基于多因素改进型PSOSVM算法的中长期负荷预测

中长期负荷预测作为电力规划与调度中的重要一环,其影响因素有着多样性和不确定性等特点.选取支持向量机作为中长期负荷预测的核心算法,筛选多种区域宏观经济因素,利用粒子群(PSO)寻优与循环寻优的改进型算法对支持向量机(SVM)的参数进行优化及负荷预测.仿真结果显示,改进型PSOSVM算法有着较高的预测精度.     

5G NR FDD与WCDMA系统共存研究

为推动5G在中频段的重耕,研究了中频段NR FDD系统与WCDMA系统在相同地理区域邻频共存时的系统间干扰造成的性能损失,分析了在不同功率参数、不同拓扑结构、AAS/NON-AAS 2种天线模型下,4个干扰场景的仿真结果.最后给出NR FDD系统与WCDMA系统共存建议以及共存措施.     

A MAC protocol to support hybrid antennas in a wireless LAN

Hybrid Distributed Coordination Function （HDCF）, a modified medium access control protocol of IEEE 802.11 standard, is proposed in this paper to support both smart adaptive array antennas and normal omni-directional antennas simultaneously in one wireless LAN. Omni-directional antennas follow the standard Distributed Coordination Function （DCF） and smart antennas follow the Directional DCF （DDCF）. The proposed DDCF is based on Hybrid Virtual Carrier Sense （HVCS） mechanism, which includes Omni-directional Request-To-Send/Clear-To-Send （ORTS/OCTS） handshake mechanism and directional data transmission. HDCF is compatible with DCF. When a node transmits in a directional beam, the other nodes can multiplex the physical channel. Hence, HDCF supports Space Division Multiple Access （SDMA）. Simulation results show that HDCF can support hybrid antennas effectively and provide much higher network throughput and lower delay and jitter than DCF does.     

A new procedure for determining specific filter cake resistance from filtration data

A new procedure has been developed for the determination of specific filter cake resistance from experimental filtration data. Unlike the conventional procedure which treats constant-pressure filtration data through the t/V vs. V plot and yields a single value of the average specific cake resistance (α_av) from a given experiment, this new procedure allows the establishment of the relationship of α_av vs. the cake compressive stress (p_s) over a range of p_s values. Results from the new procedures were compared with those obtained from the procedure based on the t/V vs. V plot as well as those from compression-permeability (C-P) measurements. Discussions on the possible improvement of the new procedure are also presented.     

Platinum Nanoparticles Anchored on TiO2/C Nanowires as a High Performance Catalyst for Hydrogen Peroxide Eletroreduction

In this paper, we employed the as‐prepared TiO₂/C core/shell nanoarrays (TiO₂/C) obtained by a facile thermal evaporation method as a three‐dimensional (3D) architecture to support Pt nanoparticles through an optimized electrodeposition process. The morphology and structure of the as‐prepared electrode are characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Its catalytic performance towards H₂O₂ electroreduction in basic medium is evaluated by linear sweep voltammetry (LSV) and chronoamperometry (CV). Results revealed that the electrode exhibits significantly high catalytic activity. The current density reached –0.172 A cm⁻² in 1 mol dm⁻³ NaOH and 0.5 mol dm⁻³ H₂O₂ at –1.1 V (vs. Ag/AgCl). This high performance might be due to the 3D electrode architecture inheriting the high electronic conductivity from carbon shell and providing a short pathway for the ion diffusion, and the using of Pt owning an excellent catalytic activity.     

变压器油质量的主要影响因素及改进探讨

评价变压器油电气性能的指标主要是介质损耗因素（90℃）、击穿电压。而变压器油介质损耗因素、击穿电压的影响因素主要是杂质和水分。润滑油茂名分公司通过改造抽真空过滤系统,增强脱水效果,有效降低介质损耗因素和含水量,提高击穿电压,确保变压器油的质量。     

CaO—CaF_2—SiO_2熔剂脱磷脱硫特性的研究

在 P_(co)=1atm,1300℃条件下研完了 CaO-CaF_2-SiO_2三元渣用作中磷铁水预处理熔剂进行脱磷脱硫的特性。研究结果表明:CaO饱和的 CaO-CaF_2-SiO_2三元渣具有很强的同时脱磷脱硫能力,组成为48%CaO、22%SiO_2、30%CaF_2的渣的磷容量为10~(25),硫的分配系数10~3以上。     

Deposition of boron-containing coatings by electron-beam evaporation of boron-containing targets

Boron-containing films are promising materials for improving the hardness, wear-resistance and durability of mechanical parts used in industry. We describe a novel approach for deposition of such coatings – by using electron-beam evaporation of boron-containing target material (pure boron or boron nitride) in inert (helium) or chemically-active (oxygen, nitrogen, residual atmosphere) gases at medium vacuum. Boron-containing films deposited on titanium substrates were characterized using a nanohardness tester and a non-contact 3D profilometer. Elemental composition of the coatings was studied using raster electron microscope equipped with a device for EDX analysis. All boron-containing coatings provided significant improvement (by a factor of 4–16) in the microhardness of the substrate surface.     

水辅助注塑大直径介质导管制品的冷却分析

采用数学分析方法，通过假设、简化分析模型，用数学模型来表述物理模型，确定了水辅助注塑(VAIM)大直径介质导臂制品的冷却时间，并运用算例和国外试验的结果进行验证。结果发现：水辅助注射成型新工艺可以更加显著地缩短注塑周期，降低制件壁厚，允许制件有更大的实际直径。因此，VAIM技术可用来高效率地生产大直径、高质量、薄壁的介质导臂。     

直硝高压釜损坏原因分析及改进设想

介质内氧化性物质的腐蚀性及釜内外压差与外压失稳等是造成直硝高压釜损坏的直接原因 ,提出了相应改进方案