凝汽器性能的数值模拟与布管原则

针对目前国内使用最为广泛的300 MW机组凝汽器,采用具有分布阻力和分布质量汇的多孔介质模型,数值研究了菱型、卵型、将军帽型、双峰型等典型布管凝汽器的性能,比较了不同布管形式凝汽器的壳侧压降和抽气量,总结出了凝汽器布管的一些基本原则,如管束外形以窄长锲型或山峰形为好、外围应设置辅助进汽通道、需要设置渐缩型空冷区等。     

Synthesis of N~(11)-anchoring biotinylated artemisinin derivatives and their preliminary biological assessment

Unique endoperoxide moiety of artemisinin and its derivatives has been considered the functionality exhibiting highly potent antimalarial and anticancer activities.To investigate the mechanisms of their biological actions,development of suitable molecular probes including biotinylated derivatives is of extreme significance.The synthesis and preliminary biological assessment of four new biotinylated artemisinin derivatives have been reported in this work.     

生物相容性聚碳酸酯聚氨酯微纤维人工血管的研究

以分子量为2000的聚碳酸酯(PCDL)、1,4-丁二醇(BD)和4,4-二环己基甲烷二异氰酸酯(H12MDI)为原料合成出了一系列聚碳酸酯聚氨酯(PCU)。通过NMR、红外(FT-IR)、拉力实验、差示扫描量热仪(DSC)表征了该聚氨酯的化学结构、机械性能和热性能。在25度时,PCU的杨氏模量随硬段含量增加而略有升高。在有酶催化和没有酶的条件下,考察了材料的降解性能,发现吸水率和重量损失分别低于4%和1%。细胞毒性和血液相容性检测表明材料是生物相容、无毒的。经过喷纺技术制备的人工血管具有微孔结构,初步进行体内植入研究,PCU血管具有超细纤维交联的结构,并提供开放孔。研究结果表明聚碳酸酯聚氨酯具有优异的物理性能、高生物稳定性和良好的生物相容性,因此聚碳酸酯聚氨酯是人工血管合适材料。     

蔬菜重金属污染研究进展与防治措施

通过对国内外蔬菜重金属污染的研究现状、污染来源、蔬菜对重金属的吸收与富集规律、重金属对蔬菜生理生化效应的影响等方面的论述,探讨了蔬菜中重金属污染的控制方法,为开展蔬菜重金属污染防治提供参考和借鉴.     

示波极谱滴定法测定显影液中米吐尔和对苯二酚含量

用１．５ｍｏｌ／Ｌ乙酸铵－氨（ｐＨ８．２）－无水乙醇（２：１，Ｖ／Ｖ）混合溶液为极谱底液，以Ｋ２ＣｒＯ４与米吐尔和对苯二酚的氧化还原反应为基础，用Ｋ２ＣｒＯ４作为滴定剂，以示波极谱图上ＣｒＯ４＾２－切口出现指示终点，测定显影液中米吐尔和对苯二酚的含量。本法简便易行，灵敏准确，终点直观，应用于Ｄ－７２和Ｄ－７６显影液中米吐尔和对苯二酚的测定，获得满意结果。     

光热效应增强的Au/RGO/Na2Ti3O7光催化加氢性能

将典型的光热等离激元石墨烯和纳米金简便地负载在钛酸钠(Na₂Ti₃O₇)载体上, 构建出具有较窄禁带宽度和较高光催化活性的Au/RGO/Na₂Ti₃O₇光热辅助光催化体系. 研究发现, 石墨烯片层与金纳米颗粒在光照下, 通过局域表面等离激元共振效应诱导产生大量的热电子, 以活化反应物并降低反应活化能, 其引发的光热效应还可精准提升光催化体系中反应位点附近的温度, 从而大幅提升光催化反应速率. 通过构建特殊微支结构, 进一步增强了Au/RGO/Na₂Ti₃O₇催化剂对光的捕获, 并限域锚定高表面能催化剂以增强体系的稳定性. 在光热、 光催化的高效协同增强下, Au/RGO/Na₂Ti₃O₇催化剂体系对对硝基苯酚和肉桂醛的加氢反应均表现出增强的光催化活性. 光热辅助下的Au/RGO/Na₂Ti₃O₇光催化剂在对硝基苯酚反应中的转换频率（TOF）值高达54.4 min^-1, 反应活化能显著降低至15.78 kJ/mol, 且其在长效测试中表现出良好的稳定性（4次循环催化后, 转化率的保持率近90%）.     

