Impact of Heat Treatments and Hole Density (p) on the Structural, Electrical, and Superconducting Properties of LnSrBaCu3O6+z (Ln = Eu, Sm, Nd) Compounds

In this study, we thoroughly examined the impact of heat treatments and hole count (p) on the properties of LnSrBaCu3O6+z (Ln = Eu, Sm, Nd) compounds. We focused on preparation, X-ray diffraction with Rietveld refinement, AC susceptibility, DC resistivity measurements, and heat treatment effects. Two heat treatment types were applied: oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. As the rare earth Ln’s ionic radius increased, certain parameters notably changed. Specifically, c parameter, surface area S, and volume V increased, while critical temperature Tc and holes (p) in the CuO2 plane decreased. The evolution of these parameters with rare earth Ln’s ionic radius in [AO] heat treatment is linear. Regardless of the treatment, the structure is orthorhombic for Ln = Eu, tetragonal for Ln = Nd, orthorhombic for Ln = Sm [AO], and pseudo-tetragonal for Sm [O]. The highest critical temperature is reached with Ln = Eu (Tc [AO] = 87.1 K). Notably, for each sample, Tc [AO] surpasses Tc [O]. Observed data stems from factors including rare earth ionic size, improved cationic and oxygen chain order, holes count p in Cu(2)O2 planes, and in-phase purity of [AO] samples. Our research strives to clearly demonstrate that the density of holes (p) within the copper plane stands as a determinant impacting the structural, electrical, and superconducting properties of these samples. Meanwhile, the other aforementioned parameters contribute to shaping this density (p).

活性金属Ni d电荷密度对Ni_(2)P/Al_(2)O_(3)催化剂菲加氢性能的影响

高温煤焦油中菲含量高,将菲深度加氢饱和得到全氢菲,可提升菲利用率,且全氢菲密度大,热值高,可作为喷气燃料理想组分。然而,在菲加氢反应过程中菲与中间加氢产物的竞争吸附不利于菲在催化剂上吸附活化,且对称八氢菲进一步加氢是菲加氢饱和过程的速控步骤,其吸附活化困难不易解决,催化剂活性难以满足加氢需求。根据稠环芳烃与过渡金属间π络合吸附机理,在反应物吸附活化过程中,稠环芳烃分子和活性金属分别充当电子供体和电子受体,故Ni基催化剂中活性金属Ni处于缺电子状态时利于生成全氢菲,但关于Ni缺电子量及其电子结构如何影响催化剂菲、对称八氢菲加氢性能的原因需进一步探究。此外,基于负载型Ni_(2)P催化剂稳定性高、耐硫、耐氮性强等优势,采用次磷酸盐歧化法通过调变P/Ni物质的量比制备具有不同Ni d电荷密度的Ni2P/Al_(2)O_(3)催化剂,考察Ni d电荷密度对菲、对称八氢菲吸附和反应性能的影响规律。结果表明,在320℃、5 MPa、空速1 309 h-1反应条件下,Ni-2.5P/Al_(2)O_(3)催化剂转换频率fTO最高(44.64×10^(-3)s^(-1))。通过吸附活化熵描述菲、对称八氢菲与催化剂表面间相互作用强度,发现菲、对称八氢菲在不同Ni-xP/Al_(2)O_(3)催化剂表面吸附强度不同。通过定量计算Ni d电荷密度,明确了Ni2P/Al_(2)O_(3)催化剂用于菲加氢反应时适宜Ni d电荷密度约-0.24 e,对称八氢菲加氢反应适宜的Ni d电荷密度约-0.05 e。

