肉桂醛催化选择加氢反应中双金属的协同效应

对既含有ＣＣ键又含有ＣＯ键的分子,ＣＣ键的选择加氢意义重大［１］．α,β不饱和醛选择加氢成饱和醛就属于此类．钯是已知的可在温和条件下将α,β不饱和醛选择加氢生成饱和醛最有效的催化剂之一．人们曾研究了不同钯化合物催化剂对α,β不饱和醛中ＣＣ的双键选择加...     

水热法制备富锂型Li_(2+4x)Mn_(0.6+2x)Ni_(0.6-6x)Cr_(0.8)O_4及其结构与电化学特性

采用水热法制备了系列富锂尖晶石型正极材料Li2+4xMn0.6+2xNi0.6-6xCr0.8O4(x=1/30,1/20,1/15,1/12),通过X射线衍射(XRD)、电感耦合等离子体-原子发射光谱(ICP-AES)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FTIR)、拉曼光谱、循环伏安(CV)和充放电测试等手段对其结构及电化学性能进行表征.结果表明,所制备的系列材料为富锂型高电压尖晶石结构正极材料,该系列样品在4.7 V左右有放电平台.x=1/15和x=1/12时,样品中的Cr为+3价,没有观测到Cr6+.随着x值的增大,样品中Li离子与过渡金属离子的混排减小,样品的充放电比容量逐渐增大,且2.7 V处的放电平台容量也增加.当x=1/12时,样品具有较好的充放电比容量和倍率特性,首次放电比容量为107.3 mA·h/g,20次循环后容量保持率为84.9%.     

尖海龙提取物抗癌作用的研究

制备尖海龙提取物,再将其分别作用于Hela,SK-RB-3细胞系,从细胞形态变化,细胞计数,集落形成率,细胞分裂指数变化观察体外药效,结果表明,尖海龙提取物可改变肿瘤的正常生活形态,又可显著抑制肿瘤细胞的增殖,降低集落形成率,减少分裂指数,从而证实尖海龙提取物具有抗癌活性,其在癌症的治疗与预防方面具有实用价值。     

用于微型生化分析的光探测系统

针对微生化芯片样品剂量少和与微流体芯片集成等要求,设计了两种在芯片内用分光光度法对混合后液体的吸收光谱进行探测的方法。实验利用510～840 nm的可见光光源,采用了直接探测法和消逝波探测法对样品进行探测。通过两种方法的比较证明：直接探测法具有原理简单、消耗样品量少和结构容易实现等优点;消逝波探测法具有需要样品量极少、灵敏度高和易于集成的优点。     

The role of refocusing in dynamic X-wave formation during femtosecond laser filamentation in water

<正>With the evolution of a laser pulse in water,the formation of a nonlinear X wave during femtosecond filamentation is investigated based on numerical simulations.In particular,we analyze the far-field angularly resolved spectra obtained for different temporal portions of the ultrashort pulse during its propagation. Our result shows that the refocusing of ultrashort pulse leads to the formation of dynamic X wave which essentially manifests itself as conical emission.     

高对比度紫外电光削波开关

采用电光开关产生短脉冲的技术,建立了一种抑制准分子激光放大链自发辐射放大(ASE)的方法,研制了高对比度紫外电光削波开关,并进行了原理性实验,将其应用于准分子单路主振荡功率放大系统第一级预放大器的ASE控制。实验中电光开关对比度达到了2000多,削波后的预放大器输出激光脉冲信号对比度提高至20 000多,有利于激光信号后续进一步高保真放大,为系统获得窄脉冲输出提供了技术支持。     

GC-MS法快速测定食品接触材料油墨中16种多环芳烃

以正己烷超声提取,弗罗里硅土固相萃取柱净化,以正己烷-二氯甲烷溶液(体积比1:1)洗脱,用GC-MS联用仪SIM模式外标法定量测定食品接触材料油墨中16种多环芳烃.在优化条件下,16种多环芳烃的浓度在0.1～4.0 μg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数大于0.995,检出限为0.12～3.24 ng/L.加标回收率为77.24％～ 104.76％,测定结果的相对标准偏差为1.05％～1.69％(n=6).该方法适用于食品接触材料油墨中PAHs的日常检测.     

