Possibility of Solid Hydrometeor Growth Zone Identification Using Radar Spectrum Width

In this study,the correlation between simulated and measured radar velocity spectrum width(σ_(v))is investigated.The results show that the dendrites growth zones(DGZs)and needles growth zones(NGZs)mostly contain dendrites(DN)and needles(NE),respectively.Clearσ_(v) zones(1.1<σ_(v)(m s^(-1))<1.3 and 0.3<σ_(v)(m s^(-1))<0.7 for the DGZ and NGZ,respectively)could be identified in the case studies(27 and 28 February 2016)near altitudes corresponding to temperatures of–15°C and–5°C,according to the Japan Meteorological Agency and mesoscale model reanalysis data.Oblate particles with diverse particle shapes were observed in the DGZ withσ_(v)>1.2 m s^(-1),a differential reflectivity(ZDR)higher than 0 dB,and a cross-correlation coefficient(ρhv)less than 0.96.In contrast,prolate particles with relatively uniform shapes were observed in the NGZ withσ_(v)<0.6 m s^(-1),a ZDR less than 0 dB,andρhv higher than 0.97.The simulation results show that the DN exhibited a largerσ_(v) compared to the NE,and this observedσ_(v) was strongly dependent on the wind fluctuations(v’)due to turbulence or wind shear.In contrast,the NE exhibited a significantly smallσ_(v)~0.55 m s^(-1),which converges irrespective of v’.In addition,a strong correlation between the measuredσ_(v) values at five radar elevation angles(θ=6.2°,9.1°,13.1°,19°,and 80°)and those simulated in this study confirmed the significance of the analysis results.

In situ observation of austenite grain growth behavior in the simulated coarse-grained heat-affected zone of Ti-microalloyed steels

The austenite grain growth behavior in a simulated coarse-grained heat-affected zone during thermal cycling was investigated via in situ observation. Austenite grains nucleated at ferrite grain boundaries and then grew in different directions through movement of grain boundaries into the ferrite phase. Subsequently, the adjacent austenite grains impinged against each other during the α→γtransformation. After the α→γ transformation, austenite grains coarsened via the coalescence of small grains and via boundary migration between grains. The growth process of austenite grains was a continuous process during heating, isothermal holding, and cooling in simulated thermal cycling. Abundant finely dispersed nanoscale TiN particles in a steel specimen containing 0.012wt% Ti effectively retarded the grain boundary migration, which resulted in refined austenite grains. When the Ti concentration in the steel was increased, the number of TiN particles de- creased and their size coarsened. The big particles were not effective in pinning the austenite grain boundary movement and resulted in coarse austenite grains.

Influence of the Repeated Flooding on Growth and Development of Acorus calamus Vegetation in Water-level-fluctuation Zone of the Three Gorges Reservoir

[ Objective] The research aimed to study influence of the repeated flooding on growth and development of A. calamus in water-level-fluc- tuation zone of the Three Gorges Reservoir. [ Method] A. calamus plants were exposed to water under the dark conditions respectively in Septem- ber 2009 and September 2010. Then, they were taken away from the water, and grew in natural conditions in the following March and April respec- tively （ marked as S1, S2, S1 and S2）. The plant number was conducted statistics respectively. On May 7, the leaf number was made statistics. Length, width and rapid light responding curve of the leaf were determined. [ Result] Repeated flooding restrained significantly plant germination un- der the dark condition. Plant number in S1 and S2 groups decreased by 38.9% and 33.3% respectively compared with the control. It also reduced survival rate of the plant. Plant number in S2 group decreased by 16.7% （P 〈 0.05） compared with that of S2 group when they were taken away from the water. Both of flooding promoted elongation of the leaves, restrained leaves to grow wider, and also restrained leaf formation of the plants except for S1 and S1 groups. Total leaf length of a plant decreased markedly after the second flooding which in S1 and S2 groups were 50.6% and 36.9% respectively less than that after the first flooding. Total leaf number of the plant in S1and S2 groups reduced significantly, and they were only 63.1% and 38.5% respectively of the control. Compared with the first flooding, total leaf length of a plant in the control increased signifi- cantly and decreased remarkably in S2 group after the second flooding. Furthermore, light response ability of the relative electronic transfer rate （rETR） in S1 group wasn＇t significantly different from the control, and rETRmax, in S2 group was significantly less than the control. Moreover, non- photochemical quenching （NPQ） decreased remarkably in S1 and S2 groups. It indicated that A. calamus had good restore ability of the light re- sponse, but restoring of its heat dissipation capacity was slower. [ Conclusion] Repeated flooding inhibited plant growth and population recovery of A. calamus under the dark condition.

