基于分形理论的菱镁矿粉磨程度表征研究

为了研究菱镁矿粉磨程度的定量表征，以辽宁丹东地区菱镁矿为原料，进行了磨矿试验、粒度检测试验、磨矿细度试验，应用分形理论，建立了用于表征粉磨菱镁矿颗粒粒度分布的体分形维数数学关系。结果表明:体分形维数与磨矿细度呈非线性关系，当体分形维数均值达到极大值，即D₃=2.4662时，对应的磨矿细度为-0.074 mm含量81.6%，通过浮选试验发现此时浮选指标最好。该研究实现了菱镁矿粉磨程度的定量表征，建立了体分形维数与选矿浮选的联系。      

A two-stage vision-based method for measuring the key parameters of ball screws

Ball screws are crucial for improving the reliability and interchangeability of transmission mechanical systems; however, existing contact measurement methods that utilise stylus contact are not efficient, which precludes their use for rapid in-situ geometry evaluation. This paper presents a vision-based two-stage method for rapid measurement of key parameters (raceway arc radii and centre distance) of ball screws. The edge contour information is extracted from the acquired image using the dual-tree complex wavelet transform and non-maximal suppression. In the matching stage, a shape-matching algorithm is used for detecting approximate geometrical centres of raceway arcs. The refinement stage, on the other hand, is implemented for acquiring precise dimensional results. Furthermore, the method of averaging multiple measurements is performed to suppress random noise. A comparative experiment is presented to validate the robustness of the proposed method. Based on experimental results, the calculated mean absolute errors in the measurement of the two raceway arc radii and the centre distance are found to be 0.0082 mm, 0.0079 mm and 0.0055 mm, respectively. This study therefore paves the way for key parameter measurement without removing ball screws.     

Fe-BHA用于白钨矿的浮选分离

将FeCl3与苯甲羟肟酸按一定比例混合,形成一种金属离子螯合物Fe-BHA,用于白钨矿-方解石人工混合矿浮选分离。在pH值为7.7时,取得最佳的白钨精矿回收率为68.00%,白钨矿分离指数为2.83,可实现白钨矿在较高精矿回收率的前提下与方解石的有效分离;而在白钨矿-萤石人工混合矿的浮选分离试验中,在pH值11.0时,取得的萤石精矿回收率为78.20%,分离指数为3.51,理论上可以实现白钨矿与萤石的分离。Fe-BHA用于香炉山白钨矿实际矿石的粗选验证试验,在适宜条件下,可获得产率为30.53%、精矿中WO3品位为1.56%、回收率为63.50%的白钨精矿,相比同条件下单独使用苯甲羟肟酸的浮选结果较好。白钨矿的红外光谱证明了Fe-BHA在白钨矿表面化学吸附的存在。     

An extended software defined optical networks slicing architecture

Optical Networks are composed of multiple devices, from multiple vendors. Normally these networks have a huge transmission capacity. The Slicing of Optical Networks is not a new concept, but continues to be very important, since the capacity of Optical Networks keeps evolving. Most of the time the slicing is manually configured by system operators. Besides being laborious and error-prone, such configuration limits the clients’ ability to customize and configure the network according to their own needs. One way out of this problem is to separate from these devices the control of and the data from the planes. The Software Defined Networks (SDNs) propose the separation of planes while also offering network operators the flexibility to create and manage applications, enabling them to reduce the network costs by globally optimizing the network’s resources, reducing the staff needed to configure it, and contributing for less violation of the service level agreement (SLA). SDN can also help operators to maximize their profit by generating more revenue through mechanisms that increase availability and failure resiliency, maximize throughput, allow for fast dynamic reprovisioning and enable network virtualization. The goal of this paper is to propose a Software Defined Optical Networks Slicing Architecture (SONA) extension (eSONA). that permits defining components such as topology manager, inventory manager, slice manager and path provisioner, and thus enable Optical Networks slicing. It has proved to be capable of managing different slices and provisioning a path on a given slice over the same physical optical network. It has showed an excellent performance, taking little time to provision paths, even with a large number of nodes, which are crucial for optical environments.     

