从2015汉诺威国际农机展浅谈拖拉机发展趋势

结合2015汉诺威国际农机展上呈现出的拖拉机新技术,系统阐述国外拖拉机企业的发展特点,并给出国内拖拉机企业的发展建议。     

保润剂对烟草叶表面微结构的影响

\t\t\t\t\t目的\t\t\t\t\t考察金钱草多糖保润剂对片烟原料干燥过程的影响规律,为从动力学角度理解保润剂对片烟原料的保润效果奠定理论基础。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t测试施加金钱草多糖保润剂的许昌片烟(X2F)原料在不同干燥温度的水分含量变化,确定原料水分散失的薄层干燥动力学方程,获得内部水分有效扩散系数及干燥活化能。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t金钱草多糖可增强片烟原料的持水能力,显著降低原料的干燥速率常数和水分有效扩散系数,添加纯水和施加保润剂原料的水分有效扩散系数分别在1.286 8×10⁻¹²~1.671 8×10⁻¹² m²/s和1.074 0×10⁻¹²~1.611 0×10⁻¹² m²/s之间,干燥活化能分别为8.42 kJ/mol和13.9 kJ/mol。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t金钱草多糖可提高片烟原料的保润性能,二项分布指数函数模型和Page模型可较好地描述片烟原料水分散失历程,为从动力学角度理解保润剂对片烟干燥过程中水分散失的影响提供了思路。\t\t\t\t     

紫薇新品种淡爪平盘紫和大花淡爪直枝粉

淡爪平盘紫和大花淡爪直枝粉是通过广泛收集紫薇多种源、多品种的种子开展混合种子育苗,采用自然杂交实生选育法选育出的紫薇新品种。无性系遗传稳定性实验结果表明,这2个新品种遗传性状稳定、适应性广、抗逆性强、观赏价值高,是优良的园林观赏树种,在城市景观中已被推广应用。     

Analysis on the effect of runoff retention and pollution load control for two vegetation roofs during rainfall events

In order to understand the effect of runoff retention and pollution load control for vegetation roofs during rainfall events, the evaluation criterion of vegetation roof performance is redefined and two vegetation roofs are established artificially based on the code for the design of roof greening, which is investigated during rainfall events. Results show that ophiopogon japonicus roof can delay the production of runoff by 25〖XC半字线.tif,JZ〗48 min compared to the rain occurring and retention runoff volume by 40%〖XC半字线.tif,JZ〗58%, while sambucus dhinensis roof can make the generation of runoff 60〖XC半字线.tif,JZ〗130 min later than the rain beginning and runoff volume retention can be as high as 54%〖XC半字线.tif,JZ〗80%. In addition to PO 3-4 P, the reduction of pollution load of NO -2 N, NH3 N, TP, COD, TN and NO -3 N by both vegetation roofs can reach 95.1%〖XC半字线.tif,JZ〗98.6%, 87.2%〖XC半字线.tif,JZ〗93%, 72.4%〖XC半字线.tif,JZ〗83%, 76%〖XC半字线.tif,JZ〗81.8%, 68.7%〖XC半字线.tif,JZ〗78.4% and 40.9%〖XC半字线.tif,JZ〗60.6% respectively. The level of pH, COD, NH3 N and TP in vegetation roofs runoff can meet class Ⅲ surface water standard. Meanwhile, both vegetation roofs have similar effect in neutralization acid deposition (i.e., from 5.8〖XC半字线.tif,JZ〗6.0 (in rain water) to 7.0〖XC半字线.tif,JZ〗7.6 (in eco roof runoff water)). Plants grown on vegetation roofs can influence the performance of vegetation roofs. Based on the results, ophiopogon japonicus has an advantage of sambucus chinensis in controlling phosphorus pollution, while sambucus chinensis manifests better in reducing nitrogen load. Vegetation roofs are becoming an important urban landscape more and more, and study results in this paper provide references for the improvement of vegetation roofs construction and more reasonable evaluation of their running performance.     

Role of NF-κB in inducing HEL cell proliferation and apoptosis during human cytomegalovirus infection

AIM:To investigate whether human cytomegalovirus(HCMV) regulate human embryonic lung fibroblast(HEL) cell proliferation and apoptosis by activating NF-κB.METHODS:Immunohistochemistry and Western blot analysis were used to detect the NF-κB translocation and/or Bcl-2 and the levels of I-κBα during HCMV infection. Apoptotic cell were examined by flow cytometry, and the HEL cell proliferation was determined by MTT.RESULTS:The levels of NF-κB in the nucleus reached highly 48 h postinfection, and the levels of I-κBα were low 24 h postinfection. The activity of NF-κB was inhibited 120 h postinfection. The levels ofbcl-2was accorded with the activity of NF-κB. HCMV promoted HEL cells to proliferate before 72 h postinfection and induced apoptosis 120 h postinfection.CONCLUSION:NF-κB plays a role in HEL cell proliferation and apoptosis during HCMV infection, and it involves in the pathological mechanisms of diseases associated with HCMV infection.     

