961 resultados para 6-55


Relevância:

60.00% 60.00%

Publicador:

Resumo:

中华植生藻(Richelia sinica HB 58)是最近分离培养的一个固氮蓝藻新种。该藻能在水生111(HB111)无氮培养基中,在130μE/(m~2·s)下于4—8h内呈指数生长。在指数生长期间,当温度分别采用29℃,35℃和38℃培养时,生长速率均随温度增高而加快,以38℃时为最快;增代时间随温度增高而缩短,在38℃时10.5h为一代。用80%丙酮提取色素,其叶绿素a含量为5.14—6.55 mg/g干重。与固氮鱼腥藻(Anabaena azotica HB686)和稻田鱼腥藻(A. oryz

Relevância:

60.00% 60.00%

Publicador:

Resumo:

盐泽螺旋藻(Spirulina subsalsa)的水溶性色素粗提物经过硫酸铵沉淀和羟基磷灰石(HA)柱层析后可以分出两种藻胆蛋白,即藻蓝蛋白(c-PC)和别藻蓝蛋白(APC)。它们的纯度(指其在可见光部分的最大吸收与280nm处吸收之比)可分别达到7.27(c-PC)和6.55(APC)。而一般认可的纯度标准,PC为5,APC为6。纯化后的c-PC和APC在聚丙烯酰胺凝胶电泳(PAGE)中仅见一条色带,其最大吸收峰分别在620_(nm)和650_(nm),其室温荧光发射峰分别为642_(nm)和657_

Relevância:

60.00% 60.00%

Publicador:

Resumo:

代码优化是编译器的重要阶段,是编译技术的研究重点。优化算法复杂度高,需要有效地测试用例生成方法对其进行充分的测试。提出了一种测试用例自动生成方法,能直观简单地生成具有可优化成分的程序,有针对性地对编译优化进行有效测试。重点介绍了该方法的基础、程序控制结构生成算法,并介绍了基于本方法实现的一个编译器自动测试工具。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

智能玻璃能够根据人的意愿或者外界环境的变化动态的调节太阳光的输入,是新一代的建筑节能玻璃,目前引起广泛的关注。本文选取了两种典型的智能玻璃——电致变色玻璃和VO2热色玻璃,采用动态能耗分析软件EnergyPlus分别对其建筑节能特性进行了分析,具体研究内容如下: (1)讨论了电致变色玻璃不同控制方式对其节能效果的影响。结果表明,电致变色玻璃选用合适的控制方式可以显著降低建筑的能耗,但如果控制方式选用不当,采用电致变色玻璃后建筑的能耗反而会高于采用普通白玻的能耗。此外,无论在何种控制方式下,采用电致变色/LOW-E的节能效果都要优于电致变色/白玻中空玻璃。 (2)对VO2光学薄膜的膜系结构进行了优化,研究了外观颜色与膜层厚度的关系,设计出的TiO2(135nm)/VO2(50nm)/ITO(45nm)/glass三层膜结构相对于VO2(50nm)/glass的单层膜结构,太阳能调节量提高了从3.7%提高到9.8%,半导体状态时的可见光透过率从33.6%提高到55.5%,金属状态时的可见光透过率从34.0%提高到50.0%,同时半导体与金属状态时的膜面发射率都有很大程度的降低。 (3)研究了VO2热色玻璃的热学性能和建筑节能特性,重点分析了膜层结构、膜面位置、建筑的地理位置等因素对VO2热色玻璃建筑节能效果的影响。结果表明,对于单层VO2热色玻璃,其功能膜面朝向室内比朝向室外可以获得更好的节能效果,而对于由VO2热色玻璃与白玻组成的双层玻璃,其功能膜面位于室内玻璃的外侧时VO2很难起到相应的调节作用。另外,与其他类型的玻璃相比,虽然一定膜层结构下VO2热色玻璃在不同地区的建筑能耗低于白玻,但是在全年以采暖为主的严寒地区和全年以空调为主的夏热冬暖地区,VO2热色玻璃的节能效果分别不及高透型和遮阳型LOW-E玻璃。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