预热温度对激光选区熔化成形30%SiC_(p)/AlSi10Mg复合材料力学性能的影响

基板常温工况下激光选区熔化成形中等体积分数SiC_(p)/Al复合材料存在孔洞、裂纹等冶金缺陷,从而导致成形零件致密度低、力学性能差等问题。首先研究了固定优化成形工艺参数时,基板预热温度(200~400℃)对45μm的30%(质量分数,下同)SiC_(p)/AlSi10Mg成形零件表观致密度和力学性能的影响;进一步提高SiC_(p)质量分数至50%,再次评价了上述基板预热温度对成形性能的影响。结果表明,当SiC_(p)质量分数为30%时,升高基板预热温度可以减少成形零件的孔洞和裂纹,成形零件的表观致密度及力学性能显著提高;当基板预热至400℃时,成形零件表观致密度最高达到97.98%,与此同时极限抗压强度和极限抗拉强度分别为578 MPa和56 MPa;随着SiC_(p)质量分数进一步增加至50%,基板预热温度对成形零件致密化和力学性能的强化效果逐步减弱。本研究证明高温预热基板能够有效抑制激光选区熔化成形中等体积分数SiC_(p)/Al复合材料的冶金缺陷,为增材制造SiC_(p)/Al复合材料提供了工程应用解决方案。

Modified White Hole Enthalpy Coupled to Quantum Bose-Einstein Condensate at Extremely Low Entropy

We model the universe as a white hole, and in the process we perform detailed analysis of the enthalpy equation of the modified white hole, and we get a much detailed picture of when and how did;quantum gravity (cosmology) phase, inflationary phase, and the acceleration phase of the universe happened. We determine the field equations of the modified white hole and evolve the scale factor and compare the evolution to the thermodynamic properties of the universe. We also illustrate that the strong energy condition is violated, but both the null energy condition and the strong cosmic censorship are not violated. Lastly, we couple the enthalpy to the Bose-Einstein condensate at extremely low entropy at the quantum gravity (cosmology) regime. Thereafter, we determine the unstable condition of the Bose-Einstein quantum equation which we interpret as the moment when the big bang occurred.

Thin bed responses and correction methods for cased hole density logging

The study of the thin bed responses and correction methods in cased hole density logging can provide a theoretical basis for research to improve data processing methods. By using the Monte Carlo program MCNP, the change of detector count from thin beds with the vertical depth was calculated at different casing thicknesses. The calculation showed that with the low density thin bed moving upward, detector count first increased to a maximum then decreased. The responses of a thin bed with a high density were opposite to those of a thin bed with a low density. The change curve was symmetrical, and the maximums or minimums appeared at the midpoint between the detector and source. Besides, detector count increased with increasing thin bed thickness. At a specific thin bed thickness, further increase of thin bed thickness resulted in a slow increase of detector count then the count rate leveled off. In actual logging, the influence of adjacent formations on density log measurements can be ignored. Finally, based on numerical simulation correction methods for the dual influence of casing and thin beds are discussed.

NeoMinkowskian Cosmological Black Hole, Poincaré’s Gravific Electron and Density of CBR

In the previous paper (JMP 2014) we showed that there exists a NeoMinkowskian Gravitational Expanding Solution of GR (General Relativity) with CC (Cosmological Constant). We prove now that NeoMinkowskian Vacuum (non-baryonic Fluid), with gravitational (first) density (dark energy) and gravitational waves (at light speed), corresponds to the Gravitation Field of a Cosmological Black Hole (CBH). The latter predicts furthermore a basic emission of Radiation (CBR) from Hubble spherical singular Horizon to the inside of CBH (unlike Hawking’s emission) at an initial singular time. Our solution is then compatible with a well-tempered Big Bang and Expanding Universe (Escher’s Figure, see Penrose, 3) but incompatible with inflation. The latter is based on Hypothesis of a so-called Planck’s particle (Lemaitre’s primitive atom) characterized by a so-called Planck length. We prove that we can short-circuit this unstable particle with a stable cosmological Poincaré’s electron with gravific pressure. It is well known that electron is a stranger in usual Minkowskian vacuum (dixit Einstein). The stranger electron can be perfectly integrated in NeoMinkowskian Radiation fluid and then also (with its mass, charge and wavelength) in (second density of) CBR. Everything happens as if the leptonic mass of the electron were induced by our cosmological field. The unexpected cosmological model proposed here is the only one that predicts numerical values of (second) density and temperature of CBR very close to the observed (COBE) values.

