Ｒetrieval of Secchi disk depth using MODIS satellite remote sensing and in situobservations in the Yellow Sea and the East China Sea

海水透明度是描述水体光学特征的一个重要参数,也是海洋水质调查中的一个重要指标。利用2个航次的黄东海透明度数据和MODIS遥感反射率数据,进行了黄东海透明度的遥感反演研究,建立了透明度单波段模型、波段比值模型、三波段模型以及基于固有光学特性的半分析模型。结果表明,三波段模型具有较高精度,反演值与实测值之间的平均相对误差为19%、决定系数为0.719、均方根误差为1.47 m。黄东海透明度估测模型的建立,有利于利用遥感影像对黄东海透明度进行全面估测,对于监测黄东海水质状况具有重要意义

多壁碳纳米管负载铂的甲苯加氢脱芳催化剂

以多壁碳纳米管(CNTs)为载体制备了负载型Pt催化剂Pt/CNTs并将其用于催化甲苯加氢脱芳(HDA)反应.结果表明,在1.0%Pt/CNTs催化剂上,在0.4MPa,373K,PhCH3/H2摩尔比=6/94和GHSV=120L/(h.g)的反应条件下,甲苯转化率可达100%,比反应速率为0.0523mmol/(s.m2),分别是γ-Al2O3和AC负载各自最佳Pt负载量催化剂1.4%Pt/γ-Al2O3和2.4%Pt/AC上相应值的1.17和1.18倍.甲苯加氢产物全部为甲基环己烷,其他可能的加氢产物均在气相色谱检测限以下.催化剂的表征研究揭示,用CNTs代替γ-Al2O3或AC作为载体并不会引起所负载Pt催化剂上甲苯HDA反应的表观活化能发生明显变化.与γ-Al2O3或AC负载的相应催化剂相比,一方面,CNTs负载的Pt催化剂易于在较低温度下还原活化,并且其工作态催化剂表面催化活性Pt物种(Pt0)所占表面Pt摩尔分率有所提高;另一方面,CNTs负载的Pt催化剂对H2具有较高的吸附/活化和储存能力.这些促进效应对催化剂HDA活性的提高都有重要贡献

血清一阶导数荧光光谱诊断早期恶性肿瘤

利用Wistar大鼠接种恶性肉瘤模拟人患上癌症。取Wistar大鼠眼静脉血制备血清,并用乙醇简单处理得上层清液,扫描获得其一阶导数荧光光谱,确定上层清液原卟啉发射带(630 nm附近)的峰高,观察到健康Wistar大鼠与癌变大鼠的血清样存在明显差异,10例癌变样假阳性率为0,而20例正常样中仅有1例假阳性达到了恶性肿瘤早期诊断的目的

Purification of Multiwalled Carbon Nanotubes and Characterization of Their Oxygen-Containing Surface Groups

Corresponding author. Email: [email protected].[中文文摘]用兼具酸性和氧化性的HNO3水溶液可方便地除去残留在原生态多壁碳纳米管(CNT)上的Ni-MgO催化剂组分,同时在其表面产生某些含氧官能团,使原生态多壁碳纳米管的疏水性表面变为亲水性表面.采用Boehm中和滴定法以及X射线衍射(XRD)、热脱附谱(TPD)、傅里叶变换红外(FTIR)光谱和X射线光电子能谱(XPS)等技术对HNO3处理过的多壁碳纳米管的相组成和表面含氧官能团进行测量和表征.结果表明:所生成表面含氧官能团的总量以经7.0mol·L-1硝酸378K处理24h的CNT为最高;3种主要表面含氧官能团的含量高低顺序为,羧基>内酯型羧基>酚型羟基.[英文文摘]We conveniently removed the Ni-MgO catalyst components from an as-grown multiwalled carbon nanotube (CNT) using an aqueous HNO3 solution with strong acidity and oxidizability as a purifying reagent. Some oxygen-containing surface groups were generated at the CNT surface, which converted the hydrophobic surface into a hydrophilic surface. The phase composition and the oxygen-containing surface groups of the CNTs treated by nitric acid were determined and characterized using Boehm′s neutralizing titration method and X-ray powder diffraction (XRD), temperature-programmed desorption (TPD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. The results indicated that the total content of the formed oxygen-containing surface groups was the highest for the CNTs treated with 7.0 mol·L-1 aqueous HNO3 at 378 K for 24 h. The content of the three major oxygen-containing surface groups was: carboxyl>lactonic carboxyl>phenolic hydroxyl.国家重点基础研究发展规划项目(973)(2009CB939804);福建省重大科技专项专题项目(2009HZ0002-1

氢气在碳纳米管基材料上的吸附-脱附特性

利用高压容积法测定多壁碳纳米管(MWCNTs)及钾盐修饰的相应体系(K+-MWCNTs)的储氢容量,并用程序升温脱附(TPD)方法表征研究氢气在MWCNTs基材料上的吸附-脱附特性.结果表明,在经纯化MWC-NTs上,室温、9.0MPa实验条件下氢的储量可达1.51%(质量分数);K+盐对MWCNTs的修饰对增加其储氢容量并无促进效应,但相应化学吸附氢物种的脱附温度有所升高;K+的修饰也改变了MWCNTs表面原有的疏水性质.在低于723K的温度下,H2/MWCNTs体系的脱附产物几乎全为氢气;773K以上高温脱附产物不仅含H2,也含有CH4、C2H4、C2H2等C1/C2烃混合物;H2/K+-MWCNTs储氢试样的脱附产物除占主体量的H2及少量C1/C2烃混合物外,还含水汽,其量与吸附质H2源水汽含量密切相关.H2在碳纳米管基材料上吸附兼具非解离(即分子态)和解离(即原子态)两种形式

