Rational Designs for Lithium-Sulfur Batteries with Low Electrolyte/Sulfur Ratio

Lithium-sulfur batteries (LSBs) are considered a promising next-generation energy storage device owing to their high theoretical energy density. However, their overall performance is limited by several critical issues such as lithium polysulfide (PS) shuttles, low sulfur utilization, and unstable Li metal anodes. Despite recent huge progress, the electrolyte/sulfur ratio (E/S) used is usually very high (≥20 µL mg⁻¹), which greatly reduces the practical energy density of devices. To push forward LSBs from the lab to the industry, considerable attention is devoted to reducing E/S while ensuring the electrochemical performance. To date, however, few reviews have comprehensively elucidated the possible strategies to achieve that purpose. In this review, recent advances in low E/S cathodes and anodes based on the issues resulting from low E/S and the corresponding solutions are summarized. These will be beneficial for a systematic understanding of the rational design ideas and research trends of low E/S LSBs. In particular, three strategies are proposed for cathodes: preventing PS formation/aggregation to avoid inadequate dissolution, designing multifunctional macroporous networks to address incomplete infiltration, and utilizing an imprison strategy to relieve the adsorption dependence on specific surface area. Finally, the challenges and future prospects for low E/S LSBs are discussed.     

基于新型光纤的传输技术探讨

随着互联网的高速发展，引发了网络流量、电信骨干网流量急速增长，使得网络容量的提升迫在眉睫。目前，100G 系统已经商用，超100G系统能够更有效地解决流量和网络带宽持续增长带来的压力，本文主要介绍新型单模光纤的特性以及探讨基于新型单模光纤的传输技术。     

不同热解工艺下半焦的微观结构特点及其对燃烧性能的影响

摘要：对比研究了3种直立内热炉半焦(熄焦方式分别为水泡熄焦、喷水熄焦及烟气干熄焦)及一种流化床热解半焦的微观结构及燃烧性能。通过对半焦组成、孔隙结构、有机官能团、碳化学结构及半焦微晶结构分析，获得了不同低温热解工艺半焦的组成及微观结构特点，明确了组成及微观结构与燃烧性能之间的关系。结果表明，不同热解工艺半焦的组成和微观结构差异明显，其对半焦的燃烧性能影响显著。干熄焦碳化学结构缺陷比例大，快速热解半焦孔隙结构发0达、挥发分高，与水喷焦相比水泡焦石墨化程度低；水喷焦燃烧性能优于水泡焦，干法所得半焦的燃烧性优于湿法；半焦的挥发分含量决定其燃点，在快升温速率条件下孔隙结构对半焦的燃烧性能影响较大，而慢升温速率条件下有序化度对半焦的燃烧性能影响较大。     

超高强7055铝合金铸锭均匀化工艺优化

采用光学显微镜、扫描电镜、差热分析及透射电镜等手段,对一种航空用超高强7055铝合金大尺寸铸锭的均匀化工艺进行分析与优化。提出分级提高均匀化温度的方法,在确保不发生过烧的情况下,最大限度改善铸锭质量。结果显示:低温预均匀化时,铸锭中析出大量的Al₃Zr相,能够大幅度降低对后续挤压变形的再结晶比例;对铸锭采用400 ℃×4 h+465 ℃×16 h+474 ℃×8 h的分级均匀化处理工艺,能够显著消除铸锭中低熔点相的含量,提高铸锭质量,同时相比于原工艺节省约13 h。新的均匀化处理工艺,不仅提高了生产效率,还能够为后续工艺提供良好的铸锭。     

SNCR脱硝技术在液态排渣煤粉工业锅炉中的应用

为了检验选择性非催化还原（SNCR）脱硝技术在高效低NO_x液态排渣煤粉工业锅炉中的应用效果，本文在一台8.4MW有机热载体锅炉炉膛内开展了SNCR脱硝技术工业化试验研究。选用尿素作为还原剂，搭建了工业化SNCR脱硝试验平台。在10%、15%、20%三种浓度尿素溶液下进行了不同尿素溶液喷射量、不同氧含量、不同锅炉负荷下的SNCR脱硝试验研究。试验结果表明，提出的“低NO_x燃烧+SNCR脱硝”耦合技术方案是可行的，SNCR脱硝效率在80%以上，完全能够达到烟气中NO_x低于50mg/m³的超低排放要求。     

Automated classification of simulated wind field patterns from multiphysics ensemble forecasts

In this study, we have proposed an automated classification approach to identify meaningful patterns in wind field data. Utilizing an extensive simulated wind database, we have demonstrated that the proposed approach can identify low‐level jets, near‐uniform profiles, and other patterns in a reliable manner. We have studied the dependence of these wind profile patterns on locations (eg, offshore vs onshore), seasons, and diurnal cycles. Furthermore, we have found that the probability distributions of some of the patterns depend on the underlying planetary boundary layer schemes in a significant way. The future potential of the proposed approach in wind resource assessment and, more generally, in mesoscale model parameterization improvement is touched upon in this paper.     

纳米氧化锌/低密度聚乙烯膜中锌向食品的迁移研究

目的研究纳米氧化锌/低密度聚乙烯膜(low density polyethylene film,LDPE)中锌(Zn)向食品的迁移行为,探究其迁移规律。方法选取2种食品模拟物(3%乙酸及超纯水)及真实食品(食用白醋及瓶装水),在3种不同实验温度下(70、40及20℃),研究锌向食品模拟物的迁移规律。采用扫描电子显微镜(scanning electron microscope,SEM)和原子力显微镜(atomic force microscope,AFM)表征纳米ZnO/LDPE膜的表面形貌。结果锌向酸性模拟物中的迁移率远远大于水性模拟物中的迁移率,其中锌向酸性模拟物中的最大迁移率分别为22.7%,20.3%及18.6%(ZL-1,ZL-2及ZL-2#),向水性模拟物中的最大迁移率分别为9.9%,5.7%及4.9%(ZL-1,ZL-2及ZL-2#);锌向酸性食品的迁移量(1.59~5.03 mg/g)同样高于向水性食品的迁移量(2.98~24.60μg/g);随着纳米ZnO的初始含量变大迁移率变小;而偶联剂的加入对锌的迁移有一定的抑制作用。随着纳米ZnO浓度的增加,在薄膜中观察到纳米ZnO的不规则形貌。结论纳米ZnO/LDPE膜不适合在高温下包装食物,且其在酸性食品中的安全隐患高于水性食品。     

单一低渗透突出煤层水力冲孔工艺优化应用分析

为了有效提高单一低渗透突出煤层的瓦斯抽采效率，以高压水射流冲击理论为指导，针对平煤股份八矿己组突出煤层特征建立数值模型，模拟分析水力冲孔应力分布规律，通过现场实测分析冲孔有效影响范围，进一步优化设计冲孔参数、指导现场施工。现场应用表明，水力冲孔是一种行之有效的方法，对单一低渗透突出煤层实施水力冲孔卸压增透、提高瓦斯抽采效果具有重要意义。