Effective accumulated temperature and developmental threshold temperature for Semanotus bifasciatus(Motschulsky) in Beijing

In order to understand the occurrence and development of Semanotus bifasciatus （Motschulsky）, a borer insect of Platycladus orientalis in parts of northern and eastern China and to improve its prediction, the developmental threshold temperature （C1） and effective accumulated temperature （K） of S. bifasciatus were determined under conditions of constant and variable temperatures. The results show that under constant temperatures the value of C1 has a range of 8.90±1.77℃and the value of K lies between 95.19±13.14 degree-day for eggs; the values for larvae are C1= 13.26±3.06℃ and the number of degree-day is K 2,885.07±187.87 degree-day; for pupae the ranges are C1 = 8.93±2.49℃ and K= 131.20±25.63 degree-day. Under the condition of ambient temperatures, the values for eggs are C1= 17.33±1.24℃ and K= 70.79±8.99 degree-day. It is suggested that S. bifasciatus adults over-winter in a state of dormancy, not at a diapause. Warm winter may accelerate the life cycle ofS. bifasciatus. Equations can be used to predict an early occurrence ofS. bifasciatus.

Experimental study on the accumulative effect of multiple pulses on acceleration sensor

Intentional electromagnetic interference is a serious threat to the safety of electronic devices. Multiple electromagnetic pulses will be coupled and transmitted to electronic devices through the cables.Accumulative effects are generated, which make it easier for damage to occur in the electronic devices. In this article, the working principle of micro-silicon acceleration sensors is introduced. The accumulative effects of multiple pulses on acceleration sensors is studied by a large number of injection experiments.The accumulation trends of multiple pulses with different pulse numbers and intervals are analyzed. The damaged structures inside abnormal sensor amplifiers were observed via optical microscopy and scanning electron microscopy. The experimental results show that the accumulative effect is strengthened with increased pulse number or decreased pulse interval, and the threshold voltage for multiple pulses on the acceleration sensor decreases. The threshold voltage for a single pulse is 321.57 V. When the pulse interval is 1 μs and the pulse number is 5, the threshold voltage for multiple pulses is 163.42 V,which is reduced by 49.12% compared with a single pulse. These results provide a reference for the damage design of electromagnetic pulse weapons.

Payoff-based accumulative effect promotes cooperation in spatial prisoner’s dilemma

We study the effect of accumulative payoff on the evolution of cooperation in the evolutionary prisoner＇s dilemma on a square lattice. We introduce a decaying factor for the accumulative payoff, which characterizes the extent that the historical payoff is accumulated. It is shown that for fixed values of the temptation to defect, the density of cooperators increases with the value of the decaying factor. This indicates that the more the historical payoff is involved, the more favourable cooperators become. In the critical region where the cooperator density converges to zero, cooperators vanish according to a power-law-like behaviour. The associated exponents agree approximately with the two-dimensional directed percolation and depend weakly on the value of the decaying factor.

Study on Accumulative Effect of Enterprise Symbiotic Space in Agricultural Circular Economy

Enterprise symbiotic behavior is one of the main inter-finn organizational modes in agricultural circular economy, and the importance of its accumulative effect of enterprise symbiotic space is no less than its industry dimensionality. Based on this point, this article firstly started fi＇om the space factor and the symbiotic relationship and spatial clusters of the agricultural enterprise were analyzed, accordingly the clusters＇ analysis framework was introduced. And then the cost model, learning curve and the knowledge stock change were set up and the accumulative mechanism of a rational agricultural enterprise in the symbiotic space was discussed. Therefore, a further analysis on all kinds of accumulative effects of agricultural enterprise was carried on. Finally, we got conclusions fi＇om three aspects in this article; meanwhile, we obtained the enlightenment for the related enterprises in light of the reality.

