共查询到17条相似文献，搜索用时 78 毫秒
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2013年11月15日,美国环境保护署（EPA）在美国国会2007年制定的《能源独立和安全法案（Energy Independence and Security Act,EISA）》的基础上,提出了混合可再生燃料标准草案,并宣布征集公众意见。 相似文献
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2013年6月20日,美国Amyris公司和法国Total公司宣布,在巴黎航空表演中,使用植物糖类生产的可再生喷气机燃料的表演飞行成功了。这是第一次在欧洲采用空中客车的表演试飞,明确表明了两家公司取得了燃料国际标准制定机构ASTM国际认证。 相似文献
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Thomas W. Jeffries ;Rita C. L. B. Rodrigues ;William R. Kenealy ;Carl J. Houtman 《生物产业技术》2008,(1):31-31
农业废弃物和木材残渣是生产乙醇和聚合物前体的潜在来源。生物质的使用有可能取代石油和煤炭,从而减少温室气体的排放。美国的生物炼制倡议包括6个主要的商业示范项目,开发更好的生物催化剂的研发新项目,进行新原料和转化技术创造的长期努力。要用生物质生产燃料和化学品,首先必须释放半纤维素糖类和预处理残余纤维素,然后还要水解和发酵所有可用糖。 相似文献
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美国先进生物燃料技术政策与态势分析 总被引：2，自引：0，他引：2
刘润生 《中国生物工程杂志》2010,30(1):117-122
美国是生物燃料大国,更是先进生物燃料研发强国。美国制定了宏大的生物燃料发展目标,采取了有力的政策支持措施,组织实施了生物质计划,将纤维素乙醇作为目前先进生物燃料研究、开发和示范的焦点,并已着手第三代生物燃料的研发。美国政府十分重视生物燃料的规划分析和部际协调工作,在立足于基础研究和应用研究前沿的基础上,大力推进技术示范与商业化,正努力加速向先进生物燃料转变。 相似文献
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为了评价清胃散配方颗粒与标准汤剂主要物质基础的一致性,以高效液相色谱(HPLC)特征图谱相似度及主要物质基础(没食子酸、芍药苷、阿魏酸、异阿魏酸、表小檗碱、升麻素、盐酸小檗碱、盐酸巴马汀及丹皮酚)的含量为指标,运用多变量统计分析方法进行评价。结果表明：配方颗粒与标准汤剂HPLC特征图谱相似度为0.870～0.888。主成分分析(PCA)可明显区分配方颗粒与标准汤剂,标准汤剂中平均质量分数为表小檗碱(0.019 3±0.007 1)%、盐酸小檗碱(0.058 3±0.027 0)%、盐酸巴马汀(0.028 0±0.011 6)%,显著低于配方颗粒(P<0.05);标准汤剂中阿魏酸平均质量分数(0.030 7±0.007 5)%,显著高于配方颗粒(P<0.05)。正交偏最小二乘法分析(OPLS-DA)变量重要性投影(VIP)结合单因素方差分析(ANOVA)得VIP>1、P<0.05,筛选主要差异性成分为盐酸小檗碱、盐酸巴马汀、表小檗碱、阿魏酸和升麻素。结果表明：清胃散配方颗粒与标准汤剂主要物质基础不一致,主要原因可能是标准汤剂中黄连转移率低,本研究可为开展清胃散配方... 相似文献
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Renewable energy policies in the electricity and transportation sectors in the United States are expected to create demand for biomass and food crops (corn) that could divert land from food crop production. We develop a dynamic, open‐economy, price‐endogenous multi‐market model of the US agricultural, electricity and transportation sectors to endogenously determine the quantity and mix of bioenergy likely to be required to meet the state Renewable Portfolio Standards (RPSs) and the federal Renewable Fuel Standard (RFS) if implemented independently or jointly (RFS & RPS) over the 2007–2030 period and their implications for the extent and spatial pattern of diversion of land from other uses for biomass feedstock production. We find that the demand for biomass ranges from 100 million metric tons (MMT) under the RPS alone to 310 MMT under the RFS & RPS; 70% of the biomass in the latter case can be met by crop and forest residues, while the rest can be met by devoting 3% of cropland to energy crop production with 80% of this being marginal land. Our findings show significant potential to meet current renewable energy goals by expanding high‐yielding energy crop production on marginal land and using residues without conflicting with food crop production. 相似文献
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Chad Hellwinckel Christopher Clark Matthew Langholtz Laurence Eaton 《Global Change Biology Bioenergy》2016,8(1):245-256
A socioeconomic model is used to estimate the land‐use implications on the U.S. Conservation Reserve Program from potential increases in second‐generation biofuel production. A baseline scenario with no second‐generation biofuel production is compared to a scenario where the Renewable Fuels Standard (RFS2) volumes are met by 2022. We allow for the possibility of converting expiring CRP lands to alternative uses such as conventional crops, dedicated second‐generation biofuel crops, or harvesting existing CRP grasses for biomass. Results indicate that RFS2 volumes (RFS2‐v) can be met primarily with crop residues (78% of feedstock demand) and woody residues (19% of feedstock demand) compared with dedicated biomass (3% of feedstock demand), with only minimal conversion of cropland (0.27 million hectares, <1% of total cropland), pastureland (0.28 million hectares of pastureland, <1% of total pastureland), and CRP lands (0.29 million hectares of CRP lands, 3% of existing CRP lands) to biomass production. Meeting RFS2 volumes would reduce CRP re‐enrollment by 0.19 million hectares, or 4%, below the baseline scenario where RFS2 is not met. Yet under RFS2‐v scenario, expiring CRP lands are more likely to be converted to or maintain perennial cover, with 1.78 million hectares of CRP lands converting to hay production, and 0.29 million hectares being harvested for existing grasses. A small amount of CRP is harvested for existing biomass, but no conversion of CRP to dedicated biomass crops, such as switchgrass, are projected to occur. Although less land is enrolled in CRP under RFS2‐v scenario, total land in perennial cover increases by 0.15 million hectares, or 2%, under RFS2‐v. Sensitivity to yield, payment and residue retention assumptions are evaluated. 相似文献
