松木粉／聚醚砜树脂复合材料的制备及选择性激光烧结试验

以松木粉、聚醚砜树脂为材料,用SHR－10A型高速混合机制备松木粉／聚醚砜树脂复合粉末;用HRPS－ⅢA型激光粉末烧结快速成型机,遴选出复合粉末可用于选择性激光烧结工艺参数及适宜的预热温度,烧结成型。测量了不同松木粉质量比对复合粉末力学性能的影响,观察并测量了输入不同的能量密度时,烧结试件的成型效果和力学性能。结果表明：随着松木粉质量比的增加,木塑复合材料的力学性能降低。对于松木粉质量比为20％的木塑复合粉末,当输入的能量密度为0．128 J／mm3时,复合粉末即可成型;当输入的能量密度为0．312 J／mm3时,木塑复合材料的拉伸强度达到4．8465 MPa,弯曲强度为8．2152 MPa,冲击强度为1．2574 MPa,此时力学性能最强;若输入的能量密度大于0．312 J／mm3时,出现过烧现象,力学性能下降。采用扫描电镜对烧结件断面的形貌进行了表征。     

两种生物膜工艺对污染物去除效果的比较研究

在室温下,用竹丝、塑料两种材料作为生物膜载体,使用SBR工艺对比研究这两种生物膜处理工艺去除污染物的实验结果及作用机理。实验结果表明:竹丝填料反应器对高锰酸盐指数、NH3-N(氨氮)、硝酸盐氮、亚硝酸盐氮、TP(总磷)的去除率分别为31.8%~51.9%、53.3%~71.9%、69.2%~84.0%、21.1%~33.3%、51.1%~74.5%,与塑料填料反应器相比具有明显的优势。因为竹丝填料是天然载体,其具有亲水基团和良好的生物亲和性,并且生物量多,这就使得微生物容易在竹丝填料上生长并快速形成生物膜,并且其生物膜的总体性能要比塑料填料反应器内生物膜的总体性能要好。总的来看,塑料填料反应器的处理效果不如竹丝填料反应器。     

大棚番茄连续套蒜第3年作物生产和土壤养分分析

【目的】研究大棚番茄与大蒜(青蒜)连续套种3年对作物的生物效应和土壤养分含量的影响。【方法】2010-08-2011-07,在塑料大棚内以番茄单作为对照,设番茄套作大蒜和番茄套作青蒜2个处理,在秋茬番茄行间套种大蒜或青蒜,大蒜(青蒜)生长持续到春季,此时定植春茬番茄,分析比较不同模式连续种植第3年时的作物生物效应和土壤养分含量。【结果】与番茄单作相比,套蒜处理对秋茬番茄生长和产量有一定促进作用,并能显著提高其主要品质指标,但套蒜处理对春茬番茄生长和产量有显著的竞争性抑制作用。套作大蒜和青蒜对番茄根结线虫有一定抑制作用,其防病效果在秋茬番茄上分别为54.9%和60.0%,在春茬番茄上分别为34.3%和39.4%。套蒜处理可明显提高秋茬和春茬番茄土壤碱解氮和速效磷含量,但对土壤速效钾含量影响效果不同。不同套作模式的年产值不同,套作大蒜和青蒜处理分别较番茄单作增值11.0%和11.9%。【结论】连续套蒜可消减大棚番茄根结线虫病,提高年产值。     

Assessment of plastic ingestion by pole-caught pelagic predatory fish from O'ahu,Hawai'i