Developmental Threshold Temperature and Effective Accumulated Temperature of Potosia brevitarsis Lewis

[ Objective] The paper was to study the relationship between temperature and development of Potosia brevitarsis Lewis. [ Methods] Six constant tem- peratures （21, 24, 27, 30, 33 and 36 ℃ ） were set in the laboratory to study developmental threshold temperature and effective accumulated temperature of P. brevitarsis. [ Result] The developmental durations of various states of P. brevitarsis were shortened with the increasing temperature ranged from 21 ℃ to 36 ℃ ; the developmental rates were accelerated with the increasing temperature. The developmental threshold temperatures of egg, larva, pupa and pre-ovipesition of adult were estimated to be 12.79, 9.15, 14.86 and 13.80 ℃, respectively; the effective accumulated temperature were 136.25, 3 031.31,308.92 and 98.35 d · ℃, respectively. The developmental threshold temperature and effective amcumulated temperature for one complete generation were 9.96 ℃ and 3 628.73 d · ℃, re- spectively. Combined with meteorological data, the theoretical generation number of P. brevitarsis occurred in Shihezi was presumed to be one per year, which was basically coincided with actual occurrence generations in fields. [ Conclusion] The paper provided theoretical basis for effective control against P. brevitarsis.

Effects of temperatures on the development and reproduction of the armyworm, Mythimna roseilinea: Analysis using an age-stage, two-sex life table

The armyworm Mythimna roseilinea（Walker） is a major pest of grain crops in South China. So far little is known about its basic biology and ecology, making prediction of population dynamics difficult. This study examined the relationships of individual development and population growth with temperature based on an age-stage, two-sex life table of M. roseilinea reared on maize in the laboratory at 18, 21, 24, 27 and 30℃. The highest values of net reproductive rate（R_0） and fecundity were observed at 21 and 24℃, respectively. Both the intrinsic rate of increase（r） and finite rate of increase（λ） increased significantly and mean generation time（T） decreased significantly with increasing temperature. M. roseilinea was able to develop, survive and lay eggs at all temperature regimes tested. Development rates of the egg, larval, pupal, as well as the whole pre-oviposition stages had a positive linear relationship with temperature. The calculated development threshold temperatures of egg, larval, pupal, pre-oviposition and total pre-oviposition stages were 13.29, 8.39, 14.35, 7.42, and 12.24℃, respectively, and their effective accumulated temperatures were 63.59, 445.00, 211.11, 89.02, and 698.95 degree-days, respectively. These results provide insight into temperature-based phenology and population ecology of this insect pest and will allow population prediction and management available in the field.

Effects of Overpressured Fluid Flow on Petroleum Accumulation in the Yinggehai Basin

The Yinggehai Basin is a strongly overpressured Cenozoic basin developed in the northern continental shelf of the South China Sea. The flow of overpressured fluids in this basin has given rise to strong effects on petroleum accumulation. (1) The overpressured fluid flow has enhanced the maturation of shallow-buried source rocks, which has caused the source rocks that would have remained immature under the conduction background to be mature for hydrocarbon generation. As a result, the overpressured fluid flow has increased the volume and interval of mature source rocks. (2) The overpressured fluid flow has strong extraction effects on the immature or low-mature source rocks in the shallow parts. This has increased, to some extent, the expulsion efficiency of the source rocks. More importantly, the extraction effects have strongly limited the effectiveness of biomarker parameters from oil and condensate in reflecting the source and maturity of the oil and gas. (3) The flow has caused the sandstones in the shallow parts to get into the late diagenesis stage, and significantly reduced the porosity and permeability of the sandstones. This study confirms that even in sedimentary basins in which no topography-driven groundwater flow systems have ever developed, the cross-formation migration of overpressured fluids and the resultant energy conduction and material exchange can significantly affect the thermal regime, source rock maturation and sandstone diagenesis. As a result, the effects of overpressured fluid flow must be taken into account in analyzing the mechanism of petroleum accumulation.

Effect of Austenite Recrystallization on Microstructure and Properties of Q345 Steel

The Q345 plate steel austenite recrystallization behavior and strain accumulation during rolling were investigated through thermal simulation and rolling. The effect of the recrystallization behavior on the microstructure and properties of the steel was discussed and analyzed. The control principles of the pass reduction in the austenite recrystallization region and partial recrystallization region were established. It is found that to increase the thickness of intermediate billet in the finish temperature interval of 880-820℃ is favorable to grain refinement. The result has been applied to the industrial production of the 3 500 mm plate mill of Shougang Group. The average grain size of the steel plate conforms to ASTM No. 10-12, and the grade of band structure has been reduced to below 1.5.