木质纤维素原料种类多、分布广、数量巨大,通过燃料乙醇生产技术、厌氧沼气发酵技术将其转化成乙醇、沼气等二次能源,一定程度上可以缓解化石能源的不断消耗所带来的能源危机,也解决了农林废弃物引起的环境污染问题。其中以木质纤维素原料生产燃料乙醇,还可以避免以淀粉类和糖类原料生产燃料乙醇时带来的“与人争粮”等一系列问题。因此具有重要的经济效益、环境效益和社会效益。 然而,木质纤维素原料结构致密,木质素包裹在纤维素、半纤维素外围,导致其很难被降解利用,必须进行适当的预处理,去除木质素,打破原有的致密结构,利于原料的后续利用。因此,预处理成为木质纤维素原料能源化利用的关键。而目前预处理环节的费用过于昂贵,于是寻找一种高效、低成本的预处理方法是当今研究的热点。 本论文采用组合白腐真菌对木质纤维素原料进行生物预处理研究,与其他物理化学法相比,该法有着专一性较强、反应温和、不造成环境污染、成本低等优势。白腐真菌主要通过分泌木质素降解酶对木质素进行降解,从而破坏原料的致密结构,提高后续利用效率。所以木质素降解酶酶活的高低是影响原料预处理效果的一个关键因素。于是本论文首先通过将白腐真菌进行组合的方式提高木质素降解酶(漆酶,Lac)酶活;接着对组合菌的菌株相互作用机理进行研究,阐明组合菌Lac 酶活提高的原因,为菌株组合提高Lac 酶活这种方法的应用提供理论依据,同时也为后续组合白腐真菌预处理木质纤维素原料提供指导;进一步采用固态发酵和木质素降解酶两种方式对木质纤维素原料进行预处理研究,最大化去除木质素成分,破坏原料的致密结构;最终对预处理后原料的酶解糖化进行初步研究,为原料后续的能源化应用奠定基础。具体研究结果如下: (1) 以实验室保存的三株主要分泌Lac 的白腐真菌为出发菌株,筛选得到一组Lac 酶活明显提高的组合菌55+m-6,其中菌株55 为Trametes trogii sp.,m-6 为Trametes versicolor sp.,组合后Lac 酶活较单菌株分别提高24.13倍和4.07 倍。组合菌的最适产酶条件为pH 6.5、C/N 16:1、Tween 80 添加量为0.01%,在该条件下组合菌的Lac 酶活峰值比未优化时提高4.11倍。 (2) 对组合菌55+m-6 菌株间相互作用机理进行研究,发现菌株之间不存在抑制作用;平板培养时,菌丝交界处Lac 酶活最高并分泌棕色色素;液体培养时,菌株m-6 对组合后Lac 酶活的提高起着更为重要的作用:菌株m-6的菌块、过滤灭菌胞外物以及高温灭菌胞外物均能明显刺激菌株55 的Lac产生;菌株55、m-6 进行组合后,同工酶种类未发生增减,但有三种Lac同工酶浓度有所提高;对菌株胞外物进行薄层层析和质谱分析,结果表明组合前后菌株胞外物中各物质在浓度上存在较大的变化。推测组合菌Lac酶活的明显提高,主要是由于菌株m-6 胞外物中的一些物质能刺激菌株55 分泌大量Lac 进行代谢,且这些刺激物质并非菌株m-6 特有,菌株55自身也可以代谢生成,但是适当的浓度才能刺激Lac 的大量分泌。 (3) 将组合菌55+m-6 用于固态发酵预处理木质纤维素原料,发现其对玉米秆的降解程度最大,在粉碎度40 目、含水率65%的最优处理条件下,处理至第15d,秸秆失重率为41.24%,其中木质素、纤维素、半纤维素均有降解,且Lac 和纤维素酶(CMC)酶活以及还原糖量均达到峰值。 (4) 对玉米秆进行木质素降解酶预处理,发现Lac/1-羟基苯并三唑(HBT)系统对玉米秆木质素的降解效果最好,在最优处理条件时,即HBT 用量0.2%、处理时间1d、Lac 用量50U/g,木质素降解率可达12.60%。预处理后玉米秆的致密结构被破坏,比表面积增大,利于后续酶与纤维素、半纤维素成分的结合。 (5) 对预处理后的玉米秆进行酶解糖化,其中组合菌固态发酵预处理后玉米秆的糖化率比对照高4.33 倍;Lac/HBT 系统预处理后玉米秆的糖化率比对照高2.99%,糖化液中主要含有木糖、葡萄糖两种单糖。 There are many kinds and large quantities of lignocellulosic biomass widely distributed on the earth. They can be converted into secondary energy such as fuel ethanol, biogas, et al., which can relieve the energy crisis caused by consumption of fossil energy resources and solve the problem of environmental pollution caused by agriculture and forestry waste. Meanwhile, the production of fuel ethanol from lignocellulosic biomass can ensure food supply to human kind instead of starch- and sugar-containing raw materials. So the energy conversion of lignocellulosic biomass contributes considerable economic, environment and social benefits. However, lignocellulosic biomass has the compact structure, in which lignin surrounds cellulose and hemicellulose, so it must be pretreated before energy usage and pretreatment is one of the most critical steps in the energy conversion of lignocellulosic biomass. At present, the cost of pretreatment is too expensive, so looking for an efficient and low-cost pre-treatment method is one of recent research hot spots. In this research, combined white rot fungi pretreatment method was used, which had some advantages in low cost, high specificity, mild reacting conditions and friendly environmental effects compared with the other physical and chemical methods. White rot fungi secrete lignin degrading enzymes to degrade the content of lignin and damage the contact structure of lignocellulosic biomass, so the activity of the lignin degrading enzymes is the key factor to the degradation effect of raw materials. Firstly, the combined fungi with high laccase activity were screened; secondly, the interaction mechanism between strains was studied, and the cause of higher laccase activity after strains combination was also preliminary clarified; under