Renewable hydrogen from nonvolatile fuels by reactive flash volatilization

Droplets of nonvolatile fuels such as soy oil and glucose-water solutions can be flash evaporated by catalytic partial oxidation to produce hydrogen in high yields with a total time in the reactor of less than 50 milliseconds. Pyrolysis, coupled with catalytic oxidation of the fuels and their fragments upon impact with a hot rhodium-cerium catalyst surface, avoids the formation of deactivating carbon layers on the catalyst. The catalytic reactions of these products generate approximately 1 megawatt of heat per square meter, which maintains the catalyst surface above 800 degrees C at high drop impact rates. At these temperatures, heavy fuels can be catalytically transformed directly into hydrogen, carbon monoxide, and other small molecules in very short contact times without the formation of carbon.     

超声波辅助提取草莓多酚的工艺优化

[目的]采用响应面分析法优化草莓多酚的超声波辅助提取工艺参数,为草莓多酚的产业化生产提供参考。[方法]考查了料液比、乙醇浓度、超声功率及超声时间对草莓中多酚得率的影响,在单因素试验结果的基础上用Box-Benhnken法进行3因素3水平的试验设计,以多酚得率为响应值,对所得数据进行整理分析,并建立二次多项回归数学模型,优化草莓多酚的提取工艺。[结果]超声波辅助乙醇提取草莓中总多酚最佳工艺为:当料液比为1∶30g·mL~(-1)时,乙醇浓度60%,超声功率585W、超声时间25min,在此条件下草莓多酚得率为10.959mg·g~(-1)。[结论]与常规提取法相比,超声波辅助提取工艺提取率具有提取时间短,提取溶剂用量少,提取效率高的优点。     

Fuel ethanol from cellulosic biomass

Ethanol produced from cellulosic biomass is examined as a large-scale transportation fuel. Desirable features include ethanol's fuel properties as well as benefits with respect to urban air quality, global climate change, balance of trade, and energy security. Energy balance, feedstock supply, and environmental impact considerations are not seen as significant barriers to the widespread use of fuel ethanol derived from cellulosic biomass. Conversion economics is the key obstacle to be overcome. In light of past progress and future prospects for research-driven improvements, a cost-competitive process appears possible in a decade.     

Renewable cathode materials from biopolymer/conjugated polymer interpenetrating networks

Renewable and cheap materials in electrodes could meet the need for low-cost, intermittent electrical energy storage in a renewable energy system if sufficient charge density is obtained. Brown liquor, the waste product from paper processing, contains lignin derivatives. Polymer cathodes can be prepared by electrochemical oxidation of pyrrole to polypyrrole in solutions of lignin derivatives. The quinone group in lignin is used for electron and proton storage and exchange during redox cycling, thus combining charge storage in lignin and polypyrrole in an interpenetrating polypyrrole/lignin composite.     

Renewable chemical commodity feedstocks from integrated catalytic processing of pyrolysis oils

Fast pyrolysis of lignocellulosic biomass produces a renewable liquid fuel called pyrolysis oil that is the cheapest liquid fuel produced from biomass today. Here we show that pyrolysis oils can be converted into industrial commodity chemical feedstocks using an integrated catalytic approach that combines hydroprocessing with zeolite catalysis. The hydroprocessing increases the intrinsic hydrogen content of the pyrolysis oil, producing polyols and alcohols. The zeolite catalyst then converts these hydrogenated products into light olefins and aromatic hydrocarbons in a yield as much as three times higher than that produced with the pure pyrolysis oil. The yield of aromatic hydrocarbons and light olefins from the biomass conversion over zeolite is proportional to the intrinsic amount of hydrogen added to the biomass feedstock during hydroprocessing. The total product yield can be adjusted depending on market values of the chemical feedstocks and the relative prices of the hydrogen and biomass.     

醇法提取红树莓总黄酮的工艺条件研究

采用醇法提取红树莓总黄酮,用紫外分光光度法测定其含量,研究了影响提取率的主要因素,采用正交法确定了最佳提取工艺.结果表明,各因素对总黄酮提取的影响次序为:提取温度>料液比>乙醇浓度>提取时间,最佳提取条件为:以70%乙醇溶液为提取剂,按料液比为l g:16 ml加入,在80℃下回流提取4 h.在此条件下红树莓果总黄酮的提取率为O.139 7%.     

