Construction and Weight Distributions of Binary Linear Codes Based on Deep Holes

Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, we consider constructing binary linear codes by combining deep holes with binary BCH codes. In this article, we consider the 2-error-correcting binary primitive BCH codes and the extended codes to construct new binary linear codes by combining them with deep holes, respectively. Furthermore, three classes of binary linear codes are constructed, and then we determine the parameters and the weight distributions of these new binary linear codes.

Modeling the Interior of Black Holes Utilizing a 4-D Spatial Blackbody Radiation Model with an Exponential Distribution

This is a second follow up paper on a model, which treats the black hole as a 4-D spatial ball filled with blackbody radiation. For the interior radiative mass distribution, we employ a new type of truncated probability distribution function, the exponential distribution. We find that this distribution comes closest to reproducing a singularity at the center, and yet it is finite at 4-D radius, . This distribution will give a constant gravitational acceleration for a test particle throughout the black hole, irrespective of radius. The 4-D gravitational acceleration is given by the expression, , where R is the radius of the black hole, MR is its mass, and is the exponential shape parameter, which depends only on the mass, or radius, of the black hole. We calculate the gravitational force, and the entropy within the black hole interior, as well as on its surface, identified as the event horizon, which separates 3-D from 4-D space. Similar to a truncated Gaussian distribution, the gravitational force increases discontinuously, and dramatically, upon entry into the 4-D black hole from the 3-D side. It is also radius dependent within the 4-D black hole. Moreover, the total entropy is shown to be much less than the Bekenstein result, similar to the truncated Gaussian. For the gravitational force, we obtain, , where Mr is the radiative mass enclosed within a 4-D volume of radius r. This unusual force law indicates that the gravitational force acting upon a layer of blackbody photons at radius r is strictly proportional to the enclosed radiative energy, MrC2, contained within that radius, with 0.1λ being the constant of proportionality. For the entropy at radius, r, and on the surface, we obtain an expression which is order of magnitude comparable to the truncated Normal distribution. Tables are presented for three black holes, one having a mass equal to that of the sun. The other two have masses, which are ten times that of the sun, and 106 solar masses. The corresponding parameters are found to equal, , respectively. We compare these results to the truncated Gaussian distribution, which were worked out in another paper.

Mechanical property and deformation mechanism of gold nanowire with non-uniform distribution of twinned boundaries:A molecular dynamics simulation study

The mechanical property and deformation mechanism of twinned gold nanowire with non-uniform distribution of twinned boundaries(TBs)are studied by the molecular dynamics(MD)method.It is found that the twin boundary spacing(TBS)has a great effect on the strength and plasticity of the nanowires with uniform distribution of TBs.And the strength enhances with the decrease of TBS,while its plasticity declines.For the nanowires with non-uniform distribution of TBs,the differences in distribution among different TBSs have little effect on the Young's modulus or strength,and the compromise in strength appears.But the differences have a remarkable effect on the plasticity of twinned gold nanowire.The twinned gold nanowire with higher local symmetry ratio has better plasticity.The initial dislocations always form in the largest TBS and the fracture always appears at or near the twin boundaries adjacent to the smallest TBS.Some simulation results are consistent with the experimental results.

Quasi-Local Energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence

We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum complex. We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq. We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases.

RELOCATION ALGORITHM FOR NON-UNIFORM DISTRIBUTION IN MOBILE SENSOR NETWORK

Energy is the determinant factor for the survival of Mobile Sensor Networks(MSN).Based on the analysis of the energy distribution in this paper,a two-phase relocation algorithm is proposed based on the balance between the energy provision and energy consumption distribution.Our main objectives are to maximize the coverage percentage and to minimize the total distance of node movements.This algorithm is designed to meet the requirement of non-uniform distribution network applications,to extend the lifetime of MSN and to simplify the design of the routing protocol.In ad-dition,test results show the feasibility of our proposed relocation algorithm.

Study of the Non-Uniform Distribution of Earthquake Risk Within Potential Sources

Potential sources are aggregates of probable future epicenters.In this area,for source models currently,in common use for seismic risk analysis in China,the mean area of each potential source is about 3000-4000 km2.It is assumed that seismic risk has a uniform distribution within the range of each potential source,but studies have shown that the uniform distribution model to a large extent may give an underestimation of the seismic risk.In this paper,the relative distribution of historical epicenters in space within potential sources is discussed,a method is proposed to quantitatively describe the non-uniform distribution of strong earthquakes within potential sources,and some preliminary results are given.By using the results of this paper,seismic risk analysis and seismic zonation can be made more scientific and more reasonable.

