Impact of Crop Rotation on Pathotype and Genetic Structure of Phythophthora sojae in Fields

To estimate the impact of crop rotation on the pathotype and genetic structure of Phythophthora sojae in fields, 372 isolates of P. sojae were obtained from long-term localisation experimental fields in Heilongjiang Province of China. The hypocotyl inoculation method was used to characterize the virulence of P. sojae on 13 differential cultivars, and the amplified fragment length polymorphism（AFLP） technique was used to analyze difference in the genetic structure of P. sojae. The results indicated that an abundant diversity of genetic structures and pathotypes of P. sojae, a more uniform distribution of pathotypes and less dominance of pathotypes occurred in corn-soybean and wheat-soybean rotation fields than in a continuous soybean mono-cropping field. These findings suggested that P. sojae did not easily become the dominant race in rotation fields, which maintain disease resistance in soybean varieties. Therefore, the results of this study suggested that Phytophthora stem and root rot of soybeans could be effectively controlled by rotating soybeans with non-host crops of corn and wheat.

NUMERICAL ANALYSIS OF BIFURCATION BUCKLING FOR ROTATIONALLY PERIODIC STRUCTURES UNDER ROTATIONALLY PERIODIC LOADS

By considering the characteristics of deformation of rotationally periodic structures under rotationally periodic loads, the periodic structure is divided into some identical substructures in this study. The degrees-of-freedom (DOFs) of joint nodes between the neighboring substructures are classified as master and slave ones. The stress and strain conditions of the whole structure are obtained by solving the elastic static equations for only one substructure by introducing the displacement constraints between master and slave DOFs. The complex constraint method is used to get the bifurcation buckling load and mode for the whole rotationally periodic structure by solving the eigenvalue problem for only one substructure without introducing any additional approximation. The finite element (FE) formulation of shell element of relative degrees of freedom (SERDF) in the buckling analysis is derived. Different measures of tackling internal degrees of freedom for different kinds of buckling problems and different stages of numerical analysis are presented. Some numerical examples are given to illustrate the high efficiency and validity of this method.

Discussion on rotational tectonic stress field and the genesis of circum-Ordos landmass fault system

When the resultant of applied forces does not pass through the center of an active landmass, the landmass will rotate, giving rise to a rotational tectonic stress field. The motion of a fault along the principal stress plane is de-termined by the mechanic features of the plane. Tensile fractures occur on the faults in the direction of the principal extensional stress plane, and fault-depression basins will be formed under a long-term action. Thrusting and over-thrusting occur on faults in the direction of the principal compressional stress plane, or folds may be formed as a result. Information on geology shows that the North China landmass, which remained stable and intact for a long time, became disjointed in the Eogene period. In the course of disjunction, anticlockwise rotation took place in the Shanxi-Hebei-Shaanxi (Jin-Ji-Shan) landmass, giving rise to the fault-depression system in its periphery. In the Pliocene epoch the landmass lost stability and its eastern boundary moved westward. As a result, the Shanxi gra-ben system appeared and Ordos landmass was formed. Structural and mechanic features of the main faults around Jin-Ji-Shan landmass can be explained with principal stress plane of a rotational tectonic stress field.

High Spin Structure in ^(106)Pd

The high spin states of 106pd have been populated through the 100Mo（11B, lp4n）106Pd reaction using a beam energy of 60 MeV provided by the Beijing HI-13 tandem accel- erator at China Institute of Atomic Energy. By analyzing the V-3＇ coincidence relation and DCO raios of transitions, 3 rotational bands with 13 new states and 22 new 7 transitions belonging to 106pd were constructed. Bands 2 and 3 with negative parity were supposed to build on the vh1l/297/2 and vh11/2ds/2 configuration, respectively.

Numerical simulation of water-slag elbow erosion-inhibiting by regulating the slag injection position with a novel preceding rotating sheet structure

The elbow erosion seriously jeopardizes the safe and stable operation of water–slag discharge pipeline of the coal gasification system.This work simulated water–slag elbow characteristics with various slag injection positions by simulating five simplified and representative erosion categories,including A-type horizontal-vertical elbow with an upstream flow,B-type horizontal-vertical elbow with a downstream flow,C-type vertical-horizontal elbow with an upstream flow,D-type vertical-horizontal elbow with a downstream flow and E-type horizontal-horizontal elbow.Compared with the C/D-type elbow,where particles were injected uniformly,the A-type elbow and E-type elbow were found to increase erosion rate,while the B-type elbow decreases erosion rate.An interesting discovery is that the elbow erosion rate is relatively low for small particles when particles are injected from the middle and bottom positions of the inlet section of the elbow.Based on the observation,a novel preceding rotating sheet structure was developed to regulate the particle injection position.It shows an excellent anti-erosion performance by reducing the maximum erosion rate of particles with diameters of 50,100,and 200μm by 23%,35%,and 43%,respectively.

