Research on the Development of Fibroin and Nano-Fiber from Silk Cocoons for Regenerated Tissue Engineering Applications by Electro-Spinning

In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue applications. The purpose of the research is to prepare a silk-fibroin nano-fiber solution for potential applications in tissue engineering. Using a degumming process, pure silk fibroin protein is extracted from silk cocoons. The protein solution for fibroin is purified, and the protein content is determined. The precise chemical composition, exact temperature, time, voltage, distance, ratio, and humidity all have a huge impact on degumming, solubility, and electro-spinning nano-fibers. The SEM investigates the morphology of silk fibroin nano-fibres at different magnifications. It also reveals the surface condition, fiber orientation, and fiber thickness of the silk fibroin nano-fiber. The results show that regenerated silk fibroin and nano-fiber can be used in silk fibroin scaffolds for various tissue engineering applications.

Spectra of spontaneous Raman scattering in taper-drawn micro/nano-fibers

We study the spontaneous Raman scattering （RS） in taper-drawn micro/nano-fibers （MNFs） by employing the photon counting technique. The spectra of RS in five MNFs, which are fabricated by using different heating flames （hydrogen flame or butane flame） and with different diameters, are measured within a frequency shift range of 1435 cm- 1_3200 cm- 1. From the measured spectra, we observe the RS peaks originated from silica and a unique RS peak with a frequency shift of - 2905 cm-1 （- 87.2 THz）. Unlike the former ones, the latter one is not observable in conventional optical fibers. Furthermore, the unique peak becomes obvious and starts to rapidly increase with the decrease of the diameter of MNFs when the diameter is smaller than 2 μm, and the intensity of the unique peak significantly depends on the heating flame used in the fabricating process. Our investigation is useful for the entanglement generation or optical sensing using taper-drawn MNFs.

An energetic nano-fiber composite based on polystyrene and 1,3,5-trinitro-1,3,5-triazinane fabricated via electrospinning technique

Electrospinning is a simple technique used to fabricate polymeric nano-fibrous membranes.These nano-fibers have found a wide range of valuable applications in the biomedical field.However,it has not been utilized with solid high explosives yet.Herein,the electrospinning technique has been used to fabricate polystyrene(PS)/1,3,5-trinitro-1,3,5-triazinane(RDX)composite nanofibers.The governed electrospinning parameters,voltage,distance from the collector,flow rate,mandrel rotating speed,time,and solution concentration,that greatly affect the morphology of the obtained nanofibers were optimized.The fabricated PS/RDX nano-fibers were characterized using scanning electron microscopy(SEM),X-ray diffractometer(XRD),and Fourier Transform Infrared(FTIR)spectroscopy.The impact and friction sensitivities of PS/RDX were also measured.The thermal behavior of the prepared composite and the pure materials were studied by the thermal gravimetric analysis technique(TGA).SEM results proved the fabrication of PS/RDX fibers in the nano-size via electrospinning.FTIR spectroscopy confirmed the existence of the characteristic functional groups of both PS and RDX in the composite nano-fibers.XRD sharp peaks showed the conversion of amorphous PS into crystalline shape via electrospinning and also confirmed the formation of PS/RDX composite.The PS fibers absorbed the heat and increased the onset decomposition of the pure RDX from 181.5 to 200.7℃in the case of PS/RDX fibers.Interestingly,PS/RDX nano-fibers showed the relatively low impact and friction sensitivities of 100 J and 360 N respectively.These results could introduce PS/RDX nanofibrous composite in the field of explosives detection with high levels of safety.

