Analysis of sex pheromone production and field trapping of the Asian corn borer(Ostrinia furnacalis Guenée)in Xinjiang,China

Identifying the sex pheromone systems of local pest populations facilitates their management,especially for moth species that show significant geographic variation in sex pheromone communication.We investigated the pheromone production and behavioral responses of the Asian corn borer(Ostrinia furnacalis Guenée;ACB)in Xinjiang,China.The ACB produces three compounds:(Z)-12-tetradecenyl acetate(Z12-14:Ac)and(E)-12-tetradecenyl acetate(E12-14:Ac)which are two sex pheromone compounds,and n-tetradecyl acetate(14:Ac)which has variable roles in mediating behavioral responses.The ratios of these three compounds produced in female gland are geographically distinct among different populations.Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers(i.e.,Z and E12-14:Ac)and the proportions of 14:Ac in the ternary blend respectively averaged 60.46%(SD=5.26)and 25.00%(SD=7.37),with their probabilities normally or near-normally distributed.Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males,while other ratios that deviated from the gland ratios showed reduced field captures.The ternary blend was significantly more attractive to males than the E/Z isomers in the field,indicating a functional role of 14:Ac as the third pheromone component used by the local population.Additionally,the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350μg attracted significantly more males compared to other dosages.Therefore,the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang.

Effect of the Double Frequency of Trap Field in a Paul Trap

The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.

Density Calculation for NaCl-H_2O Solutions in the Liquid-Solid TwoPhase Field in NaCI-H_2O Three-Phase Inclusions

Three-phase NaCl-H_2O fluid inclusions featuring halite dissolution temperature（Tm）higher than vapor bubble disappearance temperature（T_h） are commonly observed in porphyry copper/molybdenum deposits,skarn-type deposits and other magmatic- hydrothermal ore deposits.Based on ｜ΔV_1｜（the absolute value of volume variation of NaCl-H_2O solution in a heating or cooling process of inclusions）= ｜ΔV_s｜（the absolute value of volume variation of the halite crystal in a heating or cooling process of inclusions） and on the principle of conservation of the mass of NaCl and H_2O,we systematically calculated the densities of NaCl-H_2O solutions in the solid-liquid two-phase field for temperatures（T_h） from 0.1℃ to 800℃ and salinities from 26.3 wt%to 99.2wt%.Consequently for the first time we obtained the upper limit of the density of NaCI-H_2O solutions in the solid-liquid twophase field for T_b〈T_m inclusions with variant salinities.The results indicate that for inclusions of the T_h〈T_m type with the same T_h,the higher the T_m or salinity is,the higher the density of the NaClsaturated solution will be.If a group of fluid inclusions were homogeneously trapped,they must have the same T_h value and the same T_m or salinity value.This may be used to distinguish homogeneous,inhomogeneous,and multiple entrapments of fluid inclusions.

Mechanical stress in high-temperature superconducting ring-shaped bulk during the pulsed-field magnetization

The high-temperature superconducting(HTS)bulk has a higher critical current density and can trap the larger magnetic field.When the high-temperature superconducting bulk is magnetized by the pulsed-field,it will be subjected to electromagnetic stress and thermal stress.Furthermore,the bulk may be damaged under larger mechanical stress or strain during the pulsed-field magnetization.In this paper,the electromagnetic field,the temperature and the mechanical response of the ring-shaped bulk are simulated based on the electromagnetic and mechanical governing equations,and the simulated trapped field is consistent with the experimental results given in the reference.The stress distribution on the top surface of the ring-shaped bulk during pulsedfield magnetization is opposite to the case of field cold magnetization.Moreover,the inner edge on the middle plane of the bulk may be broken more easily than the outer edge during the pulsed-field magnetization.Afterward,the influences of the size of the inner radius,ambient temperature and rise time of the applied field are presented.Finally,the mechanical stress of the bulk with the cooling process is investigated,and the tensile stress on the surface can be enhanced by the cooling process.

