Multi-stratum resources resilience in software defined data center interconnection based on IP over elastic optical networks

IP over elastic optical network is a very promising networking architecture to interconnect data centers. It can enable efficient resource utilization and support heterogeneous bandwidth demands in cost-effective, highly available, and energy-effective manner. In case of aggregation elastic optical network node failure, to ensure a high-level quality of service for user request after the failure becomes a research focus. In this paper, we present a novel multi-stratum resources resilience (MSRR) architecture for the data center services in software defined data center interconnection based on IP over elastic optical networks. The MSRR can enable joint optimization of IP network, elastic optical network, and application stratum resources, and enhance the service resilience and the data center responsiveness to the dynamic end-to-end service demands. Additionally, a service-aware resource collaborative resilience strategy for MSRR is introduced based on the proposed architecture, which can provide the restoration using the multiple stratums resources in case of failure. The overall feasibility and efficiency of the proposed architecture are experimentally verified on our testbed. Moreover, the network performances are quantitatively evaluated through the simulation under heavy traffic load scenario in terms of path blocking probability, resource occupation rate, and path resilience latency.     

大气光通信中迭代检测算法研究

基于对数正态(L-N)湍流信道模型,研究了LDPC编码大气光通信多输入多输出(FSO-MIMO)系统迭代检测算法。分析了内迭代与外迭代次数对系统性能及计算复杂度的影响,并针对PDA检测算法复杂度高的问题,提出了一种基于反馈阈值的M-PDA迭代检测算法。改进的算法利用译码输出的比特先验信息对发送比特进行分类,从而降低检测复杂度,并通过选取合适的阈值,可以获得更好的检测性能。仿真结果表明,实验时需要综合考虑计算复杂度和性能,选取合适的内外迭代次数,仿真条件下,误码率为10-5、反馈阈值为0.7时,可以获得0.15dB的性能增益。     

Water-Surface-Mediated Precise Patterning of Organic Single-Crystalline Films via Double-Blade Coating for High-Performance Organic Transistors

Application-oriented growth of patterned organic semiconductor (OSC) thin films with a single domain is a nonnegotiable requirement for the manufacturing of high-performance organic electronic devices. However, the prevalent selective-wetting patterning method remains a challenge in controlling the density of nucleation events in microscale spaces, resulting in thin films with high grain boundary density and no preferential orientation spherulites. Herein, a simple double-blade-coating printing technique using a combination of wetting-patterned substrates to produce an array of highly crystalline OSC thin films is developed. Specifically, the approach confines the OSC crystallization on a molecular-flat water surface in specific areas, enabling a significant reduction in the number of nuclei. Consequently, patterned 2,7-dioctyl[1]benzothieno[3,2-b] benzothiophene (C₈-BTBT) thin films comprising single-crystal domains are achieved with an exceptionally high yield of 62.5%. The organic field-effect transistor array developed from such patterns of C₈-BTBT single-crystalline films exhibits an excellent average mobility of 11.5 cm² V⁻¹ s⁻¹ which is 12.5-fold higher compared to that of the reference sample fabricated via conventional single-blade coating. It is believed that this approach can be widely applied to other soluble organic materials, thereby opening up opportunities for fabricating multicomponent integrated electronics.     

Extracting embedded messages using adaptive steganography based on optimal syndrome-trellis decoding paths

Privacy protection is the key to maintaining the Internet of Things (IoT) communication strategy. Steganography is an important way to achieve covert communication that protects user data privacy. Steganalysis technology is the key to checking steganography security, and its ultimate goal is to extract embedded messages. Existing methods cannot extract under known cover images. To this end, this paper proposes a method of extracting embedded messages under known cover images. First, the syndrome-trellis encoding process is analyzed. Second, a decoding path in the syndrome trellis is obtained by using the stego sequence and a certain parity-check matrix, while the embedding process is simulated using the cover sequence and parity-check matrix. Since the decoding path obtained by the stego sequence and the correct parity-check matrix is optimal and has the least distortion, comparing the path consistency can quickly filter the coding parameters to determine the correct matrices, and embedded messages can be extracted correctly. The proposed method does not need to embed all possible messages for the second time, improving coding parameter recognition significantly. The experimental results show that the proposed method can identify syndrome-trellis coding parameters in stego images embedded by adaptive steganography quickly to realize embedded message extraction.     

