基于重叠分段和FrFT的VCO非线性度检测方法*

VCO非线性度检测是实现其非线性度精确校正的前提,研究VCO非线性度检测方法具有重要理论意义和实用价值。针对目前基于微元法和分数阶傅里叶变换的VCO非线性度检测方法在抗噪性、实时性等方面存在的不足,提出了一种基于重叠分段和分数阶傅里叶变换的VCO非线性度检测方法。所提方法采取重叠分段的策略以抑制噪声干扰,在分数阶傅里叶变换域进行幅度峰值搜索时改用收敛速度快的黄金分割法以增强实时性。仿真实验表明所提方法具有良好的抗噪性,分段重叠率为0.25时其检测的均方根误差约为现有方法的1/2;当重叠率小于2/3时,其实时性也优于现有方法。     

Energy efficiency in cloud computing based on mixture power spectral density prediction

Due to the budget and environmental issues, adaptive energy efficiency receives a lot of attention these days, especially for cloud computing. In the previous research, we developed a combined methodology based on nonparametric prediction and convex optimization to produce proactive energy efficiency-oriented solution. In this work, the predictive analysis was further enhanced by deriving the mixture power spectral density to model the complex cloud monitoring statistics. By engaging the improved technique to the predictive analysis, the prediction process was more adaptive to handle the fluctuation in system utilization. As a consequence, the optimization process could subsequently produce more appropriate setting for energy savings. After the infrastructure setting has been made available, the instruction of virtual machine migration was created and implemented by the cloud orchestrator. This instruction condensed the services into the pool of active facilities, satisfying the objective of power efficiency. Eventually, any physical machine out of the power configuration would be gradually terminated. Compared to our former method, the effectiveness of the proposed technique has been proven by cutting down 4.92% of energy consumption, while still maintaining a similar quality of services.

     

Performance implications of internet channels in financial services: A comprehensive perspective

Advances in information technology (IT) have forced financial services firms to explore new organizational forms and deliver service innovation. Given the obvious differences in the business model in which the financial services sector provides online services, it is natural to ask whether the emergence of Internet channels leads to superior achievement. Using a sample of twenty-four Taiwanese publicly traded financial services firms from 1997 to 2003, this empirical study attempts to assess the Internet channel??s effect on firm performance by means of applying event study methodology and data envelopment analysis. Results show that the magnitudes of average abnormal returns are uniformly positive and increase the operating efficiency of firms following announcements via Internet channels. This work therefore concludes that Internet channels have positive influences on firm performance.     

Utilizing an Animal Model to Identify Brain Neurodegeneration-Related Biomarkers in Aging

Glycine N-methyltransferase (GNMT) regulates S-adenosylmethionine (SAMe), a methyl donor in methylation. Over-expressed SAMe may cause neurogenic capacity reduction and memory impairment. GNMT knockout mice (GNMT-KO) was applied as an experimental model to evaluate its effect on neurons. In this study, proteins from brain tissues were studied using proteomic approaches, Haemotoxylin and Eosin staining, immunohistochemistry, Western blotting, and ingenuity pathway analysis. The expression of Receptor-interacting protein 1(RIPK1) and Caspase 3 were up-regulated and activity-dependent neuroprotective protein (ADNP) was down-regulated in GNMT-KO mice regardless of the age. Besides, proteins related to neuropathology, such as excitatory amino acid transporter 2, calcium/calmodulin-dependent protein kinase type II subunit alpha, and Cu-Zn superoxide dismutase were found only in the group of aged wild-type mice; 4-aminobutyrate amino transferase, limbic system-associated membrane protein, sodium- and chloride-dependent GABA transporter 3 and ProSAAS were found only in the group of young GNMT-KO mice and are related to function of neurons; serum albumin and Rho GDP dissociation inhibitor 1 were found only in the group of aged GNMT-KO mice and are connected to neurodegenerative disorders. With proteomic analyses, a pathway involving Gonadotropin-releasing hormone (GnRH) signal was found to be associated with aging. The GnRH pathway could provide additional information on the mechanism of aging and non-aging related neurodegeneration, and these protein markers may be served in developing future therapeutic treatments to ameliorate aging and prevent diseases.     