Enhanced Tunicate Swarm Optimization with Transfer Learning Enabled Medical Image Analysis System

Medical image analysis is an active research topic,with thousands of studies published in the past few years.Transfer learning(TL)including convolutional neural networks(CNNs)focused to enhance efficiency on an innovative task using the knowledge of the same tasks learnt in advance.It has played a major role in medical image analysis since it solves the data scarcity issue along with that it saves hardware resources and time.This study develops an EnhancedTunicate SwarmOptimization withTransfer Learning EnabledMedical Image Analysis System(ETSOTL-MIAS).The goal of the ETSOTL-MIAS technique lies in the identification and classification of diseases through medical imaging.The ETSOTL-MIAS technique involves the Chan Vese segmentation technique to identify the affected regions in the medical image.For feature extraction purposes,the ETSOTL-MIAS technique designs a modified DarkNet-53 model.To avoid the manual hyperparameter adjustment process,the ETSOTLMIAS technique exploits the ETSO algorithm,showing the novelty of the work.Finally,the classification of medical images takes place by random forest(RF)classifier.The performance validation of the ETSOTL-MIAS technique is tested on a benchmark medical image database.The extensive experimental analysis showed the promising performance of the ETSOTL-MIAS technique under different measures.

多策略改进的被囊群算法在入侵检测中的应用

针对被囊群优化算法应用于网络入侵检测系统存在算法收敛速度较慢,容易陷入局部最优解的缺陷,提出一种适用于XGBoost的参数寻优以及特征选择的改进被囊群优化算法。应用Tent混沌映射和自适应步长两种策略加快算法的收敛,融合莱维飞行策略增强个体的路径扰动帮助算法更好跳出局部最优解。仿真结果表明,改进后优化算法收敛速度更快,更加稳定,寻优精度更高,在XGBoost上的应用相较于其它机器学习算法,取得了更好的检测结果,有效提高了网络入侵检测的性能。

柯西变异的混沌自适应被囊群算法

针对被囊群算法(TSA)收敛速度慢,寻优精度低,易陷入局部极值等问题,提出了基于柯西变异的混沌自适应被囊群算法(KZCTSA).首先,采用Circle混沌初始化整个被囊种群,提高种群多样性,提升算法全局搜索能力;其次,引入自适应权重调整算法参数分配,平衡算法全局寻优和局部开拓能力;最后,使用柯西变异协调算法跳出局部最优能力.通过在10个基准测试函数上与其他算法比较寻优结果,并进行Wilcoxon、Fiedeman秩和检验评价算法性能,结果表明KZCTSA具有更好的求解精度和收敛速度.

采用改进被囊群算法的多冷水机组负荷分配优化

为了降低中央空调系统的运行能耗,针对多冷水机组负荷分配优化问题,提出一种随机森林特征优选结合核函数极限学习机的冷水机组能效预测模型,通过剔除冗余特征提高预测精度;然后提出一种混合策略改进的被囊群算法,融合鲸鱼螺旋搜索策略改进个体更新方式,引入非线性动态权重平衡全局探索和局部开发,使用空翻扰动策略避免陷入局部最优;最后在能效模型的基础上,采用改进被囊群算法对多冷水机组负荷分配进行优化;实验结果表明,随机森林特征优选的方法可以有效地提高能效预测模型的准确度;改进被囊群算法通过优化机组的启停状态和负荷率可以有效发挥系统的节能潜力,与原有方法相比能耗降低约6%;说明该方法适用于多冷水机组的负荷分配优化问题。

Seasonal abundance and distribution of pelagic tunicates (Chordata: Thaliacea) in the central South China Sea

A total of 168 macro-zooplankton samples from 42 stations in the central South China Sea （12° ～20° N, 111°～118°E, an area of about 64 × 10^4 km^2 ） were collected in September 1983 （autumn） , April 1984 （spring） , August 1984 （summer） and December 1984 （winter）. Twenty-three species and subspecies of tunicates were found, of which Thalia democratica complex （including T. d. orientalis and T. d. echinata） and Doliolum denticulatum were the dominant species, and accounted for 95.7% , 90. 0%, 91.8% and 90. 5% of the total tunicates found in autumn, winter, spring and summer, respectively. The highest abundance （with a mean of 2.37 ind./m^3 ） occurred in autumn. There are strong correlations between the abundances of the tunicates and those of phytoplankton and chlorophyll a concentration. However, tunicates also aggregate in areas with low primary production in the autumn survey, probably due to the water circulation pattern.

