通信用VRLA蓄电池组的可靠性研究

VRLA蓄电池组是当前通信电源系统中主要的储能装置,它的可靠性对通信电源可靠性有着重要影响.文章主要从蓄电池组的接线方式上对蓄电池组的可靠性进行了计算分析,相比先串联后并联方式,先并联后串联方式可有效提高蓄电池组的可靠性.同时,文中还通过冗余设计、正确的使用维护措施来提高蓄电池组的可靠性.     

一种新的点目标无源极化校准方案

极化校准是极化散射矩阵正确获取的重要步骤之一,大口径雷达的极化校准一直是一个难点。为此,提出一种新的无源极化校准方案,该方案利用已校准的小口径雷达来校准大口径雷达。首先,通过外场实验用单个二面角校准小口径雷达;然后,小口径雷达发射信号照射卫星,大小口径两部雷达同时接收并进行信号处理,给出相应的校准算法,最后,通过专业电磁计算软件获得定标体以及卫星散射矩阵的理论值,仿真实验结果验证了提出的极化校准方案的有效性。     

基于FPGA的Kalman滤波器的设计

针对电路设计中经常碰到数据的噪声干扰现象,提出了一种Kalman滤波的FPGA实现方法。该方法采用了Ⅱ公司的高精度模数转换器ADS1251以及Altera公司的EPIC12,首先用卡尔曼滤波算法设计了一个滤波器,然后将该滤波器分解成简单的加、减、乘、除运算。通过基于FPGA平台的硬件与软件的合理设计,成功地实现了数据噪声的滤除设计,并通过实践仿真计算,验证了所实现滤波的有效性。     

氨纶涤泡绉的染整工艺探讨

根据氨纶的特性,结合工厂条件对氨纶涤泡绉的退,煮,漂,染,整的基本工艺进行初步探讨,并介绍了氨纶涤泡绉的起绉风格与产品的幅宽加工系数之间的关系。     

基于速度触发的提前切换算法在LTE-R中的应用研究

随着高铁的快速发展,铁路移动通信系统对切换时延、切换成功率等要求更为苛刻。该文针对铁路长期演进(LTE-R)系统提出基于速度触发的提前切换算法,通过提前进行信令交互、设置切换预承载点切换的方式抑制过早或过迟切换所带来的通信中断、掉话等问题。通过信令流程图进行理论分析,并对长期演进(LTE)各结构类型数据计算可知,该算法均可缩短切换时延,其中TDD帧结构类型2时效果最为显著。最后通过仿真对比得到提前切换算法相比传统切换算法有着更高且更稳定的切换成功率,验证算法的有效性,为LTE-R在未来铁路专网的应用提供技术支持。     

RICB：基于缓冲区溢出的整数溢出漏洞动态分析

Integer overflow vulnerability will cause buffer overflow. The research on the relationship between them will help us to detect integer overflow vulnerability. We present a dynamic analysis methods RICB (Run-time Integer Checking via Buffer overflow). Our approach includes decompile execute file to assembly language; debug the execute file step into and step out; locate the overflow points and checking buffer overflow caused by integer overflow. We have implemented our approach in three buffer overflow types: format string overflow, stack overflow and heap overflow. Experiments results show that our approach is effective and efficient. We have detected more than 5 known integer overflow vulnerabilities via buffer overflow.     

In_（0．2）Ga_（0．8）As／GaAs应变多量子阱结构的光调制反射和热调制反射谱的研究

对Ｉｎ（０．２）Ｇａ（０．８）Ａｓ／ＧａＡｓ应变多量子阱在７７Ｋ下的光调制反射谱（ＰＲ）和热调制反射谱（ＴＲ）进行了实验研究．对ＰＲ结果的线形拟合指认了应变多量子阱中子能级的跃迁，并与理论计算结果作了比较．实验对比确认ＰＲ中１１Ｈ、１３Ｈ等跃迁结构为非耦合态、具有电场调制机构的一阶微商性质．而１１Ｌ、３１Ｈ、２２Ｈ等跃迁结构为阶间耦合态，对这些隧穿耦合的低场调制产生三阶微商特性．     

Hierarchical Carbon Nanotubes with a Thick Microporous Wall and Inner Channel as Efficient Scaffolds for Lithium–Sulfur Batteries

The proposal herein is based on an efficient sulfur host, namely hierarchical microporous–mesoporous carbonaceous nanotubes (denoted as HMMCNT) that feature a thick microporous wall and inner hollow channel. The electrochemical performance of the composite (HMMCNT‐S) is studied systematically at different discharge cut‐off voltages and at varying sulfur content. The cycling behavior in different voltage windows is compared and the highest specific capacity is shown for HMMCNT‐S‐50 in the range of 1.4–2.8 V. These results imply that better energy densities can be achieved by controlling the discharge cut‐off voltage. Moreover, we show that when the sulfur loading is 50% (HMMCNT‐S‐50), the cycling and rate performance is better than that of the composite loaded with 40% sulfur (HMMCNT‐S–40). Benefiting from the attractive hierarchical micro/mesoporous configuration, the obtained hybrid structure not only promotes electron and ion transfer during the charge/discharge process, but also efficiently impedes polysulfide dissolution. More specifically, the electrode can deliver a specific capacity of 558 mA h g^‐1 even after 150 cycles at a high rate of 1600 mA g^‐1 with a decay rate of only 0.13% per cycle. Considering the beneficial structure of these carbon nanotubes, it is very feasible that these structures may also be used in other research fields, including in catalysis, as supercapacitors, in drug‐delivery applications, for absorption, and so on.     

A Hierarchical 3D Graft Printed with Nanoink for Functional Craniofacial Bone Restoration

An ideal craniofacial bone repair graft shall not only focus on the repair ability but also the regeneration of natural architecture with occlusal loads-related function restoration. However, such functional bone tissue engineering scaffold has rarely been reported. Herein, a hierarchical 3D graft is proposed for rebuilding craniofacial bone with both natural structure and healthy biofunction reconstruction. Inspired by the bone healing process, an organic–inorganic nanoink with ultrasmall calcium phosphate oligomers and bone morphogenetic protein-2 incorporated is developed for spatiotemporal guidance of new bone. Based on such homogeneous nanoink, a biomimetic graft, including a cortical layer containing Haversian system, and a cancellous layer featured with triply periodic minimum surface macrostructures, is fabricated via projection-based 3D printing method, and the layers are loaded with distinct concentrations of bioactive factors for regenerating new bone with gradient density. The graft exhibits excellent osteogenic and angiogenic potential in vitro, and accelerates revascularization and reconstructs neo-bone with original morphology in vivo. Benefiting from such natural architecture, loading force is widely transferred with reduced stress concentration around the inserted dental implant. Taken from native physiochemical and structural cues, this wstudy provides a novel strategy for functional tissue engineering through designing function-oriented biomaterials.