Lax Pairs for Integrable Six-Vertex Model with Color Parameters

Using the colored Yang-Baxter equation, the Lax pairs for the system with color parameters and periodic boundary conditions are derived. The explicit expressions of the Lax pairs for the six-vertex standard R matrices of both the Baxter and free-Fermion types are given.     

红色荧光粉NazCa1-x-2y-zBiyMoO4∶Eu3+x+y发光研究

采用高温固相法制备系列红色荧光粉Naz Ca1-x-2y-zBiyMoO4 ∶ Eu3+x+y (y,z=0,x=0.24,0.26,0.30,0.34,0.38; x=0.30,y=0.01,0.02,0.03,0.04,0.05,0.06,0.07,z=0; x=0.30,y=0.04,z=0.38).用X射线粉末衍射(XRD)法测试了所制样品晶相结构.采用荧光光谱仪对样品的发光性能进行了表征,结果表明:当Eu3+单掺杂量浓度x=0.30时,荧光粉(Ca0.70 MoO4∶Eu3+0.30)的发光强度最强;当Eu3+-Bi3+共掺杂量浓度y=0.03时,电荷迁移带(CTB)强度达到最强,而对于Eu3+特征发射峰,当共掺杂浓度y＜0.03时,位于393 nm处的激发峰强度比464 nm强,共掺浓度y＞0.03时,464 nm峰比393 nm峰强,共掺浓度为y=0.04时,393和464 nm处两峰位置强度都达到最强.作为电荷补尝剂的Na2 CO3掺入上述荧光粉中后,荧光粉激发和发射强度明显地增强.结果表明,通过调节Bi3+ /Eu3+掺杂比例可以改变位于近紫外光393 nm和蓝光区464 nm处激发光相对强度.     

HIAF高能辐照终端感生放射性

本工作是基于蒙特卡罗模拟软件FLUKA对高能强流重离子加速器（HIAF）高能辐照终端感生放射性进行初步研究。该终端可运行质子最高能量为9.3 GeV,最大流强是1.45×1012 pps（particle per second）。研究内容包括:（1）预测高能辐照终端内活化物质的放射性活度特性;（2）预测不同冷却时间高能辐照终端内残余剂量率分布。研究结果表明,HIAF正常运行时高能辐照终端内的感生放射性主要受束流垃圾桶活化产生的放射性核素影响。当加速器连续运行100天冷却4小时,垃圾桶表面残余剂量率为2.375 mSv·h-1。终端内空气中13N和15O动态饱和比浓度大于其对应的导出空气浓度。冷却水中13N和15O的活度大于对应的ALI_min。该研究是HIAF辐射防护基础研究以及加速器环境影响评价的一项重要内容。The Monte Carlo code FLUKA was used to predict the induced radioactivity of high-energy irradiation terminal of HIAF. The maximum energy of proton is 9.3 GeV, and the maximum current is 1.45×1012 pps (particle per second). In this study we were to predict:(1) the activity properties of activated substances in the experimental terminal; (2) the residual dose rate distribution in the experimental terminal at different cooling time. The results indicate that the induced radioactivity in the high energy irradiation terminal of the HIAF is mainly affected by the radionuclide induced in the beam dump. The residual dose rate on the surface of the beam dump is 2.375 mSv·h-1, after 100 d irradiation and 4 h cooling. The dynamic saturation ratio of 13N and 15O induced in the air inside the terminal is higher than its corresponding derived air concentration. The activity of 13 N and15O induced in cooling water is higher than its ALI_min. This study is a part of radiation protection basic research and environmental impact assessment for HIAF.