1. Although the frequency of occurrence of plastic ingestion in the large-sized dolphinfish and tunas taken by the Hawai'i longline fishery is very low (frequency of occurrence < 5% of sampled individuals), the ingestion of plastic in smaller-sized specimens caught with pole-and-line gear by commercial and recreational fishers has not been investigated.
2. This study examined ingestion of >0.25 mm marine plastic debris (MPD) by four predatory fish species caught by commercial fishers around the Main Hawaiian Islands, and documented ingestion in three species: 85.7% of albacore tuna (n = 7), 40.0% of skipjack tuna (n = 10) and 12.5% of dolphinfish (n = 8).
3. Yellowfin tuna (n = 10) did not contain any MPD, probably owing to the high proportion of empty stomachs (60%).
4. For skipjack tuna, the frequency of occurrence of MPD ingestion was significantly higher for the smaller-sized specimens caught with pole-and-line (40%), compared with the larger-sized specimens caught with longlines (0%).
5. For dolphinfish, the frequency of occurrence of MPD ingestion was similar for the similar-sized specimens caught with pole-and-line and with longlines.
6. The ingested MPD items were micro–meso plastics, between 1 and 25 mm. While most ingested items were fragments, albacore also ingested line and skipjack also ingested sheets.
7. The predatory fishes ingested light MPD items that float in sea water, but there were species-specific differences in their polymer composition: albacore contained more polypropylene and polyethylene, and skipjack contained more elastomers, characterized by a high percentage of ester plasticizers.
8. Altogether, these results suggest that albacore and skipjack tunas ingest plastic of different types and polymers. Yet more research is needed to understand how differences in vertical distribution, foraging ecology and diet influence the MPD sampled by these predatory fish species.

     

伏天灌水覆膜对土温变化及西瓜枯萎病防治

为探明南方伏天灌水覆膜土温变化特点,2004和2005年伏天,对连作大棚西瓜地灌水后畦面覆盖不同颜色、不同层数的塑料薄膜与土温变化特点和防治西瓜枯萎病（Fusariurn oxysporurn f. sp.niveum）的关系作了研究,结果表明,灌水覆膜能明显增加表土下5～20 cm土层的温度,增温幅度达10～15℃（同露地相比）;增温效果以双层白膜最好,单层白膜次之。单层白膜覆盖l0 d后其土表下5～20 cm土层的温度全天可维持40℃以上。大棚内灌水覆盖单层白膜25 d以上对第一茬连作西瓜枯萎病防效达     

磁化水膜下滴灌对新疆棉田土壤脱盐效果的影响

通过3a试验研究了磁化水膜下滴灌对土壤脱盐效果及对棉花生长发育和产量的影响。结果表明：磁化水能有效的降低土壤含盐量,促进棉花生长发育,提高棉花产量和品质。在0-60cm土层,磁化水的纯脱盐率在20%～30%,同时对土壤中的SO42-、Cl-含量也有明显的降低。磁化水滴灌棉花较对照增产皮棉144.7kg/hm2,可增收2025.8元/hm2,磁化水滴灌促进了棉花的增产增收。     

覆盖对烟田土壤酶活性及烤烟叶片荧光特性的影响

通过对烤烟大田3种不同覆盖方式的覆盖效应比较表明:覆盖明显增强了土壤过氧化氢酶和蔗糖酶活性,对脲酶活性有一定抑制作用;在烤烟生长前期,液膜覆盖处理土壤过氧化氢酶活性较对照和地膜覆盖处理分别平均提高5.72%、23.19%,且覆盖处理间差异达0.05显著水平;覆盖处理的蔗糖酶较对照平均提高0.8%,但3个处理间差异均不显...     

晚播小麦覆膜增产作用研究

覆膜能明显的增温、保墒提墒、加速养分释放,对晚播小麦的根系生长及分蘖等起着重要的促进作用。为小麦健壮生长,增加群体,加快生育进程和增产创造了良好的有利条件。试验表明,覆膜后可使分蘖增加43.11％,次生根增加46.71％,单株干重增加108.78％,穗数增加69.10％,增产率达95.86％,纯收益1hm~2增加900多元。     

塑盘旱育抛秧技术在杂交稻制种上的应用

太湖县在杂交稻制种母本上应用塑盘旱育抛秧技术，１９９６年平均单产２．７６ｔ／ｈｍ２，比对照常规制种增产１０．６４％；１９９７年平均单产３．３１ｔ／ｈｍ２，比常规制种增产１５．８％。应用关键技术是培育健壮秧、抛足基本苗、合理安排播差期。