Thermodynamic investigation on properties of gasohol

The heat capacities (C-p) of three types of gasohol (which consisted of 20 wt % ethanol and 80 wt % unleaded gasoline 93(#) (system S1), 30 wt % ethanol and 70 wt % unleaded gasoline 931 (system S2), 40 wt % ethanol and 60 wt % unleaded gasoline 930 (system S3), where "93(#)" denotes the octane number) were measured by adiabatic calorimetry in the temperature range of 80320 K. A glass transition was observed at 94.24, 95.15, and 95.44 K for system S1, S2, and S3, respectively. A solid-solid phase transition and solid-liquid phase transition were observed at 135.18 and 151.30 K for system S1, 131.82 and 152.10 K for system S2, and 121.29 and 155.09 K for S3, respectively. The polynomial equations for C, with respect to the thermodynamic temperature (T), and with respect to the content of ethanol (x), were established through the least-squares fitting. The thermodynamic functions and the excess thermodynamic functions of the three samples were derived using these thermodynamic relationships and equations.

人工苜蓿草地土壤理化性状变化

为了明确西北旱地种植苜蓿对土壤物理性状、水分和养分的影响,对其进行了较为详尽地探讨。种植苜蓿能增加土壤团聚体含量,提高土壤通气透水能力。苜蓿生长发育时需要大量消耗土壤水分,连续多年种植苜蓿会导致土壤干燥化;种植苜蓿能提高土壤有机质和氮素水平,降低土壤磷、钾含量。施肥既能平衡土壤养分又能增加产草量。

水稻叶片光谱对亚铁胁迫的响应

在湖泊富营养化治理过程中,除了要注意控制氮、磷的输入,还应考虑铁(Fe)的调控作用.本文基于"Fe假说",探索性地将植物光谱效应应用于湖泊水体富营养化遥感预警机制研究.在水培条件下分析了亚铁(Fe2+)胁迫对水稻(Oryza sativaL.)体内Fe含量、叶绿素浓度及可见-近红外特征光谱的影响,并对其相关关系进行了深入探讨;同时,应用3个光谱定量化指标A1(Fe2+胁迫水稻叶片在460~670nm波段反射率变化积分值)、A2(Fe2+胁迫水稻叶片在760~1000nm波段反射率变化积分值)、S(Fe2+胁迫水稻叶片光谱曲线红边"蓝移"强度)分别建立了水稻叶片Fe含量与叶片光谱之间的定量相关关系模型.结果表明,随培养液中Fe2+浓度的升高,水稻体内Fe含量逐渐增加,叶绿素浓度降低,叶片光谱反射率在可见光波段升高,在近红外波段降低,同时红边发生"蓝移".水稻叶片的3个光谱指标A1,A2,S与叶片中Fe含量都具有显著相关性,相关系数分别为0.933(P<0.01),-0.965(P<0.01)和0.946(P<0.01),且A1,A2��S3个参数都能够较好地模拟(复相关系数R2>0.96)和估测水稻叶片Fe含量.

物候模式识别在生态动力预报中的应用

以物候资料和数值天气预报模式输出图为基础,应用模式识别和数理逻辑判断的自动化技术,阐述制作生态动力预报的原理、方法和步骤.生态动力预报技术使传统的物候学在气象学和自动化技术支持下,扩展应用到生态预报业务领域,使物候预报从单站预报阶段发展到区域预报阶段,同时促进了农业气象预报方法从定性、统计阶段向动力预报阶段发展.该方法在农作物播种、长势、灌溉与施肥、病虫害防治等方面具有广阔的应用前景.

Synthesis and Luminescence Properties of CdS Nanoparticles

CdS nanoparticles were successfully prepared by polyol method with PVP-K30 as a surfactant. The microstructure, size and morphology of the products were investigated in detail by XRD, TEM and SEM. The results indicate that uniform CdS nanospheres were achieved. Photoluminescence properties of the resulted nanoparticles (S1 and S3) were investigated, and the results indicate that the CdS nanoparticles could be used as a potential blue light emitting material.

虎眼万年青多糖对小鼠免疫功能的调节作用

依据虎眼万年青组分中多糖对小鼠巨噬细胞吞噬功能的影响,筛选并优化出60%醇浓度中性多糖活性组��S3,进而研究其对体液免疫、细胞免疫及细胞因子变化的影响,并从细胞和分子水平探讨其作用的机理.方法:采用溶血素测定方法,测��S3对小鼠脾细胞溶血素抗体的诱导作用;采用3H-TdR渗入法,测��S3对ConA诱导小鼠脾淋巴细胞的增殖作用;采用3H-TdR后标记法,测��S3对NK细胞细胞毒活性的影响;以ELISA法测��S3对小鼠脾细胞IL-2产生的影响;利用流式细胞术,检��S3对T淋巴细胞亚群CD3、CD4、CD8、CD4/CD8阳性细胞百分率的影响;采用RT-PCR方法检测IL-2 mBNA的表达水平.结果:S3高、中剂量组能明显增强小鼠脾细胞溶血素抗体的形成(P<0.05);各剂量组均能明显增强ConA诱导的淋巴细胞增殖能力(P<0.001);各剂量组均能增强NK细胞的细胞毒活性并促进IL-2的产生(P<0.001,P<0.01);高、中剂量组CD8阳性细胞百分率明显降低(P<0.001),各剂量组均能显著地提高CD4/CD8阳性细胞百分率(P<0.001);高剂量组可明显促进脾细胞中细胞因子IL-2的mRNA表达,使表达量增加(P<0.05).结论:S3具有较强的增强机体多种免疫功能的作用,可利用开发为一种免疫增强药物.

