基于门控循环单元与误差修正的短期负荷预测

针对负荷预测模型迭代训练过程中存在误差积累的问题,提出结合叠式双向门控循环单元（SBiGRU）、完整自适应噪声集成经验模态分解（CEEMDAN）和误差修正的组合预测模型. 建立SBiGRU模型学习在气温、日期类型影响下负荷序列的时序特征,误差特征体现在SBiGRU模型预测产生的误差序列中;使用CEEMDAN算法将误差序列分解为数个本征模态函数（IMF）分量与趋势分量,对每项分量再次建立SBiGRU模型进行学习与预测,并对各分量的预测值进行序列重构,得到误差的预测结果;对预测结果进行求和以修正误差. 模型评估结果表明,组合模型的预测准确精度为98.86%,与SBiGRU、BiRNN、支持向量回归等方法相比,该模型具有更好的精度.     

低压电器产品紧固螺钉的计算及设计

对低压电器螺钉连接的强度进行了理论分析和探讨。得出螺钉连接的可靠性设计数据，对金属薄板件小螺纹孔翻边成形的设计提出了设计依据和数值。     

YWZ2电力液压制动器的可靠性考核

介绍了ＹＷＺ２电力液压制动器的故障形式分类及加权系数，给出了可靠性考核的样品故障记录，并对考核结果进行了分析。     

Wind-Thermal Environmental Characteristic of Multi-Variable Passive Enhanced Natural Ventilation System for High and Large Space Building

Natural ventilation effects in high and large space buildings of tropical areas greatly affect the air conditioning energy consumption. Aiming at nearly zero energy building design, this paper mainly contributes to provide theoretical basis and reference for thermal comfortable air conditioning system design of high and large space buildings. Taking a theatre in Hainan as study object, a newly composite enhanced natural ventilation system is proposed by integrating the underground tunnel-based earth to air heat exchange system and the solar chimney. Ventilation quantity, air velocity and air temperature field, human vertical temperature gradient difference under 24 simulation working conditions are considered and analyzed by using ANSYS Fluent. For the underground tunnel, results show that Group Two with double underground tunnels and side air supply location shows its advantages in cooling effects and air supply uniformity. Then for the solar chimney, results show that the solar radiation intensity contributes to larger difference in transmission power and leads to different cooling effects. On the whole, the system under working condition No. 7 with 120 m long, side air supply, double underground tunnel and 20 m high, 1 m wide, 0.6° absorber plate angle solar chimney shows its priority in better comprehensive performance.     

具有输出网络的有源R滤波器的设计

本文提出具有输出网络的双运放二阶有源R滤波器的综合设计原理.用无源网络的综合方法解决有源网络的综合问题.在实现双二次函数的滤波特性时文中提出的电路具有输出阻抗低的优点.     

位置伺服系统的变结构模型跟踪控制

本文用变结构系统和滑模控制理论对一般位置系统的自适应模型跟踪控制提出了一种新的方法。该控制系统保持了现有自适应模型跟踪系统的优良特性,并能在参考模型阶数低于对象模型的条件下,保证系统输出快速跟踪其模型输出。理论分析和仿真结果表明:该控制方法设计简单,便于在线实现,并能同时应用于半闭环系统和全闭环系统。此外,该控制系统鲁棒性强,能明显改善系统的动态特性。     

Synthesis of alkali-metal-doped C60 nanotubes

C₆₀ nanotubes have been synthesized by a solution-solution method. After degassing in a dynamic vacuum, the C₆₀ nanotubes doped with alkali metals by means of vapor evaporation method. Different temperatures have been studied to evaporate the alkali metals for the doping experiments. Raman spectrum was further employed to analyze the doping concentration of the obtained samples. It was found that all three alkali metals (Li, Na and K) used can be efficiently doped into the C₆₀ nanotubes, forming A_xC₆₀ nanotubes. The doping concentration of Li, Na changed from low to high level, depending on the experiment temperatures, while K doping always gave saturated doping. The melt points, the ionic sizes and vapor pressures of alkali metals were thought to affect the final doping results.     

Superconductive superhard phase of BC7: Predicted via ab initio calculations

We present a first-principles study on a phase of BC₇ with Amm2 space-group symmetry (we call o-BC₇), which is selected from more than a dozen of candidates via energetic, mechanical and dynamical stabilities within a wide pressure scale from 0 to at least 100 GPa. Our calculated results show that this structure is highly incompressible with large bulk and shear modulus of 388 GPa and 430 GPa, respectively, which is even higher than cubic BN. Further investigations revealed that the Vickers hardness (H_v ≈ 49.5 GPa) is higher than t-BC₃ reported recently. And the superconducting critical temperature is calculated to be 38 K, which is comparable to that of MgB₂.     

Numerical simulation and validation of gas-particle rectangular jets in crossflow

This paper presents a numerical study of a gas-particle flow in three inclined rectangular jets in crossflow. The predicted gas phase velocities and particle phase velocities are validated against previously reported experimental data. Two turbulence models, the standard k-? model and Shear Stress Transfer (SST) model, are used to model the gas phase turbulence. This work shows that both models provide acceptable predictions of the gas flow and mixing generated by the three jets. Neither model could accurately reproduce the jet core and the flow near bottom wall. The particle phase in this flow comprises a large number of small particles. Thus particles follow the gas phase flow closely and any errors in the turbulence model and gas flow predictions are passed on to the particle phase simulation. This paper also includes a literature review on rectangular jets in crossflow and gas-particle laden jets in crossflow.     

Three new five-coordinated mercury (II) dyes: Structure and enhanced two-photon absorption

A new donor-bridge-acceptor (D-π-A) type ligand (L: 4′-(4-[4-(imidazole)styryl]phenyl)-2,2′:6′,2″-terpyridine) with two-photon absorption and coordination ability was designed and synthesized. Self-assembly of the ligand with HgX₂ (X = Cl, Br, I) yielded a series of new coordination complexes (Dyes 1-3) with five-coordinated mercury (ΙΙ), which were characterized by single crystal X-ray diffraction determination. Solvent molecules and various weak interactions, including hydrogen bonds (C-H···N, C-H···X) and π-π interactions played significant roles in the final topological structures. Linear and nonlinear optical properties of the ligand and three dyes were described. Experimental results revealed that two-photon absorption cross sections of three dyes are extraordinary stronger than that of ligand.