广州地区甜玉米测土配方施肥指标体系研究

在对广州地区土壤养分状况进行调查的基础上,通过系统的“3414”试验,建立了相对产量与土壤养分回归方程,从宏观上评价了广州地区甜玉米主产区土壤养分丰缺指标,初步建立了甜玉米施肥指标体系.通过对萝岗、番禺、增城、南沙4个试验点的甜玉米产量与施肥量进行回归分析,建立氮、磷、钾三元二次肥料效应函数:Y=727.83+15.13N-0.28P+11.70K-0.28N2+9.025P2-0.19K2-0.16NP+0.01NK-0.13PK(R2=0.91).对该回归方程进行显著性检验,P＜0.05,表明氮磷钾肥施用量与产量有显著的回归关系,结合单、双因素分析结果,推荐广州地区甜玉米理论每667 m2产1 000kg的氮、磷、钾肥最佳施肥量约为24、7、19 kg.施肥经济效益分析表明,氮、钾肥的收益在一定范围内与施肥量成正比,磷肥施用量过高会出现负收益现象.施肥经济效应分析结果与三因素效应方程分析结果一致.     

西安镇滨河绿地野生草本植物多样性分析

为给乡村环境中人为干扰后的生态恢复提供理论依据,以西安镇主要河道或干渠滨水绿地中25个样地为调查对象,调查了各样地野生草本植物的种类、组成和盖度,运用物种丰富度指数(R)、Simpson优势度指数(C)、Shannon-Weiner多样性指数(H)作为样地物种多样性的测度指标,分析了物种的多样性差异。结果表明:西安镇滨河绿地的25个样地中共有草本植物18科25属34种。物种组成以禾本科、菊科、藜科、香蒲科和小二仙草科植物为主,植物种类以芦苇、拂子茅、狗尾草、翅碱蓬、普香蒲和穗状狐尾藻为主。从多样性相关指数来看,物种丰富度指数(R)为10～22、Simpson优势度指数(C)为0.11～0.45、Shannon-Weiner多样性指数(H)为1.7～3.3。各样地差异性较大,主要是人为干扰差异性所致,较少的人为干扰促进了个别物种成为优势种,排挤其他物种生存,降低了物种多样性;道路建设和农业基础设施建设等较强的人为干扰破坏了局部生态平衡,也在一定程度上降低了植物物种多样性。     

涂料和遮阳网覆盖对大棚环境和辣椒光合特性的影响

利用涂料和遮阳网对塑料大棚进行了覆盖处理,研究涂料和遮阳网覆盖对棚内环境和辣椒光合特性的影响,结果表明,涂料的遮阳降温效果与其稀释比例有关,稀释比例越小,遮阳降温效果越好;除阴雨天棚内地温外,遮阳网具有明显遮光降温作用;相比遮阳网,1 3涂料能够降低阴雨天和早晚时分的遮光率,改善棚内光照,延长光照时间,降温效果好;遮阳网覆盖导致辣椒的净光合速率、气孔导度和蒸腾速率显著下降,胞间CO2浓度显著上升,不利于辣椒的光合作用,而涂料覆盖有助于改善中午强光时辣椒的光合作用,使其净光合速率和气孔导度显著上升,蒸腾速率显著下降。     

生长调节剂对油菜产量及氮素利用效率的影响

采用土培试验,以高氮素利用效率油菜品种2号及低氮素利用效率油菜品种6号为试验材料,在不同氮素水平上,研究了油菜生育后期涂抹生长素(IAA)、细胞分裂素(6-BA)及脱落酸(ABA)3种不同生长调节剂对产量及氮素利用效率的影响。结果表明:生长调节剂能提高油菜单株角果数、每角果粒数、千粒重、籽粒产量及生物产量。与低氮素利用效率油菜品种6号相比,高氮素利用效率油菜品种2号增加效果更加明显。同时生长调节剂对氮素生理效率的影响与品种及氮水平的高低有着密切的关系。     

邵阳市烟叶产业可持续发展问题探讨

针对邵阳市烟叶生产的现状,在分析当前烟叶生产发展存在的问题的基础上,提出了发展邵阳烟叶生产的对策。邵阳市烟叶生产历史悠久,但目前存在着产业基础设施建设薄弱、土壤资源保护不够、烟农素质整体偏低,先进种植技术的推广速度与烤烟发展速度不协调等问题。为此,提出了加强基础设施建设,推进基本烟田土地整理,抓好从烟人员管理和烟农队伍培训,全面推进基地单元标准化生产为主的措施和对策。     