硅、氮共掺杂碳点荧光粉的制备及发光性能

采用N-苯基对苯二胺和3-氨基丙基三甲氧基硅烷为原料,通过光化学催化法合成了高荧光强度的硅、氮共掺杂碳点（Si/N-CDs）。通过透射电子显微镜（TEM）、X射线光电子能谱（XPS）、荧光光谱、X射线衍射（XRD）和红外光谱（FT-IR）等对Si/N-CDs进行了表征。制备的 Si/N-CDs形貌呈球形,平均直径约6.45 nm,在365 nm紫外光照射下发明亮的蓝绿色荧光,量子产率可达30.8%,连续30 d测试Si/N-CDs均保持高的荧光强度。用Si/N-CDs替代传统的红/绿/蓝三基色稀土荧光粉中的蓝/绿稀土荧光粉,并与红色荧光粉（Sr,Ca）AlSiN₃∶Eu²⁺复合制备白光二极管（White Light Emitting Diode, WLED）。在60 mA电流下运行WLED,可实现86.9的高显色指数和7.76 lm/W的发光效率,色坐标是（0.3773, 0.3734）,色温为4062 K,并且色点位于黑体普朗克轨迹上,表明制备的WLED可以产生高质量的照明效果。硅、氮共掺杂碳点具有简便的制备方法和优异的光学性质,并能够代替蓝/绿色稀土荧光粉与红光荧光粉复合制备高质量照明的WLED,扩展了碳点在发光器件中的应用。同时,Si/N-CDs兼具低毒性、稳定的光学性质和简单的合成工艺,使其在蓝色和绿色稀土荧光粉的替代中具有潜在的商业应用前景。     

Covalent Organic Frameworks with trans-Dimensionally Vinylene-linked π-Conjugated Motifs

Vinylene-linked covalent organic frameworks(COFs) are a class of promising porous organic materials that feature fully π-conjugated structures, high crystallinity, permanent porosity, ultrahigh chemical stability, and extraordinary optoelectronic properties. Over the past 5 years, this kind of material has been witnessed rapid development either in chemical synthesis or in potential applications. In this review, we summarize the chemistry to synthesize vinylene-linked COFs, especially the synthetic strategies involving activation of aryl methyl groups for condensation reaction. We then scrutinize the state-of-the-art development in properties and functions of this kind of COFs. Our own opinions on the further development of the vinylene-linked COFs are also presented for discussion.     

Synergistic Catalysis of Enzymes and Biomimetic MOFs:Immobilizing Cyt c on Two-dimensional MOFs to Enhance the Performance of Peroxidase

Metal-organic frameworks(MOFs) have been widely regarded as promising carriers for enzyme immobilization owing to their advantages in improving loading and regulating interaction with enzymes. However, they are still suffering from the problems of slow mass transfer and compromising activity. In this paper, the active two-dimensional(2D) MOF of Cu-TCPP(Fe)[TCPP=tetrakis(4-carboxy-phenyl)porphyrin], which possesses the biomimetic architecture of peroxidase, was adopted to anchor cytochrome(Cyt c) for the enhancement of catalytic activity. The atomic/nanometer thickness and micrometer lateral dimension of 2D MOFs can ensure the full exposure of immobilized enzymes and a shorter diffusion distance for the reactant molecules. Besides, the active carrier can provide synergistic catalysis and activity compensation during the reaction. When tested in the decomposition reaction of H₂O₂, Cyt c/Cu-TCPP(Fe) exhibited nearly twice catalytic activity and an accelerated catalytic rate compared to free Cyt c.