基于多尺度CSRBFs的地层三维地质建模

基于矿山多源数据实现地层三维地质建模是数字矿山研究中的一项重要工作，其成果有助于矿山资源评估、生产规划编制等工作的有序进行。采用插值方法对离散采样的非均匀点状数据进行处理，是精准构建矿体模型的关键。然而，矿体建模常用的插值方法在处理数据时，很少有效顾及数据的非均匀性。基于多尺度CSRBFs插值方法，提出了一种可以处理非均匀数据的地层三维建模技术。首先从多源数据中提取非均匀的地质离散点数据集。然后，使用多尺度CSRBFs插值构建地层表面模型，插值步骤包括：①样品点获取与单位法向量计算；②通过八叉树空间索引构建层次点集；③使用多尺度CSRBFs方法在样品点集上由粗到细逐层插值，计算地层表面隐式函数；④地层隐式曲面可视化。最后，使用提出的断层建模方法在连续地层表面构建正断层、逆断层和交叉断层模型。研究表明：多尺度CSRBFs（Multi-scale CSRBF， MsCSRBF）插值方法通过十折交叉验证获得的平均误差为0.943 m，精度优于反距离加权法（Inverse Distance Weighted， IDW）和普通克里金法（Ordinary Kriging， OK），且MsCSRBF方法相比于IDW和OK方法插值运算效率更高。上述分析表明：多尺度CSRBFs差值方法能够针对非均匀数据进行地层表面模型的高精度、快速重建。     

Microemulsion synthesis of ms/tz-BiVO4 composites: The effect of pH on crystal structure and photocatalytic performance

In this work, BiVO₄ composites, containing the tetragonal zircon phase (tz-BiVO₄), and monoclinic scheelite phase (ms-BiVO₄), were synthesized using the microemulsion method. The effect of pH on phase composition and photocatalytic activity were investigated. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), a ms/tz-BiVO₄ composite forms at pH = 1.0 and pure ms-BiVO₄ is obtained in the pH range 4.0–10.0. The three primary steps in preparing BiVO₄ were monitored by optical microscopy and the role played by the microemulsion on the phase composition of BiVO₄ is explained. Photoluminescence spectroscopy (PL), UV–visible diffuse reflectance spectroscopy (UV-DRS), Brunauer-Emmett-Teller (BET), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were employed to characterize the physical and chemical properties of BiVO₄ composites. The composite formed at pH = 1 exhibited the lowest hole-electron (h⁺-e^-) recombination rate, resulting in the highest photocatalytic activity towards microcystin-LR (MC-LR), with near 100% removal of MC-LR in 5 h. ESR and trapping experiments indicated that MC-LR degradation was mediated primarily by hydroxyl radicals (•OH), superoxide radicals (O₂^•−) and photogenerated holes (h⁺).     

二维反三角超混沌系统及其在图像加密上的应用

为了进一步提高混沌系统的混沌特性，为图像加密算法提供更可靠的混沌系统，增强图像加密算法的安全性，提出了一种基于二维反三角超混沌系统的新型图像加密算法。首先，在一维三角混沌函数的基础上构建了一个二维反三角超混沌系统，通过分岔图和Lyapunov指数等仿真实验，验证了该系统具有更广的混沌区间和更强随机性的迭代序列，遍历性更加优秀；然后，基于此混沌系统，采用"置乱-扩散"策略，根据不同密钥生成的不同超混沌序列，对图像矩阵进行无重复置乱和循环移位扩散，循环三次得到密文，完成加密过程；最后，对图像加密方案进行了直方图分析、密钥空间分析、相邻像素相关性分析、明文敏感性分析和信息熵分析等性能测试。其中密文图像的相关指标参数像素变化率（NPCR）和统一平均变化强度（UACI）的测试值非常接近于它们的理想期望值，信息熵的测试结果约为7.997，也非常接近于理想期望值8。实验结果表明，此图像加密系统具有更可靠的安全性，抵抗攻击能力强，在图像安全领域具有较好的应用前景。     

