非同轴多层介质椭圆柱体的电磁散射—任意方向斜入射电磁波

本文基于椭圆柱谐基函数展开，对非同轴任意多层介质椭圆柱体的电磁散射进行了严格地电磁场分析，利用Ｍａｔｈｉｅｕ函数及其加法定理，在各层边界面上进行场的匹配，获得了任意方面斜入射电磁波下电磁散射解析解。     

Microwave dielectric properties of Ca[(Li1/3Nb2/3)1−x Tix]O3−δ ceramics with glass

The effect of the addition of glass on the densification, low temperature sintering, and microwave dielectric properties of the Ca[(Li_1/3Nb_2/3)_1−x Ti_x]O_3−δ(CLNT) was investigated. Addition of glass (B₂O₃-ZnO-SiO₂-PbO system) improved the densification and reduced the sintering temperature from 1150^∘C to 900^∘C of Ca[(Li_1/3Nb_2/3)_1−x -Ti_x]O_3−δ microwave dielectric ceramics. As increasing glass contents from 10 wt% to 15 wt%, the dielectric constants (ε_r) and bulk density were increased. The quality factor (Q⋅f₀), however, was decreased slightly. The temperature coefficients of the resonant frequency (τ_f) shifted positive value as increasing glass contents over Ti content is 0.2 mol. The dielectric properties of Ca[(Li_1/3Nb_2/3)_0.75Ti_0.25]O_3−δ with 10 wt% glass sintered at 900^∘C for 3 h were ε_r = 40 Q·f₀ = 11500 GHz, τ_f = 8, ppm/°C. The relationship between the microstructure and dielectric properties of ceramics was studied by X-ray diffraction (XRD), and scanning electron microscope (SEM).     

Y对Al-Zr合金微观组织与性能的影响

研究了不同Y含量(0.02%,0.05%,0.10%)对Al-0.16Zr合金铸态、轧制态和时效态的微观组织、硬度和电导率的影响。结果表明,Y含量为0.05%和0.10%时,能显著的细化合金晶粒。随着Y含量增加,晶粒细化效果逐渐增强。铸态Al-0.16Zr合金在350℃时效过程中,Y添加具有显著的时效强化效果,Y含量越高,达到峰值时效所需时间越短。但是由于共格Al3Zr沉淀相的析出,点阵失配畸变场的存在将导致合金电导率降低。而在轧制态合金的时效过程中,位错密度的降低引起退火软化,但是Y的添加仍明显提高了合金的硬度。综合考虑,轧制态Al-0.16Zr-0.10Y合金经350℃×30h时效后具有最优的硬度和电导率。     

乙硫氮作捕收剂时无机调整剂加药顺序对典型硫化矿物浮选的影响

研究了乙硫氮作捕收剂时无机调整剂硫酸锌、亚硫酸钠、硫化钠和硫酸铜不同加药顺序对典型硫化矿物黄铜矿、方铅矿、闪锌矿和黄铁矿浮选行为的影响.结果 表明,调整剂与捕收剂的加药顺序对硫化矿物浮选的影响不同.与调整剂先加时相比,乙硫氮先加,硫酸锌对黄铜矿和方铅矿浮选的抑制作用减弱;硫酸锌、低用量硫酸铜、亚硫酸钠或硫化钠对闪锌矿浮...     

一类非线性不确定系统的鲁棒H∞控制

针对自由系统、外部干扰输入矩阵和控制输入矩阵都具有加法不确定性的一类非线性不确定系统,利用Hamilton-Jacobi不等式,得到了非线性不确定系统具有鲁棒H∞特性的充分条件,并且给出了控制器的一种形式。     

The effects of hydrogen addition on soot formation in counterflow diffusion n-heptane flames

The effects of H₂ addition on soot formation are investigated in counterflow diffusion n-heptane flames. Three effects including chemical, thermal, and dilution are fully isolated and characterized by additions of H₂, He, and Ar. Soot volume fractions are measured using LE-calibrated LII technique, and flame temperatures are measured using OH-TLAF method along with a thermocouple. Numerical simulations are conducted with a detailed mechanism with soot model. The simulated soot volume fractions and flame temperatures are in good agreement with experimental data. The experimental results show that H₂ addition can greatly reduce the soot formation. It is also found that the chemical and dilution effects suppress soot formation, while the thermal effect with increasing flame temperature promotes soot formation. Kinetic analysis suggests that HACA growth rate could be the dominant factor that controls the final soot formation through the three effects due to H₂ addition.     

Digital workplace transformation: Subtraction logic as deinstitutionalising the taken-for-granted

Digital technology enables the transformation of work and workplaces. Previous digital workplace transformation (DWT) literature has shown how organisations add new digital technologies to create new workplace routines. However, such an emphasis on addition may hinder scholarship from recognising that some established workplace technologies and routines must disappear for new ones to emerge. Adopting the concept of deinstitutionalisation, we examine the rationale for and the process of how an organisation abandons workplace routines that conflict with its intended DWT. Referring to this as subtraction logic, we advance two contributions. First, we conceptualise how deinstitutionalisation of established workplace routines and technologies unfolds in DWT by outlining a process model that synthesises addition and subtraction. Second, we highlight the underlying rationales for DWT. With these insights, we shift the gaze from the dominant addition logic, which advocates for appropriating new digital technologies, to the equally important value of subtraction, i.e., removing existing workplace technologies (or inscribed institutional rules) to abandon workplace routines that conflict with the intended DWT. Hence, our study highlights the oft-ignored subtraction logic in DWT.