the guidance of the mechanism, lignocellulosic biomass was pretreated by the combined fungi; lastly, the enzymatic hydrolysis of pretreated lignocellulosic biomass was also preliminary studied; all of the researches could lay the foundation for the energy application of lignocellulosic biomass. The specific research results were as follows: (1) The combined fungi 55+m-6 with significant higher laccase activity were screened from the three white rot fungi stored in our lab which mainly secreted laccase. Strain 55 and strain m-6 were Trametes trogii sp. and Trametes versicolor sp., respectively. The laccase activity of combined fungi was 24.13 and 4.07-fold than strain 55 and strain m-6, respectively. The optimized condition for laccase production of the combined fungi in liquid medium was pH 6.5, C/N 16:1 and Tween 80 0.01%. In this optimized condition, the laccase activity of combined fungi was 4.11-fold higher comparing with which in non-optimized medium. (2) The interaction mechanism between strain 55 and strain m-6 was further studied, and no inhibition effect was observed. Brown pigment was secreted on the junction of the two strains on the plate, where the highest laccase activity was detected. Strain m-6 was much important to boost laccase activity of combined fungi in liquid medium, and strain 55 was stimulated by fungal plug, filter sterilized extracellular substances and high temperature sterilized extracellular substances of strain m-6 to produce laccase. The types of laccase isozymes did not change after combining strain 55 and strain m-6, but the concentrations of three types increased. Mass Spectrometry and TLC analysis of extracellular substances of each strain showed that concentration of some substances considerably changed after strains were combined. It was supposed that the cause of higher laccase activity of combined fungi was mainly due to some extracellular substances of strain m-6 with the appropriate concentration which stimulated laccase secretion of strain 55 and generated not only by strain m-6 but also by strain 55. (3) Combined fungi 55+m-6 were used to lignocellulosic biomass pretreatment with the type of solid-state fermentation. The highest degree of degradation of corn straw was obtained, including the rate of weight loss was 41.24% and the lignin, cellulose and hemicellulose were degraded partially under the optimized condition of 40 mesh, 65% water content on 15th day. Laccase, CMCase activities and content of reducing sugar reached the maximum value on that day. (4) Lignin degrading enzymes from combined fungi 55+m-6 were used for corn straw pretreatment. The most remarkable degradation of lignin in corn straw with Lac/1-hydroxybenzotriazole (HBT) system was observed, and the 12.60% lignin degradation was obtained under the optimized condition of 0.2% HBT, 50 U/g laccase for 1 d. After pretreated by Lac/HBT, the tight structure of corn straw was demolished and specific surface area increased, which had advantages for accessible of enzyme to cellulose and hemicellulose. (5) The corn straws pretreated by combined fungi 55+m-6 with the type of solid-state fermentation and Lac/HBT were used for enzymatic hydrolysis, and the saccharification rates of each pretreatment type were 4.33 times and 2.99% higher than CK, respectively. The enzymatic hydrolysis liquid of corn straw pretreated by Lac/HBT mainly contained xylose and glucose.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

