Agricultural Non-point Source Pollution in China:Evaluation,Convergence Characteristics and Spatial Effects

In this study,an inventory analysis approach was used to investigate the intensity of agricultural non-point source pollution(ANSP)and its spatial convergence at national and provincial levels in China from 1999 to 2017.On this basis,spatial factors affecting ANSP were explored by constructing a spatial econometric model.The results indicate that:1)The intensity of China's ANSP emission showed an overall upward trend and an obvious spatial difference,with the values being high in the eastern and central regions and relatively low in the western region.2)Significant spatial agglomeration was shown in China's ANSP intensity,and the agglomeration effect was increasing gradually.3)In the convergence analysis,a spatial lag model was found applicable for interpretation of the ANSP intensity,with the convergence rate being accelerated after considering the spatial factors but slower than that of regional economic growth.4)The spatial factors affecting the ANSP intensity are shown to be reduced by improving agricultural infrastructure investment,labor-force quality,and crop production ratio,while the expansion of agricultural economy scale and precipitation and runoff have positive impact on ANSP in the study region.However,agricultural research and development(R&D)investment showed no direct significant effect on the ANSP intensity.Meanwhile,improving the quality of the labor force would significantly reduce the ANSP intensity in the surrounding areas,while the precipitation and runoff would significantly increase the pollution of neighboring regions.This research has laid a theoretical basis for formulation and optimization of ANSP prevention strategies in China and related regions.

Gravitational Faraday effect in curved space-time induced by high-power lasers

Gravitational field produced by high-power laser is calculated according to the linearized Einstein field equation in weak field approximation. Gravitational Faraday effect of electromagnetic wave propagating in the above gravitational field is studied and the rotation angle of polarization plane of electromagnetic wave is derived. The result is discussed and estimated under the condition of present experiment facility.

The effects of the intertropical convergence zone on the easterly jet stream during Northern summer

In this paper, a strong 1TCZ process and an 1TCZ - absent process during FGGE in 1979 were selected for comparison to explore how they were subject to the influence of the evolution of the upper easterly jets.

Was Polchinski Wrong? Colombeau Distributional Rindler Space-Time with Distributional Levi-CivitàConnection Induced Vacuum Dominance. Unruh Effect Revisited

The vacuum energy density of free scalar quantum field in a Rindler distributional space-time with distributional Levi-Cività connection is considered. It has been widely believed that, except in very extreme situations, the influence of acceleration on quantum fields should amount to just small, sub-dominant contributions. Here we argue that this belief is wrong by showing that in a Rindler distributional background space-time with distributional Levi-Cività connection the vacuum energy of free quantum fields is forced, by the very same background distributional space-time such a Rindler distributional background space-time, to become dominant over any classical energy density component. This semiclassical gravity effect finds its roots in the singular behavior of quantum fields on a Rindler distributional space-times with distributional Levi-Cività connection. In particular we obtain that the vacuum fluctuations have a singular behavior at a Rindler horizon . Therefore sufficiently strongly accelerated observer burns up near the Rindler horizon. Thus Polchinski’s account doesn’t violate the Einstein equivalence principle.

Learning Effect and Productivity Convergence of Chinese Industrial Enterprises

The main purpose of this paper is to test the production efficiency of different Chinese property industrial enterprises.Based on the large sample panel data of industrial enterprises of the National Bureau of Statistics,we found that although the production efficiency of China-funded enterprises is generally weaker than foreign-funded enterprises,some China-funded enterprises have better learning ability.On the one hand,dynamic analysis found that private enterprises have significant learning ability.On the other hand,the results of convergence analysis show that China’s private enterprises have the potential to gradually catch up with the frontier level of world production efficiency and have better learning ability to catch up potential.And state-owned enterprises tend to be more efficient at the beginning of their establishment,but their productivity is fairly slow to improve,especially for state-owned enterprises with high efficiency sub-samples,so that it’s hard for them to continue improving their efficiency.Institutional analysis found that the marketization process helped the China enterprises to improve their learning ability and China should continue to strengthen the reform of property rights and promote the marketization process.

THE DIVERGENCE-CONVERGENCE EFFECT OF SURFACE CURRENT AND ITS ACTION ON THE BOHAI SEA

The action of the wind field and the influence of topography can cause divergence or convergence of surface current. The existence of the divergence-convergence effect is proved and the dynamical significance of the divergent or convergent state and its link with many marine phenomena are pointed out. Divergence fields of surface current in the Bohai Sea in winter and summer are obtained by numerical modelling describing the divergence-convergence character of seasonally wind-driven current. The relation between the effect and seasonal marine phenomena is discussed. Study on the divergence-convergence effect of surface current (DCESC)can be an indirect method for testing the calculated results.