带有太阳能充电功能的蔬菜大棚温度检测装置研究

基于C51单片机和PT100温度检测技术,设计了一种带有太阳能充电功能的大棚温度自动检测装置。该装置由太阳能电池板、A/D转换器、蓄电池、单片机、温度检测电路等模块组成。通过PT100热电阻桥式测温电路,对大棚温度进行实时监测;利用单片机控制技术实现太阳能电池板和蓄电池之间的充放电管理;利用八位点阵终端显示实时温度值。通过实验验证装置性能稳定,运行良好。     

可见光通信中空间调制技术的研究进展

空间调制(SM)技术作为一种多天线传输技术,已经逐步应用到可见光通信(VLC)系统中,并成为该领域的研究热点。在介绍SM技术基本原理的基础上,从有效性、可靠性及与其他调制技术相结合三个方面分析总结了光空间调制(OSM)技术的研究进展,讨论了OSM技术的应用现状以及未来的发展趋势。     

下贝氏体碳化物源的高温电镜观察

在JEM-1000超高压透射电镜高温台中对40CrMnSiMoV钢310℃等温所得下贝氏体进行定点动态观察的结果表明,原先无碳化物的贝氏体铁素体内,在高于等温转变温度经一定时间回火后,析出了典型下贝氏体碳化物。这说明下贝氏体铁素体是过饱和碳的。奥氏体中也可析出碳化物,但不具备下贝氏体碳化物的典型特征。     

Metastable Zirconium Phosphate under Nanoconfinement with Superior Adsorption Capability for Water Treatment

In confined space with length scale of several nanometers, the phase behavior of matter, e.g., nucleation and crystallization, is completely different from its analogue in bulk. However, in environmental applications, the relationship between the nanoconfined crystallization behavior of inorganic crystals and their properties for pollutant removal is rarely elucidated. Herein, an unusual formation of zirconium phosphate (ZrP) crystals as a mixture of both thermodynamically stable α‐ and metastable γ‐phases inside the nanoconfinement of 7.9 nm pores of mesoporous polystyrene (MPS) is reported. This consequently changes the interaction between ZrP and toxic metal cations from nonspecific electrostatic attraction of normal α‐ZrP to highly specific inner‐sphere coordination of nanoconfined γ‐ZrP, which exhibits remarkable reactivity as well as reusability for the removal of toxic metals. The results of this study contribute to a better understanding of the use of nanoconfinement for the regulation of material properties.     

粗颗粒煤水混合物的稠度和流变特性的研究

燃煤增压流化床的燃料制备与输送系统往往需采用气力输送方法送入加压罐后再送入炉内，系统复杂．采用煤水混合燃料泵送技术则可解决上述困难．提出了用塌落度测定方法判断０～６ｍｍ粗颗粒煤水混合物的可泵性，并选择适于泵送的较佳颗粒级配．建立了泵送与管道输送试验台进行粗颗粒徐州煤水混合物的流变特性试验，所得的泵送流变试验数据处理后的模型，可用于商用粗颗粒煤水混合物输送系统的设计计算．     

Cr、Co、Mn磁性对ZnO压敏特性影响的机理研究

研究了不同浓度Cr、Co和Mn的掺杂对ZnO-PbO-B2O3陶瓷压敏特性的影响.实验表明,ZnO平均晶粒尺寸随各元素掺杂量增加而逐渐变大,压敏电压也随之升高,非线性系数随各元素掺杂量增加而先增大后减小,漏电流先减小后增大.分析认为,过渡族金属元素掺杂对ZnO压敏材料电性能的影响不仅与电子的能级有关,与其自旋特性也紧密相连.ZnO中掺杂的Cr、Mn、Co元素随机取代其中的部分Zn原子后,Cr2+、Mn2+、Co2+在ZnO中产生局域磁矩,会对与其取向不同的自旋电子产生强的散射,这样可增大ZnO陶瓷电阻率和提高其非线性特性.