以黄土高原地区典型草本(白羊草)、灌木(沙棘)和乔木(辽东栎)为对象,研究了3种植物细根比根长在不同土层的分布状况以及与其它细根参数和土壤物理因子之间的相关性。结果表明,3种植物细根比根长的变化范围为6~55 mm/mg。在0~80cm土层,白羊草、沙棘和辽东栎细根比根长变化范围分别为18~55 mm/mg,14~40 mm/mg,6~33 mm/mg。3种植物0~80cm土层平均细根比根长从大到小依次为白羊草>沙棘>辽东栎。3种植物0~10cm土层细根比根长依次为沙棘>辽东栎>白羊草,10~80cm依次为白羊草>辽东栎>沙棘,表明3种植物细根比根长不仅在这两土层中的分布不具一致性,而且与0~80cm土层平均比根长也不具有一致性,进一步说明3种植物沿土壤剖面的生物量分配策略不同。相关分析表明,3种植物细根比根长与其它细根参数之间的相互关系各不相同,制约程度存在差异。与土壤物理因子的相关分析表明,3种植物细根比根长均随土壤含水量的增加而减少。土壤各级水稳性团聚体和土壤颗粒对3种植物细根比根长并无一致的影响。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

To explore the changes of soil chemical properties in vegetable greenhouse,a comparative study was carried out with the samples gathered from vegetable greenhouse fields and their adjacent upland fields in Damintun Town,Xinming County,Liaoning Province.The results showed that compared with upland fields,the contents of soil organic carbon and total nitrogen in greenhouse fields increased significantly.At the depth of 0~30 cm,soil organic carbon in greenhouses of 1-,4-and 10-year increased by 31.09%,35.44%,and 66.80%,respectively,compared with the upland soil.Soil nitrate content at the depth of 0~30 cm in greenhouse fields was 5.05~12.49 times as much as that in upland fields.The nitrate content in different soil layers increased with the increasing age of greenhouse field.,e.g.,at the depth of 20~30 cm,soil nitrate content was significantly higher in 10-year than in 1-and 4-year greenhouse field,with an increase of 65.73% and 50.89%,respectively,and 6.55 times as much as that in upland field,which indicated that soil nitrate transported downwards,and obviously enriched in deeper soil layers under heavy application of fertilizer.Also with the increasing age of greenhouse field,soil pH decreased,while soil soluble salts accumulated.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

本文研究了电感耦合等离子体原子发射光谱分析Kalman滤波法测定高纯氧化铕中的14种其他稀土杂质的方法。Kalman滤波法有效地消除光谱干扰,可利用受干扰的光谱灵敏线,因而可提高灵敏度,是一种在大量基体存在下测定痕量杂质的有效方法。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

(TPP)Ni(Ⅱ)氧化反应的电化学和光谱电化学研究严川伟,王振新,林祥钦(中国科学院长春应用化学研究所电分析化学开放实验室,国家电化学和光谱研究分析中心长春130022)关键词镍卟啉,阴离子配位,电化学,光谱电化学镍卟啉是一类重要的仿生模型化合物,...

Relevância:

60.00% 60.00%

Publicador:

Resumo:

合成了化合物YCa_2Cu_3Oy,这个化合物结构属正交晶系a=6.528A, b=5.421(?),c=10.404(?)。氧含量y=6.55。Yca_2Cu_3Oy是黑色n型半导体材料,室温电阻率1.2×10~5Ω·cm。测量了该化合物的R—T关系,并把它的组成、结构和性质与超导化合物YBa_2Cu_3Oy进行了对比和分析。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

本文介绍利用功能高分子活性材料,采用熔融压片成膜的方法研制了PVC膜氯离子选择电极,并对电极性能进行测试并做了临床应用试验,结果表明:电极在10~(-1)M Cl~-中稳定性好,响应时间快,在10~(-1)~10~(-4)M Cl~-中电极呈能斯特响应,其斜率为56~57mV/pCl~-。经临床检测血液标本,该电极抗蛋白、脂类、血球能力强,可以满足临床检测的要求。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