Mixed time discontinuous space-time finite element method for convection diffusion equations

A mixed time discontinuous space-time finite element scheme for secondorder convection diffusion problems is constructed and analyzed. Order of the equation is lowered by the mixed finite element method. The low order equation is discretized with a space-time finite element method, continuous in space but discontinuous in time. Stability, existence, uniqueness and convergence of the approximate solutions are proved. Numerical results are presented to illustrate efficiency of the proposed method.

EMPIRICAL BAYES TEST PROBLEMS OF VARIANCE COMPONENTS IN RANDOM EFFECTS MODEL

Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that the proposed EB decision rules are asymptotically optimal with convergence rates near O(n-1/2). Finally, an example concerning the main result is given.

Differential Quadrature Method for Bending Problem of Plates with Transverse Shear Effects

A differential quadrature (DQ) method for orthotropic plates was proposed based on Reddy' s theory of plates with the effects of the higher-order transverse shear deformations. Wang-Bert's DQ approach was also further extended to handle the boundary conditions of plates. The computational convergence was studied, and the numerical results were obtained for different grid spacings and compared with the existing results. The results show that the DQ method is fairly reliable and effective.

On the structural features of fiber suspensions in converging channel flow

The structural features of fiber suspensions are dependent on the fiber alignment in the flows. In this work the orientation distribution function and orientation tensors for semi-concentrated fiber suspensions in converging channel flow were calculated, and the evolutions of the fiber alignment and the bulk effective vis-cosity were analyzed. The results showed that the bulk stress and the effective viscosity were functions of therate-of-strain tensor and the fiber orientation state ; and that the fiber suspensions evolved to steady alignment and tended to concentrate to some preferred directions close to but not same as the directions of local stream-lines. The bulk effective viscosity depended on the product of Reynolds number and time. The decrease of ef-fective viscosity near the boundary benefited the increase of the rate of flow. Finally when the fiber alignment went into steady state, the structural features of fiber suspensions were not dependent on the Reynolds numberbut on the converging channel angle.

Convergent mechanism of roadway driven along with strong roof of special thick stratum and its controlled measures

The trapezoidal cross-section roadway, driven along with its medium and fine grain sandstone roof in special thick stratum, was situated in shale strata. Rock-lining wall was employed in roadway, which its roof is in the free situation. Under the action of virgin stress, the surrounding rock of roadway was in stability. While under the action of fixed abutment pressure arisen from protection pillar of roadway, which its two sides?seams were extracted, free strong roof of roadway was in the stability. But its two sides?rock-lining walls was fractured, partially broken into pieces, and its floor heave was ob-vious. The velocity of floor heave is 0.4～0.8 mm/d. The size of broken zone of sur-rounding rock of roadway increases doubly. An effective load coefficient of surrounding rock to was quoted illustrate these phenomena. The main reasons of roadway conver-gence are that, rock property of surrounding rock is inferior, protection pillar affects its stability, and supporting pattern employed is improper. At last, effective measures to control roadway convergence should be bolting and grouting lining, which mainly con-solidates surrounding rock of roadway.

Effects of water and ice clouds on cloud microphysical budget:An equilibrium modeling study

The effects of water and ice clouds on the cloud microphysical budget associated with rainfall are investigated through the analysis of grid-scale data from a series of two-dimensional cloud-resolving model equilibrium sensitivity simulations. The model is imposed without large-scale vertical velocity. In the control experiment, the contribution from rainfall （cM） associated with net evaporation and hydrometeor loss/convergence is about 29% of that from the rainfall （Cm） associated with net condensation and hydrometeor gain/divergence and about 39% of that from the rainfall （CM） associated with net condensation and hydrometeor loss/convergence. The exclusion of ice clouds enhances rainfall contribution of CM, whereas it reduces rainfall contributions of Cm and cM. The removal of radiative effects of water clouds increases rainfall contribution of CM, barely changes rainfall contribution of Cm and reduces the rainfall contribution of cM in the presence of the radiative effects of ice clouds. Elimination of the radiative effects of water clouds reduces the rainfall contributions of CM and Cm, whereas it increases the rainfall contribution of cM in the absence of the radiative effects of ice clouds.

Orbital effect in the stationary axisymmetric field

This paper uses an elegant mathematical method to calculate the orbital effects in the axisymmetric field created by the spinning mass with electric charge and a large number of magnetic monopoles. In comparison with that in the Reissner-Nordstroem （R-N） field, the correction terms caused by the spinning mass decrease the advanced effect as the revolution direction of the test particle coincides with that of the Kerr field, however, the correction terms caused by the spinning charged mass increase the advance effect as the revolution direction of the test particle coincides with that of the Kerr-Newman-Kasnya （KNK） field. Generalizing the effect in the axisymmetric field, it obtains interesting results by discussing the parameters of the celestial body, these parameters provide a feasible experimental verification of the general relativity.

