太阳能辅助闭式热源塔热泵系统冬季制热性能

热源塔热泵系统以空气为冷热源,在冬季制热时其性能会随环境温度的降低而降低。为此研发了可应用陕南地区农村建筑的太阳能辅助闭式热源塔热泵系统,试验研究了冬季工况下系统的制热性能,初步分析了太阳热能与空气热能的互补机理。研究结果表明:系统制热量范围为12.1～15.2 k W,热泵机组性能系数范围为2.3～3.5,系统能效比范围为1.5～2.4,供热温度高于41℃;冷却水温度对压缩机耗电量的影响程度大于防冻溶液温度,冷却水平均温度每升高1℃,压缩要耗电量增加98.1 W,而防冻溶液平均温度每升高1℃,压缩机耗电量减小9.5 W;太阳能辅助热源塔热泵制热模式下,热泵机组通过改变防冻溶液与空气和集热工质换热温差的方法来改变防冻溶液从空气和集热水箱中的吸热量,以实现空气热能与太阳热能的互补。建议在实际应用中应避免供热温度过高以减小压缩机耗电;在集热水箱温度较高时通过降低风机频率减小风机耗电以提高系统综合能效,但应避免风机低频率工作可能给机组安全运行带来的隐患。     

汉中农村夯土民居墙体材料绿色改性研究

为了探索汉中山区生土建筑合适的墙体改性材料,对目前常见的生土改性材料进行归纳分析,笔者认为天然可再生材料淀粉有应用潜能,对素土,不同掺量的生石灰、熟石灰和淀粉改性生土进行了直接剪切试验,试验表明淀粉可用于山区生土建筑的改性,为汉中山区生土材料的改性研究提供科学参考。     

冲突管理在图书馆中的应用

冲突是组织中常见的一种对抗性的人际互动形式。本文阐述了冲突的分类、影响,并提出冲突管理在图书馆组织中的应用。     

Measuring consumer response to ‘Gala’ apples treated with 1-methylcyclopropene (1-MCP)

Post-harvest apple treatment with 1-methylcyclopropene (1-MCP) was previously found to inhibit fruit ripening but also to inhibit the production of volatile compounds that contribute to apple flavor. The first objective of this study was to determine if consumers could distinguish 1-MCP treated and untreated Gala apples [Malus sylvestris L. (Mill.) var. domestica Borkh. Mansf.] following long-term storage. Chemical analysis showed 1-MCP treated fruit had reduced flavor volatiles compared to untreated fruit. Consumer difference tests showed they could distinguish between 1-MCP treated and untreated fruit. A second objective was to compare consumers’ acceptance for 1-MCP treated to untreated apples. Both 1-MCP treated and untreated apples received high overall liking scores that were not significantly different. Equal numbers of consumers indicated preference for 1-MCP treated and untreated fruit and there was no difference in purchase intent. However, subsets of consumers who eat Gala, Fuji or Red Delicious apples showed preference for untreated over 1-MCP treated fruit compared to consumers who do not eat these varieties.     

Effect of 1-methylcyclopropene on postharvest quality of Chinese chive scapes

The effect of 1-methylcyclopropene (1-MCP) on postharvest quality and lignification of Chinese chive scapes (Allium tuberosum Rottler ex Sprengel) was examined during storage at 20 °C. The results showed that the treatment with 0.5 μL L^?1 1-MCP significantly delayed weight loss and opening rate of flowers, maintained higher chlorophyll and ascorbic acid contents, inhibited respiration, reduced the activities of the enzymes phenylalanine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation. The results suggest that 1-MCP treatment may be a promising technique to maintain postharvest quality of Chinese chive scapes.     

喹诺酮类(吡哌酸、诺氟沙星)药物的热分解特性研究

分别采用差示扫描量热法(DSC)、热重法(TG)和微分热重法(DTG),研究了喹诺酮类(吡哌酸、诺氟沙星)抗菌药的热分解动力学过程,计算了其热分解动力学参数——活化能(E),分析了其热分解机理,并剖析了喹诺酮类药物有机结构上的差异。     

ScMYB原核蛋白诱导表达的影响因素研究

[目的]探讨ScMYB原核蛋白诱导表达的影响因素,优化表达条件。[方法]利用构建的ScMYB::pEASY-E1为表达载体,研究了诱导剂IPTG浓度、诱导时间、诱导温度及菌体浓度对该蛋白表达的影响。[结果]诱导剂IPTG浓度对表达量影响不大,其表达主要与诱导时间、温度及菌体浓度有关。[结论]在37℃诱导4 h,当OD600达0.6～1.0时,ScMYB原核蛋白诱导表达量最大。     

水溶性盾叶薯蓣皂苷及其药理活性研究进展

盾叶薯蓣甾体皂苷包含水溶性皂苷和脂溶性皂苷2大类,其中水溶性盾叶薯蓣皂苷是传统中医药临床药理的重要活性基础,但没有进行系统性地研究。该文对近年来水溶性盾叶薯蓣皂苷的化学成分、分离纯化及药理活性等方面的研究进行综述,为甾体皂苷类新药研发及皂素工业生产中对水溶性盾叶薯蓣皂苷回收利用提供理论参考。     

苹果果肉中水不溶性膳食纤维的提取工艺研究

[目的]优化提取苹果中水不溶性膳食纤维的工艺。[方法]采用碱浸法提取苹果果肉中水不溶性膳食纤维,通过正交试验确定了碱浸法的最佳提取工艺条件。[结果]影响碱浸法提取苹果果肉中水不溶性膳食纤维的各因素主次关系为料液比碱液浓度温度浸提时间,最佳提取工艺是A3B1C2D2,即料液比为1∶11 g/ml、碱液浓度为0.25 mol/L、温度50℃、时间2.0 h,此条件下产率为35.46%。[结论]苹果果肉中含有较多的膳食纤维,从苹果中提取水不溶性膳食纤维市场开发意义较大。     

核桃微量元素含量的测定

[目的]研究核桃中的微量元素,为核桃的开发应用提供依据。[方法]采用微波消解溶样,用火焰原子吸收光谱法(FASS)测定了核桃中K、Ca、Mg、Cu、Mn、Zn、Fe 7种微量元素的含量。[结果]核桃中Zn、Cu、Mn、Fe、Mg、K、Ca 7种微量元素含量依次为56.25、36.50、34.50、102.00、280.75、1 929.50、452.50μg/g,回收率在98.6%～100.9%,除了Ca和Cu的测定存在一定的误差,其他元素的RSD在0.03%～1.30%。[结论]该方法所用仪器设备简单,操作步骤方便,结果令人满意。