对铅酸蓄电池用红丹的认识

红丹,被选为铅酸蓄电池铅氧化物作电池活性物料,应该是“原始级”的,它曾被用于涂膏式和管式正极板,以改善极板化成时间,提高深循环性能。但是,在最近几十年,红丹使用几乎消失。今天,由于同样的历史原因,很多公司又考虑在他们的极板中使用或已经使用红丹。本文也基于今天的原因,想通过对铅蓄电池中红丹的一些认识,讨论红丹的物理和化学性质,进一步了解它在铅酸蓄电池生产中对电池生产、性能、节约成本潜力的影响,也包括它的生产和处理方法,企与同仁交流。     

Quantum transport of pseudospin-polarized Dirac fermions in gapped graphene nanostructures

We investigate the unusual features of the quantum transport in gapped monolayer graphene, which is in a pseudospin symmetry-broken state with a net perpendicular pseudomagnetization. Using these pseudoferromagnets (PFs), we propose a perfect pseudospin valve effect that can be used for realizing pseudospintronics in monolayer graphene. The peculiarity of the associated effects of pseudospin injection and pseudospin accumulation are also studied. We further demonstrate the determining effect of the sublattice pseudospin degree of freedom on Andreev reflection and the associated proximity effect in hybrid structures of PFs and a superconductor in S/PF and PF/S/PF geometries. In particular, we find a peculiar Andreev reflection that is associated with an inversion of the z component of the carriers pseudospin vector. Our results show that the gapped normal graphene behaves like a ferromagnetic graphene and the effect of the pseudospin degree of freedom in gapped graphene is as important as the spin in a ferromagnetic graphene.     

离子液体/聚合物电解质在双电层电容器中的应用

以P(VDF-HFP)为基体,与离子液体1-乙基-3-甲基咪唑钅翁四氟硼酸盐(EMIBF4)和1-丁基-3-甲基咪唑钅翁六氟磷酸盐(BMIPF6)制备出离子液体/聚合物电解质凝胶膜,并组装了活性炭电极双电层电容器(EDLC)。基于EMIBF4/P(VDF-HFP)和BMIPF6/P(VDF-HFP)聚合物电解质(质量比2∶1)的双电层电容器,比电容分别为38.5 F/g和20.9 F/g。基于EMIBF4/P(VDF-HFP)的双电层电容器显示了优良的电化学性能。     

超高功率型双电层电容器的研制

双电层电容器作为一种新型的功率储能器件,具有储能密度高、放电功率大、环境适应能力强等特点.利用涂覆工艺制备了活性碳电极,设计了具有低直流内阻特点的双电层电容器结构,并在此基础上组装了超高功率双电层电容器.经过直流放电、短路放电、温度特性、寿命特性的电化学特性测试,结果显示该电容器峰值功率密度达到16.54 kW/kg,...     

Engineered tunneling layer with enhanced impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

Here, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on th...     

Effect of lateral strain on gate induced control of electrical conduction in single layer graphene device

We study numerically the effect of various types of in-plane strain on the electronic transport property in the single layer graphene connected to two metallic electrodes, with the special attention to the dependences on the gate voltage, channel length, the type of strain, and the strength of the strain. Our calculations have shown that the combination of the shear and the armchair-directional strain can be used to obtain a clear threshold behavior in the gate voltage dependence of the current as expected from the previously reported strain induced bandgap opening. Moreover, we predict the strain induced increase of the current density for small strain regime.     

Towards realistic modeling of plasmonic nanostructures: a comparative study to determine the impact of optical effects on solar cell improvement

Journal of Computational Electronics - Plasmonic structures may improve cell performance in a variety of ways. More accurate determining of the optical influence, unlike ideal simulations, requires...     

负序方向元件在同杆双回线中的动作行为分析

由于同杆双回线自身的特殊性,使得在常规线路保护中有着广泛应用的负序方向元件的性能受到影响。从同杆双回线的故障特点出发,利用六序故障分量法分析了负序方向元件在同杆双回线各种典型故障情况下的动作行为。结果表明,在发生ⅠBCⅡBG,ⅠBCⅡCG跨线故障时,Ⅱ回线两侧的负序方向元件有可能拒动;在发生ⅠAⅡBCG,ⅠABCⅡBCG,ⅠABCⅡAG跨线故障时,两回线路总有一回线路两侧的负序方向元件拒动。利用电磁暂态仿真软件PSCAD/EMTDC搭建同杆双回线仿真模型,仿真结果也验证了这一结论。     

