Y-Mn-O负载的Ni基催化剂用于乙酸自热重整产氢

为了有效地从生物质衍生的乙酸中获得高氢气产率,通过水热法合成了一系列的NiMnY催化剂并用于乙酸自热重整(ATR)过程中,并采用X射线衍射(XRD)、N2吸附-脱附测试、H₂程序升温还原(H₂-TPR)探究催化剂中的内在联系。在Ni_0.39Mn_0.61YO_3.11±δ催化剂中,经焙烧后形成了类钙钛矿型(Ni,Mn)YO3物相;经氢气还原后,转化为含有Mn O、Y₂O₃和高分散Ni纳米粒子的热稳定的Ni-Mn-Y-O物种。Ni_0.39Mn_0.61YO_3.11±δ具有高效稳定的产氢催化性能,乙酸转化率高达100%,氢气产率达到2.68 mol_(H₂)·mol_HAc^-1。     

平板型太阳热水器板芯高温耐久性实验方法研究

为了研究平板型太阳热水器板芯表面的高温耐久性,结合国外的实验方法及国内的应用特点设计了本实验方法.该方法以板芯表面光学性能的衰减来推断系统的寿命,即在一定的高温实验条件下模拟加速衰减过程,以板芯表面光学性能衰减小于5%作为判断板芯合格标准.     

乳腺癌改良根治术后应用高负压引流的效果观察和护理

乳腺癌是女性常见的恶性肿瘤之一,改良根治术是目前国内治疗乳腺癌的最常用方法[1]。皮下积液和皮瓣坏死是改良根治术的常见并发症,其发生率约为10%-30%[2]。在引起皮下积液和皮瓣坏死的众多因素中,术后创面引流不畅是一个关键的原因。我科采用一次性高负压引流系统应用于乳腺癌改良根治术后患者,取得了良好的效果,现报道如下。     

碱熔融-电感耦合等离子体原子发射光谱法测定氧化铟锡烧结混合粉中5种杂质元素

采用氢氧化钠熔融样品,热水浸取后盐酸酸化,建立了碱熔融-电感耦合等离子体原子发射光谱(ICP-AES)法测定氧化铟锡烧结混合粉中Fe、Ca、Mg、Al和Si等元素的分析方法.试验结果表明:称取0.500 0 g试样,加入0.80 g氢氧化钠,在灰化炉中熔融120 min,可将样品完全溶解.基体铟和锡的干扰采用基体匹配法消除,被测元素之间没有光谱干扰.钠盐对硅的测定有一定影响,可在标准溶液中加入一定量氢氧化钠予以消除.对方法进行精密度和加标回收试验,测得结果的相对标准偏差均小于5%,方法加标回收率在90%~105%之间.     

Effect of In_x Ga_(1-x )N “continuously graded” buffer layer on InGaN epilayer grown by metalorganic chemical vapor deposition

In this paper we report on the effect of an In x Ga1-x N continuously graded buffer layer on an InGaN epilayer grown on a GaN template.In our experiment,three types of buffer layers including constant composition,continuously graded composition,and the combination of constant and continuously graded composition are used.Surface morphologies,crystalline quality,indium incorporations,and relaxation degrees of InGaN epilayers with different buffer layers are investigated.It is found that the In x Ga1-x N continuously graded buffer layer is effective to improve the surface morphology,crystalline quality,and the indium incorporation of the InGaN epilayer.These superior characteristics of the continuously graded buffer layer can be attributed to the sufficient strain release and the reduction of dislocations.     

Effect of InxGal-xN ＂continuously graded＂ buffer layer on InGaN epilayer grown by metalorganic chemical vapor deposition

In this paper we report on the effect of an lnxGal xN continuously graded buffer layer on an InGaN epilayer grown on a GaN template. In our experiment, three types of buffer layers including constant composition, continuously graded composition, and the combination of constant and continuously graded composition are used. Surface morphologies, crystalline quality, indium incorporations, and relaxation degrees of InGaN epilayers with different buffer layers are investigated. It is found that the InxGa1-xN continuously graded buffer layer is effective to improve the surface morphology, crystalline quality, and the indium incorporation of the InGaN epilayer. These superior characteristics of the continuously graded buffer layer can be attributed to the sufficient strain release and the reduction of dislocations.     