一株可发酵木糖产乙醇细菌的筛选

为获得高效利用木糖生产乙醇的菌株,以木糖为唯一碳源,从腐败的落叶层土壤采样进行分离筛选,获得1株可发酵木糖生产乙醇的细菌,初步鉴定其为阴沟肠杆菌(Enterobacter cloacae),并对该菌株发酵木糖生产乙醇的工艺条件进行了优化.结果表明:在微氧、发酵温度35℃、接种量6%、初始pH值6.5的条件下,用该菌株发...     

红麻秸秆发酵转化燃料乙醇

红麻秸秆含纤维素42.31%、半纤维素22.58%、木质素23.79%.分别采用热水和3%硫酸、1.5%烧碱溶液对红麻秸秆进行预处理(121℃,60 min),通过纤维素酶催化水解,红麻秸秆平均纤维素转化率分别达到12.23%、25.62%和85.34%,说明碱性预处理比较适合.以10 g碱处理红麻秸秆样品为底物的同步糖化发酵试验表明,当发酵168 h后,乙醇浓度达到26.06 mg.mL-1,乙醇产率达到理论产率的76.71%.     

Escape of hydrogen from venus

Recombination of O(2)(+) represents a source of fast oxygen atoms in Venus' exosphere, and subsequent collisions of oxygen atoms with hydrogen atoms lead to escape of about 10(7) hydrogen atoms per square centimeter per second. Escape of deuterium atoms is negligible, and the ratio of deuterium to hydrogen should increase with time. It is suggested that the mass-2 ion observed by Pioneer Venus is D(+), which implies a ratio of deuterium to hydrogen in the contemporary atmosphere of about 10(-2), an initial ratio of 5 x 10(-5) and an original H(2)O abundance not less than 800 grams per square centimeter.     

Presence of nonoxidative ethanol metabolism in human organs commonly damaged by ethanol abuse

Acetaldehyde, the end product of oxidative ethanol metabolism, contributes to alcohol-induced disease in the liver, but cannot account for damage in organs such as the pancreas, heart, or brain, where oxidative metabolism is minimal or absent; nor can it account for the varied patterns of organ damage found in chronic alcoholics. Thus other biochemical mediators may be important in the pathogenesis of alcohol-induced organ damage. Many human organs were found to metabolize ethanol through a recently described nonoxidative pathway to form fatty acid ethyl esters. Organs lacking oxidative alcohol metabolism yet frequently damaged by ethanol abuse have high fatty acid ethyl ester synthetic activities and show substantial transient accumulations of fatty acid ethyl esters. Thus nonoxidative ethanol metabolism in addition to the oxidative pathway may be important in the pathophysiology of ethanol-induced disease in humans.     

利用响应曲面法优化乙醇提取红山药色素工艺条件

通过红山药色素溶剂提取筛选,运用Box-Bebnken响应曲面设计法,以乙醇浓度、液料比、溶剂pH值、温度为自变量,以色素提取液的D460nm.值为指标,BSM分析法优化乙醇提取红山药色素工艺,并对红山药色素粗品进行化学成分初步鉴定.结果表明:乙醇为红山药色素提取最佳溶剂.乙醇法提取最佳工艺条件为:乙醇体积分数60%,液料比10 mL:lg,pH值3.08,温度为79.0℃,此时红山药色素粗品得率为(30.24±0.26)%,/次性提取率达72.63%,色价39.4.化学成分初步鉴定表明色素粗品中主要含有黄酮类化合物.     

硫酸铵预处理-乙醇提取法制备橘皮黄色素

将新鲜橘皮粉碎,先进行预处理:置于含有18%硫酸铵、乙醇和水的比例为1∶1的溶液中,用超声处理10 min,离心分离出橘皮;然后用乙醇在常温和超声作用下提取4次,每次提取的时间为10 min。合并提取液,蒸出溶剂,得到色素产品,其色价为E1%1 cm(426 nm)=38,收率为1.8%。     

柠檬酸-磷酸氢二钠缓冲液法提取紫甘薯花青素的工艺研究

【目的】探索一种更好的紫甘薯花青素提取方法,为提高青花素的开发利用奠定基础。【方法】采用柠檬酸－磷酸氢二钠缓冲液法提取4个不同品种（系）紫甘薯（万紫56、宁紫甘薯1号、1024．20、0929．115）的花青素,并通过采用单因素试验及正交试验,从材料状态（鲜样／干样）、提取温度、提取次数等3个影响因素对其提取工艺进行优化。【结果】各因素对紫甘薯花青素提取量的响应主次顺序为：提取温度〉材料状态〉提取次数;综合考虑提取效率及生产成本,柠檬酸－磷酸氢二钠缓冲液法提取紫甘薯花青素的最佳工艺条件：以鲜样为提取材料,提取温度控制在60％,提取1次,在最佳工艺条件下,花青素提取量为25．72mg／100g.【结论】以柠檬酸－磷酸氢二钠缓冲液法提取紫甘薯花青素具有经济、高效、方便、快捷等特点,值得推广应用。     