BACKSIDE EFFECT OF BISTATIC AIRBORNE CLUTTER CHARACTERISTICS AND ITS APPLICATIONS IN GMTI

An interesting clutter characteristic of bistatic radars is presented, which is named as backside effect. In such an effect, the range-dependent ground clutter spectrum can be easily aligned, and Space-Time Adaptive Processing (STAP) is to be more applicable and effective for the Ground Moving Target Indication (GMTI) in bistatic systems. The backside effect is proved by the numerical calculation method and explained in point of the geometry. At last a new spectrum aligning method is induced, i.e., ADC and Rotation (ADCR), which can gain a further performance improvement on GMTI.

民族地区巩固拓展脱贫攻坚成果同乡村振兴有效衔接研究——以内蒙古自治区为例

在全面脱贫取得胜利和全面推进乡村振兴事业的历史交汇节点上,巩固拓展脱贫攻坚成果同乡村振兴有机衔接,是预防返贫风险、扎实推进乡村振兴战略的必然要求。内蒙古自治区脱贫攻坚取得显著性成果,但推进脱贫攻坚与乡村振兴有效衔接中仍存在困境,农牧区基础设施建设滞后,返贫风险长期存在,产业发展存在局限,新型农牧专业人才匮乏,缺乏内生动力,农牧区生态功能下降。内蒙古巩固脱贫攻坚成果同乡村振兴有效衔接应做好政策、规划和体制机制的有效衔接,加快农牧区基础设施建设,建立防止返贫长效机制,推动产业融合发展,完善农牧区人才队伍建设,激发农牧民发展的内生动力,持续加强生态文明建设。

PIPBQ Effect Aware SER Analysis for Combinational Logic Circuits

Technology scaling results in the propagation-induced pulse broadening and quenching（PIPBQ） effect become more noticeable.In order to effectively evaluate the soft error rate for combinational logic circuits,a soft error rate analysis approach considering the PIPBQ effect is proposed.As different original pulse propagating through logic gate cells,pulse broadening and quenching are measured by HSPICE.After that,electrical effect look-up tables（EELUTs） for logic gate cells are created to evaluate the PIPBQ effect.Sensitized paths are accurately retrieved by the proposed re-convergence aware sensitized path search algorithm.Further,by propagating pulses on these paths to simulate fault injection,the PIPBQ effect on these paths can be quantified by EELUTs.As a result,the soft error rate of circuits can be effectively computed by the proposed technique.Simulation results verify the soft error rate improvement comparing with the PIPBQ-not-aware method.

三次台风登陆后雨带列车效应特征对比

为探讨台风雨带列车效应导致极端降水的可能形成方式和流型配置,利用多源观测资料,对2015年第13号台风苏迪罗(过程1)、2013年第23号台风菲特(过程2)和2005年第9号台风麦莎(过程3)登陆减弱后的对流雨带列车效应现象进行对比分析。结果表明:三次过程大暴雨区都发生在浙江东部丘陵东侧迎风坡,且具有雨带走向与环境背景气流基本一致及水汽通量辐合集中在850 hPa以下的共性,但其环境背景明显不同。过程1和过程2均由台风外围对流雨带引起,其中过程1雨带位于台风低压与副热带高压之间,垂直风切变和对流有效位能较大,水汽来自低纬度海面且湿层深厚;过程2发生在陆上台风残涡与海上另一个台风之间的鞍型场内,垂直风切变和对流有效位能较小,水汽来自同纬度海面,湿层仅位于对流层中下部。过程3由台风内核区雨带引起,垂直风切变强,对流有效位能最小。进一步分析发现在不同环境垂直风廓线和湿度廓线下三次过程雨带的结构和组织方式呈现出明显差异。在过程1中,对流发展较高,冷池与偏东气流间形成较深厚边界层辐合,所构成边界的两侧斜压结构促进来自海面暖湿空气在力管项作用下在边界暖湿一侧抬升,雨带两侧正负散度配置加强了对流的组织化程度,使对流单体长时间沿雨带长轴移动;在过程2中,偏东气流与弱冷池之间风向相反,风速相当,辐合较浅薄,暖云降水起主要作用,新单体不断在雨带东边界生成、西边界消亡,雨带停滞少动引发持续强降水;在过程3中,内核区雨带较大程度受台风涡旋动力学影响,对流发展高度低,为典型的热带海洋降水型,结构随高度略向外侧倾斜,对流单体在台风本体东侧低空东南风急流脉动产生的风速辐合作用下反复被激发并向下游移动,引发极端强降水。以上事实说明,导致极端降水的台风雨带列车效应形成方式多样,其短时临近预报面临重大挑战。

