在探讨D2D 对通信技术未来发展的导向作用基础上，明确了影响D2D 系统设计的多个因素，即D2D 设
备发现、资源分配、缓存技术、D2D-MIMO。从而勾画出基于D2D 技术的光纤前传和软件定义网络实现数据/控制分离的扁平化5G 架构，提出负责接入的下层宏/小基站蜂窝网和负责管理的上层网络云的管理机制。将D2D技术、SDN 技术、边缘计算和物联网技术等关键技术引入未来移动通信网络已经成为研究领域的热点，针对与之相关的、未来大规模网络的移动性、QoS 和大数据特性进行了讨论。
On the basis of discussing the guiding role of D2D in the future development of communication technology, this paper makes clear the factors influencing the design of D2D system, namely D2D hypothesis Standby discovery, resource allocation, caching techniques, d2d-mimo.Thus, the flat 5G architecture for data/control separation is outlined based on D2D technology of optical fiber prepreel and software-defined network, and the management mechanism of the lower macro/small base station cellular network responsible for access and the upper network cloud responsible for management is proposed.The introduction of D2D technology, SDN technology, edge computing and Internet of things into the future mobile communication network has become a hot topic in the research field. (2020-03-10, PDF, 592KB, 下载9次)
IPC-WHMA-A-620D EN线缆及线束组件的要求与验收国际标准
IPC/WHMA-A-620D is the only industry-consensus standard for Requirements and Acceptance of Cable and Wire Harness Assemblies. IPC/WHMA-A-620D describes materials, methods, tests and acceptance criteria for producing crimped, mechanically secured and soldered interconnections and the related assembly activities associated with cable and harness assemblies.
IPC/WHMA-A-620D was developed by IPC and the Wire Harness Manufacturers Association (WHMA) (An affiliate of IPC). (2020-02-10, PDF, 1406KB, 下载5次)
接线模式的合理选择将有利于提升中压配电网的综合优化水平。在研究苏州地区电缆网接线模式的供电可靠性和经济性的基础上，提出了 3 种兼顾供电可靠性和经济性的电缆接线模式的选取方法 。
Reasonable selection of wiring mode will be conducive to improving the comprehensive optimization level of medium voltage distribution network. On the basis of studying the reliability and economy of power supply of cable network connection mode in Suzhou area, three selection methods of cable connection mode considering both reliability and economy of power supply are put forward. (2019-08-05, PDF, 844KB, 下载2次)
OPC与西门子PLC通讯设置,调试,有三个文件
1.s7-200通过以太网模块和kepserver连接.pdf
2.s7-300与上位机通信.pdf
3.西门子S7与上位监控软件通讯(总结).pdf
OPC with Siemens PLC communication setting, debugging, there are three files
1. S7-200 through Ethernet module and kepserver connection. PDF
2. Communication s7-300 and the upper machine. PDF
3. Siemens S7 and upper monitor software communication (summary). PDF (2019-05-29, PDF, 243KB, 下载5次)
系统总体设计，结合底层ZigBee无线传感网络的特点和系统总体网络监控的要求，将该系统设计分为四部分：无线传输模块、数据处理模块、以太网传输模块、上位机显示界面。
The system design is divided into four parts: the wireless transmission module, the data processing module, the Ethernet transmission module and the upper computer display interface, combined with the characteristics of the underlying ZigBee wireless sensor network and the requirements of the system overall network monitoring. (2018-05-29, PDF, 6624KB, 下载1次)
CMT2300A 是一款超低功耗，高性能，适用于各种127 至
1020 MHz 无线应用的OOK，(G)FSK 射频收发器。它是
CMOSTEK NextGenRFTM 射频产品线的一部分，这条产品线
包含完整的发射器，接收器和收发器。CMT2300A 的高集成
度，简化了系统设计中所需的外围物料。高达+20 dBm 及-121
dBm 的灵敏度优化了应用的链路性能
