SiO_2接枝聚酰胺胺树枝状大分子在PS超临界CO_2发泡中的作用研究

在纳米SiO2表面引入聚酰胺胺树枝状大分子(PAMAM),再通过原子转移自由基聚合(A-TRP)合成了一种核-壳结构的SiO2-PAMAM-PS,将改性的纳米SiO2添加到PS基体中作为超临界CO2发泡的成核剂。红外光谱(IR)、差示扫描量热仪(DSC)、热重(TG)等结果表明,SiO2表面成功引入了PAMAM,并且接枝上了PS链段。透射电镜(TEM)显示该成核剂具有核-壳结构及其在PS基体中可以较均匀分散。将添加了改性SiO2的PS进行了超临界CO2发泡,利用扫描电镜(SEM)对泡孔结构进行了表征,结果表明:相比于纯发泡PS,成核剂的加入,改善了PS的泡孔结构,使泡孔尺寸显著减小,泡孔密度明显增加。     

中国区域CO_2排放影响因素实证研究

在测算我国1997～2007年间省级CO2排放量的基础上,通过对面板数据单位根检验及协整检验,并以此建立面板数据环境库兹涅兹曲线(EKC)模型,研究全国及东、中、西部地区CO2排放量与经济增长、产业结构及能源消费结构之间的相互关系。实证结果表明,考察期中全国和东部地区EKC曲线呈倒N型,中、西部地区CO2排放量则随人均GDP单增,工业比重及煤炭消费比重的降低都将导致CO2排放量的减少。     

CO2气井试气过程中的水合物防治

天然气在试气、试采和生产地面流程流动的过程中,必须采取节流降压的措施才能确保施工正常进行。由于节流会造成下游压力降低,气体迅速会膨胀,致使分子间距离增大,这时就必须供给充足的能量以克服分子间的引力。但由于气体膨胀速度很快,来不及与外界进行热交换,故所需的能量只能由消耗气体本身的能来供给,从而使气体冷却,温度降低,在管壁内外产生冰冻现象,经常出现水合物冻堵管线而导致停产。为解决上述问题,给出了一些在实际中行之有效的措施,以供参考。     

Tracking structural evolution: operando regenerative CeOx/Bi interface structure for high-performance CO2 electroreduction

Unveiling the structural evolution and working mechanism of catalysts under realistic operating conditions is crucial for the design of efficient electrocatalysts for CO₂ electroreduction, yet remains highly challenging. Here, by virtue of operando structural measurements at multiscale levels, it is identified under CO₂ electroreduction conditions that an as-prepared CeO₂/BiOCl precatalyst gradually evolves into CeO_x/Bi interface structure with enriched Ce³⁺ species, which serves as the real catalytically active phase. The derived CeO_x/Bi interface structure compared to pure Bi counterpart delivers substantially enhanced performance with a formate Faradaic efficiency approaching 90% for 24 hours in a wide potential window. The formate Faradaic efficiency can be further increased by using isotope D₂O instead of H₂O. Density functional theory calculations suggest that the regenerative CeO_x/Bi interfacial sites can not only promote water activation to increase local ^*H species for CO₂ protonation appropriately, but also stabilize the key intermediate ^*OCHO in formate pathway.     

京津冀CO2排放的时空差异及影响因素研究

研究京津冀CO₂排放的时空特性及影响因素,对实现京津冀生态环境协同治理具有重要的理论及实践意义。本文首先对2000—2014年京津冀CO₂排放的时空特性进行了分析,然后利用LMDI分解方法对京津冀CO₂排放的影响因素进行总体分析。并在此基础上,结合LMDI分解方法和M-R空间分解方法,本文具体分析了京津冀CO₂排放时空差异的影响因素。研究发现：① 研究期内京津冀CO₂排放增长迅速,从2000年的3.67亿t增长到2014年的10.02亿t。其中,河北对京津冀CO₂排放贡献最大,达到72.02%。② 经济总量（贡献度：152.17%）是导致京津冀CO₂排放增长的主要因素。能源利用效率（贡献度：-56.29 %）和能源结构调整（贡献度：-34.39 %）是抑制京津冀CO₂排放增长的主要因素。此外,产业结构调整、收入提高和城镇化也是导致京津冀CO₂排放增长的重要因素。③ 京津冀各地区CO₂排放差异不断扩大。经济总量大和能源利用效率低是河北CO₂排放高于京津翼平均水平的主要原因,以优质能源为主的能源结构是北京CO₂排放低于京津翼平均水平的主要原因。     

O2／CO2气氛中生物质燃烧及 NO 排放特性研究

采用热重分析仪、管式炉试验研究了反应温度、燃料种类、氧浓度等操作参数对稻壳、稻杆、花生壳3种生物质在 O2／CO2气氛下的燃烧特性和 NO 排放特性。试验结果表明：随着 O2含量的增大,3种生物质的挥发分和固定碳的燃烧性能均随之增加;当反应温度由700℃增加到800℃时,NO 的平均排放量随温度升高迅速增加,当反应温度高于800℃,NO 平均排放量增幅趋于平缓;NO 平均排放量和氮转换率随着燃料中 N 含量的增加而减少;NO 平均排放量随氧气浓度变化较小,低于 NO 排放标准。增加 O2浓度有助于促进生物质在 O2／CO2气氛中的燃烧,同时对 NO 生成的影响较小。     

H_2S对Q235钢在CO_2介质中的腐蚀影响及缓蚀研究

采用失重法研究了H2S对Q235钢在CO2介质中的腐蚀影响及咪唑啉缓蚀剂的缓蚀性能,并用电子探针分析了Q235钢表面的腐蚀产物膜,结果表明:常压CO2-H2S溶液中,H2S加速了CO2的腐蚀,在高压CO2-H2S溶液中,Q235钢腐蚀速率的对数lgRCO2-H2S与二氧化碳分压的对数lgPco2不成线性关系,实验室合成的咪唑啉化合物具有较好的缓蚀效果。     

细菌培养箱温度和浓度的实时控制

文章分析了温度和CO2浓度实时控制原理和实现的方法，介绍了以单片机为基础的一个实时控制电路。     

制备方法对Cu—Mn／ZrO2催化剂合成甲醇反应性能的影响

分别用草酸盐胶态共沉淀法和碳酸钠并流共沉淀法制备了Cu-Mn/ZrO2催化剂，发现催化剂的前驱物及其制备的均匀程对催化剂的反应性能影响很大，均匀沉淀法促进了催化剂的分散及组元之间的相互作用，明显提高了CO加氢合成甲醇的反应活性。三种元素之间的协同效应对合成甲醇反应的活性有决定性的作用，同时发现反应可能是一个受扩散影响较大的过程。     

Catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 in NO＋CO reaction

Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.