In order to improve the matrix performance of impregnated diamond drill bit to better meet the drilling needs,the effects of the addition of nano-WC and nano-NbC particles on the matrix material together with the mech...In order to improve the matrix performance of impregnated diamond drill bit to better meet the drilling needs,the effects of the addition of nano-WC and nano-NbC particles on the matrix material together with the mechanical properties and microstructure of the diamond-matrix composite material of the Fe-based diamond drill bit were studied by using the method of uniform formula design,regression analysis and solution finding.An indoor drilling test was also carried out using the fabricated impregnated diamond drill bit.The results showed that after the addition of nano-NbC and nano-WC,the hardness and flexural strength of the matrix material got improved,as the flexural strength of the diamond composite material increased to 4.29%,the wear-resistance ratio increased to 8.75%,and the tighter the chemical bonding between the diamond and the matrix.This,indicates that the addition of nanoparticles has a positive significance in improving the performance of the diamond composite.The results of the drilling test showed that the mechanical drilling speed of the impregnated diamond drill bit after nanoparticle strengthening is 25.85%higher than that of the conventional drill bit,and the matrix wear was increased by 17.5%.It proves that nanoparticles can improve the drilling performance and efficiency of drill bit.展开更多
出版物的结构化处理是语义出版发展的基础。图书交换标签集(Book Interchange Tag Suite,BITS)是一套面向科技类图书的结构化表示模型。本文通过分析BITS模型的元素和结构,比较BITS与期刊标签集JATS以及电子书标准Docbook和DITA的异同,...出版物的结构化处理是语义出版发展的基础。图书交换标签集(Book Interchange Tag Suite,BITS)是一套面向科技类图书的结构化表示模型。本文通过分析BITS模型的元素和结构,比较BITS与期刊标签集JATS以及电子书标准Docbook和DITA的异同,并结合中文科技类图书的特点,以探讨BITS对中文图书的适用性和改进方向。展开更多
本文提出一种多协议,可变位宽发射机系统,最高数据位宽40 bits,最高数据速率10.312 5 Gbps.整个系统由归一化数据位宽(Normalization of Data Width,NMDW)变换电路,40:1合路器(MUX),时钟分布电路及3抽头前馈均衡器(Feed-Forward-Equaliz...本文提出一种多协议,可变位宽发射机系统,最高数据位宽40 bits,最高数据速率10.312 5 Gbps.整个系统由归一化数据位宽(Normalization of Data Width,NMDW)变换电路,40:1合路器(MUX),时钟分布电路及3抽头前馈均衡器(Feed-Forward-Equalizer,FFE)组成,文章中提出了改进的40:1 MUX电路结构.本文采用SMIC 40 nm CMOS工艺,电源电压1.1 V.发射机(Transmitter,TX)整体功耗34mW@10.3125 Gbps,信道前差分输出眼图最大幅度大于800 mV.同时,本发射机支持4种不同协议,7种不同数据速率,9种工作状态,工作温度范围-45℃~125℃.展开更多
随着计算机软硬件技术及超大规模集成电路技术的发展,电子设计自动化(EDA)逐渐取代了传统的电子设计方法,而成为现代电子设计的基本手段。仿真是EDA技术的典型特征,从一个既定的设计任务(16bits比较器)开始,从设计构思、在EDA仿真软件(M...随着计算机软硬件技术及超大规模集成电路技术的发展,电子设计自动化(EDA)逐渐取代了传统的电子设计方法,而成为现代电子设计的基本手段。仿真是EDA技术的典型特征,从一个既定的设计任务(16bits比较器)开始,从设计构思、在EDA仿真软件(Modelsim SE 5．6)平台上编写VHDL仿真软件、进行仿真测试等方面全面地介绍了进行系统计算机仿真的全过程。展开更多
随着城区高楼大厦不断建起,在高楼内布放室分,实现深度覆盖已成为4G建设的一个主要目标方向,但要在高楼内布放BBU,其时钟GPS布放就难上加难,一方面物业不充许、一方面施工难度大。写字楼与酒店是不同意把GPS馈线从楼顶往下布放的。这样...随着城区高楼大厦不断建起,在高楼内布放室分,实现深度覆盖已成为4G建设的一个主要目标方向,但要在高楼内布放BBU,其时钟GPS布放就难上加难,一方面物业不充许、一方面施工难度大。写字楼与酒店是不同意把GPS馈线从楼顶往下布放的。这样大楼内室分建设成本翻倍增加。为解决这难题,保山无线中心IPRAN维护小组,提出2种解决方案,方案一:采用1588v2实现时间同步,但IPRAN需要收费License,投资成本高。方案二:采用同步以太网实现频率同步,设备根据SSM(Synchronization Status Message)进行选源。该方案无论是IPRAN设备还是4G基站都不需要收费,能满足FDD频率同步要求。为此保山无线中心选取方案二做实验,选取精度较高的BITS(2Mbps)作为IPRAN的时钟源。展开更多
基金National Center for International Research on Deep Earth Drilling and Resource Development,Faculty of Engineering,China University of Geosciences(Wuhan)(No.DEDRD-2022-08).