本研究论文属于国家科学基金重点研究项目“东海关键海洋通量过程的研究”计划的一个组成部分,通过1998年夏季东海航次,测定了颗粒有机碳的(Particulate Organic Carbon)含量,并研究了东海夏季POC含量的分布特点以及影响因素。同时,通过模式计算了部分站位的POC的垂直表观通量。然后,根据海水悬浮物质、底质物和浮游生物中的DOC的含量,定量的研究了东海的再悬浮现象,计算得到32°N断面和PN断面部分站位的再悬浮比,并计算得到了这些站位的POC净垂直通量,使我们对东海的POC净沉积通量有了一个定量的认识和把握。通过研究,我们发现东海夏季的POC的分布特点是:(1)近岸区域有明显的高值区的存在,并随离岸距离的增加而降低,这主要是受长江径流的影响;(2)在以(32°N, 125°E-125.5°E)为中心的冷涡表层海域存在着另一个POC含量的高值区,随深度增加而降低,在25米层以下随深度的增加而增加,在近底层形成一个新的高值区,研究表明表层高值区主要受生物生长的控制,而底层的高值区的存在与该区域的涡动层或上升流的存在有一定的关系;(3)同时,在东海所研究的两个断面,TSM(Total Suspended Materials)和POC的含量之间表现出了较好的相关性。通过模式研究,计算了六个站位八个层次的POC的垂直通量,其垂直通量为12.43 mg·m~(-2)·d~(-1)-148.23 mg·m~(-2)·d~(-1),最大值为148.23 mg·m~(-2)·d~(-1),出现在107站(32°N, 125°E)10米层,最小值为12.43 mg·m~(-2)·d~(-1),出现在111站(32°0.08N, 125°59.57'E)的底层。通过对东海再悬浮比率的定量研究,计算了五个站和个层次的再悬浮比率。结果表明:(1)表层海水中悬浮物质的再悬浮比率在47.4%-79.18%之间;底层的再悬浮比率在72.75%-96.96%之间;(2)再悬浮比率的最大值出现在106站(32°N, 124°30'E)的底层,而再悬浮比率的最小值出现在102站(32°N, 122°30'E)的表层。在POC重直通量和再悬浮模式计算的基础上,我们计算得到了六个站位八个层次的POC净垂直通量,颗粒有机碳的净垂直通量最大值出现在107站(32°N, 125°E)的10米层,为117.4 mg·m~(-2)·day~(-1);最小值出现在111站(32°0.08'N, 125°59.57'E)的底层为0.79 mg·m~(-2)·day~(-1)。通过几个站位的模式计算估算了东海颗粒有机碳平均的净沉积通量,其大约为6.55 mgC·m~(-2)·day~(-1),即2.39gC·m~(-2)·y~(-1)。从而使我们对东海的颗粒有机碳的净垂直通量有了一个定量的认识。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

自动通用胶片判读仪是一种高智能化的精密光学测试设备,采用了计算机控制飞点扫描技术、精密光学测量技术、图象跟踪测量与信息处理技术。飞点管分辨率达4096×4096象元,通过光学系统胶片上获得6.55μm高分辨率,飞点扫描方式灵活多样且可随意控制,通用于目前我国靶场所有的电影经纬仪和高速摄影机35mm胶片的数据判读。具有自动判读和半自动判读两种工作模式,自动判读的速度为5帧/秒,自动判读的精度为σ=±0.011mm,半自动判读的精度为σ=±0.009mm,测量数据可以记录、打印和显示。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The steady-state pharmacokinetic profile of indomethacin was examined in twelve healthy volunteers (4 m, 8 f; 20-34 y) and in 12 elderly subjects (7 m, 5 f; 70-88 y). Two formulations of indomethacin were examined, providing duplicate data for each subject group. The subjects received each formulation of indomethacin (25 mg tid) for 6 days in a single blind crossover fashion. On day 7, after an overnight fast, a final 25 mg dose of indomethacin was given and plasma concentrations measured over the following 12 h. Kinetic parameters Cpmin, Tmax and AUC (0-12 h) were determined. There were no differences in the pharmacokinetic parameters between young and elderly subjects or between data for the two formulations of indomethacin. AUC values (micrograms.ml-1.h), for example, for the two formulations in the young subjects were 5.85 and 6.85 while the values for the elderly subjects were 6.55 and 6.50 respectively. When each treatment period was considered independently there was a significant difference between young and elderly subjects with regard to compliance. The rates of non compliance (over and under compliance) using a capsule count technique were, however, low with a mean maximum value of 5.8% being recorded for the elderly subjects.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

GPR40, free fatty acid receptor 1 (FFAR1), is a member of the GPCR superfamily and a possible target for the treatment of type 2 diabetes. In this work, we conducted a bidirectional iterative investigation, including computational modeling and site-directed mutagenesis, aimed at delineating amino acid residues forming the functional "chemoprint" of GPR40 for agonist recognition. The computational and experimental studies revolved around the recognition of the potent synthetic agonist GW9508. Our experimentally supported model suggested that H137(4.56), R183(5.39), N244(6.55), and R258(7.35) are directly involved in interactions with the ligand. We have proposed a polarized NH-pi interaction between H137(4.56) and GW9508 as one of the contributing forces leading to the high potency of GW9508. The modeling approach presented in this work provides a general strategy for the exploration of receptor-ligand interactions in G-protein coupled receptors beginning prior to acquisition of experimental data.