A facile and green preparation of high-quality CdTe semiconductor nanocrystals at room temperature

One chemical reagent, hydrazine hydrate, was discovered to accelerate the growth of semiconductor nanocrystals (cadmium telluride) instead of additional energy, which was applied to the synthesis of high-quality CdTe nanocrystals at room temperature and ambient conditions within several hours. Under this mild condition the mercapto stabilizers were not destroyed, and they guaranteed CdTe nanocrystal particle sizes with narrow and uniform distribution over the largest possible range. The CdTe nanocrystals (photoluminescence emission range of 530-660?nm) synthesized in this way had very good spectral properties; for instance, they showed high photoluminescence quantum yield of up to 60%. Furthermore, we have succeeded in detecting the living Borrelia burgdorferi of Lyme disease by its photoluminescence image using CdTe nanocrystals.     

小型浅水地震勘探船的设计与应用管理

小型浅水地震勘探船在过渡带、浅海区域的石油地震勘探施工中起到气枪激发、OBC地震电缆收放和浅水钻井下炸药功能。这些船舶的良好设计、高可靠性以及严格的现场管理,对生产效率起到非常重要的作用。本文介绍了三种小型船舶的设计原则、功用以及现场管理的经验。     

木聚糖酶对马尾松KP浆漂白机理的探索

采用常规分析方法对纸浆卡伯值、粘度和戊聚糖含量等进行分析 ,又采用紫外光谱、高效液相色谱、凝胶渗透色谱及扫描电镜等仪器分析方法分别对酶解浆、酶解液及酶解浆稀碱抽出液进行了分析。结果认为 ,木聚糖酶用于化学浆漂白的机理是其降解了残余木质素中的LCC结构和部分木聚糖 ,从而节省了后序化学漂剂的用量 ,提高了纸浆白度     

Visual Studio中串行通信方法实时性能测试

为合理、高效地应用Visual Studio中的串口通信方法,利用Win32 API函数Query Performance Counter和Query Performance Frequency设计出能比较精确测试、分析基于Visual Basic中的Active X控件、Visual C++中的Active X控件和Win32 API函数的3种Visual Studio平台上串行通信方法的实时性能测试系统。该系统的硬件由4台配置基本相同的PC和连接它们的RS-232C接口线构成,软件包括串行数据发送模块、基于以上方法的串行数据接收模块及相关分析模块。实验结果表明:API方法的通信响应速度比VC控件法、VB控件法分别快约175%、220%,数据接收速度分别快约8倍、9倍。     

煤矿特大突水原因分析与通道探查技术

矿井突水灾害严重威胁煤矿的安全生产,有效防治矿井水害对煤矿安全具有特殊意义.文章以某矿工作面运输巷掘进期间特大突水事件为背景,从矿井开采实践、奥灰水位变化和水质分析结果3个方面综合确定此次突水水源为奥灰水,并根据突水实际情况,分析可能引起此次突水的导水构造,针对突水通道探查的难点制定了相应的通道探查方案.探查结果表明,2~#煤层底板以下存在一条落差为120 m的正断层,使得煤层底板与下盘奥灰含水层的间距不足30 m,剩余隔水层的厚度和强度均不足以抵抗高压奥灰水,致使巷道掘进期间,高压奥灰水突破巷道围岩,发生奥灰特大突水灾害.     

Nano‐Intermetallic AuCu3 Catalyst for Oxygen Reduction Reaction: Performance and Mechanism

This paper introduces a new approach for catalyst design using the non‐precious metal Cu as one of the catalytic active centers. This differs from previous studies that considered precious metals to be responsible for the catalytic reaction in precious alloys. Intermetallic AuCu₃/C nanoparticles with a diameter of 3 nm were developed for the first time, with uniform dispersion and a narrow size distribution. The ca. 3 nm as‐synthesised AuCu₃/C showed superior catalytic performance for oxygen reduction reactions (ORR) in alkaline solutions, with comparable half‐wave potential and 1.5 times mass current density of commercial Pt/C at 0.80 V (vs. reversible hydrogen electrode (RHE)). The advanced catalytic activities are mainly attributed to the synergetic effects of electro‐active atomic Au and Cu on the particle surface, in which Cu helps to activate the O₂ molecule and Au benefits OH^? desorption. The excellent durability and methanol tolerance exhibited in alkaline solutions provide another advantage for AuCu₃/C to be considered as a potential alternative cathode catalyst in alkaline fuel cells.     

西藏高山松制浆性能的评价

对西藏高山松制浆性能进行了研究，认为高山松是一种较优良的长纤维造纸原料，具有很好的工业应用前景。     

固溶处理对铸态Mg-4.8Al-2.7Ca-0.4Mn合金组织及力学性能的影响

采用光学显微镜、扫描电镜、X射线能谱仪、X射线衍射仪、硬度测试及拉伸性能测试等手段分别研究了铸态Mg-4.8Al-2.7Ca-0.4Mn合金固溶处理前后的组织演变及力学性能。结果表明,铸态Mg-4.8Al-2.7Ca-0.4Mn合金的微观组织中,α-Mg相呈现典型的枝晶形态,枝晶间分布着大量在凝固过程中形成的Al₂Ca相;固溶处理对第二相的形貌有显著影响,随着固溶时间的增加,枝晶偏析减弱,Al₂Ca相从网状分布演变为多边形或细块状;经500 ℃固溶4 h,合金具有较好的综合拉伸性能,抗拉强度、屈服强度及伸长率分别达到222.0 MPa、182.5 MPa和4.5%。