Floating-zone growth and property characterizations of high-quality La_(2-x)Sr_xCuO_4 superconductor crystals

We have grown underdoped （х = 0.11, 0.12） and optimally doped （x = 0.16）La2-хSrхCuO4 single crystals by the traveling-solvent floating-zone technique.In order to prepare good quality cuprate crystals,we have made much effort to optimize the preparation procedures.For example,we haveadopted the sol-gel route to prepare a highly fine and homogeneous La2-хSrхCuO4 precursor powder for fabricating a very dense ceramic feed rod used for the floating-zone growth,and we have also used quite a slow growth rate. The high quality of the grown crystals has been verified by double-crystal x-ray rocking curves,with the full-width-at-half-maximum being only 113-150 arcseconds, which are the best data reported so far for La2-хSrхCuO4 crystals.The superconducting critical temperatures of the grown crystals are 30, 31 and 38.5 K for х = 0.11, 0.12 and 0.16 samples, respectively,according to magnetic measurements.

Characteristics of fault zones and their control on remaining oil distribution at the fault edge: a case study from the northern Xingshugang Anticline in the Daqing Oilfield, China

Most major oil zones in the Daqing Oilfield have reached a later,high water cut stage,but oil recovery is still only approximately 35%,and 50%of reserves remain to be recovered.The remaining oil is primarily distributed at the edge of faults,in poor sand bodies,and in insufficiently injected and produced areas.Therefore,the edge of faults is a major target for remaining oil enrichment and potential tapping.Based on the dynamic change of production from development wells determined by the injection-recovery relationship at the edge of faults,we analyzed the control of structural features of faults on remaining oil enrichment at the edge.Our results show that the macroscopic structural features and their geometric relationship with sand bodies controlled remaining oil enrichment zones like the edges of NNE-striking faults,the footwalls of antithetic faults,the hard linkage segments（two faults had linked together with each other to form a bigger through-going fault）,the tips of faults,and the oblique anticlines of soft linkages.Fault edges formed two types of forward microamplitude structures：（1） the tilted uplift of footwalls controlled by inverse fault sections and（2） the hanging-wall horizontal anticlines controlled by synthetic fault points.The remaining oil distribution was controlled by microamplitude structures.Consequently,such zones as the tilted uplift of the footwall of the NNW-striking antithetic faults with a fault throw larger than 40 m,the hard linkage segments,the tips of faults,and the oblique anticlines of soft linkage were favorable for tapping the remaining oil potential.Multi-target directional drilling was used for remaining oil development at fault edges.Reasonable fault spacing was determined on the basis of fault combinations and width of the shattered zone.Well core and log data revealed that the width of the shattered zone on the side of the fault core was less than 15 m in general;therefore,the distance from a fault to the development target should be larger than 15 m.Vertically segmented growth faults should take the separation of the lateral overlap of faults into account.Therefore,the safe distance of remaining oil well deployment at the fault edge should be larger than the sum of the width of shattered zone in faults and the separation of growth faults by vertical segmentation.

Fault-Growth Pattern of the South Margin Normal Fault of the Yuguang Basin in Northwest Beijing and its Influencing Factors

Based on high-resolution remote sensing image interpretation, digital elevation model 3-D analysis, field geologic field investigation, trenching engineering, and ground-penetrating radar, synthetic research on the evolution of the Yuguang Basin South Margin Fault （YBSMF） in northwest Beijing was carried out. We found that the propagation and growth of faults most often occurred often at two locations： the fault overlapping zone and the uneven or rough fault segment. Through detailed observation and analysis of all cropouts of faults along the YBSMF from zone a to zone i, we identified three major factors that dominate or affect fault propagation and growth. First, the irregularity of fault geometry determine the propagation and growth of the fault, and therefore, the faults always propagate and grow at such irregular fault segments. The fault finally cuts off and eliminates its irregularity, making the fault geometry and fault plane smoother than before, which contributes to the slipping movement of the half-graben block in the basin. Second, the scale of the irregularity of the fault geometry affects the result of fault propagation and growth, that is, the degree of the cutting off of fault irregularity. The degree of cutting off decreases as irregularity scale increases. Third, the maximum possible slip displacement of the fault segment influences the duration of fault propagation and growth. The duration at the central segments with a large slip displacement is longer than that at the end segments with a smaller slippage value.