Controlling factors of marine shale gas differential enrichment in southern China

Based on the exploration and development practice of marine shale gas in Fuling, Weiyuan, Changning, Luzhou and Southeast Chongqing in southern China, combined with experiments and analysis, six factors controlling differential enrichment of marine shale gas are summarized as follows:(1) The more appropriate thermal evolution and the higher the abundance of organic matter, the higher the adsorption and total gas content of shale will be.(2) Kerogen pyrolysis and liquid hydrocarbon cracking provide most of the marine shale gas.(3) The specific surface area and pore volume of organic matter rich shale increased first and then decreased with the increase of thermal evolution degree of organic shale. At Ro between 2.23% and 3.33%, the shale reservoirs are mainly oil-wet, which is conducive to the enrichment of shale gas.(4) The thicker the roof and floor, the higher the shale gas content. The longer the last tectonic uplift time and the greater the uplift amplitude, the greater the loss of shale gas will be.(5) The buried depth and dip angle of the stratum have different controlling and coupling effects on shale gas in different tectonic positions, resulting in two differential enrichment models of shale gas.(6) The effective and comprehensive matching of source, reservoir and preservation conditions determines the quality of shale gas accumulation. Good match of effective gas generating amount and time, moderate pore evolution and good preservation conditions in space and time is essential for the enrichment of shale gas.

MATHEMATICAL MODELING OF NEAR-WALL FLOWS OF TWO- PHASE MIXTURE WITH EVAPORATING DROPLETS

In the framework of the two-continuum approach, using the matched asymptotic expansion method, the equations of a laminar boundary layer in mist flows with evaporating droplets were derived and solved. The similarity criteria controlling the mist flows were determined. For the flow along a curvilinear surface, the forms of the boundary layer equations differ from the regimes of presence and absence of the droplet inertia deposition. The numerical results were presented for the vapor-droplet boundary layer in the neighborhood of a stagnation point of a hot blunt body. It is demonstrated that, due to evaporation, a droplet-free region develops near the wall inside the boundary layer. On the upper edge of this region, the droplet radius tends to zero and the droplet number density becomes much higher than that in the free stream. The combined effect of the droplet evaporation and accumulation results in a significant enhancement of the heat transfer on the surface even for small mass concentration of the droplets in the free stream.

The effect of spherical aberration on temperature distribution inside glass by irradiation of a high repetition rate femtosecond pulse laser

In this paper, we study the effect of spherical aberrations on the light intensity and the temperature distribution in the focal region in a 250-kHz femtosecond laser irradiated Ag^＋-doped borosilicate glass. When a focused beam goes through an interface between air and glass, spherical aberration will result in the separation of the focal point and then cause a clear change of the light intensity distribution along the incident direction. That phenomenon will further influence the longitudinal cross-section temperature distribution in glass. Here we use Ag nanoparticle formation as a marker for establishing temperature distribution and we find that the formation of nanoparticle shows a strong dependence on the temperature field and the detailed precipitation process is also discussed.

Changes of Essential Substance Contents in Exorista civilis Rondani during Diapause Stage

[ Objective ] The paper was to study the occurrence regularity of Lysiphlebus testaceipes Cresson. [ Method ] With Aphis craccivora Koch as the breeding host, developmental duration, development threshold temperature and effective accumulative temperatme of L. testaceipes Cresson were studied at six constant tem- peratures of 12, 16, 20, 24, 28 and 32℃ in the laboratory, respectively. [ Result] The developmental durations of each growth stage of L. testaceipes Cresson were shortened with the increasing temperature ranged from 12 to 32℃, and the growth rate was significantly accelerated with the increasing temperature. However, when the temperature was up to 32℃, the growth and development from mummy to adult was suppressed, and the developmental duration was extended for 0.45 d than that at 28℃. The developmental durations from egg to adult at 12, 16, 20, 24, 28 and 32℃ were 38.50, 21.25, 14.11, 12.17, 10.28 and 9.01 d, respectively. The developmental threshold temperatures of egg-mummy, mummy-adult and egg-adult were estimated to be 6.5, 6.25 and 5.36℃, respectively; and the effective accumulated temperatures were 136.28, 75.74 and 227.23 d·℃, respectively. [ Conclusion] Forecast formula of developmental duration and Logistic models were established according to effective accumulated temperature and developmental threshold temperature.

