一类双边障碍问题的积极集算法

双边障碍问题是一类应用十分广泛的问题.使用积极集算法求解带T-单调算子对应的双边障碍问题,建立了算法的单调收敛性定理.     

Simultaneous mineralization of CO2 and recovery of soluble potassium using earth-abundant potassium feldspar

CO2 capture and storage(CCS) is an important strategy in combatting anthropogenic climate change.However,commercial application of the CCS technique is currently hampered by its high energy expenditure and costs.To overcome this issue,CO2 capture and utilization(CCU) is a promising CO2 disposal method.We,for the first time,developed a promising method to mineralize CO2 using earth-abundant potassium feldspar in order to effectively reduce CO2 emissions.Our experiments demonstrate that,after adding calcium chloride hexahydrate as an additive,the K-feldspar can be transformed to Ca-silicates at 800 C,which can easily mineralize CO2 to form stable calcium carbonate and recover soluble potassium.The conversion of this process reached 84.7%.With further study,the pretreatment temperature can be reduced to 250 C using hydrothermal method by adding the solution of triethanolamine(TEA).The highest conversion can be reached 40.1%.The process of simultaneous mineralization of CO2 and recovery of soluble potassium can be easily implemented in practice and may provide an economically feasible way to tackle global anthropogenic climate change.     

Expression, purification and characterization of the soluble CuA domain of cytochrome c oxidase ofParacoccus versutus

The key subunit Ⅱ of cytochrome c oxidase (CcO) contains a soluble binuclear copper center (Cu_A) domain. The Cu_A domain of Paracoccus versutus was cloned, expressed, purified and characterized. The gene encoding the Cu_A domain in pET11d vector was expressed in E. coli BL21 (DE3). The results showed that the Cu_A domain was expressed mostly in inclusion bodies and the Cu_A domain protein synthesized in E. coli cells represents approximately 10 percent of the total cellular proteins. Dissolved in urea, dialyzed and recombined with Cu⁺/Cu²⁺ and purified by the Q-sepharose fast flow anion-exchange column and Sephadex G-75 gel filtration column, the soluble purple-colored protein, which shows a single band in electrophoresis, was obtained. The UV-visible absorption spectrum of Cu_A domain showed that there are intense band at 478 nm and a shoulder peak at 530 nm, and two weak bands at 360 and 806 nm respectively, which can be assigned to the charge transfer and the interactions of obitals of Cu—S and Cu——Cu in the mixed-valence binuclear metal center (Cu₂S₂R₂). The far-UV CD spectrum indicated that this domain is predominantly in β-sheet structure. The fluorescence spectra showed that its maximal excitation wavelength and maximal emission wavelength are at 280 and 345 nm, respectively.     

Preparation and characterization of aligned carbon nanotubes coated with titania nanoparticles

Titania (TiO2) is an environmental-friendly photo- catalyst material with high stability and efficiency, so its preparation methods received extensive atten- tion[1―4], and the products were advanced from dis- persed nano-powder and fastness nano-film[5,…     

火焰热离子鉴定器同柱测定7种有机磷农药残留量

用火焰热离子检测器（ＦｌａｍｅｔｈｅｒｍｉｏｎｉｃｄｅｔｅｃｔｏｒＦＴＤ）柱子选用ＯＶ－１弹性石英毛细柱一次测定地下水中的甲胺磷，乐果，二嗪农，甲基对硫磷，毒死蜱，杀扑磷，马拉硫磷７种有机磷农药残留量，得到了监测残留量极低的地下井水有机磷农药残留分析方法。     

斜交隧道-土体相互作用体系振动台试验设计

为研究复杂斜交地铁隧道-土体相互作用体系的地震响应规律,系统阐述了交地铁隧道-土体相互作用体系振动台试验中方案设计的关键问题并进行了分析,详细介绍了地震模拟振动台系统、相似比设计原则、模型体系整体布置、传感器布设、试验工况加载方案等试验设备与技术,重点说明了模型土的配制、刚性模型箱的设计及其边界合理性的验证,同时根据远离隧道的中远场测点的加速度响应结果评价配制的模型土的合理性。本次振动台试验可为今后空间交叉地铁隧道-土体相互作用体系的大型振动台试验设计提供借鉴与参考。     

Peat molecular fossils recording paleoclimatic change and organism replacement

The occurrence of the dominant C₂₃ n-alkane derived from bryophyte was demonstrated to be related to the cold climate, based on the GC and GC/MS analyses on a 40-cm long peat core, in which this compound exponentially varies in abundance with the depth corresponding to the well-known second Little Ice Age. Both the variation of the chemical components of modern bryophyte resulted from climatic change and the ecological data about the biological growth influenced by climate shed light on the point that the variation of this compound in the peat was related to the cold climate. This was also evidenced by the previously-reported lacustrine data. In addition, the variations of the ratios of ketones/esters and C₂₄ n-alkene/n-alkane (C_24︰1/C_24︰0) display the trend identical with that of organisms, implicating the replacement between bryophyte and monocotyledon occurring in the peat core.     

一种基于循环回归的推荐算法

提出了一种基于循环回归的推荐算法.首先,对原数据集中的评分数据及缺失值进行离散化处理,然后对离散化数据进行回归模型训练,此过程循环执行并最终建立推荐系统.在离散化阶段,对比不同的离散方法,并对它们的分类粒度开展研究.在模型训练阶段,讨论回归算法对于模型性能的影响.数值计算实验表明,本算法较之近年非常热门的SVDFeaute方法,能够产生更小的均方根误差,验证了算法的有效性.     

Construction of the glucose isomerase deficient strain ofStreptomyces M1033 by homologous recombination

After the establishment of the transformation conditions ofStreptomyces diastaticus No.7 Strain M1033, the integration plasmid pXW for homologous recombination, which contains a 600 bp fragment of incompleteGI (G138P. G247D) gene, has been constructed in order to realize the stable overexpression of theGI (G138P. G247D) which is valuable for large-scale industrial production. The Gigene’s disruption has been realized by pXW’s integration into M1033 chromosomes via homologous recombination andGI deficient strain ofStreptomyces M1033 has been obtained. The reliability of introduction of mutation has been proved by analysis of recombinant fragment and affirmance of existence of the mutation, as well as detection of the stability of the deficient strain.