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511.
<正>1.Editor's note On 30 November 2016,the Brookings-Tsinghua Center for Public Policy(BTC),Caixin Video,and Columbia Global Centers(Beijing)jointly hosted a Seminar on the Future of Global Governance and Climate Change Action in a Changing Political Landscape.Leading experts on China's environmental policy and climate  相似文献   
512.
The level of genetic diversity of 13 Chinese populations of S. rostratum was investigated using nine microsatellite loci. The genetic diversity of the Weisanlu population in Hebei province was the highest and the Hohhot population was the lowest. The genetic differentiation among the populations was highly significant (P < 0.001). A total of 68.54% of the total genetic variation of population was within populations, and the genetic variation between populations accounted for 31.46%. The long-distance dispersal of its seeds by human transport mainly resulted in the rapid dispersal of S. rostratum in China.  相似文献   
513.
The solar radiation data are of high importance to the solar energy systems. Conventional methods to obtain the solar radiation data are from weather stations, solar radiation models, commercial software databases, and field measurements. In the present study, a new daily global solar radiation model is proposed, by combining the quadratic function of sunshine fraction and sine function of the day of the year. The solar radiation model calculated data are then compared with China Meteorological Data Sharing System (CMDSS) data, TRNSYS data, and field-measured data in Northwest China climate. It is found that the newly proposed solar radiation model has better performance than the other nine solar radiation models in the literature. The solar radiation model calculated data fit well with the CMDSS annually average data. The TRNSYS data are a bit larger than the CMDSS annually average data in summer half year and a little smaller than those in winter half year. The solar radiation model and the CMDSS annually average data have the best correlation, whereas the TRNSYS data and the field-measured data have the worst correlation. The solar radiation model calculated data have the best correlation with the other three data sources.  相似文献   
514.
锰铜铈氧化物催化剂氧化NO性能及动力学研究   总被引:1,自引:0,他引:1  
实验以TiO2为载体采用浸渍法制备CuOx/TiO2、CeOx/TiO2、CuCeOx/TiO2和MnCuCeOx/TiO2催化剂,考察这些催化剂氧化NO活性,探究Cu、Ce摩尔比和添加Mn元素对CuCeOx/TiO2催化剂氧化NO活性的影响,使用扫描电镜观察催化剂表面结构。研究发现,Cu、Ce元素配合后的CuCeOx/TiO2催化剂氧化活性明显好于单独含Cu、Ce的催化剂,当Cu、Ce摩尔比为Cu:Ce=1∶2时,CuCeOx/TiO2催化剂氧化活性最好,在NO浓度500×10-6,O210%,空速为24 000 h-1,350℃时,NO氧化度为0.62;添加Mn元素可以提高CuCeOx/TiO2催化剂低温氧化活性,250℃时,MnCuCe/Ti-3和MnCuCe/Ti-5催化剂氧化度为0.53和0.69,300℃时,MnCuCe/Ti-3和MnCuCe/Ti-5催化剂氧化度均为0.76;此外,实验还研究了NO在MnCuCe/Ti-3催化剂上反应的动力学方程。  相似文献   
515.
为了探索丝状菌的致密途径、解决丝状菌污泥膨胀的难题,从丝状菌的自身特点及外部条件出发研究了其在污泥膨胀及致密过程中菌丝体的演替规律。研究发现,致密生长的大絮体对丝状菌的种类是有选择性的,那些丝体较弯曲、丝体强度较大、贮存能力强的菌丝体更利于形成聚集态生长。另外,研究表明,不同种类丝状菌的生长势和存贮能力不同,对底物的利用上亦存在着竞争关系。实验中存在的几个菌种对PHB颗粒的存贮能力由高到低依次为:Nostocoida limicolaⅡ、Type 1851、Type 0701、Type 021N型菌体。  相似文献   
516.