Crystal structure and mechanism of (Z)-1-[2-(phenyl-bromide-chloride)vinyl]-1-cyclohexanol

The crystal structure and mechanism of the title molecule are described. This crystal is orthorhombic, belonging to space group PC21/B with a=1,002 1(2) nm, b=1.483 0(3) nm, c=2.173 6(4) nm, V=3.230 39(2) nm(3), Z=2, D-c=1.80 g/cm(3), R=0.069 3. The structure was solved by direct method. The tin atom of the title compound exists in two distorted-trigonal-bipyramidal geometry, defined by two carbon, one bromide, one chloride and one oxygen atoms leading to a five-membered chelate ring. In the structure, the five-membered ring containing the intermolecular O-->Sn has a half chair conformation.

Purification of R-phycoerythrin from Porphyra haitanensis (Bangiales, Rhodophyta) using expanded-bed absorption

R-phycoerythrin (R-PE) was purified from leafy gametophyte of Porphyra haitanensis T. J. Chang et B. F. Zheng (Bangiales, Rhodophyta) by a simple, scaleable procedure. Initially, phycobiliproteins were extracted by repeated freeze-thaw cycles, resulting in release from the algal cells by osmotic shock. Next, R-PE was recovered by applying the crude extract with a high concentration of (NH4)(2)SO4 salt directly to the expanded-bed columns loaded with phenyl-sepharose. An expanded-bed volume twice the settled-bed volume was maintained; then low (NH4)(2)SO4 concentration was used to develop the column. After two rounds of hydrophobic interaction chromatography (HIC), R-PE was purified by anion-exchange column. The method was also successful with free-living conchocelis of P. haitanensis. The purified R-PE was identified with electrophoresis, and absorption and fluorescence emission spectroscopy. The results were in agreement with those previously reported. The yield with a spectroscopic purity (OD565/OD280) higher than 3.2 (the ratio of A(565)/A(620) <= 0.02) was 1.4 mg . g(-1) of leafy gametophyte of P. haitanensis. For the free-living conchocelis of P. haitanensis extract, R-PE could be purified successfully with only one round of HIC. The yield with a spectroscopic purity (OD565/OD280) higher than 3.2 (the ratio of A(565)/A(620) <= 0.02) was 5.0 mg . g(-1) of free-living conchocelis of P. haitanensis. The method described here is a scaleable technology that allows a large quantity of R-PE to be recovered from the unclarified P. haitanensis crude extract. It is also a high protein recovery technology, reducing both processing costs and times, which enhances the value of this endemic Porphyra of China.

海洋红藻鸭毛藻化学成分及抗氧化活性的研究

本论文采用DPPH（αα-二苯基-β-苦味酰自由基）自由基清除法和β-胡萝卜素-亚油酸氧化法对采自青岛沿海的28种海藻的粗提物进行了抗氧化活性筛选，以2,6-二叔丁基-4-甲基苯酚(BHT)、没食子酸(GA)和抗坏血酸(AscA)作为阳性对照。结果发现大多数海藻都表现了不同程度的抗氧化活性。其中，鸭毛藻Symphyocladia latiuscula的抗氧化活性最强。 鸭毛藻粗提物的乙酸乙酯相在两种方法中都表现了最强的抗氧化活性，乙酸乙酯相通过VLC被进一步分为7个组分(F1–F7)。其中F1对DPPH自由基的清除率最强，而在β-胡萝卜素-亚油酸实验中F4的抗氧化活性最强。 另外，还测定了粗提物、各相和各组分的总酚含量和还原能力。其中28种海藻粗提物的总酚含量变化范围为0.10到8.00 mg没食子酸/g海藻干重，还原能力变化范围为0.07到11.60mg抗坏血酸/g海藻干重。统计分析发现，对于粗提物和各相，抗氧化活性和总酚含量以及和还原能力都存在很强的正相关。这些结果将有助于进一步分析抗氧化活性强的海藻，从而确定活性原理。 由于鸭毛藻的抗氧化活性最强，所以对它的化学成分做进一步的调查。采用硅胶柱层析、制备薄层层析、凝胶Sephadex LH-20柱层析、反相硅胶柱层析、半制备HPLC及重结晶等手段分离得到19个化合物。运用各种现代波谱技术（IR、UV、ESI-MS、EI-MS、FAB-MS、HR-FAB-MS、1D-NMR、2D-NMR等）鉴定了它们的结构，其中包括4个新化合物：化合物S1 1-(2,3,6-三溴-4,5-二羟基苄基)-四氢吡咯-2-酮、化合物S2 1,2-双(2,3,6-三溴-4,5-二羟基苯基)乙烷、化合��S3 6-(2,3,6-三溴-4,5-二羟基苄基)-2,5-二溴-3,4-二羟基苄甲醚和化合物S4 2,3,6-三溴-4,5-二羟基苄甲砜，以及5个已知化合物和10个首次从鸭毛藻中报道的化合物。 分离到的溴酚化合物S1-S10具有显著的DPPH自由基清除活性，其IC50值在8.1-24.7 µM之间，且它们的活性是BHT（IC50 = 81.8 µM）的3.3到10倍左右。初步的构-效关系研究发现，分子中的羟基数目与活性有直接关系。