Identification of pore size in porous SiO2 thin film by positron annihilation

Positron annihilation lifetime and Doppler broadening of annihilation line techniques have been used to obtain information about the small pore structure and size of porous SiO2 thin film produced by sputtered Al-Si thin film and etched Al-Si thin film. The film is prepared by an Al/Si 75：25 at.-% （A175Si25） target with the radiofrequency （RF） power of 66 W at room temperature. A 5 wt.-% phosphoric acid solution is used to etch the Al cylinders. All the A1 cylinders dissolved in the solution after 15 h at room temperature, and the sample is subsequently rinsed in pure water. In this way, the porous SiO2 on the Si substrate is produced. From our results, the values of all lifetime components in the spectra of Al-Si thin film are less than 1 ns, but the value of one of the lifetime components in the spectra of porous SiO2 thin film is τ = 7.80 ns. With these values of lifetime, RTE （Rectangular Pore Extension） model has been used to analyze the pore size.     

Y-Mn-O负载的Ni基催化剂用于乙酸自热重整产氢

为了有效地从生物质衍生的乙酸中获得高氢气产率,通过水热法合成了一系列的NiMnY催化剂并用于乙酸自热重整（ATR）过程中,并采用X射线衍射（XRD）、N₂吸附-脱附测试、H₂程序升温还原（H₂-TPR）探究催化剂中的内在联系。在Ni_0.39Mn_0.61YO_3.11±δ催化剂中,经焙烧后形成了类钙钛矿型（Ni,Mn）YO₃物相;经氢气还原后,转化为含有MnO、Y₂O₃和高分散Ni纳米粒子的热稳定的Ni-Mn-Y-O物种。Ni_0.39Mn_0.61YO_3.11±δ具有高效稳定的产氢催化性能,乙酸转化率高达100%,氢气产率达到2.68 mol_H2·mol_HAc^-1。     

基于多指标含量测定结合化学计量学的不同产地丹参品质差异分析

为对比分析产地对丹参中酚酸类和丹参酮类成分的影响,采用超高效液相色谱（UPLC）及超高效液相色谱－三重四极杆质谱联用技术（UPLC－QQQ－MS）同时测定来自山东、河南、陕西、四川、安徽共408份丹参中23种化学成分的含量,并对数据进行多元统计分析。研究发现17种酚酸类及6种丹参酮类成分在不同产地丹参中均存在显著差异。山东的丹参样品中丹参酮类成分含量最高,四川的样品中丹酚酸B含量最高,安徽丹参的紫草酸、丹酚酸Y、丹酚酸A、丹酚酸D和丹酚酸E等的含量最高。多种模式识别方法均可用于不同产地丹参的判别分析,线性判别分析（LDA）为产地溯源的最佳模型。正交偏最小二乘法判别分析（OPLS－DA）表明不同产地丹参的化学成分差异较大,不同来源丹参的质量差异标志物不仅限于丹酚酸B、丹参酮Ⅰ、隐丹参酮、丹参酮ⅡA,其他丹酚酸类及丹参酮类也是重要的质量标志物。该研究对全国不同主产区的栽培丹参进行多指标含量测定及建模分析,所建立的定量方法专属性强、准确高效,可为不同产地丹参的质量控制及产地判别提供参考。     

Fabrication of GaN-based LEDs with 22° undercut sidewalls by inductively coupled plasma reactive ion etching＊

We use a simple and controllable method to fabricate GaN-based light-emitting diodes （LEDs） with 22° undercut sidewalls by the successful implementation of the inductively coupled plasma reactive ion etching （ICP-RIE）. Our exper- iment results show that the output powers of the LEDs with 22° undercut sidewalls are 34.8 rnW under a 20-mA current injection, 6.75% higher than 32.6 mW, the output powers of the conventional LEDs under the same current injection.