温度对户用厌氧发酵沼气池产气的影响

[目的]研究温度对户用厌氧发酵沼气池产气的影响。[方法]以标准户用沼气池和红泥沼气袋为研究对象,对比研究了温度对两个厌氧发酵沼气池产气性能的影响。[结果]沼气产生和产气率高低与温度密切相关。临安地区,标准户用沼气池稳定产气的气温阈值约为4.0℃(沼气池内温度在7.0℃以上),而红泥沼气袋稳定产气所需的气温阈值为7.0℃(沼气袋内温度在14.7℃以上)。[结论]该研究为临安地区冬季适时采取保温或增温措施以提高户用厌氧发酵沼气池的产气效率提供了一定的科学参考。     

补药控制偏高磷化氢浓度熏蒸锈赤扁谷盗生产试验

针对灯光诱捕和取样检查都发现锈赤扁谷盗发生数量较多的储藏稻谷,实仓进行了补充施药控制偏高磷化氢浓度杀虫试验,试验仓房的气密性为500 Pa正压半衰期为30 s.试验结果为:在粮面施用磷化铝粉剂和通风口施用磷化铝片剂后,环流20 h仓内磷化氢浓度可达130 mL/m3～170 mL/m3,施药3d后两种剂型药剂都达到了释放磷化氢的高峰(800 mL/m3),随后磷化氢浓度较快地下降.通过分别2次补充施药后,保持磷化氢浓度在400 mL/m3以上的时间达6d,300 mL/m～400 mL/m3的时间达9d,200 mL/m3～300 mL/m3的时间7d.试验仓熏蒸中磷化氢控制偏高浓度(大于300 mL/m3)的时间达到了15 d.在此偏高浓度下,9d后大部分害虫死亡,整个熏蒸过程实现了完全杀死锈赤扁谷盗.     

HDPE含量对木塑复合材料力学性能的影响

通过改变高密度聚乙烯(HDPE)和聚苯乙烯(PS)的混合比例,设计了7种制作木塑复合材料的方案,HDPE∶PS分别为0∶10、1∶9、2∶8、3∶7、4∶6、5∶5、10∶0。按照不同设计方案,选用相应的挤出工艺参数制作木塑复合材料型材,按照塑料检测标准对其进行力学性能检测以及扫描电镜观察,找出最优的配方工艺。     

Effect of maternal soil treatment on first year growth and autumn frost hardiness of Pinus sylvestris L. full‐sib families

After‐effects of maternal soil treatment, controlling for photoperiod and weather conditions, were tested in a nursery experiment with Pinus sylvestris L. seedlings. Three full‐sib crosses were replicated in 4 different soil treatment plots of a grafted experimental seed orchard (63"54'N). Weight of filled seeds, percentage of empty seeds, first year hypocotyl and epicotyl length, and autumn frost hardiness (from artificial freeze testing) were evaluated. Systematic effects from maternal soil treatment were small compared to family differences for all characters studied. However, epicotyl length of the progenies showed a positive relationship with N needle content of the mother grafts. The results also indicated an important interaction between maternal soil treatment and autumn frost hardiness of the families. It is suggested that the altered mother tree treatment could lead to a change in progeny performance, corresponding to a 1.5 degree difference in latitudinal origin of natural stand seedlings. The results demonstrate the advantages of providing the mother tree with uniform conditions in early progeny testing.     

辽西地区玉米秸秆还田覆膜对土壤含水量的影响

为了研究辽西地区玉米秸秆还田覆膜对土壤水分含量的影响,在大田中设置了玉米秸秆不同还田量的试验。试验设计为4个秸秆还田量水平,对照为秸秆不还田。结果表明:不同秸秆还田量各处理0～40 cm土层土壤含水量和对照比较都有明显提高,而且除了600 kg.hm-2还田处理外,差异都达到了极显著水平,同一个处理土壤各层次之间的含水量多数差异都达到了显著或者极显著水平,且总体趋势表现为表层含水量低于中下层。但综合来看,还田量12 000 kg.hm-2效果最佳,适合在当地推广。     

Pharmacokinetics of famciclovir and penciclovir in tears following oral administration of famciclovir to cats: a pilot study

