Aerial Application of Chemicals at Low and Ultra-low Volume Against Main Pests of Citrus and Olive Trees in Tunisia and Libya

Encouraging results were obtained in low and ultra-low volume aerial applications against Ceratitis capitata Wied. in Tunisia (Malathion LV 96%) and against this pest and against Dacus oleae Gmel. in Libya (with Malathion LV, phosphamidon 50 and 100% a.i. and dicrotophos 100%). The mixture rates of insecticide and bait were also considered.     

提高特殊柱塞泵往复密封寿命的优化设计

针对输送含颗粒介质柱塞泵的柱塞、填料寿命问题,从接触型往复密封的摩擦学机理出发,通过优化匹配柱塞直径、行程及泵速各参数,合理控制柱塞的线速度,降低摩擦速度,对柱塞填料密封进行优化设计;通过求解间隙中的流体力学层流运动问题,合理控制冲洗液的压力,保证全压密封系统中接触区的液膜处在混合润滑状态下工作,使密封副有良好的润滑;提出了两种填料函方案,并和采用不同表面处理工艺的柱塞及多种填料搭配组合进行试验.试验结果表明,密封累计运行了4 455 h后,组合1和组合2柱塞的磨损仅为0.03 mm和0.05 mm;在生产实际中,改进后的密封设计,使柱塞及填料的使用寿命从原来的1 500 h提高到4 500 h以上.     

Generation,sink, and emission of greenhouse gases by urban soils at different stages of the floodplain development in Moscow

Purpose

The purpose of this research was to study the generation, sink, and emission of greenhouse gases by soils on technogenic parent materials, created at different stages of the Moskva River floodplain development (1—construction and 2—landscaping of residential areas).

Materials and methods

Field surveys revealed the spatial trends of concentration and emission of the greenhouse gases in following groups of soils: Retisols (RT-ab-ct) and Fluvisols (FL-hu, FL-hi.gl) before land engineering preparation for the construction, Urbic Technosols Transportic (TC-ub-ar.tn and TC-ub-hu.tn) at stage 1 and Urbic Technosols Folic (TC-ub-fo) at stage 2. CO₂ and CH₄ concentration in soils and their emission were determined using subsurface soil air equilibration tubes and the closed chamber method, respectively. Bacterial methane generation rate (MGR) and methane oxidation rate (MOR) were measured by kinetic methods.

Results and discussion

In natural soils MOR is caused only by intra-aggregate methanogenesis. The imbalance of methane generation and oxidation was observed in FL-hi.gl. It caused CH₄ accumulation in the profile (7.5 ppm) and its emission to the atmosphere (0.11 mg CH₄ m^?2 h^?1). RT-ab-ct acted as the sink of atmospheric methane. CO₂ emission was 265.1?±?24.0 and 151.9?±?37.2 mg CO₂ m^?2 h^?1 from RT-ab-ct and FL-hi.gl, respectively. In Technosols CH₄ concentration was predominantly low (median was 2.7, 2.9, and 3.0 ppm, in TC-ub-ar.tn, TC-ub-hu.tn, and TC-ub-fo, respectively), but due to the occurrence of peat sediments under technogenic material, it increased to 1–2%. Methane emission was not observed due to functioning of biogeochemical barriers with high MOR. In TC-ub-ar.tn and TC-ub-hu.tn, the barriers were formed at 60-cm depth. In TC-ub-fo, the system of barriers was formed in Folic and Technic horizons (at 10- and 60-cm depth). CO₂ emission was 2 times lower from TC-ub-ar.tn and TC-ub-hu.tn and 1.5 times higher from TC-ub-fo than from natural soils.

Conclusions

Greenhouse gas generation, sink, and emission by natural soils and Technosols in floodplain were estimated. CO₂ and CH₄ content in Technosols varied depending on the properties of parent materials. Technosols at stage 1 did not emit CH₄ due to formation of biogeochemical barriers—soil layers of high CH₄ utilization rates. Urbic Technosols (Folic) at stage 2 performed as a source of significant CO₂ emission.

