长相关业务流经成形器后的输出特性研究

网络中业务流的自相似性正日益受到重视，因为它的网络性能有着很大的影响，本文采用计算机仿真的方法，对输入长相关（ＬＲＤ－Ｌｏｎｇ－ＲａｎｇｅＤｅｐｅｎｄｅｎｔ）业务的成形器的输出序列的特性进行了研究。当长相关业和使用分形布朗运动（ＦＢＭ－ＦｒａｎｃｔａｌＢｒｏｗｎａｉｎＭｏｔｉｏｎ）模型时，我们的研究表明，在不同的信元丢失率（ＣＬＲ－ＣｅｌｌＬｏｓｓＲａｔｅ）下，成形器输出序列的自相关特性与输入序更     

灯泵钛宝石激光器高压开关电源

介绍了一台重复率运转的灯泵掺钛宝石激光器的开关电源。其中包括高压开关电路和双预燃电路。电源输出功率达２ｋＷ，重复率为５Ｈｚ。     

CONVERGENCE PROPERTIES OF HIGHER-ORDER MOMENT AND CUMULANT ESTIMATES

The sample estimates of higher-order statistics are studied. Under certain conditions, the almost sure convergence of the third- and fourth-order moment and cumulant estimates of stationary processes is established. The rate of almost sure convergence is obtained for the sample estimates of third- and fourth-order moment and cumulant. Additionally, it is shown that the third- and fourth-order moment and cumulant estimates are asymptotic normal.     

Effect of cooling and aging on microstructure and mechanical properties of Sn－9Zn solder

The microstructure and tensile properties of Sn-9Zn solder under different cooling and aging condition were studied.During solidification, the distribution of Zn-rich phases and grain size in the microstructure of Sn-9Zn solder were decided by the cooling rate.The Zn-rich phase in Sn-9Zn solder under furnace cooling, air cooling and water cooling media was separately existed as coarsen dendritic and needle like shape, fine needle like shape and very fine rod-like shape, respectively.After aging, the coarsen dendritic was broken and the coarsen needle like Zn-rich phase was partly changed into fine distribution of Zn-rich phase for Sn-9Zn solder with furnace cooling, and the rod-like Zn phase in the Sn-9Zn solder under water cooling was changed to conglomerated Zn with needle shape.During tensile testing on Sn-9Zn solder, tensile strength and ductility reached the best with water cooling, but decreased with aging effect.Meanwhile, the ductility of solder with air cooling and the strength of solder with furnace cooling increased with aging.The fracture mode was ductile and was independent of cooling media and aging effect.The size and depth of dimples decreased from water, furnace to air cooling.After aging, number and size of dimples increased on the solder with furnace cooling and air cooling.The change on the size of dimples for the Sn-9Zn solder under different cooling condition and with aging effect was accordance to the tensile properties.     

一种基于基音预测的信息隐藏算法

针对低速率语音编码问题,提出一种基于基音预测的信息隐藏算法。在基音预测编码过程中,采用控制基音闭环搜索的自适应码本搜索范围方法,实现秘密信息的嵌入,在进行语音压缩的同时完成信息隐藏。实验结果证明,该算法具有良好的隐蔽性,且计算复杂度较低。在编码标准G.729a中,秘密比特信息嵌入速率统计平均最高可达374.636 bit/s,PESQ恶化改变率在10.4%以内,检测正确率在66%左右。     

超高水材料袋式长壁充填开采覆岩控制技术研究与应用

系统分析了超高水材料袋式充填开采采场覆岩结构的特点,得出了工作面支架需控岩层范围及其变化特征,揭示了长壁充填开采“支架-围岩”关系,明确了提高充填率是超高水材料袋式充填开采覆岩下沉控制的关键因素。结合亨健矿2515工作面充填开采地质与开采技术条件,开发并实施了隔板布置优化、采空区埋管补注浆充填、离层区打钻补注浆充填等充填率保障技术与工艺。现场实测结果表明,超高水材料袋式充填开采工作面矿压显现缓和、采场围岩破裂范围较小且能有效控制地表下沉：① 工作面巷道顶底板最大移近量为258 mm,两帮最大移近量为183 mm,围岩变形较小;② 微震监测系统表明,2515工作面超前破裂范围为20~30 m,围岩破裂高（深）度为顶板以上40 m至底板以下10 m,1个月后（推进距离60 m左右）已充填区域微震事件逐渐消失;③ 地表最大下沉量为265 mm,实测下沉系数为0.06。     

关于进入工业火焰的煤粉颗粒温升速率的探讨

从传热角度对煤粉微粒进入高温环境的温度变化进行了初探,对沉降试验炉和煤粉炉内的煤颗粒与环境的换热及有关试验进行对照比较,其结果表明热传导是微粒与外界换热的主要形式。针对流化床锅炉的特点及大小不同的煤颗粒的温升速率进行了探讨。     

高效浓密机在瓮福基地的应用

本文叙述了一种底流浓度可达 70 %以上的高效浓密机及其应用。瓮福矿肥基地使用了2台此种高效浓密机 ,其生产能力相当于 7台普通浓密机。高效浓密机的特点是特殊的给矿方式使絮凝剂能快速有效地与矿浆混合 ,高效浓密机的操作应注意控制好给矿的特性、絮凝剂的用量以及保持给矿量和底流的平衡。     

最优切削速度和进给量的实用算法

以最大生产率和最低成本为优化目标,建立了切削速度和进给量２个加工条件最优化的数学模型,讨论了求解这２个切削用量最优值的实用算法。     

金刚石表面金属化（镀膜）的试验研究

利用化学镀和真空镀 2种方法对金刚石表面进行金属化处理的试验研究结果表明 ,镀膜金刚石较未镀膜金刚石的抗压强度、热稳定性等性能和碎岩效果均有很大提高 ,其中真空镀Ti的效果最好。真空镀Ti-Cr金刚石表面上形成的碳化物TiC、Cr2 C3等中的C可能来自金刚石本身。真空镀是一种很有前景的金刚石表面处理方法。