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1.
Bt A是由 Bt伴孢晶体和阿维菌素制成的 ,对小菜蛾幼虫作用方式与阿维菌素相似 ,主要表现为胃毒和触杀作用 ,但效果比阿维菌素好。当用 1mg/m L溶液触杀处理小菜蛾 4龄幼虫背板 72小时后 ,Bt A引起的小菜蛾死亡率为 36 .7% ,显著高于阿维菌素的 2 0 .0 % ,而 Bt伴孢晶体几乎没有触杀作用。 Bt A、Bt伴孢晶体和阿维菌素对小菜蛾胃毒 4 8h的 LC50 分别为 :0 .0 136 mg/m L、0 .0 0 5 9mg/m L、0 .72 74 mg/m L。  相似文献   

2.
福建省各地小菜蛾对不同类型杀虫剂抗性水平的比较   总被引:4,自引:0,他引:4  
黄斌  郭莹 《武夷科学》2003,19(1):45-47
本文采用点滴法,比较了福建省福州、南平、厦门、龙岩等地田间小菜蛾对不同类型杀虫剂代表品种的抗性差异,并运用Shannon—Weaver的多样性指数(H’)来作为不同地方种群小菜蛾杂合度的判定指标,对其种群组成进行讨论。结果表明,厦门的种群在对菊酯与有机磷上种群杂合度较高,处于较敏感水平。对阿维茵素,福州种群与厦门种群组成相似,抗性水平相当。而龙岩种群抗性杂合度与频率相对较低,正处于发展中。  相似文献   

3.
银杏外种皮杀虫活性成分研究   总被引:2,自引:0,他引:2  
采用活性追踪法从银杏外种皮中分离出杀虫活性成分银杏酚和白果酸.银杏酚对萝卜蚜的LD50为0.582 4μg/头,对小菜蛾3龄幼虫的LC50为2.0613g/L;白果酸对萝卜蚜的LD50为0.332 8 μg/头,对柑橘红蜘蛛、小菜蛾3龄幼虫的LC50分别为2.9110g/L、4.6002g/L.  相似文献   

4.
通过10种杀虫剂对小菜蛾幼虫和小菜蛾绒茧蜂成虫的室内毒力测定试验,结果表明∶印楝素、阿维菌素、功高、锐劲特和除尽对小菜蛾具有较高的毒力,其中印楝素的毒力最高,其LC50值为1.82mg·L-1。阿维菌素对小菜蛾绒茧蜂的毒力最低,其LC50值为114.42mg·L-1。印楝素、阿维菌素、锐劲特、除尽等4种杀虫剂对小菜蛾绒茧蜂的选择指数均大于1,对天敌较为安全。  相似文献   

5.
催化褪色光度法测定痕量铁的研究   总被引:3,自引:0,他引:3  
研究了在稀 H2 SO4 介质中 ,痕量铁催化 H2 O2 氧化甲基红褪色反应 ,建立了一种高灵敏、高选择性测定痕量铁的新方法 .检出限为 5 .0× 1 0 - 7g/L,线性范围 0 .0 μg/1 0 m L~0 .4μg/1 0 m L,用于食品中铁的测定 ,结果令人满意  相似文献   

6.
固相萃取-液相色谱法同时检测4种酸性PPCPs   总被引:2,自引:1,他引:1  
建立了固相萃取-液相色谱法同时分析环境水样中水杨酸、酮洛芬、萘普生和双氯芬酸钠等4种酸性PPCPs的方法.水样用0.22μm水系膜过滤两次,C18固相萃取小柱分离富集,甲醇洗脱液直接进行液相色谱分析.实验结果显示,工作曲线范围分别为水杨酸5~200 μg/L;酮洛芬2~200 μg/L;萘普生0.5~50μg/L和双氯...  相似文献   

7.
该试验测定结果表明小菜蛾对氧化乐果的敏感性显著降低,降低约20倍,CL50为1445mg/L,说明对氧化乐果已产生了抗性,而小菜蛾对功夫菊敏感度只降低2-3倍,其LC50为4.29mg/L,说明对功夫菊酯刚开始形成抗性。  相似文献   

8.
取食农药吡虫啉后,小菜蛾对阿维菌素的敏感性会随着取食量差异而受到影响。1.8%阿维菌素对小菜蛾的LC50浓度稀释倍数(Y1)与20%吡虫啉浓度稀释倍数(X)之间存在显著的线性相关关系,函数式为:Y1=14205—1248.8ln(X);而20%吡虫啉处理过的小菜蛾羧酸酯酶比活力(Y2)与20%吡虫啉浓度稀释倍数(X)之间的线性相关关系函数式为:Y2=-0.0804+0.0196ln(x)。  相似文献   

9.
研究 Rh( )对 Lu- H2 O2 - Cu( )化学发光体系的抑制作用 ,提出在贵金属混合物中测定微量 Rh( )的新方法 :在 p H=1 2 .40~ 1 2 .6 0的碱性溶液中 ,微量 Rh( )可抑制 ( 2 .5~ 7.5)× 1 0 -3 mol/ L Lu- ( 1~ 4)× 1 0 -2 mol/ L H2 O2 - Cu( ) (与待测 Rh在同一数量级 )体系的化学发光 ,线性范围 0 .1~ 1 0μg/ m L Rh( ) ,相对标准偏差 2 % ,检出限 0 .0 4 μg/ m L Rh( ) ,已用于 7种贵金属人工混合试液和 Pt- Rh合金中 Rh的测定 .  相似文献   

10.
陈青  王海燕  林冰 《贵州科学》2001,19(3):53-55
用苯芴酮—溴化十六烷基三甲胺分光光度法测定洋葱中的微量锗 ,不经萃取分离 ,有色溶液在 5 12 nm处比色。分析方法的线性范围为 0 .0 - 2 .5 μg/m L,获得较满意结果  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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