Systematic study on the proton radioactivity of spherical proton emitters

In this study, based on a two-potential approach, we systematically investigated the proton radioactivity half-lives of spherical proton emitters with 69≤Z≤81 from the ground and/or isomeric state, choosing the nuclear potential to be a modified Woods–Saxon potential that contains the isospin effect of the daughter nucleus. It was found that the calculated half-lives could reproduce the experimental data well. Furthermore, we extended this model to predict the half-lives of 17 protonemitting candidates whose radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. For comparison, the unified fission model, Coulomb potential and proximity potential model, universal decay law for proton emission, and new Geiger–Nuttall law were also used. All the predicted results are consistent with each other.

Supersymmetry and Shape Invariance of Hartmann Potential and Ring-Shaped Oscillator Potential in the γ and θ Dimensions of Spherical Polar Coordinates

This article shows that in spherical polar coordinates, some noncentral separable potentials have super-symmetry and shape invariance in the r and θ dimensions, we choose Hartmann potential and ring-shaped oscillator astwo important examples, thus in principle the energy eigenvalues and energy eigenfunctions of such the potentials in ther and θ dimensions can be obtained by the method of supersymmetric quantum mechanics. Here we use an alternativemethod to get the required results.

Time-like geodesic structure of a spherically symmetric black hole in the brane-world

Recently Malihe Heydari-Fard obtained a spherically symmetric exterior black hole solution in the brane-world scenario, which can be used to explain the galaxy rotation curves without postulating dark matter. By analysing the particle effective potential, we have investigated the time-like geodesic structure of the spherically symmetric black hole in the brane-world. We mainly take account of how the cosmological constant α and the stellar pressure β affect the time-like geodesic structure of the black hole. We find that the radial particle falls to the singularity from a finite distance or plunges into the singularity, depending on its initial conditions. But the non-radial time-like geodesic structure is more complex than the radial case. We find that the particle moves on the bound orbit or stable （unstable） circle orbit or plunges into the singularity, or reflects to infinity, depending on its energy and initial conditions. By comparing the particle effective potential curves for different values of the stellar pressureβ and the cosmological constant α, we find that the stellar pressure parameter β does not affect the time-like geodesic structure of the black hole, but the cosmological constant a has an impact on its time-like geodesic structure.

Anisotropic Geodesic Fluid in Non-Comoving Spherical Coordinates

We start with a recently introduced spherically symmetric geodesic fluid model (arXiv: 1601.07030) whose energy-momentum tensor (EMT) in the comoving frame is dust-like with nontrivial energy flux. In the non-comoving energy frame (vanishing energy flux), the same EMT contains besides dust only radial pressure. We present Einstein’s equations together with the matter equations in static spherically symmetric coordinates. These equations are self-contained (four equations for four unknowns). We solve them analytically except for a resulting nonlinear ordinary differential equation (ODE) for the gravitational potential. This ODE can be rewritten as a Lienard differential equation which, however, may be transformed into a rational Abel differential equation of the first kind. Finally, we list some open mathematical problems and outline possible physical applications (galactic halos, dark energy stars) and related open problems.

肉源性芽孢杆菌致腐性能异质性研究

为评估芽孢杆菌的致腐潜能异质性,本研究以从腐败低温香肠中分离出来的6株芽孢杆菌为研究对象,探究其在20℃(常温)和37℃(最适生长温度)条件下的致腐性能。试验分别测定了6株芽孢杆菌的生长曲线、产酸能力、产气能力、蛋白酶活力、脂肪酶活力和淀粉酶活力。结果表明,蜡样芽孢杆菌(C)的产酸能力较强,在37℃条件下培养48 h,pH较空白组下降0.71;解淀粉芽孢杆菌(G)的产蛋白酶和淀粉酶的能力更强,其蛋白酶活力高达7.17 U/mL,37℃条件下培养至5 d的淀粉分解圈面积为16.53 cm^(2);蜡样芽孢杆菌(C)的综合腐败能力最弱,具体表现为其蛋白酶活力为2.63 U/mL,37℃条件下培养5 d的淀粉分解圈面积为7.55 cm^(2)。同时发现生长温度对菌株致腐性能有较大影响。研究结果说明芽孢杆菌菌株的致腐性能存在显著的异质性,在探究其腐败特性时,应充分考虑菌株的异质性。

