自吸式喷雾降尘性能试验

为了提高喷雾降尘效果,提出了自吸空气式喷雾器降尘的方法,分析了自吸式喷雾器降尘工作原理,设计了不同结构的试验用自吸空气式喷雾器,并对其进行了正交试验和对比试验结合的相关试验.结果表明,喉嘴距、扩散角及水压等参数对自吸空气式喷雾器的SMD值、有效射程、雾化角、吸风量等均有不同程度的影响.当喉嘴距为48 mm、扩散角为30°、水压为6 MPa时,自吸空气式喷雾器的有效射程、雾化角、SMD值达到最佳,降尘效果最好;当水压为6 MPa时,常规单喷嘴喷雾的SMD值为124.3μm,自吸喷雾SMD值为108.5μm,自吸喷雾比常规单喷嘴喷雾的SMD值降低12.7%;当水压为6 MPa时,常规单喷嘴喷雾全尘降尘效率为92.67%、呼吸性降尘效率为87.21%,而正交试验优化得出的自吸喷雾全尘降尘效率为93.6%、呼吸性降尘效率为92.69%,自吸喷雾比常规单喷嘴喷雾的全尘降尘效率提高不太明显,但呼吸性降尘效率提高较明显.     

畜禽场排出空气的净化技术

详细介绍了当前国内外对畜禽场排出空气的主要净化技术和性能,对技术的设计原理、材料选择与净化效果进行了分析评价。     

黄土高原沙尘暴时空分布格局及变化趋势分析

研究了黄土高原地区沙尘暴的时空分布格局和变化趋势,主要的工作包括利用黄土高原地区253个旗县市气象站20世纪50年代至1984年沙尘暴的多年平均值做空间插值,结合遥感影像,分析了沙尘暴的空间分布格局,呈现出从西北向东南先增多后减少,北多南少的分布。利用1961-2000年沙尘暴记录分析了沙尘暴年内的季节分布,发现沙尘暴主要发生在春季,尤其是4月。最后,对40 a间沙尘暴进行了趋势分析,发现该区沙尘暴有明显的减少趋势,在1984年发生了明显转折,这种减少趋势在空间上不具有明显差异。     

半湿润区农田风蚀物垂直分布特征

通过两种观测手段对半湿润区农田风蚀物垂直分布特征进行了研究.结果表明,半湿润区农田风蚀强度较弱,风蚀物颗粒较细,主要由极细沙和粉沙组成.风蚀物含量垂向分布遵循幂函数递减规律.反映了以悬移质为主的风沙流结构特征.农田地表特征、风速和粒级等因索均对风沙流结构具有显著影响.农田风蚀强度大小影响风蚀物在近地表的分布规律.风速增大使相对输沙量在近地表增加,上层减少.风蚀物粒级越大,则输沙量沿垂直方向递减的幅度愈大.随着高度增加,风蚀物各粒级含量中砂级组分含量减少,粉砂及粘土组分含量增加,风蚀物粒径变细,粒径范围不断收窄.最大粒径和平均粒径沿垂直方向的变化都服从指数函数递减规律.     

北京城市居住区绿地的滞尘效益

该文比较分析北京城市居住区３种不同结构类型的绿地（乔灌草型、灌草型和草坪型）的滞尘效益，并且定量估算北京城近郊８区居住区绿地滞尘量．同时认为由乔、灌、草构成合理的绿化结构，能充分利用空间，最大可能地提高绿地上的绿量，具有较好的滞尘效益．     

八种乔木滞尘效益及其与叶表面特征关系

以青岛市城阳区道路绿地8种乔木为试验材料,采用洗脱法和质量差值法研究8种乔木的滞尘能力,采用扫描电子显微镜(JEOL7500F)、扫描探针显微镜(SPI3800-SPA-400,Seiko Instruments Inc.)和Image J观察叶表面结构并测定叶表面粗糙度、叶毛数量、气孔大小和气孔密度,分析了8种乔木的滞尘能力与叶表面特征的关系。结果表明:8种乔木的季节滞尘量总体上表现为秋季>春季>夏季。紫叶李、悬铃木和毛白杨单位叶面积滞尘量较大,洋白蜡、绦柳单位叶面积滞尘量较小,紫叶李的单位叶面积滞尘量最大,平均达到2.044 7 g·m^-2,最小的绦柳为0.574 7 g·m^-2,前者是后者的3.6倍左右。通过分析叶表面结构与滞尘量的关系得出,具明显网状结构、叶表面粗糙且具明显褶皱、叶表面具沟槽或绒毛,气孔较多且开口大等特征的植物滞尘能力较强。8种乔木叶片粗糙度、叶毛数量、气孔大小和气孔密度与单位叶面积滞尘量之间具有显著正相关关系,表明叶片粗糙度、气孔大小和气孔密度越大,叶毛数量越多,叶片滞尘量越大。     

Cigarette dust particles induced lung function injury of chronic obstructive pulmonary disease in mice