CMT2300A is an ultra low power, high performance, suitable for all 127 to
1020 MHz wireless application OOK, (G) FSK RF transceiver. It is
CMOSTEK NextGenRFTM RF product line part of this product line
Contains a complete transmitter, receiver and transceiver. Gao Jicheng of CMT2300A
It simplifies the peripheral materials needed in system design. Up to +20 dBm and -121
The sensitivity of dBm optimizes the link performance of the application (2018-04-19, PDF, 1513KB, 下载4次)
本文研究的智能家居监控系统将由三大部分组成：无线传感网络模块，数
据处理模块，以太网传输模块。
The intelligent home monitoring system in this paper will be composed of three parts: the wireless sensor network module, the data processing module and the Ethernet transmission module. (2018-03-10, PDF, 6620KB, 下载1次)
W5500模块原理图, W5500是WIZnet推出的高性能以太网接口芯片系列之一,内部集成全硬件TCP/IP协议栈+MAC+PHY。全硬件协议栈技术采用硬件逻辑门电路实现复杂的TCP/IP协议簇。其应用具有简单快速、可靠性高、安全性好等显著优势；内部集成MAC和PHY工艺，使得单片机接入以太网方案的硬件设计更为简捷和高效。
The W5500 module schematic diagram, W5500 is one of the High Performance Ethernet interface chip series launched by WIZnet, which is integrated with the whole hardware TCP/IP protocol stack +MAC+PHY. All hardware protocol stack technology uses hardware logic gate circuit to implement complex TCP/IP protocol cluster. (2017-12-18, PDF, 38KB, 下载8次)
ISO_IEC_23009-1_2014 标准
ISO_IEC_23009-1_2014 (2017-07-12, PDF, 1251KB, 下载11次)
在城域网交换机日常维护中经常会发现，一些申告有丢包、大延时甚至瞬间
中断的以太网专线接入故障中都是因为交换机端口设置不规范，将速率和双工模
式设成了自动协商，如果光电收发器和用户端口也都设置为这一状态，那么会导
致使用设置为10Mbps/100Mbps 自适应的光收发器和用户端网卡用户，实际接入
速率为全双工100Mbps，这样的话该用户的实际吞吐能力可达到200Mbps；另一
方面，因有些光收发器或用户端设备不具备自协商功能或被设置为10Mbps
(100Mbps) 全双工， 从而导致交换机端口于用户端设备自协商到10Mbps
（100Mbps）半双工，进而导致接入链路延时大、丢包乃至瞬间中断。
MAN switch in the routine maintenance is often found that some declaration have packet loss, delay or even big moment
Ethernet Private Line Access interrupted because of failure in the switch port settings are not standardized, the speed and duplex mode
Type set into auto-negotiation, if the optical transceiver and the user ports are also set to this state, will lead
To use the set to 10Mbps/100Mbps adaptive optical transceivers and client card users, the actual access
Rate full-duplex 100Mbps, so the actual throughput of the user can achieve 200Mbps another
Respect, because some optical transceiver or CPE does not have auto-negotiation function or set to 10Mbps
(100Mbps) full duplex, leading to a switch port on the CPE from the negotiation to 10Mbps
(100Mbps) half duplex, which led to major access link delay, packet loss and even the moment interrupted. (2011-01-17, PDF, 61KB, 下载3次)
此文档为T.30建议书
本建议书规定了ITU-T T.4建议书定义的三类传真终端使用的规程。这些规程可以在公用
电话交换网、国际租用电路和综合业务数字网（ISDN）上传送文件。进一步，这些规程允许
人工或自动方式通信，并可以要求文件传输会话交替进行。
This document recommends books for the T.30 Recommendation provides ITU-T T.4 Recommendation defines three types of end-use of fax protocols. These protocols can be public switched telephone network, international leased circuits and integrated services digital network (ISDN) on the transmission of documents. Further, these procedures allow manual or automatic mode communications, and may require alternate file transfer session. (2010-02-21, PDF, 7450KB, 下载7次)
