth of COM crystals. On the PC/CS/dextran film, irregular COM and COT crystals are formed. The possible formation mechanisms of CaC₂O₄ on the two complex films are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

用高速摄影法确定大区爆破微差时间的研究

本文介绍了用高速摄影法研究大区微差爆破时,确定合理微差间隔时间的方法。并且提出了50～100万吨级大区多排微差爆破的合理微差间隔时间,矿山生产爆破实践证明,用高速摄影法能准确确定合理微差间隔时间。     

阳离子Gemini表面活性剂3,5-双(亚甲基十八烷基二甲基溴化铵)-1,2,4-三氮唑胶束对酯碱性水解的影响

在25℃条件下,研究了乙酸乙酯和乙酸戊酯在阳离子Gemini表面活性剂3,5—双(亚甲基十八烷基二甲基溴化铵)—1,2,4—三氮唑(简称18—triazole—18)胶束中的碱性水解反应。实验结果表明．在一定的表面活性剂浓度范围内,乙酸乙酯和乙酸戊酯在Gemini表面活性剂18—triazole—18胶束溶液中的碱性水解反应速率随表面活性剂浓度的增加呈上升趋势,达到一最大值后,随着浓度的增加呈下降趋势。实验结果还表明,18—triazole—18对乙酸乙酯碱性水解的影响较对乙酸戊酯碱性水解的影响大。随着底物疏水性的增加,乙酸乙酯和乙酸戊酯的碱性水解速率在18—triazole—18胶束中表观反应速率常数最大值分别为无表面活性剂时的5．5倍和1．1倍。     

Determination of Alizarin Red S using a novel B-Z oscillation system catalyzed by a tetraazamacrocyclic complex

A new and convenient method for the determination of Alizarin Red S by the perturbations caused by different amounts of Alizarin Red S on a novel B-Z oscillating system is proposed. This new type Belousov-Zhabotinskii involves a macrocyclic copper(II) complex [CuL](ClO₄)₂ as catalyst and malic acid as the substrate. The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. It is found that the relationship between the change in the oscillation amplitude and the logarithm of the Alizarin Red S concentration in the range of 1.5 × 10⁻⁷ to 1 × 10⁻³ M fits a polynomial model: ΔA = 659 + 184.2 log [Alizarin Red S]+ 12.9 log² [Alizarin Red S]. The RSD obtained with ten samples is 4.4%. The probable mechanism involving the perturbation of Alizarin Red S on the oscillating chemical system is also discussed.      

Ionic conductivity and interfacial stability of Li6PS5Cl–Li6.5La3Zr1.5Ta0.5O12 composite electrolyte

Solid electrolytes which possess excellent lithium-ion conductivity and chemical compatibility with electrode materials are necessary for the commercialization of all-solid-state lithium batteries. However, a single solid electrolyte meeting above requirements is difficult. Consequently, the composite electrolytes have attracted more attention. In this paper, Li₆PS₅Cl–xLi_6.5La₃Zr_1.5Ta_0.5O₁₂ (LLZTO) (x = 0, 2.5 wt%, 5 wt%, 10 wt%) composite electrolytes are prepared by a simple planetary grinding process. It has been found that adding an appropriate amount of LLZTO can increase the lithium-ion conductivity. At 30 °C, the lithium-ion conductivity increases from 2.6 × 10⁻⁴ S/cm (Li₆PS₅Cl) to 5.4 × 10⁻⁴ S/cm (Li₆PS₅Cl-5 wt% LLZTO). Besides, the addition of LLZTO to the Li₆PS₅Cl can influence the growth rate of the SEI. It has been shown that the SEI growth rate obeys a parabolic rate law, and the growth rates of Li₆PS₅Cl, Li₆PS₅Cl-2.5 wt% LLZTO, Li₆PS₅Cl-5 wt% LLZTO, and Li₆PS₅Cl-10 wt% LLZTO are 8.62, 3.53, 3.33, and 3.38 Ω/h^1/2 at 60 °C, respectively. In lithium plating and stripping experiment, the voltage of symmetrical Li/Li₆PS₅Cl/Li cell suddenly drops to 0 V after cycling 39 h at 0.103 mA/cm² (0.097 mAh/cm²). On the contrary, the Li/Li₆PS₅Cl–xLLZTO (x = 2.5 wt%, 5 wt%, 10 wt%)/Li symmetrical cell exhibits a stable voltage profile over 100 h at the same test conditions. The corresponding interfacial impedance of Li/Li₆PS₅Cl–xLLZTO (x = 2.5 wt%, 5 wt%, 10 wt%) remains stable after 10, 30, and 50 charge/discharge cycles.

     

“直接线性变换”用于爆破过程高速立体摄影解析的可行性和精度问题

高速摄影作为研究岩土爆破过程的观测手段已有数十年的应用历史,观测内容主要是爆破介质的破裂和运动。研究爆破介质的运动大多是研究其整体的移动—岩(土)体表面的鼓包运动或破碎介质群体的抛掷。     

纳米孔洞金属-有机骨架催化氧化苯甲醇动力学研究

具有纳米孔洞的金属-有机骨架材料Cu3（BTC）2（H2O）3为催化剂,过氧化氢为氧化剂,利用紫外可见光谱研究其催化氧化苯甲醇生成苯甲醛的催化反应动力学行为,系统地讨论了纳米孔洞金属-有机骨架材料的催化动力学。研究结果表明,随着反应介质的pH、催化剂与反应底物的摩尔比和反应温度的升高,准一级反应速率常数kobsd也会随...