AIM: To investigate the pathogenesis of chronic obstructive disease (COPD) in mice by using nasal drip of cigarette dust particles (DSP) induced pulmonary function damage model.METHODS: BALB/c mice were randomly divided into control group, LPS 100 mg/L group, DSP 0.75 mL/L group, DSP 1.5 mL/L group and DSP 3 mL/L group for 30 days. The method of nasal drip was used for 30 days to establish the COPD model. Rrs, Ers, Crs, Est, Cst, P-3/8Rn, P-3/8G and P-3/8H were measured for evaluating lung function of the mice in each group by the method of FlexiVent. The effect on the increase of airway resistance induced by methacholine (Mach) was determined using main bronchial rings by Myograph method. The HE, Masson and Resorcinol fuchsin staining of mouse tracheas and lung tissues were conducted. RESULTS: Continuous nasal drip with DSP for 30 days increased Rrs, Ers, Est, P-3/8Rn and decreased Crs, Cst, P-3/8G and P-3/8H in the mice. DSP significantly shifted the dose-effect curve of tracheal contraction induced by Mach to the left, increased the sensitivity of the airway to Mach, and significantly increased the maximal contractile airway effect of Mach. Exposure to DSP caused fibrosis of airway subepithelial, deposition of collagen in the airway basement membrane under the reticular plate, induced reticular plate thickening, pulmonary bronchial lumen serious deformation, and the inflammatory cell infiltration in the lung of mice. Significantly increased alveolar wall muscle fibers and collagen fibers were also observed. CONCLUSION: The lung function and pathomorphological changes of COPD mice induced by 30 days nasal drip of cigarette dust particles were similar to those of human COPD.     

Combined mutations in five wheat STARCH BRANCHING ENZYME II genes improve resistant starch but affect grain yield and bread-making quality

Increases in the proportion of amylose in the starch of wheat grains result in higher levels of resistant starch, a fermentable dietary fiber associated with human health benefits. The objective of this study was to assess the effect of combined mutations in five STARCH BRANCHING ENZYME II (SBEII) genes on starch composition, grain yield and bread-making quality in two hexaploid wheat varieties. Significantly higher amylose (∼60%) and resistant starch content (10-fold) was detected in the SBEII mutants than in the wild-type controls. Mutant lines showed a significant decrease in total starch (6%), kernel weight (3%) and total grain yield (6%). Effects of the mutations in bread-making quality included increases in grain hardness, starch damage, water absorption and flour protein content; and reductions in flour extraction, farinograph development and stability times, starch viscosity, and loaf volume. Several traits showed significant interactions between genotypes, varieties, and environments, suggesting that some of the negative impacts of the combined SBEII mutations can be ameliorated by adequate selection of genetic background and growing location. The deployment of wheat varieties with increased resistant starch will likely require economic incentives to compensate growers and millers for the significant reductions detected in grain and flour yields.     

黑河流域中游荒漠区沙尘暴、扬沙和浮尘监测及其与气候因子的关系

[目的] 分析黑河流域中游荒漠区沙尘暴、扬沙以及浮尘频次和时长的月变化和年变化,并分析其与主要气候因子的关系,为区域沙尘天气的早期预警和荒漠区的经营和管理提供依据。[方法] 利用黑河流域红沙窝荒漠化综合防治试验站的2010—2019年的沙尘天气监测数据和气象数据进行分析。[结果] 沙尘频次和时长主要集中在春季,其次是冬季,春冬两季的频次和时长各占全年的82.3%和79.4%。10 a间沙尘暴和扬沙频次总体变化趋势逐渐减少,而浮尘频次总体变化趋势逐年增加;沙尘时长总体变化趋势逐年增加。沙尘频次月变化与土壤湿度（10 cm）和大气湿度之间呈极显著负相关（p<0.01）,与风速之间呈极显著正相关（p<0.01）。扬沙年际发生频次与土壤温度（5 cm）之间呈显著负相关（p<0.05）,与大气温度之间呈极显著负相关（p<0.01）。[结论] 近10 a来,黑河流域中游荒漠区的沙尘天气主要发生在春季和冬季,破坏性较大的沙尘暴和扬沙逐年减少,而浮尘逐年增加。沙尘频次的月变化主要影响因素是浅层土壤湿度、大气湿度和风速。春季的浅层土壤湿度影响了沙尘暴和扬沙年际频次变化,浅层土壤温度影响了浮尘年际频次变化;冬季的浅层土壤温湿度和降水量影响了沙尘暴的年际频次变化,浅层土壤温度和大气温度影响了扬沙的年际频次变化。     

仔猪大肠杆菌病三价蜂胶灭活疫苗猪体血清抗体消长规律

采用大肠杆菌C83549(O149:K88ac)、C83644(O68:K99)、C83710(O9:987P)菌株制备抗原,以蜂胶为佐剂,研制仔猪大肠杆菌病三价蜂胶灭活疫苗,疫苗成品检验均符合相关要求。将疫苗免疫妊娠母猪并用凝集试验测定其所产仔猪的抗体消长规律,并研究疫苗免疫保护相关性。结果表明:妊娠母猪产前40d和15d各免疫1次所产仔猪母源抗体效价较高,仔猪在整个哺乳期都可以得到保护。同时也可运用产前30d和10d进行免疫接种方法。