考虑球面副间隙的4-SPS/CU并联机构动力学分析

基于机械系统动力学方程的增广法建立考虑球面副间隙的4-SPS/CU并联机构动力学模型。为了简化该并联机构的动力学模型,通过质量矩的方法视驱动支链为一个整体。根据含间隙球面副元素的接触方式建立该间隙运动副的运动学模型,求出含间隙球面副元素之间的接触变形量与相对接触速度。考虑到接触体之间接触刚度与机械系统动力学模型之间的耦合性,以非线性刚度系数代替Flores接触模型中的常数刚度系数而提出一种改进的接触力模型,并基于该接触力模型利用接触变形量与相对法向接触速度建立间隙运动副元素之间的法向接触力模型,为了保证数值运算的稳定性,采用具有动态修正系数的Coulomb摩擦模型,建立接触体之间的切向接触力模型。进一步把间隙运动副元素之间的接触力转换到该间隙运动副所连接的驱动支链和上平台的质心上,并把该接触力集成到4-SPS/CU并联机构动力学模型的广义力中,从而成功引入了关节间隙效应,采用Baumgarte稳定约束法避免了积分过程中的约束违约问题。通过数值分析预测球面副间隙对4-SPS/CU并联机构动力学性能的影响。

基于PPO的球形机器人目标跟随研究

球形机器人由于其优异的运动性能、出色的地形适应能力和防侧翻的特性,被广泛应用于水下探测、岸滩巡检等需要适应复杂环境的场景。然而球形机器人系统模型具有欠驱动、非线性的特点,运动控制问题复杂,在复杂应用环境下难以可靠跟随目标。为此,提出了一种基于近端策略优化(PPO)算法的球形机器人目标跟随方法。该方法基于深度强化学习理论,在球形机器人动力学模型的基础上,设计了简单高效的动作空间和表征完善的状态空间。并且为提高目标跟随方法的鲁棒性,该方法在奖励函数中引入人工势场,以使目标始终保持在机器人视野中心。仿真结果表明,所提方法能够满足既定场景的跟随需求,球形机器人使用该方法可以对随机运动目标进行可靠跟随。

易卒中型自发性高血压大鼠(SHR-SP)基底动脉反应性的研究

应用细胞内微电极记录法 ,以血管平滑肌细胞膜电位为指标 ,研究了易卒中型自发性高血压大鼠基底动脉对有代表性的二类激动剂氯化钾 (KCl) ,去甲肾上腺素 (NE)及乙酰胆碱 (ACh)的反应性。观察到SHR- SP基底动脉平滑肌细胞膜电位 (Em)为 (- 45.7± 3.9) m V,明显低于 Wistar大鼠的 (- 55.1± 2 .0 )m V(P<0 .0 5) ,故其反应性增强。KCl(1 0～ 50 mmol/L)及 NE(1 0 -8～ 1 0 -6mol/L)引起膜电位的去极化 ,ACh(1 0 -7～ 1 0 -5mol/L)引起膜电位超极化 。

Modeling static friction behavior of elastic–plastic spherical adhesive microcontact in full-stick condition

The static friction behavior of an elastic–plastic spherical adhesive microcontact between a rigid flat and a deformable sphere under combined normal and tangential loading is studied by the finite element method(FEM).The contact between the sphere and the rigid flat is assumed to be full-stick,and the sliding inception is related to a loss of tangential stiffness.The intermolecular force between the rigid flat and the sphere is assessed by the Lennard–Jones(LJ)potential,which is applied to the sphere and the rigid flat by a user subroutine.The evolution of the adhesive force with tangential displacement in the full-stick condition is revealed.The results indicate that the increasing effect of adhesive energy on the static friction coefficient gradually diminishes with an increase in the adhesive energy and the external normal load.Finally,based on an extensive parametric study,an empirical dimensionless expression is obtained to predict the static friction coefficient of the spherical adhesive microcontact considering the intermolecular force.

自然电位SP测井测试方法研究和维修案例分析

自然电位测井是最早用于地球物理勘探测井的电法测井方法之一,能直观判断岩性,计算地层水电阻率,故应用广泛。在实际应用中,由于其容易受到各种原因的干扰常常取不到理想的SP曲线。本文通过针对典型故障分析SP信号通路控制方式,对通路进行合理的方法检测和典型案例分析,探讨ERTT61XA的SP测试方法及维修技巧。

数值计算的SP-3图版

传统的ＳＰ－３图版是６０年代在实验室由电阻网络模型获得的，随着计算机技术的发展，需要新的方法取而代之。数值模式匹配法是一种已趋于成熟的方法，将其应用于ＳＰ－３图版的计算。为了处理复杂的偶极层，引入了等效原理，给出了ＳＰ－３图版之中４张的结果，以供测井分析人员研究和使用。比较表明，电模型的结果和数值计算的结果具有很好的一致性。

Hierarchical model for strain generalized streaming potential induced by the canalicular fluid flow of an osteon

