Controlled oxidation-reduction potential on dark fermentative hydrogen production from glycerol: Impacts on metabolic pathways and microbial diversity of an acidogenic sludge

The oxidation-reduction potential (ORP) is an important factor in H₂ production via dark fermentation however its effect over microbial diversity in an acidogenic sludge has not, been well studied. This work studies the effect of ORP controlled by hydrogen peroxide and potassium ferricyanide on continuous hydrogen production and microbial diversity in an acidogenic sludge fed (HRT 12 h and pH 5.5) with glycerol. Results show that the more oxidizing ORP control environment (?540 mV) improves H₂ yield by 50–70% (0.31–0.51 molH₂/mol glycerol) over non-ORP control conditions. Oxidizing ORP values were shown to enrich microorganisms of the genus Clostridium, which have been linked to high H₂ yields. Therefore, controlling ORP in an acidogenic sludge was shown to directly modify microbial diversity at the genus level, and could likely to indirectly regulate metabolic function. Additionally, metabolic pathways were regulated by the kind of agent used.     

Chemical constituents and biological research on plants in the genus Curcuma

Curcuma, a valuable genus in the family Zingiberaceae, includes approximately 110 species. These plants are native to Southeast Asia and are extensively cultivated in India, China, Sri Lanka, Indonesia, Peru, Australia, and the West Indies. The plants have long been used in folk medicine to treat stomach ailments, stimulate digestion, and protect the digestive organs, including the intestines, stomach, and liver. In recent years, substantial progress has been achieved in investigations regarding the chemical and pharmacological properties, as well as in clinical trials of certain Curcuma species. This review comprehensively summarizes the current knowledge on the chemistry and briefly discusses the biological activities of Curcuma species. A total of 720 compounds, including 102 diphenylalkanoids, 19 phenylpropene derivatives, 529 terpenoids, 15 flavonoids, 7 steroids, 3 alkaloids, and 44 compounds of other types isolated or identified from 32 species, have been phytochemically investigated. The biological activities of plant extracts and pure compounds are classified into 15 groups in detail, with emphasis on anti-inflammatory and antitumor activities.     

Simultaneous analysis of purine alkaloids and catechins in Camellia sinensis, Camellia ptilophylla and Camellia assamica var. kucha by HPLC

Simultaneous analysis of purine alkaloids and catechins in tea from dry leaves of Camellia sinensis, Camellia ptilophylla and Camellia assamica var. kucha by a reversed-phase high-performance liquid chromatography (RP-HPLC) method. This HPLC method had been proved to be appropriate for the identification and quantification of purine alkaloids and catechins, and exhibited good correlation coefficients, detection levels and recovery rates. Caffeine, theobromine, theacrine, (+)-catechin, (−)-epicatechin, (−)-epigallocatechin, (−)-epigallocatechin gallate, (−)-epicatechin gallate, (−)-gallocatechin gallate and (−)-gallocatechin were identified and quantified in the three species of genus Camellia Sect. Thea. There was 2.72% caffeine and 0.26% theobromine in C. sinensis, 4.85% theobromine in C. ptilophylla, and 1.58% theacrine, 0.94% caffeine and 0.45% theobromine in C. assamica var. kucha. Theacrine in C. sinensis and C. ptilophylla, and caffeine in C. ptilophylla were not detected. These data highlight differences in the relative proportions of purine alkaloids in the three species of Camellia Sect. Thea. In addition, different catechins were identified and quantified. The highest content of catechin in dry leaves was (−)-epigallocatechin gallate (EGCG) 3.51%, (−)-gallocatechin gallate (GCG) 9.88% and (−)-epigallocatechin gallate (EGCG) 6.78% in C. sinensis, C. ptilophylla and C. assamica var. kucha, respectively.     