Distribution and Abundance of Pelagic Tunicates in the North Yellow Sea

In this paper, the distribution patterns and abundance of pelagic tunicates in the North Yellow Sea of China during the period 2006-2007 were analyzed. Zooplankton samples were obtained with vertical towing from bottom to surface using a WP2 plankton net(200 μm mesh size; mouth area: 0.25 m2). Five species belonging to two classes were identified: Oikopleura dioica, O. longicauda and Fritillaria borealis belonging to class Appendicularia; Salpa fusiformis and Doliolum denticulatum of class Thaliacea. O. dioica and O. longicauda were the dominant species, occurring in the samples of all four seasons, with different distribution patterns. Their maximum abundance were 1664.7 ind. m-3(spring) and 1031.7 ind. m-3(spring) respectively. Following Oikopleura spp. were D. denticulatum, which was found only in autumn with an average abundance of 149.6 ind. m-3, and S. fusiformis, which was detected all the year long except for autumn with low abundance(max. abundance 289.4 ind. m-3 in summer). Only a very small amount of F. borealis was detected in summer samples, with an average abundance of 2.7 ind. m-3. The relationship between tunicates abundances and the environmental factors was analyzed using the stepwise regression model for each species. The variation of appendicularian abundance showed a significant correlation with the surface water temperature and with the concentration of Chl-a. No relationship was found between tunicates abundance and salinity, likely due to the slight changes in surface salinity of the studied area during the four seasons. Salps abundance and that of doliolids were significantly correlated to bottom water temperature, indicating that these two species(S. fusiformis and D. denticulatum) migrate vertically in the water column. In particular D. denticulatum, known to be a warm water species, showed not only an important correlation with water temperature, but also a spatial distribution connected to the warm currents in the North Yellow Sea. The occurrence of D. denticulatum represents an interesting result never found in past research work. Water temperature, algal distribution and currents were the most relevant environmental factors influencing the tunicate abundance and distribution in the North Yellow Sea. Further research is needed in order to get more information on the ecology of these organisms and to better understand their role in the ecosystem including the oceanic food web.

Preparation of Carbon Nano-fiber Washcoat on Porous Silica Foam as Structured Catalyst Support

This paper reports how a hairy layer of carbon nano-fibers can be prepared on the macro-porous silica foam produced by the sphere templating method. Firstly, three-dimensional close-packed crystals of polystyrene spheres are assembled on porous disk substrate by vacuum filtration or evaporation. The polystyrene template is annealed slightly above the glass transition temperature in order to strengthen the colloidal crystal and ensure interconnection of the spheres so as to obtain porous materials with open structure. Following the treatment of hexdecyltrimethylammonium bromide, the polystyrene template is filled with silica colloidal solution, which solidifies in the cavities. Then the polystyrene particles are removed by calcination at 843K, leaving behind porous silica foam. Scanning electron microscopy images demonstrate that silica foam has uniform and open structured pores. Nickel particles were deposited on porous silica foam layer by the dipping method and porous carbon nano-fiber washcoat was prepared by catalytic decomposition of ethene over small nickel particles.

Facile Fabrication of Conductive Paper-based Materials from Tunicate Cellulose Nanocrystals and Polydopamine-decorated Graphene Oxide

Conductive papers made from graphene and its derivatives are important for the development of electronic devices; however, elastomer-based matrices usually make it difficult for the conductive sheets to form continuous conductive networks. In this work, we used tunicate-derived cellulose nanocrystals （TCNC） instead of traditional elastomers as the matrix for polydopamine （PDA）-coated and reduced graphene oxide （GO） to prepare conductive paper, which, at a low concentration, were better for the formation of conductive networks from conductive sheets. It was found that the Young’s modulus of the conductive paper produced via this strategy reached as high as 7 GPa. Meanwhile, owing to the partial reduction of GO during the polymerization of dopamine, the conductivity of the conductive paper reached as high as 1.3×10-5 S/cm when the PDA-coated GO content was 1 wt%, which was much higher than the conductivity of pure GO （-4.60×10-8 S/cm）. This work provides a new strategy for preparing environmentally friendly conductive papers with good mechanical properties and low conductive fller content, which may be used to produce high-performance, low-cost electronic devices.