Ti(C,N)粉末制备技术的研究及进展

概括了国内外Ti(C,N)粉末的制备技术,特别系统地介绍了Ti(C,N)粉末的制备技术的最新进展,分析了这些制备技术的工艺过程和工艺特点,讨论了其存在的问题和发展趋势。     

碲铜系合金在饱和NH4Cl溶液中的腐蚀行为

用全浸失重法,研究了碲铜系合金在饱和NH4Cl溶液中的抗腐蚀性能,结合扫描电镜(SEM)、能谱仪(EDS)等测试方法,初步探讨了合金在饱和NH4Cl溶液中的腐蚀行为及腐蚀机制,结果表明碲铜系合金的抗腐蚀性优于纯铜,其腐蚀速率低于纯铜,原因在于碲、镁的加入,可降低纯铜中的非金属杂质含量,同时碲、镁的加入,可沿铜晶界以化合物的形式析出,有利地阻碍了纯铜的沿晶腐蚀.     

Hygroresponsive Torsional Yarns and Actuators Based on Cascade Amplification of the Deformation

Fiber-based hygroresponsive torsional actuators provide desirable merits, such as light weight and shapeability, for developing smart systems to harvest energy from moisture which is a ubiquitous natural resource. A key challenge in this development is to realize moisture-triggered actuation combining large actuation and rapid responses. Here, a multiscale design strategy is explored to create high-performance hygroresponsive torsional actuators consisting of chitosan and multiwalled carbon nanotubes (MWCNTs). The superior actuation performance arises from the synergism of contributing factors at different scales, including 1) MWNCTs accelerate the water transport in primary twisted fibers (PTFs), fostering the rotation of PTFs upon moisture stimuli; 2) in situ-formed hierarchically-assembled twists realize cascade amplification of moisture-triggered actuation. Specifically, PTFs are self-twisted to generate secondary helical yarns, that are subsequently over-twisted to yield tertiary coiled yarn. The resultant yarn actuator can reach a maximum rotation speed of 11 400 rpm in 5 s, output gravitational potential energy of 2.4 J kg⁻¹ and gravitational potential power of 0.053 W kg⁻¹ during contraction. This work represents the first design of fiber-based actuators by virtue of moisture-triggered in situ formation of yarns. The established principles of multiscale design will enable high-performance fiber-based hygroresponsive actuators toward advanced intelligent textile and soft robotics.     

医药副产含磷废盐的提纯研究

随着精细化工及中间体产品的发展,各类副产废盐量不断增加,由于其产生量大及难处理等特点,成为阻碍行业发展的一大瓶颈。主要开展了医药副产含磷废盐的提纯实验研究,针对废盐产生的途径和特性,采用洗脱剂（甲醇-乙醇）+活性炭混合洗脱与重结晶的方式,分别去除废盐中的有机物和氯化钠,回收可利用的磷酸盐,实现废盐的提纯资源化。当洗脱剂与废盐的体积质量比为1 mL/g、洗脱剂甲醇与乙醇的体积比为4∶6、活性炭用量为废盐质量的0.4%时,废盐中的有机物得到了有效去除。随后对得到的混盐进行重结晶得到回收磷酸盐,回收磷酸盐的纯度可达98%以上,符合工业磷酸盐行业标准的要求。将含磷废盐提纯回收磷酸盐,1 t废盐的处理成本约为174.24元,可回收0.61 t磷酸盐,实现了废盐的资源化再利用。     

（LPCCa）2（MgNi）17合金的吸放氢性能

研究了用部分Ca取代LPC（LPC为无钕镧镨铈混合稀土金属），同时用部分Ni取代Mg的（LPCCa）2（MgNi）17合金的吸放氢性能。比较了不同温度下，不同成分配比对合金贮氢性能的影响。其中，（LPC）1.9Ca0.1Mg15Ni2合金具有相对较低的放氢温度和较大的放氢节，住275℃的放氢量达3．43％（质量分数）。分析了（LPC）1.9Ca0.1Mg15Ni2的微观结构，同时对合金放氢温度降低的原冈进行了讨论。     

多孔钯的制备及其结构与性能

研究了以钯粉和碳酸钠为原料制备多孔钯的烧结-溶解新工艺，用FESEM分析了多孔钯的微观结构形貌，并进一步研究了制备的多孔钯的力学性能和氢同位素的交排换代性能。结果表明，烧结-溶解工艺能稳定地制备出孔隙率为85．29％-87．82％的多孔钯，其压缩强度大于2MPa。室温下孔隙率为87.30％的多孔钯对氘的单位质量吸收量为0．0767L／g，氢同位素排代交换率为86．2％。