Gradient Structured Copper by Rotationally Accelerated Shot Peening

A new technology-rotationally accelerated shot peening（RASP）, was developed to prepare gradient structured materials. By using centrifugal acceleration principle and large steel balls, the RASP technology can produce much higher impact energy compared to conventional shot peening. As a proof-of-concept demonstration, the RASP was utilized to refine the surface layer in pure copper（Cu） with an average grain size of 85 nm. The grain size increases largely from surface downwards the bulk, forming an800 ？m thick gradient-structured surface layer and consequently a micro-hardness gradient. The difference between the RASP technology and other established techniques in preparing gradient structured materials is discussed. The RASP technology exhibits a promoting future for large-scale manufacturing of gradient materials.

Numerical study on three-dimensional flow field of continuously rotating detonation in a toroidal chamber

Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.

Triaxial Shape, Signature Splitting, and Shape Coexistence in ^(127,129,131)Nd

Signature splitting and shape coexistence at high spin in the neutron deficient nucleus ^129Nd are investigated with the configuration-dependent cranked Nilsson-Strutinsky approach. The calculated bands are compared with the observed signature partner bands and very good agreement results at high spin are obtained. The observed deformed bands are confirmed as normal and highly deformed and their properties are explained theoretically. Terminating states in ^129Nd and other terminations are predicted. There is shape coexistence within the same configuration from lowspin states to high-spin states. Possible normal and highly deformed bands with rotation around the intermediate principal axis in several interesting configurations of ^129Nd are discussed. The experimental results for ^131Nd are simply discussed and the calculated bands are in good agreement with observed bands at high spin. TriaxiM shapes in ^127 Nd with a triaxial deformation of γ -12° are predicted and should be observed experimentally. The value of negative γ of π（h11/2）^4v（h11/2）^7 configuration increases with neutron number increasing in ^127,129,131Nd. The triaxial shape evolutions with neutron number increasing in ^127,129,131Nd and in ^126,128,130,132pr are explained by the strong driving force of specified single particle orbitals towards to triaxial shape.

Energy Absorption Characteristics of a Novel Asymmetric and Rotatable Re-entrant Honeycomb Structure

Based on the symmetric re-entrant honeycomb(S-RH)structure with negative Poisson’s ratios,a novel asymmetric and rotatable re-entrant honeycomb(AR-RH)structure was proposed.Both the S-RH structure and AR-RH structure were produced by the 3D printing technology.Through experimental test and finite element simulation,the deformation mechanism and energy absorption characteristics of the AR-RH structure and the S-RH structure with negative Poisson’s ratios at different impact velocities were compared.The experimental test and finite element simulation results show that the novel AR-RH structure with negative Poisson’s ratios has stronger energy absorption capacity than the S-RH structure,and it has been verified that the rotatability of AR-RH can indeed absorb energy.Furthermore,the degree of asymmetry of the AR-RH structure was discussed.

Synthesis,characterization,and phase transition of an inorganic-organic hybrid compound,[(3-nitroanilinium^＋)(18-crown-6)][IO4^-](CH3OH)

A novel inorganic-organic hybrid supramolecular compound,[（3-nitroanilinium^＋）（18-crown-6）][IO4]（CH3OH）（1）,was discovered as phase-transition materials displaying dielectric anomalous behaviors.The yellow block crystal formed by N-H…O hydrogen bonding that made contact through the cavity of 18-crown-6 was characterized by single-crystal X-ray diffraction,elemental analysis,infrared analysis,thermogravimetric analysis,differential scanning calorimetry,and potential-energy calculations.Differential scanning calorimetry measurements indicate that the compound experiences a reversible phase transition at around 220 K.Temperature-dependent dielectric measurements further confirm the phase transitions.Potential-energy calculations demonstrate that the phase transition occurs due to the molecular order-disorder rotation of CH3OH,whereas the space grouping of the crystal remains unchanged.