Preparation of Carbon Nano-fiber Washcoat on Porous Silica Foam as Structured Catalyst Support

This paper reports how a hairy layer of carbon nano-fibers can be prepared on the macro-porous silica foam produced by the sphere templating method. Firstly, three-dimensional close-packed crystals of polystyrene spheres are assembled on porous disk substrate by vacuum filtration or evaporation. The polystyrene template is annealed slightly above the glass transition temperature in order to strengthen the colloidal crystal and ensure inter- connection of the spheres so as to obtain porous materials with open structure. Following the treatment of hexde- cyltrimethylammonium bromide, the polystyrene template is filled with silica colloidal solution, which solidifies in the cavities. Then the polystyrene particles are removed by calcination at 843K, leaving behind porous silica foam. Scanning electron microscopy images demonstrate that silica foam has uniform and open structured pores. Nickel particles were deposited on porous silica foam layer by the dipping method and porous carbon nano-fiber washcoat was prepared by catalytic decomposition of ethene over small nickel particles.

Intelligent Tunicate Swarm-Optimization-Algorithm-Based Lightweight Security Mechanism in Internet of Health Things

Fog computing in the Internet of Health Things(IoHT)is promising owing to the increasing need for energy-and latency-optimized health sector provisioning.Additionally,clinical data(particularly,medical image data)are a delicate,highly protected resource that should be utilized in an effective and responsible manner to fulfil consumer needs.Herein,we propose an energy-efficient fog-based IoHT with a tunicate swarm-optimization-(TSO)-based lightweight Simon cipher to enhance the energy efficiency at the fog layer and the security of data stored at the cloud server.The proposed Simon cipher uses the TSO algorithm to select the optimal keys that will minimize the deterioration of quality between the original and reconstructed(decrypted)images.In this study,the decrypted image quality is preserved by the peak signal-to-noise ratio(PSNR)such that consumers can generate precise medical reports from IoHT devices at the application level.Moreover,a lightweight encryption step is implemented in the fog to improve energy efficiency and reduce additional computations at the cloud server.Experimental results indicate that the TSO-Simon model achieved a high PSNR of 61.37 dB and a pixel change rate of 95.31.

Diversity and Distribution of Tunicata （Urochordata）in Tobaao

The beautiful island of Tobago is the southernmost Caribbean island. The sister island of Trinidad belongs to the Republic of Trinidad and Tobago. Thirty-two species of tunicates were collected from Tobago from depths of 40 m or less and they were listed. Tunicates listed in this work were from collections made in 1956, 1991, 1993, 2002 and 2006 and although specimens were collected from the Atlantic Ocean side of the island and the Caribbean Sea side, all species turned out to be typical Caribbean species.

浮游胶质被囊动物暴发机制及海洋碳泵效应

滤食性浮游被囊动物在开阔大洋和沿海海域中大量存在,通过黏液网来大量过滤海水浓缩食物颗粒以供种群快速增殖,是生物碳泵的关键组成,对海洋生物地球化学循环和生态系统能量流动均有重要意义。文章从浮游被囊动物生物学特征、植食性滤食作用、生活史特异性等方面综合论述了国内外关于浮游被囊动物在摄食海洋微型生物、调节海洋生物碳泵(biological carbon pump,BCP)和改变微型生物群落结构以及联系深海食物网等方面的作用。概括了国内外影响浮游被囊类暴发的食物因素、生活史特征、海洋动力过程及气候变化等相关研究进展。浮游被囊动物通过黏液过滤打包真光层微型生物,产生的粪便球和胶质死体快速沉降而输出成为胶质碳泵,从而增加BCP效率,改变微型生物碳循环途径;作为上层海洋生态系统与深海生态系统的媒介,胶质坠落在深海群落和底栖动物食物网中扮演重要作用。文章最后总结了其他胶质碳泵的相关研究进展,并提出在全球变化背景下,未来的研究应该更多地着眼于动力过程对不同生活史阶段浮游被囊动物的垂直移动和集群的影响,并将过滤摄食对微生物群落影响及繁殖策略响应与海洋物理、化学和生物环境多维度联系起来,全面解释浮游被囊类暴发的内在和外在机制,有助于准确评估海洋被囊类胶质碳泵效率及其对全球变化的响应。

