Ningxia Entry Exit Inspection and Quarantine Bureau

Yinchuan, China

Ningxia Entry Exit Inspection and Quarantine Bureau

Yinchuan, China
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Zhu M.-M.,Ningxia Academy of Agricultural science | Cai F.-H.,Ningxia Entry Exit Inspection and Quarantine Bureau | Zhang R.,Ningxia Academy of Agricultural science | Zhang Y.,Ningxia Academy of Agricultural science | And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2010

Based on geographic information system (GIS) and geostatistical analysis, this paper studied the spatial structure of Aphis gossipii Glover population in Xiangshan District of Zhongwei City, Ningxia Province, with the spatial distribution of the population simulated by ordinary Kriging interpretation. The spatial structure of A. gossipii population varied with its occurrence stage (initial, blossom, and final stage). The semivariograms of A. gossipii could be described by exponential or Gaussian model, indicating that A. gossipii had an aggregated spatial arrangement. The aggregation degrees at different occurrence stages were all beyond 45%, and the spatial correlation ranged from 10.37 km to 29.11 km. The spatial variance was greatly affected by spatial autocorrelation. The population dynamics of A. gossipii at its different occurrence stages could be easily analyzed and intuitively simulated from the two aspects of time and space by spatial distribution simulation, and thus, the occurrence position and degree of A. gossipii could be easily determined.


Li B.,Chinese Academy of Agricultural Sciences | Cao X.,Chinese Academy of Agricultural Sciences | Cao X.,Chinese Academy of Sciences | Chen L.,Ningxia Entry Exit Inspection and Quarantine Bureau | And 8 more authors.
Plant Disease | Year: 2013

Blumeria graminis f. sp. tritici, the pathogen that causes wheat powdery mildew, can oversummer as mycelia or conidia on leaves of volunteer wheat plants in cool mountainous areas in China. In this study, the regions in China where B. graminis f. sp. tritici can oversummer were identified on the basis of the probability that temperature remains below a critical temperature that is lethal to B. graminis f. sp. tritici. Two methods, one describing the relationship between the average temperature (20 to 26°C) in a given continuous 10-day period and wheat powdery mildew severity, the other describing the relationship between the average temperature (26 to 33°C) and the number of lethal days on powdery mildew development, were used to calculate the oversummering probability using weather data for 743 sites across China. Spatial interpolation based on the ordinary kriging method was conducted for the regions without observation. Oversummering probability values were similar for most locations estimated between the two methods. The B. graminis f. sp. tritici oversummering regions in China were identified to be in mountainous or high-elevation areas, including most regions of Yunnan, west and central areas of Guizhou, south and northwest Sichuan, south and east Gansu, south Ningxia, north and west Shaanxi, central-north Shanxi, west Henan and Hubei, and some regions in Qinghai, Tibet, and Xinjiang. When the oversummering sites from this study were compared with observed survey data for some of these sites, about 90% of sites where B. graminis f. sp. tritici oversummering was observed had been found suitable by both methods. The coincidence frequency and the area under the receiver operating characteristic curve for model 2 were higher, albeit only slightly, than those for model 1. Thus, both methods may be used to assist in disease management and further investigation on pathogen oversummering. © 2013 The American Phytopathological Society.


Zhang Y.,Northeast Normal University | Sun J.,Northeast Normal University | Chao K.,Ningxia Entry Exit Inspection and Quarantine Bureau | Sun H.,Northeast Normal University | And 6 more authors.
Journal of Physical Chemistry A | Year: 2012

The potential energy surfaces of the CF 3CH=CH 2 + OH reaction have been investigated at the BMC-CCSD level based on the geometric parameters optimized at the MP2/6-311++G(d,p) level. Various possible H (or F)-abstraction and addition/elimination pathways are considered. Temperature- and pressure-dependent rate constants have been determined using Rice-Ramsperger-Kassel-Marcus theory with tunneling correction. It is shown that IM1 (CF 3CHCH 2OH) and IM2 (CF 3CHOHCH 2) formed by collisional stabilization are major products at 100 Torr pressure of Ar and in the temperature range of T < 700 K (at P = 700 Torr with N 2 as bath gas, T -900 K), whereas CH 2=CHOH and CF 3 produced by the addition/elimination pathway are the dominant end products at 700-2000 K. The production of CF 3CHCH and CF 3CCH 2 produced by hydrogen abstractions become important at T -2000 K. The calculated results are in good agreement with available experimental data. The present theoretical study is helpful for the understanding the characteristics of the reaction of CF 3CH=CH 2 + OH. © 2012 American Chemical Society.


