30%苯醚甲环唑·丙环唑微乳剂高效液相色谱分析

采用高效液相色谱法分析苯醚甲环唑·丙环唑复配制剂,使C18反相柱和紫外可变波长检测器,以乙腈-水(体积比70:30)为流动相,用外标法对有效成分进行分析和定量.苯醚甲环唑和丙环唑的标准偏差分别为0.11和0.13,变异系数分别为0.73%和0.85%,平均回收率分别为99.2%和99.1%.     

气相色谱法测定梨和土壤中戊唑醇的残留消解动态

[目的]对戊唑醇在梨和土壤中的残留分析方法进行了探讨并测定了其残留消解动态.[方法]采用乙腈提取、Flolisil小柱净化、GC-μECD进行检测.[结果]梨添加标准品0.01、0.05、0.5、1 mg/kg,回收率分别为110.3％、77.8％、81.5％、74.5％;土壤中添加标准品0.01、0.05、0.5、1 mg/kg,回收率分别为110.5％、97.1％、88.4％、82.8％.通过田间试验样品检测得到的戊唑醇的消解动态方程,其在梨上半衰期为8.6 d,在土壤中半衰期为7.2 d.[结论]方法灵敏度、准确度、精密度高,仪器耗材普遍易得,能为大规模监测戊唑醇的残留情况提供参考.     

2010年小麦赤霉病发生与抗性调查研究及防控对策

分析了2010年江苏省小麦赤霉病发生特点及原因,研究了赤霉病菌菌株对多菌灵抗药性的群体分布与发展动态,并提出了今后防治对策及建议.     

Identification and Field Evaluation of the Sex Pheromone of <Emphasis Type="Italic">Orthaga achatina</Emphasis> (Lepidoptera: Pyralidae)

Orthaga achatina (Lepidoptera: Pyralidae) is the most serious pest in south China of camphor trees, Cinnamomum camphora (L.) Presl, an important urban tree species. Gas chromatography-electroantennographic detection (GC-EAD) of the sex pheromone of O. achatina showed three EAD-active components. Coupled gas chromatography/mass spectrometry analyses identified these as (Z)-11-hexadecenol (Z11–16:OH), (Z)-11-hexadecenyl acetate (Z11–16:OAc), and (3Z,6Z,9Z,12Z,15Z)-tricosapentaene (Z3,Z6,Z9,Z12,Z15–23:H). In field tests using different combinations of the three compounds, male moths were attracted to a mixture of Z11–16:OAc and Z3,Z6,Z9,Z12,Z15–23:H, but less attracted to other blends. Further field tests with different ratios of the two compounds determined the optimal ratio of the binary blend as 500:250. The addition of Z11–16:OH to Z11–16:OAc, or to the binary mixture of Z11–16: OAc and the pentaene did not yield higher catches. This shows that O. achatina uses a mixture of Type I and Type II sex pheromone components. Orthaga achatina is the third Pyraloidea species found to utilize Z3,Z6,Z9,Z12,Z15–23:H as a sex pheromone component.     

Evaluating the combination of a parasitoid and a predator for biological control of seed beetles (Chrysomelidae: Bruchinae) in stored beans

The two seed beetle species Acanthoscelides obtectus and Callosobruchus maculatus are among the economically most important pests of stored legume seeds world-wide. Insect natural enemies for biological control were considered in IPM strategies to control bean weevils in store. In this contribution, the control effect by a combination of the parasitoid Anisopteromalus calandrae and the predator Xylocoris flavipes on both seed beetle species was evaluated in a laboratory study on black eyed beans Vigna unguiculata. The combination of parasitoid and predator was most effective against both species of seed beetles. However, in C. maculatus the combination was not significantly more effective compared to A. calandrae alone, suggesting a poor effect on adults and no effect on eggs and larvae by X. flavipes. In the case of A. obtectus, the suppressive effect by the combination of the parasitoid and the predator was high. For C. maculatus, germination of black eyed beans was approximately three times higher when both natural enemies were present. The combination of A. calandrae and X. flavipes is considered a promising component for integrated control of A. obtectus.     

气相色谱法测定黄瓜、苹果中的虫螨腈残留量

为了对虫螨腈在黄瓜和苹果上的残留分析方法进行探讨,采用乙腈提取、Flolisil 小柱净化、GC-μECD进行检测。结果表明：黄瓜上添加标准品0.005、0.01、0.5μg/g 的回收率分别为115.6%、86.4%、82.8%,相对标准偏差分别为2.6%、7.6%、9.2%;苹果上添加标准品0.005、0.1、0.5μg/g 的回收率分别为109.2%、95.9%、94.6%,相对标准偏差为8.0%、4.2%、7.6%;田间试验得到的虫螨腈在黄瓜的消解动态方程为y ＝0.0431e － 0.1665x,半衰期为4.2d;虫螨腈在苹果上的消解动态方程为y=0.1115e － 0.0734x,半衰期为9.4d。本方法灵敏度、准确度、精密度高,能够为大规模监测蔬菜水果中虫螨腈的残留情况提供参考。     

Enacting a technology-based science curriculum across a grade level: The journey of teachers' appropriation

Studying teacher enactment of an innovation helps us understand the process of effective spread of a curricular innovation to teachers who have differing levels of content readiness, pedagogical orientations, teaching competency, different student profiles, and professional development experiences. Towards this, we explore how different teachers in the same grade level appropriated a common science curriculum enabled by mobile technologies in their classrooms. The innovative science curriculum: Mobilized 5E (Engage–Explore–Explain–Elaborate–Evaluate) Science Curriculum was developed through an iterative cycle of design-based research. As curriculum designs were not self-sufficient by themselves, the enactments of the teachers differed in how they leveraged on students' artifacts, how they integrated the technology into the class, the ways in which they interacted with the students, and how they scaffolded students' activities in a mobile learning setting. In this study, the teachers' enactments of mobilized 5E lessons were observed, analyzed and compared, with the aim of exploring the differences of lesson enactment amongst them. The results showed that teachers' different pedagogical orientations affected their instructions, especially their ways of technology integration in the class, and their patterns of interactions with the students. Based on the exploration of the teacher enactment of the mobilized 5E curriculum, implications are drawn concerning the implementation of innovative curricula implementation and the supports for teacher professional development of such innovation with the ultimate purpose of sustaining and scaling.     

Identification of aflatoxin B1 on maize kernel surfaces using hyperspectral imaging

A shortwave infrared (SWIR) hyperspectral imaging system with wavelength range between 1000 and 2500 nm was used to assess the potential to detect aflatoxin B₁ (AFB₁) contaminants on the surface of healthy maize kernels. Four different AFB₁ solutions were prepared and deposited on kernels surface to achieve 10, 20, 100, and 500 ppb, respectively. A drop of 20% methanol was dipped on the surface of 30 healthy kernels in the same way to generate the control samples. Based on the standard normal variate (SNV) transformation spectra, principal components analysis (PCA) was used to reduce the dimensionality of the spectral data, and then stepwise factorial discriminant analysis (FDA) was performed on latent variables provided by the PCA's. Furthermore, beta coefficients of the first three of four discriminant factors were analyzed and key wavelengths, which can represent AFB₁ and be used to differentiate different level of AFB₁ were indentified. Furthermore, 150 independent samples were used as verification set to test the reproducibility of the proposed method. A minimum classification accuracy of 88% was achieved for the validation set and verification set. Results indicated that hyperspectral imaging technology, accompanied by the PCA-FDA method, can be used to detect AFB₁ at concentrations as low as 10 ppb when applied directly on the maize surface.