Stress analytical solution for plane problem of a double-layered thick-walled cylinder subjected to a type of non-uniform distributed pressure

The stress state around circular openings,such as boreholes,shafts,and tunnels,is usually needed to be evaluated.Solutions for stresses,strains and ultimate bearing capacities of pressurized hollow cylinder are common cases.Stress analytical method for plane problem of a double-layered thick-walled cylinder subjected to a type of non-uniform pressure on the outer surface and uniform radial pressure on the inner surface is given.The power series method of complex function is used.The stress analytical solution is obtained with the assumption that two layers of a cylinder are fully contacted.The distributions of normal and tangential contact stress along the interface,tangential stress on the inner boundary and stresses in the radial direction at θ=0°,45° and 90°,are obtained.An example indicates that,when the elastic modulus of the inner layer of a double-layered thick-walled cylinder is smaller than that of the outer layer,the tangential stress is smaller than that in the corresponding point for a traditional cylinder composed of homogeneous materials.In that way,stress concentration at the inner surface can be alleviated and the stress distribution is more uniform.This is a capable way to enhance the elastic ultimate bearing capacity of thick-walled cylinder.

Downlink SINR and Rate Distribution of Ultra-Dense Het Nets with Burst Traffic

SINR distribution and rate overage distribution are crucial for optimization of deployment of Ultra-dense Het Nets.Most existing literatures assume that BSs have full queues and full-buffer traffic.In fact,due to ultra-dense deployment of small cells,traffic in small cell varies dramatically in time and space domains.Hence,it is more practical to investigate scenario with burst traffic.In this paper,we consider a two-tier non-uniform ultra-dense Het Net with burst traffic,where macro BSs are located according to Poisson Point Process(PPP),and pico BSs are located according to Poisson Hole Process(PHP).The closed-form expressions of SINR distribution and rate distribution are derived,and then validated through simulation.Our study shows that different from the result of full buffer case,the SINR distribution and rate distribution of users depend on the average transmission probabilities of BSs in burst traffic case.

The Evolution of the Charge Density Distribution Function for Spherically Symmetric System with Zero Initial Conditions

The evolution of the charge density distribution function is simulated for both the case of a uniformly charged sphere with zero initial conditions and for the case of a non-uniform charged sphere. For the case of a uniformly charged sphere the comparison of a numerical result and an exact analytical demonstrated the agreement between the results. The process of “scattering” of a charged system under the influence of its own electric field has been illustrated on the basis of both the particle-in-cell method and the solution of the Cauchy problem for vector functions of the electric field and vector velocity field of a charged medium.

Experimental study of the effects of non-uniformly distributed fine soil on mechanical properties of Shenyang–Dandong Railway coarse-grained soil

The stress produced by repeated train loads decreases with increasing railway subgrade bed depth, and slightly weathered coarse particles of subgrade bed fillings can be broken at different levels under continuous load. Thus, the mass of fine soil, with a diameter of not more than 0.075 mm, is different at different depths. Fine soil is also sensitive to frost heave and thaw settlement. In order to study the effects of non-uniformly distributed fine soil on the mechanical properties of coarse-grained soil of the Shenyang-Dandong Railway, triaxial tests were conducted with three types of specimens, un- dergoing six freeze-thaw cycle numbers （0, 1, 3, 7, 9, 12） and three confining pressures （100, 200, 300 kPa）. The freezing temperature is -5 ~C and the thawing temperature is ＋15 ~C. The stress-strain behavior, static strength, resilient modulus, cohesive force and the angle of internal friction were measured for different tested specimens. As a result, the law of static strength and resilient modulus of different specimens following the increase of freeze-thaw cycles under three confining pressures is obtained. The changing law of cohesive force and friction angle of three specimens following the increase of freeze-thaw cycles is also calculated, and the different results of different specimens are also compared.

Improving the Performance of Fixed-Bed Catalytic Reactors by Innovative Catalyst Distribution

A comprehensive mathematical model is developed to simulate the interactions of the complex processes that take place in typical catalytic chemical reactors. This mathematical model includes correlations representing various modes of mass transport and chemical reactions. To illustrate the application and value of this approach for reactor optimizations, the model is applied to the case of series reactions with a desirable intermediate compound and the risk of degradation of this compound if the process conditions are not optimized. The modeling results show that in such cases, which are very common in practice, replacing the conventional uniform catalyst distribution with a novel non-uniform distribution will significantly improve the performance of the reactor and the production of the desirable compound. Various catalyst distribution options are compared, and a novel non-uniform loading of catalyst is identified that gives a much better performance compared to the conventional approach. The model is versatile and useful for both the design as well as the optimization of the catalytic fixed-bed reactors in a wide variety of reactor and reaction conditions.