苹果中拟除虫菊酯农药残留降解规律的研究

用气相色谱法研究了苹果生长过程中拟除虫菊酯类农药的残留污染及其在苹果中的降解规律,结果表明,苹果中3种拟除虫菊酯农药随时间的推移呈下降趋势,残留量呈现甲氰菊酯>氯氰菊酯>溴氰菊酯,降解顺序速率为氯氰菊酯>溴氰菊酯>甲氰菊酯,在苹果采收前有适当的休药期可以满足安全方面的要求。     

盐胁迫对结缕草和高羊茅种子萌发的影响

用NaCl和Na2SO42种盐以9∶1的摩尔比配制浓度分别为30、60、90、120、150、180 mmol/L和210 mmol/L的混合盐溶液,作为盐胁迫处理液对结缕草和高羊茅种子进行盐胁迫发芽试验。结果表明,结缕草和高羊茅种子的发芽率均随着盐浓度的升高而呈"抛物线"型的曲线变化,结缕草的发芽率随着盐浓度的升高而降低,高羊茅的发芽率随着盐浓度的升高先升高后降低;当盐浓度达到120 mmol/L和90 mmol/L时,结缕草种子的发芽率和发芽势分别极显著地低于对照(p<0.01),当盐浓度达到150 mmol/L和120 mmol/L时,高羊茅种子的发芽率和发芽势分别显著地低于对照(p<0.01);结缕草种子萌发的耐盐半致死浓度为166.4 mmol/L,耐盐极限浓度为220.0 mmol/L,高羊茅种子萌发的耐盐半致死浓度、耐盐极限浓度分别为168.4、200.0 mmol/L;高羊茅种子萌发的耐盐性要强于结缕草。     

过程性能指数在烟梗预处理工艺参数优化中的应用

针对加湿梗成品含水率控制稳定性差、湿透率低的问题,对稳定控制一次回潮热水温度、二次回潮蒸汽压力、二次回潮加水量环节进行了系统研究,采用统计过程控制技术对加湿梗成品含水率进行控制,以提高加湿梗含水率的稳定性。通过正交试验优化了3个主要工艺参数,并进行直观分析以及生产验证,结果表明最佳工艺组合为:一次回潮水温60℃,二次回潮蒸压力0.65 MPa,二次回潮加水量0。     

Development and Application of Small Urban Watershed Storm Runoff Model in Mountain City

The small urban watershed storm runoff model of mountain city, which bases on the hydrological method and ArcEngine extension programming was developed aim at stimulating the flood situation, locating the flooding area, computing the subsiding time of flood, utilization and management of the stormwater through the rainfall data. The model was used in Panxi basin of Chongqing. The simulated situation showed that the Nash-Suttcliffe coefficient Ens is 0.56-0.76, the relatively error is 8.82%-11.8%. According to the parameter sensitivity analysis the most sensitivity parameters of the model are width of subcatchment, slope, manning coefficient and impermeable area rate. The model had analyzed the flow, full degree and number of overflowed wells to evaluate drainage capability of drainage system. Results showed that 0.52% of the drainage pipes were overload under one-year storm; compared with 5.86% and 8.20% under fifty-year storm and one-hundred-year storm respectively. By comparing the flow depth inside the wells with the placing depth the assessment results showed that 0.72% of the wells had spillover under one-hundred-year storm and 0.31% of the wells had spillover under one -year. Overall the model achieves effective management of storm runoff and assessment of the water drainage system capacity in mountainous city.     

Design of nondestructive test system for plasma clots

One of the most important measures that are used to guarantee blood transfusion safety is to detect clots in the plasma before transfusion. To overcome the disadvantages of manual detection method, this research designs a nondestructive testing (NDT) system for plasma clots inspection based on machine vision technique and artificial neural networks. The key technology for system design are studied and presented. Image acquisition is performed by custom-designed software based on MATLAB platform, and the methods of image cut, reverse color, median filter as well as gray cutting are adopted to preprocess image. The use of fisher discrimination method, combined with iterative threshold segmentation method and the selection of connected domain, can successfully eliminate the interference of air bubble and correctly extract the image of plasma clots. Plasma clots are discriminated by a recognition model based on artificial neural network BP algorithms. The results of clinical contrast experiment shows that the system can effectively detect whether plasma contains plasma clots and the new system shows a much higher degree of repeatability and stability. From the image acquisition and processing to the recognition of plasma clots, the detecting time of a sample is no more than 1 min.