Production of high degree polymerized chitooligosaccharides in a membrane reactor using purified chitosanase from Bacillus cereus

Crude chitosanase from Bacillus cereus NTU-FC-4 was separated by a cation exchanger to three fractions named CBCI, CBCII, and CBCIII. The CBCI hydrolyzed chitosan to yield dimers. The primary hydrolytic products of CBCII were low degree polymerized (DP) chitooligosaccharides. The CBCIII had the fastest reaction rate and yielded high DP chitooligosaccharides (heptamer and higher DP oligomers). When CBCIII was used in the ultrafiltration membrane reactor with enzyme/substrate ratio 0.06 unit/mg and 100 min of residence time (RT), the concentration of high DP oligomers was 9.78 mg/mL which occupied ca. 48% of total oligomers in the final product as compared to ca. 29% resulted from the crude enzyme. Decrease of RT to 50 min and 33 min, the high DP oligomers in the products were ca. 61% and 69%, respectively. This system could be operated for at least 24 h and kept a constant permeate flux and product output rate.     

A 2.4-Gsample/s DVFS FFT Processor for MIMO OFDM Communication Systems

This paper presents a new dynamic voltage and frequency scaling (DVFS) FFT processor for MIMO OFDM applications. By the proposed multimode multipath-delay-feedback (MMDF) architecture, our FFT processor can process 1-8-stream 256-point FFTs or a high-speed 256-point FFT in two processing domains at minimum clock frequency for DVFS operations. A parallelized radix-2⁴ FFT algorithm is also employed to save the power consumption and hardware cost of complex multipliers. Furthermore, a novel open-loop voltage detection and scaling (OLVDS) mechanism is proposed for fast and robust voltage management. With these schemes, the proposed FFT processor can operate at adequate voltage/frequency under different configurations to support the power-aware feature. A test chip of the proposed FFT processor has been fabricated using UMC 90 nm single-poly nine-metal CMOS process with a core area of 1.88 times1.88 mm² . The SQNR performance of this FFT chip is over 35.8 dB for QPSK/16-QAM modulation. Power dissipation of 2.4 Gsample/s 256-point FFT computations is about 119.7 mW at 0.85 V. Depending on the operation mode, power can be saved by 18%-43% with voltage scaling in TT corner.     

Effect of processing temperature on characteristics of metal-ferroelectric (BiFeO3)-insulator (HfLaO)-silicon capacitors

The effect of temperature in rapid thermal annealing (RTA) process on the physical and electrical properties of bismuth ferrite ceramic thin films on HfLaO/p-Si substrates has been investigated. In metal-ferroelectric-insulator-silicon (MFIS) capacitors, the high-k HfLaO dielectric layer was prepared as the insulator layer. On HfLaO/Si substrates the bismuth ferrite thin film was fabricated via sputtering process with a BiFeO₃ (BFO) target at room temperature followed by RTA. The RTA temperature ranged from 500 to 700 °C. It is found that the root mean square roughness of ceramic films increases for high-temperature process. The maximum ferroelectric memory window is 1.6 V obtained from a sweep voltage of ± 4 V at the lowest RTA temperature of 500 °C. This good ferroelectric memory performance can be attributed to the low leakage current as a result of smooth surface of nanocrystalline ferroelectric BFO and Bi₂Fe₄O₉ thin films.     

新型旋流器在鲁南矿业磨矿分级中的应用

介绍了鲁南矿业选矿厂一段分级由新型旋流器替代螺旋分级机的应用情况,现场运行数据表明该新型旋流器具有溢流细度高、沉砂夹细少、分级效率高的特点,可有效提高磨矿效率,降低磨矿功耗,取得了满意的效果     

The Scale of Ethnocultural Empathy: Development, validation, and reliability.

The authors present 3 studies on the initial validity and reliability of the Scale of Ethnocultural Empathy (SEE), a self-report instrument that measures empathy toward people of racial and ethnic backgrounds different from one's own. Specifically, the exploratory factor analysis yielded 4 factors: Empathic Feeling and Expression, Empathic Perspective Taking, Acceptance of Cultural Differences, and Empathic Awareness. A confirmatory factor analysis provided evidence for the stability and generalizability of this 4-factor solution. The SEE was correlated in the predicted directions with general empathy and attitudes toward people's similarities and differences. High internal consistency and test-retest reliability estimates were also found across the three studies. A discussion of how this scale can add to the research and practice regarding empathy and multicultural issues is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于测距与GNSS信息融合的车联网协同定位技术