Zhang Y.,Northeast Normal University | Sun J.,Northeast Normal University | Chao K.,Ningxia Entry Exit Inspection and Quarantine Bureau | Wang F.,Northeast Normal University | And 6 more authors.
Computational and Theoretical Chemistry | Year: 2012

The complex potential energy surfaces for the reaction of atomic radical F with CH 2CHCH 2Cl (3-chloropropene) are explored at the CCSD(T)/cc-pVTZ//MP2(full)/6-311++G(d,p) level. There are various possible reaction pathways including the addition-elimination and H-abstraction reaction. Among them, the most feasible pathway should be to produce P1 (CH 2CHCH 2F+Cl), which is in good agreement with the experiment. Among the H-abstraction reactions, the most competitive pathway is the atomic radical F abstracting hydrogen atom from allylic group. Because all of the transition states and intermediates involved in the title reaction lie below the reactants, the F+CH 2CHCH 2Cl reaction is expected to be rapid. The present results could lead us to deeply understand the mechanism of the title reaction and may provide some useful information for future experimental investigation of the title reaction. © 2011 Elsevier B.V.


Zhou H.,Chinese Academy of Agricultural Sciences | Chen L.,Ningxia Entry Exit Inspection and Quarantine Bureau | Chen J.,Chinese Academy of Agricultural Sciences | Francis F.,University of Liège | And 4 more authors.
Agroecology and Sustainable Food Systems | Year: 2013

The use of intercropping as a strategy for increasing biodiversity in fields has the potential to reduce pest damage and improve the crop production. Here, a study was undertaken to evaluate the role of different wheat-pea intercropping patterns in conserving arthropod natural enemies and suppressing cereal aphids in agroecosystems. Wheat-pea intercropping in an 8-2 row pattern of wheat and pea, respectively, preserved and augmented natural enemies more than a monoculture of wheat. The highest abundance of ladybeetles in 2008 and 2009 occurred in the 8-2 row pattern, whereas the highest densities of aphid parasitoids were found in the 4-2 row pattern in 2008 and the 8-2 row pattern in 2009. The distribution of aphid populations in the peak stage was spatially heterogeneous, and the highest density of aphids was shown visually in wheat monoculture fields. The land equivalent ratio of 1.121:1.187 for wheat-pea intercropping in 2008 and 1.114:1.174 for wheat-pea intercropping in 2009 showed that intercropping of wheat and pea has potential to improve the utilization of plant growth resources as compared to sole crops. Wheat-pea intercropping has potential to control English grain aphids effectively by enhancing the abundance of natural enemies, especially with an 8-2 row pattern of wheat-pea, respectively. © Taylor & Francis Group, LLC.


Zhang Y.,Northeast Normal University | Chao K.,Ningxia Entry Exit Inspection and Quarantine Bureau | Sun J.,Hubei Normal University | Zhang W.,Northeast Normal University | And 6 more authors.
Journal of Chemical Physics | Year: 2014

The reaction of allyl chloride with the hydroxyl radical has been investigated on a sound theoretical basis. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for important pathways in detail. The reaction mechanism confirms that OH addition to the C=C double bond forms the chemically activated adducts, IM1 (CH 2CHOHCH2Cl) and IM2 (CH2OHCHCH2Cl) via low barriers, and direct H-abstraction paths may also occur. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants. The calculated rate constants are in good agreement with the experimental data. At 100 Torr with He as bath gas, IM6 formed by collisional stabilization is the major products in the temperature range 200-600 K; the production of CH2CHCHCl via hydrogen abstractions becomes dominant at high temperatures (600-3000 K). © 2014 AIP Publishing LLC.


Zhang Y.,Northeast Normal University | Chao K.,Ningxia Entry Exit Inspection and Quarantine Bureau | Pan X.,Northeast Normal University | Zhang J.,Northeast Normal University | And 2 more authors.
Journal of Molecular Graphics and Modelling | Year: 2014

Potential energy surface for the reaction of hydroxyl radical (OH) with 3-fluoropropene (CH2CHCH2F) has been studied to evaluate the reaction mechanisms, possible products and rate constants. It has been shown that the CH2CHCH2F with OH reaction takes place via a barrierless addition/elimination and hydrogen abstraction mechanism. It is revealed for the first time that the initial step for the barrierless additional process involves a pre-reactive loosely bound complex (CR1) that is 1.60 kcal/mol below the energy of the reactants. Subsequently, the reaction bifurcates into two different pathways to form IM1 (CH2CHOHCH 2F) and IM2 (CH2OHCHCH2F), which can decompose or isomerize to various products via complicated mechanisms. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants and branching ratios. At atmospheric pressure with He as bath gas, IM1 formed by collisional stabilization is dominated at T ≤ 600 K; whereas the direct hydrogen abstraction leading to CH2CHCHF and H2O are the major products at temperatures between 600 and 3000 K, with estimated contribution of 72.9% at 1000 K. Furthermore, the predicted rate constants are in good agreement with the available experimental values. © 2013 Elsevier Inc.