Study on cumulative effects of different cultivation patterns on wetland soil environment

Cumulative effects on wetland soils under different cultivation patterns were analyzed in the experimental fields of the Ecological Experimental Station of Mire-wetlands in Sanjiang Plain. The results suggested that the paddy field combined with the glebe to act on the soil environment. Under the combination of natural and anthropological factors, the cultivation of the paddy field and the glebe obviously related with different kinds of fertility factors of soil. The remarkable relation among organic matter, total nitrogen and available nitrogen reflected the fertilization of the soil at some extent.

Switching the direction of spin accumulation in the spin Hall effect of light by adjusting the optical axis of an uniaxial crystal

We theoretically and experimentally investigate a switchable spin Hall effect（SHE） of light in reflection near the Brewster angle at an air-uniaxial crystal interface.We find a large transverse spin splitting near the Brewster angle,whose sign can be altered by rotating the optical axis.As an analogy of the SHE in an electronic system,a switchable spin accumulation in the SHE of light is detected.We are able to switch the direction of the spin accumulation by adjusting the optical axis angle of the uniaxial crystal.These findings may give opportunities for photon spin manipulating and developing a new generation of nano-photonic devices.

One droplet reaction for synthesis of multi-sized nanoparticles

Reaction kinetics of nanoparticles can be controlled by tuning the Peclet number(Pe)as it is an essential parameter in synthesis of multi-sized nanoparticles.Herein,we propose to implement a self-driven multi-dimension microchannels reactor(MMR)for the one droplet synthesis of multi-sized nanoparticles.By carefully controlling the Pe at the gas-liquid interface,the newly formed seed crystals selectively accumulate and grow to a specific size.By the combination of microchannels of different widths and lengths,one droplet reaction in the same apparatus achieves the synchronous synthesis of diverse nanoparticles.MMR enables precise control of nanoparticle diameter at 5 nm precision in the range of 10-110 nm.The use of MMR can be extended to the synthesis of uniform Ag,Au,Pt,and Pd nanoparticles,opening towards the production and engineering of nanostructured materials.This approach gives the chance to regulate the accumulation probability for precise synthesis of nanoparticles with different diameters.

Microbial diversity accumulates in a downstream direction in the Three Gorges Reservoir

Organic and inorganic materials migrate downstream and have important roles in regulating environmental health in the river networks.However,it remains unclear whether and how a mixture of materials(i.e.,microbial species)from various upstream habitats contribute to microbial community coalescence upstream of a dam.Here we track the spatial variation in microbial abundance and diversity in the Three Gorges Reservoir based on quantitative PCR and 16 S rRNA gene high-throughput sequencing data.We further quantitatively assess the relative contributions of microbial species from mainstem,its tributaries,and the surrounding riverbank soils to the area immediately upstream of the Three Gorges Dam(TGD).We found an increase of microbial diversity and the convergent microbial distribution pattern in areas immediately upstream of TGD,suggesting this area become a new confluence for microbial diversity immigrating from upstream.Indeed,the number of shared species increased from upstream to TGD but unique species decreased,indicating immigration of various sources of microbial species overwhelms local environmental conditions in structuring microbial community close to TGD.By quantifying the sources of microbial species close to TGD,we found little contribution from soils as compared to tributaries,especially for sites closer to TGD,suggesting tributary microbes have greater influence on microbial diversity and environmental health in the Three Gorges Reservoir.Collectively,our results suggest that tracking microbial geographic origin and evaluating accumulating effects of microbial diversity shed light on the ecological processes in microbial communities and provide information for regulating aquatic ecological health.