传感器优化布置是结构健康监测研究的重要内容，传感器数量和位置的选择直接关系到模态参数识别的效果及模型修正的结果等。为了达到布置在结构上的有限传感器能够测量并得到用于模态参数识别的最佳信息的目标，提出了基于数据融合的传感器优化布置方法。该方法以距离测度作为数据融合的融合度，首先通过对距离测度矩阵、支持度矩阵的计算，得到待选测点的综合支持度；其次，根据待选测点的综合支持度大小来确定传感器优化布置的位置；最后，以网架结构的传感器优化布置为例，运用峰值法进行自振频率识别，通过已选测点与未选测点识别效果的对比，验证了该方法的有效性
no content (2010-02-06, PDF, 326KB, 下载76次)
Modbus 协议是应用于电子控制器上的一种通用语言。通过此协议，控制器相互之间、控制器经由网络（例如以太网）和其它设备之间可以通信。它已经成为一通用工业标准。有了它，不同厂商生产的控制设备可以连成工业网络，进行集中监控。本文是该协议中文版。
Modbus protocol is applied to the electronic controller of a common language. With this agreement, between the controller, the controller through the network (such as Ethernet) and other communications between devices. It has become a common industry standard. With it, the control of different equipment manufacturers can be connected into the industrial network, centralized monitoring. This is the Chinese version of the agreement. (2009-08-06, PDF, 199KB, 下载3次)
MAX220–MAX249系列线驱动器/接收器，专为EIA/TIA-
232E以及V.28/V.24通信接口设计，尤其是无法提供±12V
电源的应用。
这些器件特别适合电池供电系统，这是由于其低功耗
关断模式可以将功耗减小到5μW以内。MAX225、
MAX233、MAX235以及MAX245/MAX246/MAX247
不需要外部元件，推荐用于印刷电路板面积有限的
应用。
MAX220-MAX249 family of line driver/receiver, designed for EIA/TIA-232E and V.28/V.24 communication interface design, especially unable to provide ± 12V power supply applications. These devices are particularly suitable for battery-powered systems, this is because of its low-power shutdown mode power consumption can be reduced to less than 5μW. MAX225, MAX233, MAX235 and MAX245/MAX246/MAX247 the need for external components, recommended for the limited area of the printed circuit board applications. (2008-12-24, PDF, 520KB, 下载3次)
戴尔大客户员工采购指南
1.什么是员工采购?
EPP- Employee Purchase Program (员工采购计划), 是戴尔为大客户公司员工专门定制的采购计划，优惠提供高性价比的戴尔电脑及外设产品：在网
上最低促销价基础上再额外享受3％-5％现金折扣（特价品及有特殊说明的产品除外）, 并可以随心选择升级方案和更好的服务。
2.可以享受到什么样的优惠?
折扣机型:Inspiron & Vostro& XPS
单台机器额小于RMB 13999, 每个订单可打3％折扣（订单可含SNP&Kits等产品）
单台机器额大于RMB 13999, 每个订单可打5％折扣（订单可含SNP&Kits等产品）
3.如何定购?
1). 登陆戴尔官方网站:www.dell.com.cn 或参阅员工采购指南挑选机型
2). 致电或邮件联系Dell公司员工采购专职客户经理，为您提供咨询及订购服务
3).专享折扣订单确认及付款。付款方式：信用卡、网上银行转帐、银行电汇
4).需传真如下资料给客户经理，方便完成订购:A 员工签名确认的订单；B贵单位员工牌或工作证明或名片；C信用卡授权表或银行汇款底单
5).等待签收.机器签收后3-4个礼拜注意查收您的信件.发票将以挂号信的方式寄送
err (2008-09-13, PDF, 377KB, 下载2次)
西门子技术支持网站简介 当您在使用西门子产品时可能遇到这样或是那样的问题,没关系,您可以登陆西门 子技术支持与服务网站来查找您需要的信息. 网站链接为: http://www.ad.siemens.com.cn/service/ 登陆网站后,您可以点击相关链接,查找您想要得信息,其中在"网上课堂"可以 下载西门子技术支持工程师编写的常问问题和使用入门文档,点击网页左侧的"技 术资源",进入后将显示语言切换到英文(点击网页的右上角"English"),然后 在"Search"输入框中输入您要查找的相关内容,如下载升级软件包,或是查找错 误代码的解释,或是查找相关产品的信息等等,您可能会找到很多条链接,您可以 从中选择您所需要的内容,您还可以通过点击"Product Support"进入西门子的 产品信息库,通过点击左侧的相关文件链接可以查找到西门子相关产品的详细信 息.如果您经常使用网站信息,您会觉得它已成为您解决问题的得力助手. (2008-07-17, PDF, 2726KB, 下载2次)
http://www.pudn.com/Download/item/id/512470.html
本文是英文数据手册的中文翻译，其目的是方便中国用户的阅读。它无法自动跟随原稿的更新，同时也可能存在翻译上的错误。读者应该以英文原稿为参考以获得更准确的信息。
This is the English manual data the Chinese translation, which aims to facilitate the reading of the Chinese users. It can not automatically follow the updated script, but also there may be translation errors. Readers should refer to the original English to obtain more accurate information. (2007-06-09, PDF, 2369KB, 下载6次)