A Review of Density Holes Upstream of Earth＇s Bow Shock

Larmor size transient structures with density depletions as large as 99%of ambient solar wind density levels occur commonly upstream of Earth’s collisionless bow shock.These "density holes" have a mean duration of 17.9±10.4s but holes as short as 4 s have been observed.The average fractional density depletion（δn/n） inside the holes is 0.68±0.14.The density of the upstream edge moving in the sunward direction can be enhanced by five or more times the solar wind density. Particle distributions show the steepened edge can behave like a shock,and measured local field geometries and Mach number support this view.Similarly shaped magnetic holes accompany the density holes indicating strong coupling between fields and particles.Current densities as large as 150nA·m-2 are observed at the leading compressed edge.The waves are elliptically polarized and rotating in the sense of ions（left hand） in the plasma frame.The waves appear to grow and steepen as the density holes convect with the solar wind toward the Earth.The transient nature of density holes suggests that the temporal features could represent the different stages of nonlinear evolutionary processes that produce a shock-like structure.The density holes are only observed with upstream particles,suggesting that back-streaming particles interacting with the solar wind are important. The significance of these observations is still being investigated.

How Kieffer Density Matrix Formalism Aids Different Initial Time Steps, Leading to Lorentz Violations, and Breakup of Primordial Black Holes for GW Generation

A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early universe Lorentz Violation. The author asserts that the existence of early universe Lorentz violation in turn is assisting in a breakup of primordial black holes. And that also has a tie into Kieffer different time steps as outlined. And the wrap up is given in the final part of this document.

PO2X…PX3/PH2X(X=F,Cl,Br,CH3,NH2)复合物中π-hole磷键作用的电子密度拓扑分析

磷键作为一种新型的分子键合力,因在晶体工程和超分子合成等方面的重要作用而越来越多地引起科研工作者的广泛关注。本文采用量子化学从头算和电子密度拓扑分析等方法,在MP2/aug-cc-pVTZ理论水平上,对PO_2X…PX_3和PO_2X…PH_2X(X=F,Cl,Br,CH_3,NH_2)π型复合物的结构和磷键性质进行了理论研究。研究表明:π-hole磷键复合物存在A和B两种稳定构型,分别以P…P和P…X磷键作用为主。分子中原子(AIM)、非共价作用(NCI)、电子定域函数(ELF)及适应性自然密度划分(AdNDP)分析表明,不同取代基对该类磷键作用的性质产生很大影响:当取代基为给电子基(CH_3,NH_2)时,磷键具有明显的共价作用特征;当取代基为吸电子基(F,Cl,Br)时,构型和取代基不同的磷键分别表现为非共价、部分共价或共价作用特征。自然键轨道(NBO)分析指出,分子间磷键的Wiberg键级的数值越大,磷键的共价性越强,磷键的作用强度越大。构型B的电荷转移主要是PX_3/PH_2X中X原子上的孤对电子转移到PO_2X中π*(P=O)反键空轨道。

Optimization of hole-boring radiation pressure acceleration of ion beams for fusion ignition

In contrast to ion beams produced by conventional accelerators,ion beams accelerated by ultrashort intense laser pulses have advantages of ultrashort bunch duration and ultrahigh density,which are achieved in compact size.However,it is still challenging to simultaneously enhance their quality and yield for practical applications such as fast ion ignition of inertial confinement fusion.Compared with other mechanisms of laser-driven ion acceleration,the hole-boring radiation pressure acceleration has a special advantage in generating high-fluence ion beams suitable for the creation of high energy density state of matters.In this paper,we present a review on some theoretical and numerical studies of the hole-boring radiation pressure acceleration.First we discuss the typical field structure associated with this mechanism,its intrinsic feature of oscillations,and the underling physics.Then we will review some recently proposed schemes to enhance the beam quality and the efficiency in the hole-boring radiation pressure acceleration,such as matching laser intensity profile with target density profile,and using two-ion-species targets.Based on this,we propose an integrated scheme for efficient high-quality hole-boring radiation pressure acceleration,in which the longitudinal density profile of a composite target as well as the laser transverse intensity profile are tailored according to the matching condition.