A PRELIMINARY SIMULATION OF EFFECTS OF CLIMATE CHANGE ON RICE IN THE MIDDLE AND LOWER REACHES OF CI-IANGJIANG RIVER AND WINTER WHEAT PRODUCTION ON THE HUANG-HUAI-HAI PLAIN

In this paper,based on the analysis of the variation of effective accumulated temperature and precipita- tion in the last 100 years,together with the potential impacts of greenhouse effects on the climate in China simulated with the current major climatic models(GFDL,GISS,NCAR,OSU and UKMO),the impacts of climate change on rice in the middle and lower reaches of Changjiang River and winter wheat production on the Huang-Huai-Hai Plain~* are simulated with the available weather-yield statistic models on the assumption that te- mperature variation ranges 1—4℃ and precipitation variation ranges ±10—20%.The result is that under the current planting systems and agrotechniques,the impact of climate change on wheat production is more signifi- cant than that on rice;the climatic conditions of agricultural production in the north of China will become more favourable while those in the south of the middle and lower reaches of Changjiang River remain the same;but those in the southern part of North China and the basins between Changjiang River and Haihe River are rather unstable.In general,it is difficult to reach the conclusion that advantages or disadvantages dominate in such climate changes because of uncertainties.

Understanding the failure mechanisms of microwave bipolar transistors caused by electrostatic discharge

Electrostatic discharge（ESD） phenomena involve both electrical and thermal effects,and a direct electrostatic discharge to an electronic device is one of the most severe threats to component reliability.Therefore, the electrical and thermal stability of multifinger microwave bipolar transistors（BJTs） under ESD conditions has been investigated theoretically and experimentally.100 samples have been tested for multiple pulses until a failure occurred.Meanwhile,the distributions of electric field,current density and lattice temperature have also been analyzed by use of the two-dimensional device simulation tool Medici.There is a good agreement between the simulated results and failure analysis.In the case of a thermal couple,the avalanche current distribution in the fingers is in general spatially unstable and results in the formation of current crowding effects and crystal defects.The experimental results indicate that a collector-base junction is more sensitive to ESD than an emitter-base junction based on the special device structure.When the ESD level increased to 1.3 kV,the collector-base junction has been burnt out first.The analysis has also demonstrated that ESD failures occur generally by upsetting the breakdown voltage of the dielectric or overheating of the aluminum-silicon eutectic.In addition,fatigue phenomena are observed during ESD testing,with devices that still function after repeated low-intensity ESDs but whose performances have been severely degraded.

A novel high figure-of-merit SOI SJ LDMOS with ultra-strong charge accumulation effect

A novel silicon-on-insulator（SOI） super-junction（SJ） LDMOS with an ultra-strong charge accumulation effect is proposed. It has two key features： an assisted-accumulation trench-type extending gate（TEG） with a high-k（HK） dielectric and a step-dopedN pillar（TEG-SD SJ LDMOS）. In the on-state, electrons accumulate at the sidewall of the HK dielectric from the source to the drain by the TEG. Furthermore, the high permittivity of the HK dielectric leads to an ultra-strong charge accumulation effect. As a result, an ultra-low resistance current path is formed. The specific on-resistance（Ron;sp/ is thus greatly reduced and is independent of the drift doping concentration. In the off-state, the step-dopedN pillar effectively suppresses the substrate-assisted depletion effect by charge compensation. Moreover, the reshape effect of the HK dielectric and the new electric field（E-field） peak introduced by the step-dopedN pillar enhance the drift region E-field. Hence, the BV is improved. Simulation indicates that the TEG-SD SJ LDMOS achieves an extremely low Ron;sp of 1.06 m cm^2 and a BV of 217 V. Compared with the conventional SJ LDMOS, the TEG-SD SJ LDMOS decreases the Ron;sp by 77.5% and increases the BV by 33%,exhibiting a high figure of merits（FOM=BV^2/Ron;sp/ of 44 MW/cm^2.