柠檬酸—磷酸氢二钠缓冲液法提取紫甘薯花青素的工艺研究

[目的]探索一种更好的紫甘薯花青素提取方法,为提高青花素的开发利用奠定基础.[方法]采用柠檬酸—磷酸氢二钠缓冲液法提取4个不同品种(系)紫甘薯(万紫56、宁紫甘薯1号、1024-20、0929-115)的花青素,并通过采用单因素试验及正交试验,从材料状态(鲜样/干样)、提取温度、提取次数等3个影响因素对其提取工艺进行优化.[结果]各因素对紫甘薯花青素提取量的响应主次顺序为:提取温度>材料状态>提取次数;综合考虑提取效率及生产成本,柠檬酸—磷酸氢二钠缓冲液法提取紫甘薯花青素的最佳工艺条件:以鲜样为提取材料,提取温度控制在60℃,提取1次,在最佳工艺条件下,花青素提取量为25.72 mg/100g.[结论]以柠檬酸—磷酸氢二钠缓冲液法提取紫甘薯花青素具有经济、高效、方便、快捷等特点,值得推广应用.     

大花金鸡菊乙醇提取物对植物病原真菌的抑制活性测定

通过测定大花金鸡菊(Coreopsis grandiflora)乙醇提取物及其各萃取部分对植物病原真菌的抑菌活性,寻找大花金鸡菊中的农用活性物质,为其综合开发利用提供科学依据。采用菌丝生长速率法测定对植物病原真菌的抑菌活性的结果,当浓度为2.0 mg.mL-1时,大花金鸡菊乙醇提取物对小麦赤霉病菌(Gibberella zeae)、苹果斑点落叶病菌(Alternaria alternataf.sp.mali)、辣椒炭疽病菌(Colletotrichum capsici)和黄瓜枯萎病菌(Fusariumoxysporumf.sp.cucumerinum)的抑制作用较好,抑制率分别为48.45%、31.94%、23.22%和22.69%;其中,对小麦赤霉病菌和苹果斑点落叶病菌的EC50分别为1.570和2.872 mg.mL-1。大花金鸡菊乙醇提取物不同溶剂萃取物中,正己烷层和水层的抑菌活性较高。正己烷萃取物对苹果腐烂病菌和小麦赤霉病菌的EC50分别为1.111和0.194 mg.mL-1;水层为1.878和1.390 mg.mL-1。     

Spin-polarized hydrogen atoms from molecular photodissociation

The production of spin-polarized hydrogen atoms from the photodissociation of hydrogen chloride with circularly polarized 193-nanometer light is inferred from the measurement of the complete angular momentum distributions of ground state Cl(2P3/2)and excited state Cl(2P1/2)cofragments by slice imaging. The experimentally measured and ab initio predicted a q(k) (p)parameters, which describe the single-surface and multiple-surface-interference contributions to the angular momentum distributions, are in excellent agreement. For laser pulses longer than about 0.7 ns, the polarization of the electron and the proton are both 36%.     

均匀设计优化超声波辅助乙醇提取银杏叶黄酮

以银杏叶为材料,通过超声波辅助乙醇法提取银杏叶黄酮,采用U30(105×3)混合水平均匀设计对影响超声波乙醇法提取效果的料液比、乙醇浓度、提取时间、提取温度、电磁波功率和频率等6项因素进行考查,通过逐步回归分析获得最佳理论组合。最佳提取条件:料液比1∶50、乙醇体积分数95%,超声功率100 W、超声频率1 s-1 s、提取温度67℃、提取时间45 m in;黄酮化合物提取得率为37.792 mg.g-1,并经实验证实优化提取工艺黄酮得率为36.985 mg.g-1。结果表明,均匀设计高效科学,超声波辅助乙醇提取银杏叶黄酮可用于工厂化提取黄酮类物质。     

Response to ethanol reduced by past thiamine deficiency

Ethanol-induced intoxication and hypothermia were studied in rats approximately 7 months after severe thiamine deficiency, when treated rats appeared to have recovered their physical health. Previously induced thiamine deficiency without prior ethanol exposure significantly decreased the area under the curve plotted for the concentration of ethanol in blood and also decreased behavioral impairment and hypothermia due to ethanol exposure. Pathophysiologic changes resulting from thiamine deficiency may contribute to both the pharmacodynamic and pharmacokinetic tolerance to ethanol in chronic alcoholics.