Non-thermal laser driven plasma-blocks for proton boron avalanche fusion as direct drive option

Fusion energy from protons reacting with ^(11) B,HB11,is extremely difficult or impossible when using thermal ignition by laser irradiation.This changes radically when using picosecond laser pulses with powers above petawatts dominated by nonlinear force driven ultrahigh ac-celeration of plasma blocks for a non-thermal initiation of igniting solid density HB11 fuel.For a cylindrical trapping of the reaction,laser produced ultrahigh magnetic fields above kiloTesla,have to be combined.The experimentally confirmed highly increased HB11 fusion gains due to avalanche reaction may lead to a scheme of an environmentally clean and economic power reactor.

Two-dimensional analytical model of double-gate tunnel FETs with interface trapped charges including effects of channel mobile charge carriers

A two-dimensional analytical model of double-gate（DG） tunneling field-effect transistors（TFETs） with interface trapped charges is proposed in this paper. The influence of the channel mobile charges on the potential profile is also taken into account in order to improve the accuracy of the models. On the basis of potential profile,the electric field is derived and the expression for the drain current is obtained by integrating the BTBT generation rate. The model can be used to study the impact of interface trapped charges on the surface potential, the shortest tunneling length, the drain current and the threshold voltage for varying interface trapped charge densities, length of damaged region as well as the structural parameters of the DG TFET and can also be utilized to design the charge trapped memory devices based on TFET. The biggest advantage of this model is that it is more accurate,and in its expression there are no fitting parameters with small calculating amount. Very good agreements for both the potential, drain current and threshold voltage are observed between the model calculations and the simulated results.

Jun Zheng,Minghui Wei,Siyi Quan,Yicheng Feng,Peng Wen State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,People’s Republic of China

This review paper summarizes and analyses the current literature on the synthesis of dense MgB_(2) bulk with high density and by both the modified solid reaction method and the Mg infiltration method.MgB_(2) bulk shows Telsa‐level magnetic field‐trapping ability in small volumes(1–5 cm^(3))at 15–20 K,which is beneficial for multiple applications,particularly where light weighting is beneficial.The review also compares the properties of MgB_(2) to rare earth barium cuprate bulk magnets and NbTi solenoid magnets and discuess potential applications such as magnetic lenses,compact NMR,and magnetic shielding.

Population divergence of aggregation pheromone responses in Ips subelongatus in northeastern China

The Asian larch bark beetle, Ips subelongatus, is considered to be the major pest of larch within its natural range. We investigated the electrophysiological and behavioral characteristics as well as mitochondrial DNA cytochrome oxidase subunit I sequences of L subelongatus from 13 geographic populations throughout northeastern China in order to explore population divergence of aggregation pheromone responses and the extent of potential genetic divergence. Electrophysiological analyses showed that antennae of I. sube-longatus from all the six tested populations responded strongly to （S）-（-）-ipsenol （100% detection; 0.35-0.73 mV） in gas chromatography （GC）-electroantennographic detection （EAD） analyses, while its antipode, （R）-（＋）-ipsenol was antennally inactive. I. subelon- gatus populations varied in their responses to （R）-（-）- and （S）-（＋）-ipsdienol in GC-EAD analyses. Behavioral bioassays demonstrated that （S）-（-）-ipsenol alone was significantly attractive at all the tested sites, supporting its status as a key pheromone component of L subelongatus, whereas （S）-（＋）-ipsdienol was inactive alone. Adding （S）-（＋）-ipsdienol to （S）-（-）-ipsenol did not have any effect on the trap catches from some populations in Inner Mongolia. However, （S）-（＋）-ipsdienol showed a strong synergistic effect on （S）-（-）- ipsenol from several populations in Jilin and Liaoning Provinces, and a weak synergistic effect from some transition populations in Heilongjiang Province. Furthermore, 27 mito- chondrial haplotypes were found among the 13 populations （intraspecific nucleotide di- vergence, 0.1%-1.1%）. Analyses of molecular variance and haplotype networks indicated that different geographic populations have developed some genetic variation but did not form completely independent groups. From an applied point of view, a universal synthetic binary blend ofracemic ipsenol and （S）-（＋）-ipsdienol might have a potential for monitoring or even mass-trapping of I. subelongatus across northeastern China, even though some populations only use （S）-（-）-ipsenol alone as their active pheromone component.