Effect of welding parameters on the heat-affected zone of AISI409 ferritic stainless steel

One of the main problems during the welding of ferritic stainless steels is severe grain growth within the heat-affected zone （HAZ） In the present study, the microstmctural characteristics of tungsten inert gas （TIG） welded AISI409 ferritic stainless steel were investigated by electron backscattered diffraction （EBSD）, and the effects of welding parameters on the grain size, local misorientation, and low-angle grain boundaries were studied. A 3-D finite element model （FEM） was developed to predict the effects of welding parameters on the holding time of the HAZ above the critical temperature of grain growth. It is found that the base metal is not fully recrystallized. During the welding, complete recrystallization is followed by severe grain growth. A decrease in the number of low-angle grain boundaries is observed within the HAZ. FEM results show that the final state of residual sWains is caused by competition between welding plastic strains and their release by recrystallization. Still, the decisive factor for grain growth is heat input.

Modeling and numerical investigation of slow crack growth and crack arrest in ceramic polycrystals

ntergranular slow crack growth in zirconia polycrystal is described with a cohesive zone model that simulate mechanically the reaction-rupture mechanism underlying stress and environ- mentally assisted failure. A 2D polycrystal is considered with cohesive surfaces inserted along the grain boundaries. The anisotropic elastic modulus and grain-to-grain misorientation are accounted for together with an initial stress state related to the processing. A minimum load threshold is shown to originate from the onset of the reaction-rupture mechanism to proceed where a minimum traction is reached locally and from the magnitude of the initial compression stresses. This work aims at providing reliable predictions in long lasting applications of ceramics.

PRELIMINARY RESEARCH ON CONDITIONS TO THE ESTABLISHMENT OF A MULTI LATERAL COOPERATION AND DEVELOPMENT ZONE IN TUMENJIANG

This article analyses and discusses the conditions to the establishment of Tumenjiang Multi Nation Cooperation and Development Zone based on the theory of regional polarization development against the background of Northeast Asian cooperation. It expresses the external motives and the potentialities for the emergence and growth of the above mentioned new type development zone in order to provide a theoretical basis for both domestic and foreign developers who take an active part in the cooperation of developing Tumenjiang area.

Directional induction of dopaminergic neurons from neural stem cells using substantia nigra homogenates and basic fibroblast growth factor

To date, complex components of available reagents have been used for directional induction of neural stem cells into dopaminergic neurons, resulting in a poor ability to repeat experiments. This study sought to investigate whether a homogenate of the substantia nigra of adult rats and/or basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons. Tyrosine hydroxylase-positive cells were observed exclusively after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor for 48 hours in vitro. However, in the groups treated with homogenate supernatant or basic fibroblast growth factor alone, tyrosine hydroxylase expression was not observed. Moreover, the content of dopamine in the culture medium of subventricular zone neurons was significantly increased at 48 hours after induction with the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor. Experimental findings indicate that the homogenate supernatant of the substantia nigra from adult rats and basic fibroblast growth factor could directionally induce neural stem cells derived from the subventricular zone of embryonic rats to differentiate into dopaminergic neurons in the substantia nigra with the ability to secrete dopamine.

“一带一路”沿线境外经贸合作区对东道国经济增长的影响及机制研究

境外经贸合作区是共建“一带一路”倡议的重要承接点,也是推动我国企业高质量“走出去”的重要平台,如何评估合作区建设对考察我国“一带一路”倡议成效与境外经贸合作区的实践效果具有重要参考价值。基于60个“一带一路”沿线国家的样本数据,通过渐进性双重差分法,可对境外经贸合作区对东道国经济增长的影响和内在机制进行实证分析,并对东道国经济特征和合作区类型进行异质性分析。研究结果表明:第一,境外经贸合作区的建立可以显著促进东道国的经济增长。其中,外商投资流入和贸易规模发挥了部分中介作用。第二,境外经贸合作区在促进东道国的经济增长方面具有异质性,对收入水平较低、营商制度较差的国家具有更强的经济助推作用。

Determination of the Metastable Zone Width, Nucleation Kinetics, Structural and Optical Properties of KCl Doped KAP Crystal

Slow evaporation method was used to grow pure and KCl (10 mol%) doped KAP single crystal. The solubility and metastable zone width of aqueous solutions of pure and KCl (10 mol%) doped KAP crystal were evaluated to analyze the crystallization process. Measuring the induction period τ, the critical nucleation parameters like interfacial energy (σ), energy of formation of the critical nucleus (&#916G*) were determined using the classical theory of nucleation. The structural properties and optical constants of the grown crystals have been put to test and observed that the addition of KCl results in an enhancement of properties of the crystal. Grown crystals were characterized by powder X-ray diffraction. FTIR spectra confirmed the presence of KCl in pure KAP crystal. UV- Visible spectroscopic studies revealed that addition of KCl in pure KAP crystal increased transparency from 75% to 80%. The analysis of the optical absorption data revealed the presence of both indirect and direct transitions and both of these band gaps increased with the addition of KCl. The transmittance data was analyzed to calculate the refractive index, oscillator energy, dispersion energy, electric susceptibility, zero-frequency dielectric constant and both the real and imaginary parts of the dielectric permittivity as a function of photon energy. The moments of ε(E) were also determined. The dispersion i.e. spectral dependence of the refractive index was discussed according to the single-effective oscillator model proposed by Wemple and DiDomenico.