Can sieving size affect the determination of soil available micronutrients?

<正>Dear Editor,Globally, approximately two billion people suffer from micronutrient deficiencies(Tulchinsky, 2010; Myers et al.,2014).Soil micronutrient availability is of great importance for the evaluation of soil fertility and the determination of appropriate measures for improving crop quality and human health.The diethylenetriamine-penta-acetic(DTPA)     

平原沙土区不同林分类型下土壤有机碳库特征及其影响因子

目的 明晰不同林分类型下土壤有机碳库特征,以期为平原沙土区土壤碳库的提高和生态恢复提供理论依据。 方法 以江苏省平原沙土区丰县16年生杨树纯林、柳树纯林、杨柳混交林3种林分类型及相邻的撂荒地（对照）为对象,测定0～20、20～40、40～60、60～80、80～100 cm等5个土壤层次有机碳及活性组分和土壤酶活性,计算土壤碳库管理指数,并对土壤有机碳库特征和环境因子进行相关性分析。 结果 （1）3种林分类型及对照各土层有机碳含量和储量范围分别为1.03～5.88 g·kg−1和3.53～17.55 t·hm−2。与对照相比,0～100 cm土层,3种林分类型土壤有机碳含量增加了45.2%～82.2%。杨树纯林0～100 cm土层有机碳储量分别是柳树纯林、杨柳混交林和对照的1.23、1.24、1.83倍。（2）与对照相比,0～100 cm土层,3种林分类型的土壤易氧化有机碳、可溶性有机碳和微生物生物量碳含量分别提高了28.6%～48.0%、6.8%～9.7%和21.6%～33.4%。3种林分类型土壤碳库管理指数显著高于100%（P<0.05）。（3）林分类型显著影响土壤蔗糖酶和多酚氧化酶活性（P<0.05）,杨柳混交林0～100 cm土层多酚氧化酶活性显著高于杨树纯林和对照（P<0.05）。（4）相关性分析表明,土壤有机碳库特征受多酚氧化酶和β-葡萄糖苷酶活性显著影响,有机碳含量和储量、易氧化有机碳含量及碳库管理指数受蔗糖酶、过氧化物酶活性显著影响,微生物生物量碳受蔗糖酶活性显著影响。冗余分析表明,土壤碳氮比和细根生物量是土壤有机碳库特征的主要影响因素。 结论 平原沙土区营造人工林提高了土壤有机碳及活性组分和有机碳库稳定性,杨树纯林提高土壤有机碳储量效果最好。     

金黄色葡萄球菌α-溶血素的研究进展

目的α-溶血素在金黄色葡萄球菌(金葡菌)肺炎的感染过程中起着非常重要的作用,可作为治疗金葡菌肺炎的新靶标。因此,研究百里香酚对金葡菌α-溶血素表达的影响具有重要意义。方法测定最小抑菌质量浓度(MIC)和生长曲线并进行了溶血试验、蛋白免疫印迹分析、荧光定量PCR以及细胞毒性试验。结果百里香酚对金葡菌USA300的MIC为256 μg/mL,亚抑菌质量浓度的百里香酚(32 μg/mL)可下调金葡菌hla和RNAIII的转录水平,降低α-溶血素的表达,对溶血素介导的肺癌上皮细胞A549损伤具有保护作用。结论百里香酚具有成为新型抗金葡菌感染药物的潜力。     

虾类产品鲜度判定方法

鲜度是虾类产品品质与加工适性的一个重要指标,在捕捞、收购、运输、加工和销售过程中常常需要对虾的鲜度质量进行评价.目前,对虾类产品鲜度判定方法包括感官评价、化学、微生物方法等.随着水产科学研究的深入和人们对虾类产品卫生安全要求的提高,对虾类产品鲜度的各种判定方法也有长足的发展,特别是一些快速简便的判定方法更值得关注.笔者拟对虾的鲜度变化规律、有关虾类产品鲜度判定方法和未来发展趋势进行综述,以期为虾类产品生产加工者提供理论依据.     

氮磷钾养分配比对温室土培黄瓜产量及品质的影响

在日光温室内,采用盆栽方式研究了不同氮磷钾养分配比对土壤栽培黄瓜产量及其品质的影响。结果表明：增加磷素用量和比例可以显著提高黄瓜的产量;适量氮钾肥配合增施磷肥可以增加果实中可溶性蛋白含量,适量氮磷肥配合增施钾肥可以改善果实品质,提高可溶性糖和维生素C含量,降低硝酸盐含量。