Oxygen Vacancy Modulation of Bimetallic Oxynitride Anodes toward Advanced Li‐Ion Capacitors

Binary metal oxides (such as NiCo₂O₄) are regarded as attractive electrode materials for advanced energy storage devices since they offer more electrochemical activity and higher capacity than monometal oxide. However, the volume expansion and low electronic conductivity are the main bottleneck seriously hindering their application. To overcome these barriers, a novel strategy that introduces a bimetallic oxynitride layer (NiCoON) with oxygen vacancy to the surface of NiCo₂O₄ nanowires as an anode for Li‐ion capacitors (LICs) is proposed. The oxygen vacancy on the surface and the modulation of multiple valence states are investigated by the electron paramagnetic resonance, X‐ray photoelectron spectroscopy characterization, and first‐principles calculation. Benefiting from the merits of substantially improved electrical conductivity and increased concentration of active sites, the optimized NiCoON electrode delivers remarkable capacity (1855 mAh g^?1 at 0.2 A g^?1) and rate performance. The LIC device assembled by NiCoON anodes and N‐doped carbon nanowire cathodes delivers excellent rate capability, high energy density (148.5 Wh kg^?1), and outstanding power density (30 kW kg^?1). This study provides a new pathway for developing bimetallic oxides with an improved performance in electrochemical energy storage, conversion fields, and beyond.     

Temperature‐Mediated Engineering of Graphdiyne Framework Enabling High‐Performance Potassium Storage

Graphdiyne (GDY), an emerging type of carbon allotropes, possesses fascinating electrical, chemical, and mechanical properties to readily spark energy applications in the realm of Li‐ion and Na‐ion batteries. Nevertheless, rational design of GDY architectures targeting advanced K‐ion storage has rarely been reported to date. Herein, the first example of synthesizing GDY frameworks in a scalable fashion to realize superb potassium storage for high‐performance K‐ion battery (KIB) anodes is showcased. To begin with, first principles calculations provide theoretical guidances for analyzing the intrinsic potassium storage capability of GDY. Meanwhile, the specific capacity is predicted to be as high as 620 mAh g^?1, which is considerably augmented as compared with graphite (278 mAh g^?1). Experimental tests then reveal that prepared GDY framework indeed harvests excellent electrochemical performance as a KIB anode, achieving high specific capacity (≈505 mAh g^?1 at 50 mA g^?1), outstanding rate performance (150 mAh g^?1 at 5000 mA g^?1) and favorable cycling stability (a high capacity retention of over 90% after 2000 cycles at 1000 mA g^?1). Furthermore, kinetic analysis reveals that capacitive effect mainly accounts for the K‐ion storage, with operando Raman spectroscopy/ex situ X‐ray photoelectron spectroscopy identifying good electrochemical reversibility of GDY.     

粗波分复用在远程备份系统中的应用

CWDM(粗波分复用)技术以其在系统成本、性能及可维护性等方面的优势,正逐渐成为城域网的主流技术。文中在对比和分析DWDM(密集波分复用)和CWDM技术特点的基础上,提出了采用CWDM替代基于DWDM实现远程备份的新方法,并设计了CWDM接口和基于CWDM远程备份应用的体系结构,对CWDM链路的可靠性和数据传输率进行了分析。     

基于Hadoop的气象数据分布式存储技术研究

针对目前气象数据存储所面临的海量扩张、高并发读写、结构化和非结构化数据并存以及长时间序列和大数据集检索效率低下等问题,提出了以Hadoop开源框架为基础的气象数据分布式存储方案.通过对气象数据自身属性和特点进行分析,得出了气象数据在经过充分优化的基础上,在分布式存储框架中具有很强的适应性和规模化应用的潜力;并在HBas...     

基于MATLAB的集成电路储能焊封装能量分布研究

气密性是集成电路封装中的一项重要技术指标,对于集成电路的可靠性使用具有重要作用。就气密性封装工艺中的储能焊封装技术进行了讨论,通过对储能焊设备放电过程进行分析及建模,得到了气密性焊接能量与各个工艺参数之间的关系,并利用MATLAB软件进行了模拟计算。结合具体实验,验证了理论建模及模拟的正确性,对于储能焊焊接的工艺参数设定及优化具有一定的指导意义。     

电子塑封材料南海环境贮存试验研究

对4种模塑封装材料，两种芯片涂层材料封装的微电路样品在西沙天然暴露站进行了22个月的贮存试验，并设计制作了一种简便有效的测试系统，贮存试验的结果表明，在芯片上加氮化硅钝化层比不加钝化层具有更好的防护效果；与聚酰亚胺胶内涂层相比，硅酮胶内涂层更能有效地阻止水分到达芯片的表面，由于材料本身的差异，不同厂家生产的模塑封装材料对微电路的影响也不同。     

LD泵浦Cr4+,Nd3+:YAG自调Q腔内倍频激光器研究

Cr4 ，Nd3 ：YAG晶体的激光特性得到了系统研究．在LD泵浦下，Cr4 ，Nd3 ：YAG晶体获得了1.064μm的自调Q激光输出．激光平均输出功率达到3．36W，脉宽65ns，重复频率87kHz，光-光效率为15．3％．加入KTP晶体后实现了自调Q腔内倍频，获得了532nm的绿色脉冲激光输出，平均功率达到1W，脉宽210ns，重复频率47kHz，光-光效率为6％．对自调Q激光及其腔内倍频发现的现象进行了讨论．     

热氧化制备纳米氧化锌薄膜的光致发光和室温紫外激光发射

利用低压 -金属有机汽相外延 (L P- MOCVD)工艺首先在二氧化硅衬底上生长硫化锌 (Zn S)薄膜 ,然后 ,将硫化锌薄膜在氧气中于不同温度下进行热氧化 ,制备出高质量的纳米氧化锌 (Zn O )薄膜 .X射线衍射 (XRD)结果表明 ,氧化锌具有六角纤锌矿晶体结构 .90 0℃氧化样品的光致发光 (PL )谱中 ,在波长为 3.3e V处观察到一束强紫外光致发光和相当弱的深能级发射 .紫外发光强度与深能级发射强度之比是 80 ,表明纳米 Zn O薄膜的高质量结晶 .在受激发射实验中观察到紫外激光发射 .     

LD抽运的Nd~(3+):YAG-Cr~(4+):YAG组合单晶自调Q激光器的研究

用激光二极管 (LD)连续抽运单体复合型Cr4+∶YAG Nd3 +∶YAG单晶微棒 ,获得重复频率为 10kHz ,脉冲宽度为 10ns的调Q激光输出。输出平均功率为 18mW ,实验结果与理论计算的脉冲宽度和重复频率与抽运功率之间的关系基本相符