     

基于高肥力设施土壤蔡-18菌液替代化肥对黄瓜生长与土壤生态的影响

为改善设施蔬菜土壤生态,推动化肥零增长计划实施。在土壤速效氮、磷、钾分别为283.55,574.05,1 161.3 mg/kg,有机质54.9 g/kg的高肥力日光温室中设置追施水溶性化肥(WSF)、蔡-18菌发酵液(Cai-18)和不施肥(CK)3种施肥处理,采用Miseq高通量技术、气相色谱-质谱(GC-MS)测定法、顶空固相微萃取-气质联用(HS-SPME-GCMS)分析方法测定3种施肥方式对黄瓜产量和品质、根区土壤养分含量、根际土壤微生物群落结构的影响。结果表明,WSF和Cai-18处理显著提高黄瓜产量,比CK分别增产6.21%和6.59%,Cai-18处理的氮、磷、钾用量比WSF处理分别减少93.48%,95.44%,98.63%,但两者产量差异不显著。Cai-18处理增加黄瓜酯类香气物质的种类和相对含量,提高果实的风味;WSF和Cai-18处理在黄瓜质地和可溶性糖含量差异不大,但二者果实的可溶性糖含量显著高于CK。Cai-18处理根际土壤细菌的97%相似水平下OTU分组数、菌种丰富度指数Chao-1和菌种多样性指数Shannon大于其他2种处理,而其真菌的OTU数和Shannon指数小于其他2种处理,但均没有达到显著差异。在菌群数量结构上,与WSF处理相比,Cai-18处理改善了根际土壤细菌和真菌菌群数量结构的均衡性;与CK相比,Cai-18处理根际土壤的细菌菌群数量结构均衡性更好,但真菌菌群数量结构均衡性较CK差。黄瓜拉秧后,Cai-18处理土壤速效钾含量比WSF处理降低了140.85 mg/kg (P0.05),但2种处理的有机质、水解氮和有效磷含量差异不显著;CK处理的速效钾、有效磷含量显著低于前2种处理。在肥力高的土壤上施用蔡-18菌发酵液可以改善根际土壤微生物生态环境,缓解过量施肥导致的根层土壤养分失衡问题,提高黄瓜产量和品质。     

转基因水稻秸秆还田对土壤硝化反硝化微生物群落的影响

转基因作物可能通过根系分泌物和植株残体组成的改变及外源基因的转移释放令土壤微生物群落产生变化,影响土壤微生物的生态功能。氨氧化细菌和反硝化细菌是驱动土壤硝化和反硝化过程的关键微生物,其群落结构的变化直接关系土壤氮素的转化与利用。本研究利用荧光定量PCR和PCR-DGGE技术分析了转cry1Ac/cpti双价抗虫基因水稻‘Kf8’秸秆还田降解过程中,土壤氨氧化细菌和反硝化细菌群落丰度与组成的变化,探讨转基因水稻是否存在影响稻田土壤氮素转化与N2O排放的可能。结果显示:无论是氨氧化细菌amo A基因还是反硝化细菌nirS基因,其丰度在转基因水稻‘Kf8’与非转基因水稻‘Mh86’的秸秆还田土壤中都没有显著差异;转基因水稻‘Kf8’和非转基因水稻‘Mh86’秸秆还田降解过程中0~10 cm土层中的amo A基因丰度均显著高于10~20 cm及20~30 cm土层(P0.05);各深度土层中的nirS基因丰度均存在随秸秆还田时间延长而增加的趋势。水稻秸秆还田降解过程中,转基因水稻‘Kf8’的土壤氨氧化细菌和反硝化细菌的群落多样性指数及组成,均与非转基因水稻‘Mh86’没有显著差异。相关分析结果表明土壤氨氧化细菌和反硝化细菌群落组成均与水稻秸秆还田时间存在显著相关性(P=0.002),反硝化细菌群落组成还与土层深度显著相关(P=0.024)。本研究表明转cry1Ac/cpti抗虫基因水稻秸秆还田对稻田土壤硝化和反硝化关键微生物群落不会产生明显影响。就土壤微生物群落而言,转cry1Ac/cpti抗虫基因水稻秸秆还田不存在影响土壤氮素转化与N2O排放的可能。     

高剪切匀浆泵两相流动的数值模拟

为了研究高剪切匀浆泵对物料的剪切混合效果,掌握剪切泵内流场的宏观规律和速度特性,应用三维造型软件Pro/E建立高剪切匀浆泵的水力模型,采用计算流体动力学的数值计算方法,基于Mixture混合模型,扩展的标准k-ε湍流方程及SIMPLEC算法对高剪切匀浆泵进行固液两相流的数值模拟.为了减小网格数量对计算结果的影响,对高剪切匀浆泵进行了网格的无关性检验.对不同流量和转速工况下的高剪切匀浆泵进行了数值模拟及横向比较,分析了流量和转速对剪切泵内流场的影响规律.分析结果表明：物料在经过剪切外腔后混合均匀程度显著提高,说明该剪切泵能对物料起到较好的混合均匀作用;随着流量的增大,固液两相混合均匀化速率变慢;随着转速的增大,两相混合均匀程度及速率变快,但改变转速只对转轮部分有影响,对进口区域的固相体积分数影响不大.     