A hierarchical model is developed to predict the streaming potential （SP） in the canaliculi of a loaded os teon. Canaliculi are assumed to run straight across the os teon annular cylinder wall, while disregarding the effect of lacuna. SP is generalized by the canalicular fluid flow. Ana lytical solutions are obtained for the canalicular fluid veloc ity, pressure, and SP. Results demonstrate that SP amplitude （SPA） is proportional to the pressure difference, strain am plitude, frequency, and strain rate amplitude. However, the key loading factor governing SP is the strain rate, which is a representative loading parameter under the specific phys iological state. Moreover, SPA is independent of canalicu lar length. This model links external loads to the canalicu lar fluid pressure, velocity, and SP, which can facilitate fur ther understanding of the mechanotransduction and electro mechanotransduction mechanisms of bones.

金属离子诱导Aspergillus sp. WL-Au合成纳米金的特性

纳米金凭借其独特的光电特性、良好的稳定性及生物相容性被广泛应用于工业催化、污染控制及医学诊断等领域。近年来,微生物法合成纳米金具有绿色低毒、条件温和、成本低廉等优势而倍受关注。然而,如何对纳米金的形貌尺寸进行定向调控仍有待进一步探究。该研究选取Fe^(3+)、Zn^(2+)、Al^(3+)、Co^(2+)、Ni^(2+)、Pb^(2+)及Sn^(2+)等多种金属离子,诱导曲霉菌(Aspergillus sp.) WL-Au合成纳米金,对其形貌进行定向调控。紫外-可见光谱分析结果表明,经Fe^(3+)、Sn^(2+)诱导的菌株合成的纳米金分散性较好,其余金属离子诱导菌株合成的纳米金单分散性较差、易沉聚。透射电子显微镜分析结果表明,大多数金属离子诱导菌株合成的纳米金为球形和伪球形,有少量的三角形;其中,经Fe^(3+)诱导后,菌株WL-Au胞外合成形貌均一、粒径较小的球形纳米金,而经Pb^(2+)诱导后,合成形貌均一的纳米棒。此外,Fe^(3+)诱导菌株合成的球形纳米金对4-硝基苯酚具有良好的催化还原性能,其催化速率常数k为13.3×10^(-3)s^(-1)。研究表明曲霉菌(Aspergillus sp.)WL-Au经Fe^(3+)诱导后可显著提高胞外合成纳米金的能力,且合成的纳米金具有形貌均一、分散性好、催化速率高的特点,在催化还原污染物方面具有较好的应用潜力。

Existence Theorem of the Multipliers on Riemannian Symmetric Space SL(3,H)/SP(3)

Using the method of Clerc and Stein study the multipliers of spherical Fourier transform on symmetric space to proof the multipliers theory for the space SL(3,H)/SP(3), completely avoid the complex theory of Anker, and we have gain the same result. Key words Riemannian symmetric space SL(3,H)/SP(3) - multipliers - spherical Fourier transform - invariant differential operator CLC number O 152.5 - O 186.12 Biography: LIAN Bao-sheng (1973-), male, Master, research direction: Li group and Lie algebra.

Confining Potential and Mass of Elementary Particles

In this paper we consider a model in which the masses of elementary particles are formed and stabilized thanks to confining potential, which is caused by recoil momentum at emission of specific virtual bosons by particle itself. The calculation of this confining potential Ф(R) is carried out. It is shown that Ф(R) may be in the form const or const depending on continuous or discrete nature of the spectrum of emitted bosons.

改进麻雀搜索算法的自然电位数据反演

自然电位法是一种成本低廉,野外观测操作简便的天然源地球物理勘探方法。自然电位数据反演具有病态和非线性的特征。常规反演算法分为局部优化类和全局搜索类,但基于梯度运算的局部优化算法难以求得全局最优解且反演效果依赖于初始模型的构建,而传统全局搜索算法又存在收敛速度慢,易陷入局部极值和不稳定的缺点。基于此,对一种新的全局优化策略(麻雀搜索算法)进行改进,通过混沌映射叠加反向学习策略初始化麻雀种群,再依随机概率使用Levy飞行策略更新麻雀个体位置来进一步提升算法对于解空间的探索能力和增强算法跳出局部极值的可能性。将改进前后的麻雀搜索算法分别应用于合成自然电位数据(不含与含10%、30%的随机噪声)与来自印度和法国的实测数据的反演解释中以对比检验改进算法的反演效果。理论测试结果表明:麻雀搜索算法(SSA)在无噪声干扰下的垂直圆柱和倾斜板模型数据反演误差为0.42%和0.25%,相同情况下改进麻雀搜索算法(ISSA)的反演误差为0.06%和0.07%,改进后算法拟合精度提高到3~7倍,对比目标函数收敛曲线图中ISSA的收敛速度与收敛精度都要明显优于SSA;SSA反演参数的稳定性、精度和异常响应曲线拟合程度都会随着随机噪声的加入变差,并且随着随机噪声幅值的扩大,反演效果变差的程度表现得更加剧烈;相反,ISSA既能保持快速收敛,又能获得更小的异常响应曲线拟合误差。实际数据反演结果进一步验证了改进麻雀搜索算法具有更快的收敛速度,更强的抗干扰能力和更高的反演精度以及稳定性,可有效地应用于自然电位数据的定量解释或者推广至求解其他地球物理反问题。