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四川梅花鹿的分布、数量及栖息环境的调查 总被引：4，自引：2，他引：4
1992年 7月至 1 999年 8月野外调查发现 ,四川梅花鹿现残存于青藏高原东部边缘山地、岷山山系北段 3块相互完全隔离的区域。铁布分布区 (E1 0 2°46′～ 1 0 3°1 4′、 N33°58′～ 34°1 6′)属四川省若尔盖县铁布自然保护区和占哇乡、降扎乡 ,甘肃省迭部县益哇乡、电尕乡 ,面积 860 km2 ,有鹿 630～ 650只 ;巴西分布区 (E1 0 3°0 8′～ 1 0 3°35′、 N33°33′～ 33°46′)属若尔盖县巴西乡、求吉乡、阿西茸乡、包座乡和九寨沟县的大录乡 ,面积 60 3km2 ,有鹿 1 30～ 1 50只 ;白河分布区 (E1 0 3°59′～ 1 0 4°1 0′、N33°0 5′～ 33°2 0′)属四川省九寨沟县白河自然保护区和农康乡、白河乡、罗依乡、马家乡 ,面积 390 km2 ,有鹿 30～ 45只。高原与高山峡谷的过渡地貌、山地温带气候、森林与灌丛草甸相互镶合的植被 ,加之地域偏僻、人烟稀少 ,当地藏族群众视其为神鹿 ,使上述 3个区域成为四川梅花鹿最后的避难所。 相似文献
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测定菌体浓度的简便方法 总被引：2，自引：0，他引：2
为了简便地测定测定JIS L 1902标准所规定的菌液浓度,以单位体积菌落数与吸光度(ABS值)的相关性,制成标准曲线,利用标准曲线快速准确地判断菌液浓度。 相似文献
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目的建立能准确测定四价流感病毒裂解疫苗中B型血凝素含量(单向免疫扩散法,SRD)的检测方法。方法采用双价抗原参考品SRD法对四价流感病毒裂解疫苗中两种B型血凝素含量进行测定。将B1与B2抗原参考品按质量浓度1∶1混合制备为双价抗原参考品,双价抗原和待检样品与10%裂解剂按9∶1比例裂解30 min,分别加入到含有抗血清参考品的1.5%琼脂糖凝胶板上,每孔10μL,置20~25℃放置18~24 h,经干燥、染色、脱色,测量结果。验证双价抗原SRD法的重复性和准确性。结果双价抗原SRD法测定的血凝素含量平均值比单价抗原SRD法更接近理论配制值,故双价抗原SRD法比单价抗原SRD法能更能准确检测QIV中两种B型血凝素含量,经验证双价抗原SRD法的重复性及准确性良好。结论双价抗原SRD法提高了四价流感病毒裂解疫苗B型血凝素含量检测的准确性,为精确测定四价流感病毒裂解疫苗中B型血凝素含量提供了有效的方法和数据支持。 相似文献
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Southwestern China has an area with unique natural conditions located in alpine regions at altitudes from 2000 to 5000?m; this area is referred to as the Qinghai-Tibetan plateau (QTP). Unique animals, such as yaks (Bos grunniens), are found extensively on the plateau of Southwestern China due to its unique environment. In recent years, the prevalence of fake meat products such as fake jerky has increased in this area. This research was conducted as an attempt to develop a reliable multiplex polymerase chain reaction (mPCR) detection method for identifying nine animal species found in QTP. We developed the mPCR method using the specific sites found in 12S rRNA region of these nine species, which was effective in discriminating between the nine species and was successful in terms of validated reproducibility, detection limit (<6 pg total DNA), discrimination of mixed samples, and specificity (approximately 99%) using real meat samples. Our results show that the mPCR detection method can overcome the limitations of prior detection methods, such as restriction fragment length polymorphism or high-resolution melting analysis methods. 相似文献
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分别采用五种不同条件鉴定重组CHO-C28细胞染色体。对其影响因素如用秋水仙素处理时间的长短、固定液的使用方法等进行了试验,选择出了细胞分散好、染色体形态正常、边缘清晰、便于鉴定的两种最佳条件。此方法操作简单、成功率高,适于CHO-C28细胞染色体鉴定。 相似文献
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T.J. Rink A. Sanchez S. Grinstein A. Rothstein 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1983,762(4):593-596
An increase in cytoplasmic free [Ca2+], [Ca2+]i, has been suggested as the trigger for the permeability changes that bring about cell volume restoration following exposure to anisotonic media. This idea was directly tested in human peripheral lymphocytes undergoing regulatory volume decrease following a hypotonic dilution of the suspension. [Ca2+]i was measured with the intracellularly trapped fluorescent indicator, quin2, and showed no measurable change on hypotonic swelling or during the subsequent volume decrease. Moreover, even though the incorporated quin2 adds significant Ca-buffering to the cytoplasm, regulatory volume decrease occurred normally in the quin2-loaded cells. It appears that alterations in [Ca2+]i are not involved in these processes of volume regulation. An intracellularly trapped derivative of fluorescein, bis(carboxyethyl)carboxyfluorescein, was used to monitor cytoplasmic pH, which also showed no change during regulatory volume decrease. 相似文献