烯啶虫胺、醚菊酯及其混剂对褐飞虱的毒力测定

【目的】了解烯啶虫胺、醚菊酯单剂及其混剂对褐飞虱3龄若虫的毒力作用,为开发防治褐飞虱的复配制剂提供科学依据。【方法】用稻茎浸渍法测定烯啶虫胺、醚菊酯单剂及其混剂对褐飞虱的毒力效果。【结果】烯啶虫胺、醚菊酯对褐飞虱3龄若虫的LC50分别为0.4922和9.1847mga·i·L^-1,两单剂按有效成分质量比为1∶12和1∶27（烯啶虫胺∶醚菊酯）时,共毒系数分别为249.89和138.15。【结论】烯啶虫胺和醚菊酯按有效成分质量比为1∶12和1∶27（烯啶虫胺∶醚菊酯）时有明显的增效作用。     

斑蝥素对11种害虫的杀虫活性

【目的】明确天然产物斑蝥素的杀虫谱和作用方式。【方法】采用不同生测方法,测定斑蝥素及1.0%斑蝥素乳油对11种害虫的室内毒力,观察了家蝇成虫的中毒症状。【结果】斑蝥素对家蝇成虫具有一定的胃毒作用,其48,72h的胃毒LC50分别为781.90,397.23mg/L,无触杀、熏蒸作用,其中胃毒作用较缓慢,处理约18h后才表现出明显的中毒症状;对玉米象成虫的48h胃毒LC50和触杀LD50分别为373.17mg/L和0.36μg/虫,无熏蒸活性;对大叶黄杨斑蛾4龄幼虫的24,48h触杀LD50分别为0.084,0.049μg/虫;1.0%斑蝥素乳油对烟蚜、菊姬长管蚜、桃粉蚜、萝卜蚜和月季长管蚜5种蚜虫无翅成蚜的12h触杀LC50分别为19.52,15.84,16.63,25.94,26.20mg/L;1.0%斑蝥素乳油对朱砂叶螨、麦圆蜘蛛和山楂叶螨成螨的12h触杀LC50分别为8.26,13.38,8.46mg/L。【结论】斑蝥素对多种害虫均具有不同程度的毒杀作用,其主要作用方式为触杀和胃毒。     

离体条件下雷公藤不定根生长与营养成分消耗动态研究

【目的】研究悬浮培养条件下雷公藤不定根营养成分的消耗动态与不定根生长之间的关系,为雷公藤组织培养生产次生代谢产物中培养基的改良及无机元素的及时补充提供参考。【方法】以NT为基本培养基,将雷公藤不定根悬浮培养,每隔5～10d对培养基中碳源、氮源、磷酸盐、钾盐、钙盐、镁盐等营养物质的消耗动态及不定根增长量进行测定。【结果】雷公藤不定根对碳、氮、磷酸盐以及钾、钙、镁等营养物质的消耗并不是均匀的。蔗糖、氮、磷酸盐和钾盐在培养后期几乎被耗尽,其中氮的消耗速率最快,在不定根生长进入对数期以前,氮元素已经开始大量消耗,进入对数生长期后,培养基中的氮源90%被消耗。蔗糖、磷酸盐、钾盐和钙盐的消耗表现为先快后慢,早期吸收迅速,而在快速生长期其消耗速度减慢。细胞停滞生长以后,蔗糖、氮、磷酸盐和钾盐仍有大量消耗。NT培养基中碳、氮、磷、钾在培养的前期已经不能满足不定根生长的需要。雷公藤不定根培养过程中对钙和镁的消耗相对较少,培养结束后培养基中还有48.3%的钙离子和34.2%的镁离子存在。【结论】NT培养基中,碳源、氮源、磷酸盐和钾盐不足是影响雷公藤不定根生长的主要因素。     

<Emphasis Type="Italic">Echinococcus granulosus</Emphasis>: Immunoprotection accompanyied by humoral and cytokine response against secondary hydatidosis in mice immunized with r<Emphasis Type="Italic">Eg.</Emphasis>myophilin

Objects:  

This study aimed to investigate the immunoprotection of the recombinant Eg.myophilin (rEg.myophilin) and tentatively analyze mechanism of this protection.