Computation and investigation of mode characteristics in nonlinear system with tuned/mistuned contact interface

This study derived a novel computation algorithm for a mechanical system with multiple friction contact interfaces that is well-suited to the investigation of nonlinear mode characteristic of a coupling system. The procedure uses the incremental harmonic balance method to obtain the nonlinear parameters of the contact interface. Thereafter, the computed nonlinear parameters are applied to rebuild the matrices of the coupling system, which can be easily solved to calculate the nonlinear mode characteristics by standard iterative solvers. Lastly, the derived method is applied to a cycle symmetry system, which represents a shaft–disk–blade system subjected to dry friction. Moreover, this study analyzed the effects of the tuned and mistuned contact features on the nonlinear mode characteristics. Numerical results prove that the proposed method is particularly suitable for the study of nonlinear characteristics in such nonlinear systems.     

1250°C liquidus for the CaO–MgO–SiO2–Al2O3–TiO2 system in air

Ti-bearing blast furnace slags have been regarded as an important secondary material in modern society, and the efficient recycling of Ti oxides from it is of key interest. For this reason, more thermodynamic data is needed regarding the phase relations in different composition ranges and sections. Therefore, the equilibrium phase relations of CaO–MgO–SiO₂–Al₂O₃–TiO₂ system in a low w(CaO)/w(SiO₂) ratio of 0.6–0.8 at 1250 °C in air and fixed concentrations of MgO and Al₂O₃, were investigated experimentally using a high temperature equilibration and quenching method followed by SEM-EDS (Scanning Electron Microscope and Energy Dispersive X-ray Spectrometer) analyses. The equilibrium solid phases of perovskite (CaO·TiO₂), a pseudo-brookite solid solution (MgO·2TiO₂, Al₂O₃·TiO₂)_ss, and anorthite (CaO·Al₂O₃·2SiO₂) were found to coexist with the liquid phase at 1250 °C. The calculated results of Factsage and MTDATA were used for comparisons, and significant discrepancies were found between predictions and the experimental results. The 1250 °C isotherm has been constructed and projected on the CaO–SiO₂–TiO₂-8 wt.% MgO-14 wt% Al₂O₃ quasi-ternary plane of the phase diagram. The obtained results provide new fundamental data for Ti-bearing slag recycling processes, and they add new experimental features for thermodynamic modeling of the high-order titanium oxide-containing systems.     

Transient shrinkage behavior of wustite-centered binary/ternary/quaternary/quinary-component oxide packed beds in a reducing atmosphere up to 1773 K

Wustite (FeO)-centered multicomponent oxides play an important role in the ironmaking process, and a complete understanding of their high temperature behaviors is of great importance for process optimization to achieve high efficiency and low emissions during industrial production. In this work, the transient shrinkages of FeO-centered multicomponent oxide packed beds are quantitatively determined in a reducing atmosphere up to 1773 K, and the effects of the interactions between the oxides on the shrinkage rate (SR) are qualitatively evaluated. The results show that although mixing CaO with FeO increases the SR to 0.42%/K below 1173 K, further mixing with SiO₂ or Al₂O₃ significantly limits this enhancement effect due to the formation of an olivine or spinel phase. However, in the subsequent stage, the SR increases to as high as 0.44%/K after CO is injected. The interaction between FeO and MgO leads to an SR of greater than 0.20%/K at lower temperatures, but it causes a decrease in the SR from 0.33%/K to 0.16%/K between 1173 K and 1273 K. Meanwhile, adding SiO₂ slows the reduction reaction, and the SR correspondingly decreases further to 0.04%/K. On the other hand, the interaction between CaO and Al₂O₃ takes precedence over the interaction between SiO₂ and MgO and dominates the shrinkage process in the quinary-component case, and the preferentially formed CaAl₂O₄ spinel phase hinders the formation of the Mg₂SiO₄ olivine phase.