Contact Activity of Combination Use of Three Kinds of Plant Extracts on Helicoverpa armigera

[Objectives] The aim was to study the contact activity of combination use of garlic,onion and stone calamus extracts on Helicoverpa armigera and their co-toxicity coefficient( CTC) and mixture ratio. [Methods] Leaf dipping method was used to study the contact activity of the three kinds of plant extracts against H. armigera. Based on this,the co-toxicity coefficient of the compound of the three kinds of extracts was determined. Orthogonal test was used to explore the optimal mixture ratio of the three kinds of extract for combination use. [Results]The extracts of garlic,onion and stone calamus had good inhibition and contract activity on H. armigera larvae. The LC50 values of the three kinds of plant extracts against H. armigera were 175. 0,217. 0 and 79. 2 mg/L,respectively. When the mixture ratios of stone calamus to garlic,and stone calamus to onion were both 2:1,the extract showed a synergistic effect( CTC > 120); when the mixture ratios of stone calamus to garlic,and stone calamus to onion were 1:1 and 1:2,respectively,the extracts showed an additive effect( 80 < CTC < 120); and then garlic extract and onion extract were mixed according to the ratio of 1:1,the additive effect was slight( CTC < 90). Among the three kinds of extracts,the extract of stone calamus showed the strongest contact activity,followed by that of garlic. The results of co-toxicity coefficient determination and orthogonal test showed that the contact activity of combination use of the three kinds of extracts was stronger than that of the single extract overall. When the extracts of garlic,onion and stone calamus were mixed according to the ratio of 2:3:1( mass concentration ratio),the contact activity of the compound against H. armigera reached 95. 3%. [Conclusions]The study results provide a scientific basis and theoretical reference for the development of new plant-derived pesticides based on the pharmacodynamics of garlic,onion and stone calamus.

Retrieval of Sea Surface Height from CYGNSS Data with Tropospheric Delay

An analysis of the delay Doppler maps(DDMs) data from the CYGNSS satellites is implemented to derive the sea surface height(SSH). An SSH estimation algorithm, the leading edge derivation(LED) method which is applied to the delay waveforms, is applied to the DDMs, while the tropospheric delay methods, the Saastamoinen method(SM)and the numerical method(NM) are used. The results show that when the SSH from Jason-2 is referred to as the truth, if the tropospheric delay is corrected, the SSH bias can decrease. The resulted SSH bias from the Jason-2 SSH by the LED retrieval method is of order meter. The resulted SSH deviation from the truth by the NM scheme is half as small as that by the SM scheme. Since the SM scheme is not applicable to the nonhydrostatical condition, the resulted bias is larger.The work can be applied to the Beidou system in the future.

Configuration interaction studies on the spectroscopic properties of PbO including spin-orbit coupling

Lead oxide（Pb O）, which plays the key roles in a range of research fields, has received a great deal of attention. Owing to the large density of electronic states and heavy atom Pb including in Pb O, the excited states of the molecule have not been well studied. In this work, high level multireference configuration interaction calculations on the low-lying states of Pb O have been carried out by utilizing the relativistic effective core potential. The effects of the core-valence correlation correction, the Davidson modification, and the spin–orbital coupling on the electronic structure of the Pb O molecule are estimated. The potential energy curves of 18 Λ-S states correlated to the lowest dissociation limit（Pb（~3P_g） ＋ O（~3P_g）） are reported. The calculated spectroscopic parameters of the electronic states below 30000 cm^（-1）, for instance, X^1Σ~＋, 1~3Σ~＋,and 1~3Σ^-, and their spin–orbit coupling interaction, are compared with the experimental results, and good agreements are derived. The dipole moments of the 18 Λ-S states are computed with the configuration interaction method, and the calculated dipole moments of X^1Σ~＋and 1~3Σ~＋are consistent with the previous experimental results. The transition dipole moments from 1~1Π, 2~1Π, and 2~Σ to X^1Σ~＋and other singlet excited states are estimated. The radiative lifetime of several low-lying vibrational levels of 1~1Π, 2~1Π, and 2~1Σ~＋ states are evaluated.

FABRICATION OF PIEZOELECTRIC BIMORPH USING LEAD ZIRCONATE TITANATE THIN FILM DEPOSITED BY HYDROTHERMAL METHOD

In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary （MPB）. LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.

Measuring flow velocity on frozen and non-frozen slopes of black soil through leading edge method

Flow velocity is a major parameter related to hillslope hydrodynamics erosion.This study aims to measure flow velocity over frozen and non-frozen slopes through leading edge method before being calibrated with accurate flow velocity to determine the correct coefficient for convenience of flow velocity measurement.Laboratory experiments were conducted on frozen and non-frozen soil slopes with flumes involving four slope gradients of 5°,10°,15°,and 20°and three flow rates of 1,2,and 4 L/min with a flume of 6 m long and 0.1 m wide.The measurements were made with a stopwatch to record the time duration that the water flow ran over the rill segments of 2,4 and 6 m long.Accurate flow velocity was measured with electrolyte trace method,under pulse boundary condition.The leading edge and accurate flow velocities were used to determine the correction coefficient to convert the former to the latter.Results showed that the correction coefficient on frozen soil slope was 0.81 with a coefficient of determination(R2)of 0.99.The correction coefficient on non-frozen soil slope was 0.79 with R2 of 0.98.A coefficient of 0.8 was applicable to both soil surface conditions.The accurate velocities on the four frozen black soil slopes were approximately 30%,54%,71%,and 91%higher than those on non-frozen soil slopes.By contrast,the leading edge flow velocities on the frozen soil slopes were 23%,54%,67%,and 84%higher than those on non-frozen soil slopes.The flow velocities on frozen soil slopes increased with flow rate at all four slopes,but they increased from 5 to 15°before getting stabilized.Therefore,rill flow velocity can be effectively measured with leading edge method by multiplying the leading edge velocity with a correction coefficient of 0.80.This study provides a strategy to measure rill flow velocity for studies on soil erosion mechanisms.