基于改进被囊群算法的云制造分包服务组合研究

针对云环境中制造任务数量庞大和分解复杂导致的制造周期长、成本高等问题,提出云制造分包服务组合方法。该方法是将任务分解为多个可并行执行的子任务,引入更多制造资源,提高市场竞争性,从而降低生产周期和成本。为高效求解云制造分包服务组合优化模型,对被囊群算法进行改进。首先共享种群个体信息,执行群体行为时融合周边个体位置,提高算法局部开发能力;其次共享个体历史信息,个体向同伴历史最优位置探索,提高算法全局开拓能力;最后根据当前搜索状态,种群自适应地调节全局开拓与局部开发行为,提高算法稳定性。通过仿真实验,证明所提方案对大规模制造任务的时间和成本控制优于对比方案。

多策略融合改进的自适应被囊群算法

针对被囊群算法全局搜索不充分和易陷入局部极值等问题,提出一种多策略融合改进的自适应被囊群算法(MITSA)。首先,在种群初始化中引入佳点集理论提升种群多样性;其次,提出一种多精英协同引导机制优化被囊个体位置信息,增大对未知搜索区域的勘探可能性以增强算法全局探索能力;然后将自适应权重因子引入群体行为阶段,动态平衡算法的全局与局部搜索性能;接着,为增强算法的抗停滞能力,采用依概率小波变异策略实现个体动态微调,同时利用贪婪原则保留优异信息助推种群向食物源靠近;最后基于Markov链理论对改进算法的全局收敛性进行分析论证。通过对基准测试函数和CEC2014复杂函数进行数值仿真,实验结果与Wilcoxon秩和检验结果综合验证了MITSA具有优越的收敛精度、稳健的鲁棒性和高维可拓展性。

余弦自适应混沌被囊体种群优化算法

针对被囊体种群优化算法存在易陷入局部最优、收敛速度慢等缺点,提出一种余弦自适应混沌被囊体种群优化算法。在模拟被囊体喷射推进行为中,引入余弦自适应曲线计算搜索个体间的社会作用力,从而改进算法易出现早熟的问题;并在搜索个体向最佳位置移动上增加了一种混沌行为,使其避免局部最优并拥有更快的收敛速度。采用多种标准测试函数进行测试,实验结果表明,提出的新的被囊群优化算法在保留原有算法优点的基础上具有更好的收敛速度、精度和全局最优性。

异构网络中基于被囊群算法的D2D通信资源分配

针对异构网络中D2D用户通信过程中复用蜂窝用户传输信道产生的资源分配优化问题,提出将改进被囊群优化算法用于频谱资源载波分配的能效优化问题中.首先,针对被囊群算法的收敛精度不高,易早熟以及局部最优等缺点,提出一种基于反向差分的被囊群算法(ODTSA).其次,通过为边缘D2D用户建立中继链路,大大提高了网络资源利用率.最后,在满足用户QoS的前提下,以能效最大化作为优化目标,用改进的被囊群算法进行资源分配.并将算法与TSA算法、YSGA算法、GWO以及PSO算法进行比较.仿真结果表明,所提算法相比于文中所对比算法明显提高了系统传输速率.

莱维飞行和反馈策略的自适应被囊群算法

针对被囊群算法(TSA)寻优精度低和收敛速度慢等问题,提出基于莱维飞行和反馈策略的自适应被囊群算(LFATSA).首先,通过获取别的被囊动物反馈的信息,减小其自身的不确定性,帮助被囊动物更好的定位食物的位置以及更快的搜索;其次,在被囊群算法的喷射行为中加入莱维飞行机制,能扩大搜索范围,以避免陷入局部最优;最后,采用自适应的权重分配,提高算法对全局搜索和局部搜索能力.通过在6个基准测试函数和CEC2014函数进行仿真实验以及使用Wilcoxon秩和检验方法计算p值来评估优化后的被囊群算法的性能,并与其他的智能优化算法及原算法进行比对,实验结果表明LSATSA具有更好的效果.