Reconnaissance Geophysical Study on the Southeastern Part of Al-Qashah Aera, KSA

The investigated study area locates about 72 km from Jeddah City, Makkah District, Kingdom of Saudi Arabia. The study mainly aimed to define the most significant zones of possible mineralization and outline their subsurface parameters (location and strike) in the southeast of Jabal Al-Qashah. Several geophysical methods have been conducted to carry out the goal, including ground magnetic, self-potential (SP), and induced polarization (IP) methods. Integrating these methods aims to help delineate the possible mineralization in the study area. The magnetic survey was conducted along 17 profiles where these profiles were chosen to be perpendicular to the strike of the quartz shear zone. Self-potential was applied along with five profiles covering the study area. At the same time, induced polarization was used along with one profile located at the western side of the study area corresponding to some magnetic and SP profiles. The most interesting zones of mineralization were successfully determined by comparing the results of residual magnetic profile (3), SP profile (1), and IP profile, where geological structures control some mineralization.

Convergence of Spherical Harmonic Series Expansion of the Earth＇s Gravitational Potential

Given a continuous boundary value on the boundary of a ＂simply closed surface＂ as that encloses the whole Earth, a regular harmonic fictitious field V＊（P） in the domain outside an inner sphere Ki that lies inside the Earth could be determined, and it is proved that V＊（P） coincides with the Earth＇s real field V（P） in the whole domain outside the Earth. Since in the domain outside the inner sphere Ki and the fictitious regular harmonic function V＊（P） could be expressed as a uniformly convergent spherical harmonic series, it is concluded that the Earth＇s potential field could be expressed as a uniformly convergent spherical harmonic expansion series in the whole domain outside the Earth.

梭菌对含镁方解石形态的控制及其可能机理

在Mg/Ca摩尔比为4∶1的Lagoa Vermelha培养基中对一株分离自青海湖底沉积物的梭菌SN-1(Clostridiumsp.)进行了为期55d的碳酸盐矿物培养实验,同时还完成了一组无菌对照实验。利用扫描电子显微镜对沉淀物进行了系统的观察,用X-射线衍射仪对沉淀物的矿物成分进行了测定。结果表明:(1)SN-1可以促进特殊形态含镁方解石的形成,而无菌对照实验产物中仅见不规则状的碳酸盐矿物;(2)特殊形态的含镁方解石可能是在细菌表面成核和生长的结果,它们的演化趋势是(杆状)→哑铃形→花菜状→球形。作者认为这是因为梭菌两端的带负电基团比菌体中间丰富,易聚集更多的Ca2+和Mg2+,Ca2+和Mg2+离子作为"阳离子桥"吸引CO32-,其结果是两端的晶体生长相对较快、中间生长相对较慢,进而形成哑铃形含镁方解石;"哑铃"继续生长,其两端会长成两个"花菜"或半球;若两个半球相接并闭合则发展为球状矿物。

热压与放电等离子体烧结两种工艺制备Al_2O_3/Cu复合材料

由机械合金化法(MA)制得纳米级Al2O3颗粒弥散镶嵌于微米级Cu颗粒表面的复合粉末,利用球形化工艺改善所制得复合粉的形貌及粒度范围,分别采用热压法(HP)和放电等离子体烧结(SPS)法制备Al2O3/Cu复合材料。通过测试密度、电导率、抗弯强度及SEM复合粉形貌和烧结体断口分析、微区成分分析,对比研究了Al2O3质量分数分别为0%、0.5%、1.0%、1.5%时Al2O3/Cu复合材料的物理、力学和电学性能。结果表明:不同制备工艺下随着Al2O3含量增加,材料的抗弯强度先增后降,电导率除受杂质影响外,还受材料缺陷的影响,故变化规律不明显,对于Al2O3含量相同的Al2O3/Cu复合材料,采用SPS法制备的复合材料的致密度、抗弯强度及电导率均高于HP法;在弯曲应力下两种制备方法所得复合材料均发生延性断裂。