Effects of mask wall angle on matrix-hole shape changes during electrochemical machining by mask

The influences of the mask wall angle on the current density distribution,shape of the evolving cavity and machining accuracy were investigated in electrochemical machining(ECM) by mask.A mathematical model was developed to predict the shape evolution during the ECM by mask.The current density distribution is sensitive to mask wall angle.The evolution of cavity is determined by the current density distribution of evolving workpiece surface.The maximum depth is away from the center of holes machined,which leads to the island appearing at the center of cavity for mask wall angles greater than or equal to 90°(β≥90°).The experimental system was established and the simulation results were experimentally verified.The results indicate that the simulation results of cavity shape are consistent with the actual ones.The experiments also show that the repetition accuracy of matrix-hole for β≥90° is higher than that for β<90°.A hole taper is diminished,and the machining accuracy is improved with the mask wall angle increasing.

Pre-stack seismic density inversion in marine shale reservoirs in the southern Jiaoshiba area, Sichuan Basin, China

For a typical marine shale reservoir in the Jiaoshiba area, Sichuan Basin of China, P-impedance is sensitive for identifying lithology but not suitable for indicating good shale reservoirs. In comparison, density is an important quantity, which is sensitive for identifying the organic-rich mud shale from non-organic-rich mud shale. Due to the poor data quality and incidence angle range, density cannot be easily inverted by directly solving the ill-posed pre-stack seismic inversion in this area. Meanwhile, the traditional density regularizations implemented by directly using the more robust P-impedance inversion tend to be inaccurate for recovering density for this shale reservoir. In this paper, we combine the P-impedance and the minus uranium to construct the pseudo-P-impedance（PIp） at well locations. The PIp is observed to be sensitive for identifying organic-rich mud shale and has a good correlation with density in this area. We employ the PIp–density relation into the pre-stack inversion framework to estimate density. Three types of regularization are tested on both numerical and field data： These are no regularization, traditional regularization and the proposed approach. It is observed that the proposed method is better for recovering the density of organic-rich mud shale in the Jiaoshiba area.

Quantum Entropy of Black Hole with Internal Global Monopole

Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole entropy calculation through original brick-wall model is overcome. The result of the direct proportion between black hole entropy and its event horizon area is drawn and given. The result shows that the black hole entropy must be the entropy of quantum state near the event horizon.

Low-Density Co-Inoculation with Bradyrhizobium japonicum SAY3-7 and Streptomyces griseoflavus P4 Promotes Plant Growth and Nitrogen Fixation in Soybean Cultivars

Inoculation density has a marked effect on nodulation and N fixation in soybean (Glycine max L.). Therefore, we conducted this study to determine the optimal inoculation density of Bradyhizobium japonicum SAY3-7 (SAY3-7) and Streptomyces griseoflavus P4 (P4) for plant growth, nodulation, and N fixation, and to investigate the effect of co-inoculation on selected soybean cultivars, using the optimal inoculation density. Nitrogen fixation, in terms of an acetylene reduction activity value, was measured using a flame ionization gas chromatograph. In this study, low-density single inoculation with P4 (105 or 106 cells mL-1) was associated with the highest plant biomass, compared with normal- and high-density single inoculation with P4 (107 or 108 cells mL-1). Moreover, low-density single or co-inoculations with SAY3-7 and/or P4 produced the highest nodule biomass and highest nitrogenase activity, compared with single or dual inoculation at other inoculation densities. Therefore, we evaluated low-density co-inoculation with P4 and SAY3-7, at the rate of 105 cells mL-1, on selected soybean cultivars. Low-density co-inoculation increased the plant biomass, compared with un-inoculated plants. The effects of single and co-inoculation on nodulation did not differ significantly for any of the cultivars, except “Yezin-9” in the first experiment and “Shan Seine” in the second experiment. Low-density inoculation with both bacteria increased N fixation by 15% - 75% for seven of the cultivars in the first experiment and by 15% - 39% for three of the cultivars in the second experiment, compared with single inoculation with SAY3-7. Based on the overall results, we concluded that low-density co-inoculation with P4 and SAY3-7 gave improved plant growth and N fixation.