Quantitative research of annual runoff distribution characteristics in the Dagujia River basin,Yantai,China

Mann-Kendall method and minimum variance method are used in this study to analyze the mean value variable-point of the runoff data observed by Fushan Hydrological Station in the Dagujia River basin from 1966 to 2004. Based on the results, the runoff time is divided into four periods with the similar hydrological variation character. The annual runoff distribution characters in the Dagujia River basin are discussed by using the non-uniform coefficients, concentration degree and concentration period, variation range, etc. The results indicate that: (1) River runoff is very unevenly distributed throughout the year in Dagujia River. About 90% of runoff is in the period from June to October, while the runoff from November to April of the next year is lower. (2) The annual runoff distribution characters during 1966-1971 are very similar to that of 1982-1996, and the runoff of 1972-1981 is almost similar to that of 1997-2004. (3) The annual runoff distribution characters have changed obviously during 1997-2004 compared with the other periods, which makes it more difficult to exploit and use the water resource in the future.

透水丁坝孔型对坝体附近水流特性影响研究

为深入探讨透水丁坝透水孔型对其附近水流特性的影响,通过室内高精度水槽试验,采用三维声学多普勒流速仪对矩形、方圆形和椭圆形三种透水孔型下丁坝附近水流流速进行测量,获得不同透水孔型影响下的丁坝附近水流流速和紊动强度分布特征。结果表明,坝后水流流速波动和紊动强度明显大于坝前,透水丁坝对近坝区水流影响较大,距丁坝越远,流速均匀性越好,紊动强度越小。透水丁坝的缓流效果与透水孔型密切相关,矩形透水孔的坝后缓流率为35.4%,缓流效果较好,方圆形透水孔次之,椭圆形最小,研究结果可为丁坝的透水孔型选择提供指导和参考。

多孔套筒定向压裂力学机制及影响因素分析

坚硬顶板破断释放巨大冲击动能是诱发煤矿动力灾害的重要因素之一,在特定位置断顶实现岩层的定向断裂、减小坚硬顶板悬顶长度是防治煤岩动力灾害的关键。多孔套筒压裂技术具有操作简单、适用条件广泛等优点,在坚硬顶板弱化领域有着广泛的研究前景。为深入了解多孔套筒压裂机理,采用理论分析与数值模拟方法开展了多孔套筒压裂力学机制研究,揭示了不同影响因素下孔间应力变化规律,获得了压裂过程裂缝扩展规律及力链分布特征。通过钻孔切槽可提升套筒压裂预裂效果,为确定合理的布孔参数,基于线弹性断裂力学建立了含预制缝多孔套筒压裂力学模型,给出了缝端应力强度因子、临界膨胀力及裂缝临界起裂角计算方程,获得了不同影响因素下缝端应力强度因子、临界膨胀力及临界起裂角的变化规律。研究结果表明:①侧压系数k对钻孔最小起裂应力影响显著,当侧压系数k>1时,最小起裂应力随布孔角度的增大而减小;当侧压系数k<1时,最小起裂应力随布孔角度的增大而增大。②数值模拟结果表明:套筒间存在应力叠加效应,接触力链呈“放射状”分布。套筒压裂过程以张拉破坏为主,孔心连线处变形破坏最剧烈,均沿布孔方向形成了“条带状”断裂面。③缝槽改变了缝端附近的应力分布,相较无缝槽模型环向拉应力更大。当缝槽长度为0.5倍孔半径时,临界膨胀力最小,裂缝最易发生扩展。④临界起裂角由KⅠ与KⅡ共同决定,且小于70.53°。在泵压与地应力条件无法改变的情况下,可通过调节布孔角度与预制缝槽长度实现岩石的定向压裂。

表面菱形孔795 nm VCSEL的偏振特性

795 nm垂直腔面发射激光器(VCSEL)作为铷基芯片级原子钟(Rb-CSAC)的光源,其输出光的偏振不稳定会降低Rb-CSAC的稳定度和精确度。为了满足Rb-CSAC对795 nm VCSEL偏振稳定的需求,设计了一种具有表面菱形孔的偏振稳定的795 nm VCSEL。通过有限时域差分(FDTD)法计算了VCSEL的偏振特性,结果表明VCSEL的顶部分布式布拉格反射镜(DBR)在表面菱形孔的长轴和短轴方向具有不同的反射率。反射率高的偏振模式阈值增益低,成为VCSEL优先激射的主导偏振模式。为进一步提高VCSEL的偏振抑制比(OPSR),将VCSEL的氧化孔制作成尺寸为5.5μm×4.1μm的菱形。对不同长、短轴的表面菱形孔795 nm VCSEL进行偏振测试,结果表明,当表面菱形孔的尺寸为4μm×6μm,且菱形氧化孔的长轴与表面菱形孔的长轴相互垂直时,VCSEL的OPSR可达到16.22 dB。