Zhang Y.,Northeast Normal University | Chao K.,Ningxia Entry Exit Inspection and Quarantine Bureau | Sun J.,Hubei Normal University | Su Z.,Northeast Normal University | And 3 more authors.
Journal of Physical Chemistry A | Year: 2013

The complex potential energy surface of allyl alcohol (CH 2CHCH2OH) with hydroxyl radical (OH) has been investigated at the G3(MP2)//MP2/6-311++G(d,p) level. On the surface, two kinds of pathways are revealed, namely, direct hydrogen abstraction and addition/elimination. Rice-Ramsperger-Kassel-Marcus theory and transition state theory are carried out to calculate the total and individual rate constants over a wide temperature and pressure region with tunneling correction. It is predicted that CH 2CHOHCH2OH (IM1) formed by collisional stabilization is dominate in the temperature range (200-440 K) at atmospheric pressure with N2 (200-315 K at 10 Torr Ar and 100 Torr He). The production of CH2CHCHOH + H2O via direct hydrogen abstraction becomes dominate at higher temperature. The kinetic isotope effect (KIE) has also been calculated for the title reaction. Moreover, the calculated rate constants and KIE are in good agreement with the experimental data. © 2013 American Chemical Society.


PubMed | Ningxia Entry Exit Inspection and Quarantine Bureau, Laboratory of Food, Guilin University of Technology and Nanjing University of Technology
Type: Journal Article | Journal: Se pu = Chinese journal of chromatography | Year: 2014

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of five pyrrolizidine alkaloids (PAs) (monocrotaline, senkirkine, retrorsine, seneciphylline and senecionine) in honey. The honey samples were dissolved in 0.1 mol/L hydrochloric acid solution and a strong-cation exchange column was used to purify and concentrate the target analytes. The separation of the analytes was carried out on a Phenomenex C18 column (100 mm x 4.6 mm, 2.6 microm) using the mobile phases of acetonitrile and 5 mmol/L ammonium acetate-0.1% (volume percentage) formic acid aqueous solution with gradient elution. The separated compounds were detected in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI+). The calibration curves were of good linearity in the range of 1-100 microg/L (r > 0.99). The limit of quantification of the method was 1.0 microg/kg. The average recoveries were between 73.1% to 107.1% at three spiked levels (1, 20 and 50 microg/kg) with the relative standard deviations (RSDs) in the range of 4.1% to 17.0%. The proposed method was applied to different kinds of honey from China, New Zealand, Spain and Australia. The samples included rape, vitex, sunflower, cotton, tilia tree, date, acacia, buckwheat, manuka and eucalyptus honey. Monocrotaline, senkirkine and retrorsine were not detected in the collected honey samples. However, seneciphylline and senecionine were found in most of the honey samples. The concentrations of seneciphylline and senecionine were 11.0 -31.1 microg/kg and 8.3-29.1 microg/kg, respectively.


PubMed | Ningxia Entry Exit Inspection and Quarantine Bureau and Northeast Normal University
Type: | Journal: Journal of molecular graphics & modelling | Year: 2014

Potential energy surface for the reaction of hydroxyl radical (OH) with 3-fluoropropene (CHCHCHF) has been studied to evaluate the reaction mechanisms, possible products and rate constants. It has been shown that the CHCHCHF with OH reaction takes place via a barrierless addition/elimination and hydrogen abstraction mechanism. It is revealed for the first time that the initial step for the barrierless additional process involves a pre-reactive loosely bound complex (CR1) that is 1.60 kcal/mol below the energy of the reactants. Subsequently, the reaction bifurcates into two different pathways to form IM1 (CHCHOHCHF) and IM2 (CHOHCHCHF), which can decompose or isomerize to various products via complicated mechanisms. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants and branching ratios. At atmospheric pressure with He as bath gas, IM1 formed by collisional stabilization is dominated at T600 K; whereas the direct hydrogen abstraction leading to CHCHCHF and HO are the major products at temperatures between 600 and 3000 K, with estimated contribution of 72.9% at 1000 K. Furthermore, the predicted rate constants are in good agreement with the available experimental values.

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