On convolutions of algebraic curves

We focus on the investigation of relations between plane algebraic curves and their convolution. Since the convolution of irreducible algebraic curves is not necessarily irreducible, an upper bound for the number of components is given. Then, a formula expressing the convolution degree using the algebraic degree and the genus of the curve is derived. In addition, a detailed analysis of the so-called special and degenerated components is discussed. We also present some special results for curves with low convolution degree and for rational curves, and use our results to investigate the relation with the theory of the classical offsets and Pythagorean Hodograph (PH) curves presented in Arrondo et al. (1997).     

亏格为2的超椭圆曲线上的二分算法及其优化

相对于椭圆曲线密码体制而言,超椭圆曲线密码体制(HECC)具有许多优势,如更短的操作数,更小的带宽,在同等安全条件下所用的基域小,在同样的定义域上亏格越大、曲线越多,等等.HECC中最重要且最耗时的运算是标量乘,二分法是一种比常用的倍点法更为有效的算法.对二分法作了进一步的优化,通过选择合适的曲线参数,减少二分法中域操作运算量,降低其运算复杂度,从而有效地提高了实现效率.     

用微波萃取法提取茶叶中茶多酚的工艺改进研究

以乙酸乙酯作为溶剂对茶叶进行微波萃取，同过比较不同萃取工艺的优缺点，提出，对提取出的茶多酚标准曲线法进行测定，结果表明，用此法对茶多酚的萃取率较高，且省时效率高。     

底泥对含铬废水的吸附处理研究

通过底泥吸附处理模拟含铬（Cr^6＋）废水，探讨了废水酸度、吸附时间、底泥用量、粒径对铬（Cr^6＋）吸附效果的影响。静态实验结果表明：在废水pH为10，用3．0g底泥吸附处理浓度为100mg／L的含铬废水40mL，吸附接触时间5h时，其处理效果最佳。动态实验结果表明：不同粒径底泥的最终吸附效果相差不明显；粒径对废水的流速影响较大，细粒径底泥的流速缓慢，处理所需时间长。利用底泥吸附处理含铬（Cr^6＋）废水，去除率能达到95％以上。     

花生种间杂种异源多倍化早期世代性状和SSR变化研究

以四倍体栽培种花生仲恺花4号为母本、二倍体野生种花生Arachis chacoensis为父本,对其种间杂种F1及人工加倍获得的异源六倍体S0及自交世代（S1～S3）植株的植物学性状和花粉育性进行观察,采用SSR标记研究各世代的基因组变化情况.结果显示随着自交的进行,F1～S3植株的总分枝数、第一对侧枝长和花旗瓣宽变异系数分别达到48.48％、34.56％和13.74％,表现出明显的不稳定性;F1～S3的花粉萌发率分别为0、11.03％、10.58％、16.44％和18.53％,花粉育性随着世代的增加逐渐增强;扩增出的微卫星条带在F1开始发生变化,主要包括为亲本片段的丢失、跳跃式继承和新片段的产生,随着世代的增加表现出稳定的趋势,表明微卫星及侧翼区域变化剧烈而快速,其生物学功能可能与多倍体进化过程有关.     

纪念性公园的历史天空——昆明中美二战友谊公园概念设计

公园在现代社会中已成为城市人文与历史积淀的一个重要载体。本文围绕公园的纪念主题与建筑环境的契合展开,试从本案的构思中探讨主题公园规划设计中纪念性在当下的思考与体现。     

Automatic decomposition of 3D solids into contractible pieces using Reeb graphs

This work is motivated by the need to generate volumetric spline models for isogeometric analysis. There exist numerous constructions of volumetric spline models that represent contractible solids. We present a novel decomposition algorithm that splits general solids into pieces that can be dealt with by these existing methods. More precisely, we present a method to automatically decompose solid objects in boundary representation into pieces with fewer or no tunnels by cutting them with auxiliary surfaces. The segmentation is guided by a reduced form of the object’s boundary and volume Reeb graphs with respect to several Morse functions, the level sets of which define the cutting surfaces. Special attention is paid to the selection of suitable cutting surfaces, where we employ a quality criterion to avoid the creation of badly shaped pieces.