基于根区温度和肥料浓度耦合的草莓生长调控

为探索草莓根区加热的最适温度及施肥浓度,该研究设置3个根区温度水平(不加温(8℃)、16、22℃)和3个肥料浓度水平(0.5、1.5、2.5 g/L),共计9个处理。分析了根区温度和肥料浓度协同作用对草莓产量、品质、肥料偏生产力、水分利用率的影响。结合层次分析法和CRITIC客观赋权法,运用优劣解距离法对各处理进行基于草莓产量、品质、肥料偏生产力、水分利用率的综合评价。结果表明:1)采用根区加温对设施草莓生长有促进作用。在采摘第3茬果实时,加温到16℃和22℃的处理下可以采摘的草莓植株数量相较于不加温处理明显增加。2)肥料浓度对草莓生长综合评分的影响大于根区温度。高肥料浓度(2.5 g/L)会降低草莓产量,中肥料浓度(1.5 g/L)不仅能增加单果质量,还能提高肥料偏生产力和水分利用率,具有更好的经济效益。3)基于TOPSIS综合评价建立了设施草莓生长综合评价体系,得出评分最高的处理为T5处理(16℃,1.5 g/L)。通过寻找最优区间,结果发现根区温度在13.10~18.47℃,肥料浓度在1.43~1.87g/L时,设施草莓生长效果较好。该研究结果可为设施草莓冬季及早春的温度和肥水管理提供理论依据。

Special Economic Zones Blaze New Trails

Special economic zones(SEZ) are starting points of incremental reform and opening-up in China. On the 30th anniversay of reform and opening-up,this article attempts to present a systematic review of the evolution,mechanism and performance of special economic zones as well as a pespective on SEZs' furture development.

2000-2022年宁夏不同地理分区生长季植被覆盖度时空非平稳性特征

地表植被是土壤、水体与大气之间重要的连接物质。研究不同地理分区植被覆盖度(Fractional Vegetation Cover,FVC)时空非平稳性对区域生态环境保护与规划建设具有重要意义。基于MODIS13Q1 NDVI数据及其同期气象、地形、土壤、人类活动影响因子,明确不同地理分区FVC时空变化特征及其原因。结果表明:宁夏不同地理分区下的FVC差异显著,南部山区拥有较好的FVC水平。2000-2022年宁夏FVC呈现波动式增长趋势,南部山区FVC变化最为明显,平均增长速率为0.011/a。生长季多年平均空间格局分析说明宁夏高FVC主要集中在六盘山高山区、沿黄流域和清水河流域。23年间宁夏FVC低波动区域重点位于六盘山、沙坡头自然保护区、南华山以及吴忠市和银川市城建区域,中部干旱带高波动明显,Theil-Sen Median趋势分析显示南部山区增长趋势明显,引黄灌溉区有递减趋势,Mann-Kendall显著性检验说明宁夏越往南部FVC改善越显著,Hurst趋势进一步表明了南部山区和引黄灌溉区具有高持续特点,南部山区高山区、沙坡头自然保护区、甘城子以西、贺兰山石炭井、中宁县、贺兰县月牙湖乡等区域未来将维持稳定不变,沙坡头区香山一带反持续性显著,FVC有将会得到改善,贺兰山部分地区FVC较低且持续性较强有维持现状风险。宁夏不同地理分区FVC与影响因素时空非平稳特征明显,空间序列回归系数说明人类活动对FVC产生重要影响,时间序列回归系数说明了历史时期气候因素对FVC影响波动性大。该项研究可为宁夏不同地域生态保护、建设与可持续发展提供差异化对策提供参考。

大都市成长区公共服务设施的配置优化策略——以广州开发区为例

分析大都市成长区公共服务设施配置的特征与存在问题,深入挖掘影响大都市成长区公共服务设施合理配置的因素,全面梳理公共服务设施供需关系的转变趋势,基于此提出大都市成长区公共服务设施的配置优化策略,并以广州开发区为例展开实证分析,以期为同类地区提供借鉴。