Objective To validate a means of collecting tears from cats, develop an assay for quantifying famciclovir and penciclovir in tears, and to assess famciclovir and penciclovir concentrations and pharmacokinetics in the tears of cats being treated orally with famciclovir for suspected herpetic disease. Animals Seven client‐owned cats. Procedures Cats were treated orally with a median (range) dose of 40 (39–72) mg of famciclovir/kg three times daily for at least 24 h. At various time points following famciclovir administration, tear samples were collected using Schirmer tear test strips. Tear famciclovir and penciclovir concentrations were measured using liquid chromatography‐mass spectrometry, and concentration‐time profiles were analyzed noncompartmentally. The relationship between famciclovir dose and tear penciclovir concentration near its maximum was evaluated using least squares linear regression. Results Maximum tear famciclovir concentration of 0.305 μg/mL occurred at 2.64 h; elimination half‐life was 2.28 h. Maximum tear penciclovir concentration (0.981 μg/mL) occurred 2.25 h following oral administration of famciclovir; elimination half‐life was 2.77 h. A significant positive correlation was noted between famciclovir dose and tear penciclovir concentration at various time points between 0.5 and 3.75 h following drug administration (P = 0.025). Tear penciclovir concentration exceeded the concentration shown to have in vitro efficacy against feline herpesvirus (FHV‐1) (0.304 μg/mL) in about half of samples collected. Conclusions Oral administration of 40 mg of famciclovir/kg to cats resulted in a tear penciclovir concentration‐time profile that approximated the plasma penciclovir concentration‐time profile and frequently achieved a penciclovir concentration at the ocular surface likely to be effective against FHV‐1.     

纳米TiO2/丝素蛋白多孔膜的体外降解性能

为改善丝素蛋白膜的生物活性功能,通过冷冻干燥的方法制备了纳米TiO2/丝素蛋白多孔膜,并在人体模拟体液(simulated body fluid,SBF)中进行了体外降解试验。测试结果表明:纳米TiO2/丝素蛋白多孔膜具有较好的平均孔径和孔隙率,分别为22~53μm和86%~92%;降解20 d后,孔洞界限逐渐被破坏,复合多孔膜的失重率增大到35%以上;降解后多孔膜的结晶度有大于降解前的趋势;在多孔膜的内壁有羟基磷灰石的生成,具有很好的生物活性。据此认为,采用冷冻干燥法制备的纳米TiO2/丝素蛋白多孔膜,有望进一步开发成为软骨替代材料或创面涂敷材料。     

稻草和地膜覆盖对冬季茶园保温增温作用的研究

通过对稻草秸秆覆盖、地膜覆盖等不同覆盖物表层及其对应的地表最低、最高温度23d连续测定与对比分析,研究了覆盖物对地表的保温、增温作用。各测点最低温度相关系数最小为0.889,最高温度相关系数最小为0.813,均在0.01水平显著相关,表明温度场高度相关。与对照相比,稻草覆盖使地表最低温度平均提高1.2℃以上,地膜覆盖则提高0.2℃以上。天气晴好状态下,稻草覆盖的保温作用强于地膜覆盖,且与覆草厚度无关;阴雨雪天气,稻草与地膜的保温作用均显著下降,稻草覆盖的降幅小于地膜覆盖,且覆盖厚度大降幅较小。天气晴好条件下地膜覆盖可以提高地表温度,无光环境中地膜无显著增温作用;将茶园覆盖的稻草分为晴天干草、晴天湿草、阴天干草、阴天湿草4种类型,其增温效果与稻草类型有关,且强于地膜覆盖。总之,与地膜相比,稻草覆盖保温效果好,并具有一定的增温效果,无污染,材料来源丰富,更适宜于作为冬季防寒材料。     

喷灌条件下液膜覆盖对玉米干物质积累及水分利用效率的影响

为了探讨喷灌和液膜覆盖对玉米生产的调控作用,在大田喷灌条件下,分析了3个土壤水分灌溉下限对液膜覆盖玉米生长发育过程的影响。通过对比试验,研究了液体地膜盖对玉米产量结构和水分利用效率（WUE）的影响。结果表明,高、中、低水分处理（灌水量分别为51.8、35.0、31.4 mm）生物累积量分别达到16 699.99、14 216.38和 13 239.14 kg/hm2,液膜覆盖高水分处理有利于干物质的累积,玉米的干物质累积曲线呈“慢-快-慢”趋势。液膜覆盖显著提高了玉米的百粒质量,     

直驱型风力发电系统电网侧三电平变流器研究

直驱型风力发电系统中风力发电机需要通过全功率变流器并网,电网侧变流器是全功率变换器中的关键部分.本文以三电平电压型PWM变流器作为直驱型风力发电系统电网侧变流器的主电路拓扑结构,建立了基于三相静止坐标系和两相同步旋转坐标系的数学模型,采用空间矢量脉宽调制技术,研究了电压、电流双闭环控制策略,并在PSCAD环境下,对其进行了仿真验证.仿真结果验证了电压、电流双闭环控制策略的正确性,并能够实现功率因数为1、稳定直流侧电压、无功功率独立调节的目的.