文摘In order to improve the matrix performance of impregnated diamond drill bit to better meet the drilling needs,the effects of the addition of nano-WC and nano-NbC particles on the matrix material together with the mechanical properties and microstructure of the diamond-matrix composite material of the Fe-based diamond drill bit were studied by using the method of uniform formula design,regression analysis and solution finding.An indoor drilling test was also carried out using the fabricated impregnated diamond drill bit.The results showed that after the addition of nano-NbC and nano-WC,the hardness and flexural strength of the matrix material got improved,as the flexural strength of the diamond composite material increased to 4.29%,the wear-resistance ratio increased to 8.75%,and the tighter the chemical bonding between the diamond and the matrix.This,indicates that the addition of nanoparticles has a positive significance in improving the performance of the diamond composite.The results of the drilling test showed that the mechanical drilling speed of the impregnated diamond drill bit after nanoparticle strengthening is 25.85%higher than that of the conventional drill bit,and the matrix wear was increased by 17.5%.It proves that nanoparticles can improve the drilling performance and efficiency of drill bit.
文摘出版物的结构化处理是语义出版发展的基础。图书交换标签集(Book Interchange Tag Suite,BITS)是一套面向科技类图书的结构化表示模型。本文通过分析BITS模型的元素和结构,比较BITS与期刊标签集JATS以及电子书标准Docbook和DITA的异同,并结合中文科技类图书的特点,以探讨BITS对中文图书的适用性和改进方向。
文摘随着计算机软硬件技术及超大规模集成电路技术的发展,电子设计自动化(EDA)逐渐取代了传统的电子设计方法,而成为现代电子设计的基本手段。仿真是EDA技术的典型特征,从一个既定的设计任务(16bits比较器)开始,从设计构思、在EDA仿真软件(Modelsim SE 5．6)平台上编写VHDL仿真软件、进行仿真测试等方面全面地介绍了进行系统计算机仿真的全过程。
文摘随着城区高楼大厦不断建起,在高楼内布放室分,实现深度覆盖已成为4G建设的一个主要目标方向,但要在高楼内布放BBU,其时钟GPS布放就难上加难,一方面物业不充许、一方面施工难度大。写字楼与酒店是不同意把GPS馈线从楼顶往下布放的。这样大楼内室分建设成本翻倍增加。为解决这难题,保山无线中心IPRAN维护小组,提出2种解决方案,方案一:采用1588v2实现时间同步,但IPRAN需要收费License,投资成本高。方案二:采用同步以太网实现频率同步,设备根据SSM(Synchronization Status Message)进行选源。该方案无论是IPRAN设备还是4G基站都不需要收费,能满足FDD频率同步要求。为此保山无线中心选取方案二做实验,选取精度较高的BITS(2Mbps)作为IPRAN的时钟源。