分别采用沸水浸泡、酸浸、碱浸和加热的方法对粉煤灰进行改性处理,利用FTIR仪和XRD仪对改性粉煤灰的成分和官能团进行了分析,并利用改性粉煤灰对模拟刚果红废水进行脱色。实验结果表明:碱改性粉煤灰中含有大量官能团,以及NaPl型沸石类物质,能够明显提高粉煤灰对刚果红的吸附性能;与活性炭相比,碱改性粉煤灰具有更高的性价比;在初始刚果红质量浓度为20mg/L、碱改性粉煤灰加入量为50g/L的条件下,废水的脱色率可达87.52%;碱改性粉煤灰对刚果红的吸附过程遵循二级反应动力学,较好地符合Langmuir等温式和Freundlich等温式。  相似文献   
517.
针对电容吸附除盐法的缺点,通过对电极进行绝缘处理,开发了一种新型高电压电容吸附除盐技术。实验结果表明:增大外加电压,有利于除盐效率的提高;外加电压为60V时,NaCl去除率可达90%以上;增大废水流速对吸附效果不利;反应温度对处理效果的影响不大;在NaCl质量浓度为80mg/L、外加电压为60V、反应温度为25℃、废水流速为36m/s、反应时间为30min的条件下,经一级处理和二级处理后出水的NaCl质量浓度分别为39mg/L和16mg/L,NaCl去除率分别为51.3%和80.0%。  相似文献   
518.
地面浓度反推法计算石化企业无组织排放源强   总被引:2,自引:0,他引:2       下载免费PDF全文
对某石化企业储罐区和原油脱酸装置区的无组织排放非甲烷总烃进行监测,对监测数据进行Pearson相关分析,运用地面浓度反推法计算源强。实验结果表明:原油脱酸装置区各采样线浓度间的相关性好,反推出的源强较为准确,50,100,150 m采样线的反推源强非常接近,分别为21.68,21.60,19.76 t/a;而储罐区监测浓度的相关性不佳,该区域的非甲烷总烃无组织排放源可能不单一,不适用地面浓度反推法计算其源强。  相似文献   
519.
Silk fibers in the three layers of Attacus atlas (A. atlas) cocoons have morphological structure and tensile properties similar to that of Bombyx mori silk. Attempts are being made to produce silk for commercial applications from cocoons of relatively unknown wild insects due to the unique properties of the fibers and as a source of income and employment. In this research, A. atlas cocoons were used to study the chemical composition, morphology, physical structure and tensile properties of the silk fibers in the cocoons and ability of the fibers to support the attachment and proliferation of mouse fibroblast cells. It was found that A. atlas cocoons consists of outer, intermediate and inner layer with average breaking tenacity of 4.1, 4.3 and 3.6 g/den, respectively similar to that of B. mori silk (4.3–5.2 g/den). The heavier cocoons, less restrictive rearing conditions and good properties of the fibers compared to B. mori silk makes A. atlas a potential alternative to common silks for commercial scale silk production. A. atlas fibers had about 80 % higher optical densities of cells and extensive growth of F-actin compared to B. mori silk fibers.  相似文献   
520.
In order to find an effective method for treating urea wastewater, the experiments on the hydrolysis of urea in wastewater were conducted in a fixed bed reactor with different aluminas (α-Al2O3, γ-Al2O3, and η-Al2O3) as catalysts respectively in contrast with inert ceramic particle. The results indicate that the three alumina catalysts show obvious catalytic activity for urea hydrolysis at 125 °C. The order of activity is η-Al2O3?>?γ-Al2O3?>?α-Al2O3, and the activity difference increases with increasing temperature. According to the characterization results, surface acidity has little impact on the activity of catalyst. However, it was found that surface basicity of alumina catalyst plays an important role in catalytic hydrolysis of urea, and the activity of catalyst may be also influenced by the basic strength. With η-Al2O3 as catalyst, the urea concentration in wastewater is reduced to 4.96 mg/L at a temperature of 165 °C. Moreover, the η-Al2O3 shows a good stability for urea hydrolysis. The hydrolysis of urea over η-Al2O3 catalyst can evidently reduce the reaction temperature and is promising to replace industrial thermal hydrolysis process.  相似文献   
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