支撑应力对骨小梁分布的影响及股骨头坏死因素的研究

目的通过犬股骨颈骨折螺钉内固定模型的力学检测及组织学观察,从微观角度认识骨小梁重建对股骨头坏死的影响。方法选取18只成年田园犬制作成股骨颈骨折螺钉内固定模型,于造模后12周确认所有股骨颈骨折已愈合随机分为取钉组、取钉植骨组及不取钉组,于造模后20周分离所有犬的股骨并进行股骨颈力学测试及组织学观察。结果取钉组、取钉植骨组及不取钉组断裂点载荷、最大载荷差异有统计学意义(P0.05),不取钉组与取钉植骨组断裂点载荷大于取钉组;不取钉组最大载荷大于取钉植骨组与取钉组,取钉植骨组最大载荷大于取钉组。取钉组、取钉植骨组及不取钉组骨小梁宽度与新鲜骨面积差异有统计学意义(P<0.05);不取钉组骨小梁宽度、新鲜骨面积大于取钉植骨组,且取钉植骨组大于取钉组。结论支撑应力的改变将导致骨小梁重新分布,骨小梁再分布是影响股骨头坏死塌陷的重要因素。福建省卫生系统中青年骨干人才培养项目(2014-ZQNJC-34

多壁碳纳米管及其对H_2吸附体系的Raman光谱

利用原位和非原位紫外 Raman谱法 ,对以 CH4 为碳源 ,由催化法制备的多壁碳纳米管( MWCNTs) ,K+-修饰的该类 MWCNTs,以及它们对 H2 的吸附体系进行了 Raman谱表征 ,观测到可分别归属于类石墨结构的基频模 D和 G以及它们的三阶组合频 ,表面 C-H3基和 C-H2 基等的特征Raman峰 ;H2 在这类碳纳米管上的吸附态包括解离吸附生成表面 C-H3和非解离吸附分子氢 H2 ( a) ;在相同实验条件下 ,K+-修饰体系上这两类氢吸附物种的表面浓度都比未经 K+-修饰的相应体系高

Pt catalyst supported on multiwalled carbon nanotubes for hydrogenation-dearomatization of toluene

Using home-made multiwalled carbon nanotubes (CNTs) as the support, the Pt/CNTs catalyst was prepared by an incipient wetness method. Performance of the catalyst for hydrogenation-dearomatization (HDA) of toluene was evaluated and compared with the reference catalysts supported on gamma-Al2O3 and activated carbon (AC). Over the 1.0 % Pt/CNTs catalyst under the reaction conditions of 0.4 MPa, 373 K, PhCH3/H-2 = 6/94 (mol/mol) and GHSV = 120 L/(h center dot g), the observed conversion of toluene HDA reached 100 %, and the corresponding specific reaction rate was 0.052 3 mmol/(s center dot m(2)). This value was 1.17 and 1.18 times that of the 1.4 % Pt/gamma-Al2O3 and 2.4 % Pt/AC catalysts with the respective optimal Pt loading, respectively. It was experimentally found that using CNTs in place of gamma-Al2O3 or AC as the support of the catalyst did not cause a significant change in the apparent activation energy for the toluene HDA reaction but led to a slight increase in concentration of catalytically active Pt species (Pt-0) at the surface of the functioning catalyst. In addition, the Pt/CNTs catalyst could reversibly adsorb a greater amount of hydrogen under atmospheric pressure at temperatures from room temperature to 573 K. This unique feature would help to generate a microenvironment with higher stationary state concentration of active hydrogen-adspecies at the surface of the functioning catalyst. These effects favored the toluene HDA reaction

碳纳米管及其H_2吸附体系的Raman光谱

利用紫外Raman光谱技术 ,对分别以CO和CH4为碳源、由化学催化法制备的两种多壁碳纳米管以及它们的H2 吸附体系进行Raman光谱表征 ,观测到可分别归属于类石墨结构的基频模G (1 5 80cm- 1 )和D (1 41 6cm- 1 ,缺陷诱导 ) ,以及它们的二阶和三阶组合频 2D(2 83 2cm- 1 ) ,D +G (2 996cm- 1 ) ,2G (3 1 6 0cm- 1 )和 2D +G (441 2cm- 1 )的Raman峰 ;H2在这些多壁碳纳米管上吸附有两种形式 :非解离吸附分子氢H2 (a)和解离吸附生成含氢表面物种CHX(x =3 ,2 ,1 ) ,所观测在 2 85 0 ,2 96 7和 3 95 0cm- 1 处的Raman谱峰可分别归属于表面CH2 基的对称C -H伸缩模 ,CH3基的不对称C -H伸缩模 ,以及吸附态分子氢H2 (a)的H -H伸缩