煤基活性炭用作双电层电容器电极材料

以云南小发路煤矿产无烟煤为原料,KOH为活化剂制取双电层电容器用高比表面积活性炭电极材料。系统考察了活化剂用量、活化时间和活化温度对活性炭电容特性的影响。研究结果表明,在mKOH/m无烟煤=4、升温速度为4℃/min、活化温度为750℃及保温时间为1h的工艺条件下,可制得双电极比电容达69.7F/g的无烟煤基高比表面积活性炭,由它组装的模拟双电层电容器具有良好的充放电性能和循环性能。     

Using MathCad in understanding the induction motor characteristics

Computer-aided multimedia education is increasingly popular within the classroom and laboratory. The applications of market-ready mathematical and database programming software for teaching engineering course outline is well appreciated. This article shows how MathCad can be used to introduce electrical machine characteristics simulated at different possible control modes. The undergraduate students require minimum knowledge of a programming language. The examples presented in the article show how MathCad software can be used to simplify some of the characteristics of the three-phase and one-phase induction machine. The result of introducing math software as a teaching tool at the third- and fourth-year level have been accepted and are now used as part of the practical sessions for the electrical machine and other credited courses at Birzeit University, West Bank and Gaza in the Palestine     

变压器消防水喷雾系统设计体会

火力发电厂中大量使用油浸变压器,而变压器的安全问题直接影响到火电厂的正常运行。因此对于油浸变压器必须进行准确、合适的消防设计。     

浅论我国风电接入系统的有关问题

基于世界风电发展水平和我国新的电力行业管理体制，分析了影响我国风电并网的技术和市场障碍，提出了解决这些障碍的建议和措施，目的在于促进我国风电发展。所提出的建议兼顾了参与风电发展的有关方面的利益，并考虑了当今风电发展的技术水平和国外经验。     

Simulation of pollutant dispersion in the boundary layer of the atmosphere

A mathematical model based on the solution to the eddy diffusion equation is proposed for describing the dispersion of gaseous pollutants ejected by a high-altitude point source. Analytic expressions are derived for approximating spatial distribution of pollutant concentration in the boundary layer of the atmosphere (BLA).     

关于双母线电压切换功能微机化的设计思路探讨

110 kV电压等级输电线路广泛使用双母线接线方式;电压切换功能保证了各种保护及自动装置的二次电压回路随同主接线一同切换;传统中间继电器构成的电压切换功能经常出现由于辅助触点异常或接线错误引起继电器线圈烧毁、PT反充电等问题,引起110 kV输电线路保护失去电压.110 kV输电线路的双母线电压切换功能与线路保护功能通常一体化配置,提出了一种微机化电压切换功能的设计方案,彻底解决了传统电压切换功能存在的问题,具有广泛的实际应用价值.     

关于双母线电压切换功能微机化的设计思路探讨

110 kV电压等级输电线路广泛使用双母线接线方式;电压切换功能保证了各种保护及自动装置的二次电压回路随同主接线一同切换;传统中间继电器构成的电压切换功能经常出现由于辅助触点异常或接线错误引起继电器线圈烧毁、PT反充电等问题,引起110 kV输电线路保护失去电压。110 kV输电线路的双母线电压切换功能与线路保护功能通常一体化配置,提出了一种微机化电压切换功能的设计方案,彻底解决了传统电压切换功能存在的问题,具有广泛的实际应用价值。     

Monopsony behavior in the power generation market

As the sole sellers of power to customers and buyers of wholesale power, vertically integrated electric utilities operate as both monopolies and monopsonies. Regulators account for the negative effects of monopolistic behavior, but little attention is given to the impact of monopsony. As the sole (or dominant) buyer of power in a particular market, the vertically integrated utility can constrain the market, shift risks to sellers, and force generation prices below a long-term market rate. A less competitive market enhances the utility’s opportunity to invest its own capital in generation, even at above-market prices, and even to the point of costly over-procurement.     

线路同杆并架技术在直流输电系统中应用探讨

结合直流输电系统的特点,根据线路同杆并架技术在实际应用中对传统保护造成的一些不良影响,探讨了其应用在直流输电系统中时交直流保护系统应注意的问题.文中的分析和结论,有助于提高采用线路同杆并架技术的交直流混联系统的运行可靠性.     

TN型双通道燃烧器在燃用劣质煤锅炉中的应用

针对当前电煤价格升高、煤质下降,许多电厂在燃用劣质煤时,锅炉出现频繁灭火、管壁超温、投油助燃等问题,研制了TN型双通道燃烧器。TN型双通道燃烧器是在原双通道燃烧器原理基础上,增加了“多突扩”和“煤粉浓缩”技术,使更多的煤粉在燃烧器中预热、预燃,其稳燃能力更强。应用TN型双通道燃烧器,可大大提高锅炉的稳燃能力和煤质适应性,降低锅炉助燃油用量,使锅炉运行的安全性和经济性均得到大幅提高,为电力企业降低发电成本提供可靠的技术保障。