切眼外错下孤岛工作面开采冲击危险性分析及防治措施

受矿井地质条件、开采布局及采掘接续不合理等影响,工作面布置时会留设孤岛工作面,严重影响矿井安全开采。为解决切眼外错下孤岛工作面开采冲击危险的难题,以高庄煤矿3_(上)1105孤岛工作面为例,采用理论分析、数值模拟、数据统计与分析相结合的研究方法,分析了孤岛工作面开采时覆岩结构特征、切眼外错区域应力分布规律以及巷道围岩稳定性。结果表明:切眼外错下3_(上)1105工作面开采期间超前支承应力峰值达到54.1 MPa,基于巷道围岩受力状态及变形量确定了冲击危险区域主要分布在3_(上)1107工作面切眼前后0~30 m范围。针对切眼外错区域采取了大直径钻孔卸压,通过现场监测及检验,微震、钻屑均未超过预警临界值,卸压解危效果良好。

基于Aegis的无底柱分段崩落法中深孔爆破过程模拟与应用

无底柱分段崩落法因其回采效率高、结构简单、安全性高等优势被广泛应用于地下金属矿开采,其落矿方式常采用中深孔爆破。针对传统无底柱分段崩落法中深孔爆破设计过程繁琐、模拟效果不够直观等问题,开展了基于爆破设计与分析软件Aegis的中深孔爆破过程模拟与应用研究。首先介绍了该软件的模块构成和功能,并梳理和总结了模拟分析流程;其次研究了利用模型边界限制爆破空间以及利用爆炸能量的交错状态校验孔网参数的两项关键技术;最后基于该软件对某地下矿山无底柱分段崩落法中深孔爆破进行了数值模拟。研究结果表明:单排炮孔内爆炸能量集中且充盈了整个爆腔,连续耦合的装药结构以及0.3 kg/t的炸药单耗设计较为合理;临排炮孔间爆腔壁呈相切的状态,可能存在排间能量不足以完全破碎岩体的情况,2.2 m的炮孔排距稍大;预测的多条进路爆破块度质量分布结果均出现大块占比偏高的情况,与现场的工程实践结果一致,并以其中一次爆破后的爆堆照片为例进行说明,其大块率达到了18.03%。结合Aegis软件的模拟结果,分析炮孔排距偏大可能是导致大块率偏高的主要原因。此外还对实验分段的6个开采进路进行了12次爆破试验并加以模拟验证,得到了基本一致的爆破块度质量占比结果,有效佐证了该软件的现场应用效能。

异形孔电解加工流场仿真分析

针对航空发动机零部件中的花瓣状异形孔电解加工难题,文中建立了异形孔工件三维模型并抽取流道模型,对其进行流场仿真和优化。结合电场仿真计算,通过电流密度分布预测工件阳极型面的溶解差异,完成了阴极成型边界的修正。通过流场和电场分析,优化了通液孔的数量、大小和布局,以及阴极外形曲线,完成阴极结构设计。仿真结果表明:设置加工参数电解液入口压力为0.6 MPa,出口压力为0.1 MPa时,工件表面的电解液流速、压力以及加工区域工件边界的电流密度均具有良好的均匀性。

宝山矿业公司破碎筛分系统优化

随着宝山矿业公司铁精矿、稀土精矿产量的增加,需要提高球磨机处理量来增加产量,而提高球磨机处理能力最有效的措施就是增加球磨机给料的细粒级含量,实现多碎少磨。文章对宝山矿业公司现有破碎筛分系统进行了优化,通过改进破碎机布料器、调整中碎机偏心距、改进振动筛筛网筛孔尺寸,细碎机台时产量提高了40.71 t/h,破碎机作业率大幅度降低;中碎机衬板使用寿命延长了15天,细碎机衬板使用寿命延长了30天;振动筛的筛分效率由81.43%提高至84.70%,其筛下-12 mm含量由81.43%增加至94.12%;球磨机处理量增加至380 t/h,为铁精矿、稀土精矿的增产创造了条件。

反循环气动潜孔锤进气端分流引射接头设计及结构参数分析

为解决反循环气动潜孔锤在钻进过程中岩石重复破碎及排渣效率低下的问题,笔者基于NGQ-320反循环气动潜孔锤设计了进气端分流引射接头。该接头可实现潜孔锤供气量的动态调节,其引射结构可以将部分压缩气体引入中心通道,对井底流场产生泵吸作用的同时改善冲击机构的动力供给;同时采用CFD技术研究了分流引射接头局部流场,分析了喷射孔夹角、喷射孔开口深度、喷射孔直径和喷射孔偏转角度等参数对中心通道抽吸性能的影响,确定了各项结构参数的较优取值。结果表明,分流引射接头在喷射孔开口深度320~330 mm、喷射孔夹角30°~35°、喷射孔直径12 mm、喷射孔偏转角11°~13°的情况下具有较好的抽吸性能。