为了提高车联网中车辆定位的精度,提出了基于车载雷达测距信息与全球卫星导航系统（global navigation satellite system,GNSS）信息融合的车联网协同定位方法。该方法使用极大似然估计策略建立数学模型,其本质是一个非线性优化问题。将其化简为具有多个二次等式约束的二次规划问题,并给出一种半正定松弛方法,可以高效地近似求解原问题,最后通过特征值分解法进一步改进该近似解。仿真结果表明,该信息融合方法得到的协同定位比线性化加权最小二乘方法的定位精度有显著提高;且能达到基于较大数据集的BP（back propagation）神经网络定位方法的定位精度,但无须事先训练模型,可实现高精度实时定位。     

Isolation and Characterization of Chickpea (Cicer arietinum L.) Seed Protein Fractions

Proteins of ground chickpea seeds were extracted with sodium hydroxide (NaOH) solution and precipitated with addition of acid (isoelectric precipitate (C-IP)) and by cryoprecipitation (cryoprecipitate (C-CP)). The protein isolates were characterized by Native PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), reversed-phase high performance liquid chromatography (RP-HPLC) and electrospray-ionization mass spectrometry (ESI/MS). Both the isoelectric precipitate and cryoprecipitate contained the globulin protein 11S legumins and 7S vicilins as the major protein fractions and 2S albumin proteins as a minor protein fraction. The major subunits of RP-HPLC protein fractions from both cryoprecipitate and isoelectric precipitate were found to contain subunits of both legumins and vicilins. SDS-PAGE identified legumin α-subunits with MW 40.6 and 39.5 kDa and legumin β- subunits with MW 23.5 and 22.5 kDa, and vicilin subunits with MW 70.2, 50.7, 35.0, 33.6, 18.9 and 15.5 kDa. ESI-MS molecular weights 35,366, 35,268 and 14,648 Da are likely vicilin subunits while the 24,894 Da is a legumin β-subunit.     

基于深度学习的客流量统计方法

针对目标快速移动和遮挡情况导致的客流统计存在误差的问题,设计目标的检测、跟踪、进门行为判断等策略,提出基于深度学习的餐饮业客流统计方法.首先,通过多数据集对YOLOv3-tiny模型进行训练,实现对于小目标的准确检测;进而设计多通道特征融合的目标跟踪算法,完成目标快速移动情况下的稳定跟踪;最后设计目标进门行为的判断方法,通过重叠率对目标的进门行为进行判断,实现对进门客流量的准确统计.最终通过实验验证,客流量统计的平均准确率达到93.5%.     

An Indexed-Scaling Pipelined FFT Processor for OFDM-Based WPAN Applications

In this brief, a high-throughput and low-complexity fast Fourier transform (FFT) processor for wideband orthogonal frequency division multiplexing communication systems is presented. A new indexed-scaling method is proposed to reduce both the critical-path delay and hardware cost by employing shorter wordlength. Together with the mixed-radix multipath delay feedback structure, the proposed FFT processor can achieve very high throughput with low hardware cost. From analysis, it is shown that the proposed indexed-scaling method can save at least 11% memory utilizations compared to other state-of-the-art scaling algorithms. Also, a test chip of a 1.2 Gsample/s 2048-point FFT processor has been designed using UMC 90-nm 1P9M process with a core area of 0.97 mm². The signal-to-quantization-noise ratio (SQNR) performance of this test chip is over 32.7 dB to support 16-QAM modulation and the power consumption is about 117 mW at 300 MHz. Compared to the fixed-point FFT processors, about 26% area and 28% power can be saved under the same throughput and SQNR specifications.     

基于种群个体数自适应的多尺度量子谐振子优化算法

优化算法中多种群采样方式可转化为蒙特卡洛对当前函数积分的评估, 针对不同子种群对整体评估的差异性, 提出子种群规模 (个体数) 自适应的改进策略, 并用于多尺度量子谐振子优化算法(Multi-scale quantum harmonic oscillator algorithm, MQHOA) 的改进, 同时阐述多种群策略所具有的量子特性以及量子隧道效应与寻优性能的相关性. 已有的优化算法忽视了动态调节子种群规模对寻优能力的影响, 该策略通过动态调节子种群规模, 提高适应度差的子种群发生量子隧道效应的概率, 增强了算法的寻优能力. 将改进后的算法MQHOA-d (Multi-scale quantum harmonic oscillator algorithm based on dynamic subpopulation) 与 MQHOA 及其他优化算法在 CEC2013 测试集上进行测试, 结果表明原算法 MQHOA“早熟”问题在 MQHOA-d 中得到解决, 且 MQHOA-d 对多峰函数和复合函数优化具有显著优势, 求解误差和计算时间均小于几种经典优化算法.