氢原子径向距离r~ν平均值的计算

利用氢原子径向波函数和拉盖尔多项式的性质,导出了计算氢原子径向距离r的任意整数次的平均值公式．     

低浓度二氧化硫引起蚕豆叶片过氧化氢累积及几种清除剂变化的研究

低浓度ＳＯ２（０．２６０、０．１３１ｍｇ／ｍ３）处理蚕豆植株，引起叶片内Ｈ２Ｏ２含量升高，Ｈ２Ｏ２含量的升高与ＳＯＤ活性升高有关。同时体内清除Ｈ２Ｏ２的过氧化物酶和抗坏血酸过氧化物酶活性上升，而抗坏血酸含量下降。     

Recent advances in hydrogen storage technologies based on nanoporous carbon materials

Hydrogen is a promising energy carrier that can potentially facilitate a transition from fossil fuels to sustainable energy sources without producing harmful by-products. Prior to realizing a hydrogen economy, however, viable hydrogen storage materials must be developed. Physical adsorption in porous solids provides an opportunity for hydrogen storage under low-stringency conditions. Physically adsorbed hydrogen molecules are weakly bound to a surface and, hence, are easily released. Among the various surface candidates, porous carbons appear to provide efficient hydrogen storage, with the advantages that porous carbon is relatively low-cost to produce and is easily prepared. In this review, we summarize the preparation methods, pore characteristics, and hydrogen storage capacities of representative nanoporous carbons, including activated carbons, zeolite-templated carbon, and carbide-derived carbon. We focus particularly on a series of nanoporous carbons developed recently: metal–organic framework-derived carbons, which exhibit promising properties for use in hydrogen storage applications.     

Synthesis of PbS–K2La2Ti3O10 composite and its photocatalytic activity for hydrogen production

Photocatalyst, lead sulfide (PbS )-intercalated layer perovskite-type compound (K2La2Ti3O10), was synthesized via ion-exchange reaction, butylamine pillaring and sulfuration processes under the assistance of the microwave irradiation. The structure of the photoc atalysts was determined by means of powder X-ray diffraction, scanning electron microscope, ultraviolet- visible diffuse reflection spectra and photoluminescence measu rement. And the photocatalytic activity of the composite compound for hydrogen production was also investigated. The experimental results showed that the intercalation of PbS in the layered space of K2La2Ti3O10 greatly improved the absorption edge and the photocatalytic activity. Hydrogen production of the PbS–K2La2Ti3O10 was 127.19 mmol/(g cat) after 3 h irradiation of ultraviolet light.     

Key technologies for polymer electrolyte membrane fuel cell systems fueled impure hydrogen

Hydrogen energy and polymer electrolyte membrane (PEM) fuel cells become concerned issues in recent years. Nevertheless, the construction of hydrogen refueling infrastructure and hydrogen storage and transportation constrains the commercial development of fuel cells. In this review, sources, production, storage, transportation, and purification methods of hydrogen are extensively reviewed and compared. The advantages of utilizing industrial by-product hydrogen and steam reforming gas in PEM fuel cell systems are analyzed. Using industrial wasted hydrogen can significantly reduce the cost of hydrogen. Also, it is indicated that the onboard hydrogen generation by steam methanol reforming can solve the difficulties of efficient storage and transportation of gaseous hydrogen, which means that methanol has great potential to be a convenient carrier of hydrogen. The effects of impurities contained in the reformate gas are generally introduced. After the methanol steam reforming and pretreatment purification processes, the reformate gas can be fed to PEM fuel cells. Thus, a fuel cell system integrated with onboard hydrogen production and impure hydrogen treatment subsystems is introduced, and key technologies therein for pretreatment purification and in-situ poisoning mitigation methods are reviewed. Finally, suggestions are proposed for further studies.     

氢原子的概率密度分布

利用数值计算方法绘制出氢原子的径向概率、角向概率分布、等概率曲线图和等概率曲面图，从而将氢原子的概率密度空间分布展示出来。     

Climatic significance of n-alkanes and their compound-specific dD values from lake surface sediments on the Southwestern Tibetan Plateau

The content and hydrogen isotope ratios of n-alkanes extracted from recent lake surface sediments sampled from nine lakes in three different climate zones on the Southwestern Tibetan Plateau were analyzed.Values were compared with n-alkanes in plants from lake drainages,and dD values of meteoric water,lake water,and mean annual precipitation.The results showed that n-C23was predominantly derived from aquatic plants,and n-C27–n-C33from terrestrial higher plants.The average carbon chain length of n-C27–n-C33(ACL27–33)was positively correlated with the mean annual precipitation.dD values of the long-chain n-alkanes n-C29and n-C31of terrestrial origin(varying between-214%and-169%,and-226%and-185%,respectively)were inversely correlated with mean annual precipitation;but in accordance with the average annual variations in dD(OIPC),dD values of n-C31were strongly related to the dD values of growing season meteoric water(R2=0.74).The large difference between dD values of n-C23of aquatic origin and n-C31(an average of about 27%)demonstrates the enrichment of the lake water dD compared to precipitation,caused by strong evaporation in the semiarid–arid areas of the southwestern Tibetan Plateau.Average value of en C25 31=p(-95%)is evidently higher than the value observed in European wet regions(-128%);besides,en C31(about-116%)is constant along the study transect(SD=9),which indicates that n-C31is a useful proxy for the environment.     

Magnetic field induced synthesis of (Ni,Zn)Fe2O4 spinel nanorod for enhanced alkaline hydrogen evolution reaction

Recently, the introduction of external fields(light, thermal, magnetism, etc.) during electrocatalysis reactions gradually becomes a new strategy to modulate the catalytic activities. In this work, an external magnetic field was innovatively employed for the synthesis progress of(Ni, Zn)Fe₂O₄spinel oxide(M-(Ni, Zn)Fe₂O₄). Results indicated the magnetic field(≤250 m T) would affect the morphology of catalyst due to the existing Fe ions, inducing the M-(...     

基于光伏发电量预测的含氢储能微网分段优化调度

针对多储能微网如何高效、经济运行,搭建了基于光伏发电的含氢储能、蓄电池储能的微网系统,采用一种日前预测调度与日内实时调度相结合的分段调度策略。在日前预测调度阶段,采用基于麻雀搜索算法优化支持向量机模型提高对日前的光伏发电量和负荷预测的精度,以微网最小使用成本为目标,考虑系统运行的可靠性,采用改进粒子群算法制定微网的日前最优调度策略。在日内调度阶段,考虑氢储能系统的响应延迟特性,以蓄电池为灵活补充元件,制定实时调整微网运行策略,消除预测误差带来的影响。最后,结合实际算例分析,验证了分段优化调度的可行性。结果表明,提出的方法能够有效预测数据,减少微网调度的响应时间,提高系统运行的经济性和稳定性。     

环己酮制备实验的改进

以30%H2O2 为氧化剂,用FeCl3 催化氧化环己醇可得到产率(基于环己醇)为 75%以上的环己酮,反应中无须加入相转移催化剂,考察了用量、催化剂、反应时间及反应温度对产率的影响.所用催化剂价廉易得且具有极佳的水溶性,分离回收容易,是一条绿色合成环己酮的好途径,克服了目前有机化学实验教材中采用浓HNO3、KCrO4 或KMnO4 氧化法存在污染大、反应时间长等缺点.