数字金融对农民增收的影响:基于门槛效应和空间收敛性分析

数字金融发展是否有利于提升农民收入并对农民收入差距产生影响值得深入研究。论文基于2011—2020年全国31个省(自治区、直辖市,不包含港澳台地区)的面板数据,从农民增收和收入差距的双重视角,考查数字金融的非线性门槛增收效应及对农民收入差距的空间收敛影响。研究发现,数字金融对农民收入的影响存在“边际效应递增”,即随着数字金融发展水平跨越相应门槛值,农民增收效应递增;各地区数字金融发展水平呈现“高-高”和“低-低”的空间集聚特征;进一步分析发现,农民收入水平具有显著的空间β条件收敛特征,且数字金融加剧了各省(自治区、直辖市,不包含港澳台地区)农民收入差距。论文为数字金融与农民增收关系的研究提供了一个新的视角,为优化数字金融助力农民增收、缓解农民收入差距的相关政策提供了参考。

水旱条件下小麦持绿相关性状QTL定位

干旱是影响小麦生产中最重要的非生物胁迫。延长叶片持绿周期,进而增加光合时间,提高光合效率,对小麦在旱胁迫下保证有机物积累,最终达到小麦产量的稳定具有重要的意义。了解小麦旗叶持绿性保持的发育和遗传特征,并探索与小麦持绿基因密切相关且不受环境影响的稳定的分子标记,应用于育种可大大缩短抗旱育种周期。本研究以扬麦16和中麦895衍生的174个家系的DH群体为试验材料,通过设置正常滴灌(NI)和干旱胁迫(DS)处理,对2年2个水分处理下花后10 d、14 d、18 d、22 d、26 d和30 d旗叶绿色叶面积百分率(GLA)及叶绿素相对含量(SPAD值)进行表型测定,运用Gompertz模型模拟出GLA(%)变化趋势。将达到最大衰老速度的时间(TMRS)、绿色叶面积持续期(GLAD)、平均衰老速率(ARS)、旗叶快速衰老开始的时间(T1)、旗叶快速衰老结束的时间(T2)和旗叶动态SPAD值等11个持绿相关性状进行QTL定位。结果表明,水旱条件下,DH群体和亲本不同日龄下的GLA,衰老特征参数和旗叶动态SPAD值均存在超亲分离现象,并表现出一定差异。各家系和亲本不同日龄下的GLA均呈缓慢-快速-缓慢的动态下降趋势,快速衰老主要集中在18 d、22 d和26 d。除ARS和GLA-10D呈负相关,其余性状之间均呈现正相关。各性状遗传力范围在0.50~0.81之间。连锁分析在2个及以上环境中共鉴定到27个与小麦持绿相关的稳定位点,其中11个与小麦衰老特征参数相关,16个与旗叶动态SPAD值相关,分布在1A、1B、4B、4D、5D、7B和7D染色体上,分别解释表型变异3.86%~14.11%和2.99%~17.45%。在4B、4D和7B染色体上有1个调控T1和5个调控SPAD值的QTL在3个环境中被重复检测到,分别解释8.97%~14.11%和6.85%~17.45%的表型变异。QTL聚合效应分析发现,含有Rht-D1b和AA基因型的位点对SPAD-10D具有显著的增效作用和累加效应,含有GG和TT基因型的位点对SPAD-18D具有显著的增效作用和累加效应。在4B、4D、7B和7D染色体上发现了4个效应明显的QTL簇,位于4D染色体的QTL簇中存在不受水分环境影响的区段(18.80~28.58 Mb),该区段内包含Rht-D1基因,调控SPAD-0D和SPAD-10D的位点可能受到该基因的多效应影响。候选基因分析发现TraesCS4D01G054000、TraesCS1B01G434300和TraesCS7B01G010200等8个影响持绿相关性状的候选基因。以上研究结果为小麦持绿性分子标记辅助育种提供了理论依据。

我国区域经济增长差异与收敛的时空演进特征

文章基于动态演进视角,运用Dagum基尼系数和Kernel密度估计法考察我国区域经济增长差异与收敛特征,从动态共同相关效应视角分析条件收敛的影响因素。结果表明:我国区域经济增长的总体基尼系数呈波动下降趋势。东、中、西和东北四大板块基尼系数变化趋势与我国区域经济增长总体基尼系数变化趋势一致。四大板块的区域间差异是引起我国区域经济增长差异的主要原因。东部地区经济分化是引起绝对差距扩大的主要原因。我国区域经济增长存在条件收敛,人力资本存量和物质资本存量是促进区域经济增长条件收敛的主要因素。