2D Modeling of Solar Cell Radial Junction: Study of Carriers Charge Density and Photocurrent Density in Static Mode under Monochromatic Illumination

A theoretical study of a polysilicon solar cell with a radial junction in static regime under monochromatic illumination is presented in this paper. The junction radial solar cell geometry is illustrated and described. The carriers’ diffusion equation is established and solved under quasi-neutral base assumption with boundaries conditions and Bessel equations. New analytical expressions of electrons and holes density and photocurrent are found. The wavelength and structural parameters (base radius, emitter thickness) influences on charge carriers density and photocurrent are shown and examined.

Valence band structure and density of states effective mass model of biaxial tensile strained silicon based on k·p theory

After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k·p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states （DOS） effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal-oxide semiconductor field effect transistor （MOSFET）. It also a provides valuable reference for biaxial tensile strained silicon MOSFET design.

含P_3H_3的π-hole磷键作用及取代效应的理论研究

采用量子化学计算方法,在MP2/aug-cc-pVDZ理论水平上对P_3H_3…NCX(X=H,F,Cl,Br,CN,CF_3,OH,CH_3,NH_2,OCH_3)π-hole磷键作用的性质以及取代基的影响进行了理论研究,分析了复合物的稳定结构、相互作用的强度、电子给体和电子受体间的轨道作用及电子密度拓扑性质等.研究表明,P_3H_3与NCX间的π-hole磷键作用为闭壳层非共价相互作用;色散和静电作用占主导地位,极化作用较小.NCX中不同取代基对氮原子上的静电势产生较大影响,进而改变了π-hole磷键作用的强度;较强的吸电子基(CN,CF_3,F)减弱了π-hole磷键作用强度,给电子基(OH,CH_3,OCH_3,NH_2)增加了相互作用的强度.复合物P_3H_3…NCOH中由于存在很强的LP(P)→BD*(O—H)的轨道作用,分子间相互作用强度明显增加.

Theoretical Study of Specific Heat and Density of States of MgB₂Superconductor in Two Band Model

MgB2 with Tc ≈ 40 K, is a record-breaking compound among the s-p metals and alloys. It appears that this material is a rare example of the two band electronic structures, which are weakly connected with each other. Experimental results clearly reveal that boron sub-lattice conduction band is mainly responsible for superconductivity in this simple compound. Experiments such as tunneling spectroscopy, specific heat measurements, and high resolution spectroscopy show that there are two superconducting gaps. Considering a canonical two band BCS Hamiltonian containing a Fermi Surface of π- and σ-bands and following Green’s function technique and equation of motion method, we have shown that MgB2 possess two superconducting gaps. It is also pointed out that the system admits a precursor phase of Cooper pair droplets that undergoes a phase locking transition at a critical temperature below the mean field solution. Study of specific heat and density of states is also presented. The agreement between theory and experimental results for specific heat is quite convincing. The paper is organized in five sections: Introduction, Model Hamiltonian, Physical properties, Numerical calculations, Discussion and conclusions.

Performance improvement of blue InGaN light-emitting diodes with a specially designed n-AlGaN hole blocking layer

Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.

用Copula方法得到强关联多电子体系的交换-相关穴

电子关联是多电子体系中的一个基本课题.为了描述这种关联性,人们可以引入交换-相关穴的概念、本文首先简要地回顾了交换-相关穴的定义、它与电子密度和电子对密度的关系,以及它们与概率统计学中的Copula函数之间的紧密联系.然后,提出了一个基于Copula函数的方法,从电子密度中得到交换相关穴.可以预期,所提出的方案将有助于强关联电子结构计算的未来发展.