癸二酸溶解度、介稳区及晶体生长速率的测定

旨在促进癸二酸的连续化生产,采用动态法测定癸二酸在289.25~373.15 K范围的溶解度,采用聚焦光束反射测量技术测定了癸二酸在333.15~353.15 K的介稳区,研究了饱和温度和降温速率对介稳区的影响以及过饱和度与晶体生长速率的关系。结果表明:癸二酸的溶解度随着温度的升高而增大;癸二酸的介稳区随饱和温度的增大而变窄,随降温速率的增大而变宽;癸二酸在水溶液中的晶体生长速率与晶体粒度大小无关,与过饱和度呈线性增长关系,生长速率常数为3.611×10^(-6)g/(m^(2)·s),生长级数为1.498。

番茄苗期根际加温对其生长及水分吸收的影响

[目的]本文旨在明确适宜的番茄根际加温温度,为北方早春玻璃温室中番茄苗期根际温度调控提供理论和方法依据,缓解低温环境对番茄生长的危害。[方法]在玻璃温室高架岩棉栽培条件下,采用控温加热带对番茄根际进行加温,并设置3个处理即根际不加温(CK)、根际加温至20℃(T20)、根际加温至25℃(T25),研究不同根际加温条件对早春苗期番茄生长、光合、干物质积累和水分吸收等的影响。[结果]根际加温可显著促进番茄株高、茎粗、叶片数的增加,不同时期处理T20比CK株高提高13.6%~17.0%,茎粗提高10.3%~14.3%,叶片数增加3.4%~12.5%;处理T25比CK株高提高7.2%~9.7%,茎粗提高7.7%~15.6%,叶片数增加0%~15.6%;定植后10 d,番茄净光合速率随根际温度呈先升高后降低的趋势,定植后20 d和定植后30 d,番茄净光合速率随根际温度升高而升高;根际加温促进了番茄对水分的吸收,促进了番茄茎、叶干物质积累,提早开花时间,其中处理T20比CK地上部总干重增加79.3%~85.4%,开花提早5 d,处理T25比CK地上部总干重增加29.2%~72.4%,提早开花时间3 d。[结论]T20处理番茄株高和茎粗最大、积累干物质总量最多、开花时间最早,即20℃是早春苗期番茄较为适宜的根际加温温度。

自由贸易试验区对所属区域经济增长的影响--基于川渝地区的“反事实”分析

自由贸易试验区的成立对所属区域经济增长有着重要的经济意义。以川渝地区为例,利用2008年第一季度至2019年第二季度全国省域样本的GDP季度增长率、进口额、出口额及固定资产投资额数据进行合成控制,对自贸试验区的经济效应进行反事实分析。结果显示:自由贸易试验区的成立促进了川渝地区经济增长,但该影响具有异质性。对四川而言,贸易驱动对经济增长的影响较投资驱动更加显著;对重庆而言,投资驱动大于贸易驱动,且自由贸易试验区成立的经济效应具有一定的滞后性。

高质量铟掺杂氧化镓单晶浮区法生长研究

Ga_(2)O_(3)是一种新型超宽带隙半导体材料,性能出色,在高功率电子器件和日盲深紫外探测器等领域有着巨大的应用前景。通过掺入In^(3+)离子,可以调节β-Ga_(2)O_(3)的带隙宽度和光学性质,从而进一步拓展其应用范围。本研究以高纯度Ga_(2)O_(3)、In_(2)O_(3)为原料,采用光学浮区法制备了β-Ga_(2)O_(3):9%In、β-Ga_(2)O_(3):15%In单晶。生长速度为5 mm/h时,晶体出现失透现象,在光学显微镜下观察,发现晶体中含有大量气泡缺陷,这些缺陷主要呈条状和球状,其中条状气泡的长度在50~200μm范围内,沿[010]晶体生长方向延伸。通过扫描电子显微镜观察缺陷形貌和元素分布,发现气泡周围的元素分布均匀,无杂质元素聚集。结果表明,缺陷的形成与In_(2)O_(3)高温分解有关,产生的气体未及时排出,随熔体结晶进入晶体内部形成气泡。优化晶体生长工艺解决了气泡缺陷引起的晶体失透问题,得到的透明β-Ga_(2)O_(3):9%In单晶摇摆曲线半峰宽可达44arcsec,晶体的结晶质量显著提升。本研究为生长高质量β-Ga_(2)O_(3):In体块单晶提供了解决方案,为深入了解其光电性能奠定了基础。