进气道和燃烧室形状对火花点火发动机燃烧过程影响的研究

本文针对ＣＡ６１０２发动机燃烧慢、循环变动率偏大等问题，对进气道和燃烧室进行了改进。研究了不同进气道和燃烧结构（六种匹配方案）对燃烧过程和性能的影响，发现涡流比和性能之间无单调的相关关系，与燃烧期之间存在二次抛物线型的逆变相关关系，ＣＡ６１０２发动机合适的涡流比在０．９左右，燃烧室设计因素中火花塞的位置对燃烧过程和性能影响最大，火花塞靠近中心布置方案同原机相比，最低燃油消耗率降低了４．１％，最大扭     

船舱中油的存在状态及危害分析和预防措施

介绍了船舱中油的主要存在状态包括:液态油、油烟、油雾、喷雾等。当油雾或喷雾的浓度增大到一定程度时,有引起火灾和爆炸的危险。主要预防措施可以安装油雾探测装置(OMD),OMD可通过检测油雾的浓度并发出报警信号来预防爆炸的发生。     

曲轴箱油雾探测器研制过程中几个关键问题的分析

曲轴箱油雾探测器对保证机舱工作安全性意义重大。介绍了在研制过程中涉及到的关键技术,如油雾浓度的测量方法、波长及传感器的选择、油雾样品的制取、误差修正、减少误报警等,同时指出,开发过程应严格按照有关船规要求,避免在今后产业化过程中走弯路。     

Characterisation of electric current-treated austenite using misorientation angle distributions in martensite

ABSTRACT

The angle misorientation distribution of martensite formed from electric current treated and non-treated austenite samples are studied using electron backscatter diffraction. The electric currents are pulsed with a loading width of 80 μs, at a frequency of 100?Hz and current density of 4.21 A/mm² supplied by a DC Voltage. The majority of angle misorientations are < 5° and exist within the martensite grains, while only a minority of all misorientations are derived from the prior austenite grain boundary and were found to lie in the range 20–50°. Distinct textures develop in both electric current treated and non-treated samples with increased quenching temperature. Analysis of the prior austenite shows reduced grains in the electric current treated samples at all quenching temperatures considered.

This paper is part of a themed issue on Materials in External Fields.     

A508-3钢质子辐照条件下微结构演变研究

在室温下利用190 keV质子对A508-3钢进行辐照,辐照剂量分别为0.108,0.216和0.271 dpa.对辐照前后样品的微结构进行了TEM观察.结果表明,辐照没有产生可观察到的微空洞,辐照缺陷主要是位错环,且大部分为Burgers矢量为〈100〉型的间隙型位错环;位错环大部分均匀分布在基体内,还可见位错环分布在位错线附近的情况;随辐照剂量的增加,位错环尺寸分布范围变宽,平均直径增大,当辐照剂量从0.108 dpa增至0.271 dpa时,位错环的平均直径由约1.8 nm增至约4.6 nm;位错环的数量密度在10²²m^-3数量级并随辐照剂量增加略有增加.对位错环的形成机制及辐照剂量对辐照硬化和脆化程度的影响进行了分析.在实验范围内,由位错环引起的硬化和脆化程度随辐照剂量增加而增大,未出现饱和现象.     

二乙苯制二乙烯苯精馏过程的改进

首先依据二乙烯苯精馏过程的流程叙述建立了三塔精馏数学模型,并依据该数学模型用通用化工过程模拟与优化软件ECSS进行了流程模拟.根据流程模拟结果对其进行改进一改进是将塔顶冷凝器放在塔上成为卧式分凝回流,之后再全凝,此改进可降低管路和冷凝器的压降;二是将精馏塔由板式塔改为填料塔,降低了塔板压降,有利于二乙烯苯的精馏分离.并选择了一种最能降低该精馏过程塔压降的填料.     

含Nb锆合金中第二相的吸放氢性能

参照含Nb锆合金中第二相的成分,熔炼了(Zr,Nb)_2Fe,Zr(Nb,Fe)_2和β-Nb合金.成分测试结果表明,所炼合金的成分与锆合金中的第二相相同.XRD分析结果表明,除(Zr,Nb)_2Fe外,Zr(Nb,Fe)_2和β-Nb合金的相结构也与锆合金中的第二相相同.备合金的压力-成分-温度(P-C-T)曲线和吸放氢动力学曲线表明,3种合金和纯Zr的可逆吸放氢能力按Zr(Nb,Fe)_2,(Zr,Nb)_2Fe,β-Nb和Zr顺序依次减弱.     

柴油机曲轴箱油雾探测装置研制

所述油雾探测装置系利用光透射原理设计,主要包括光路、电路、气路三部分,并设计了标定系统对试验过程进行监测。试验表明：该装置能够实时反映油雾浓度的变化,在必要时能及时发出报警信号,满足柴油机曲轴箱对油雾探测装置的性能要求。     

Managing Interfacial Hot-Carrier Cooling and Extraction Kinetics for Inverted Ma-Free Perovskite Solar Cells Over 23% Efficiency via Dion–Jacobson 2D Capping Layer

While quasi-2D perovskite is often used in inverted perovskite solar cells (PSCs) to improve the interfacial carrier transfer, the development of pure 2D perovskite with superior stability is rarely seen and the corresponding carrier-extraction kinetics remains unclear. Here, a variety of hexatomic ring cations including piperidine, pyridine, and cyclohexane are introduced to modify the perovskite/electron transport layer interface. The Dion–Jacobson phase 2D cladding (n = 1) based on 3-(aminomethyl) piperidinium is proved to form a coordinated energy landscape and homogeneous surface potential distribution, and effectively prolong the electron diffusion length (≈1.58 µm) and accelerate the hot-carrier extraction rate (2.5 times that of Control at 400 K). Furthermore, the quasi-2D treatment (n ≈ 3,4) demonstrated a slight escalation in short-circuit current, but failed to inhibit the interdiffusion of Ag, Pb, and I under illumination. Finally, one of the state-of-art power conversion efficiency (PCE) for MA-free inverted PSCs is achieved at 23.62% with increased open-circuit voltage (≈1.15 V) and fill factor (≈82.8%). Most importantly, 89% and 93.6% of initial PCE are retained after 720 h under 85 °C heating and 1000 h under maximum power point tracking, illustrating satisfactory thermal and operational stability with pure 2D perovskite capping layer.