Diel vertical migration of mesozooplankton in the northern Yellow Sea

The Yellow Sea Cold Water Mass(YSCWM),one of the most vital hydrological features of the Yellow Sea,causes a seasonal thermocline from spring to autumn.The diel vertical migration(DVM)of zooplankton is crucial to structural pelagic communities and food webs,and its patterns can be aff ected by thermocline depth and strength.Hence,we investigated zooplankton community succession and seasonal changes in zooplankton DVM at a fixed station in the YSCWM.Annual zooplankton community succession was aff ected by the forming and fading of the YSCWM.A total of 37 mesozooplankton taxa were recorded.The highest and lowest species numbers in autumn and spring were detected.The highest and lowest total densities were observed in autumn(14464.1 inds./m^(3))and winter(3115.4 inds./m^(3)),respectively.The DVM of the dominant species showed obvious seasonal variations.When the YSCWM was weak in spring and autumn,most species(e.g.Paracalanus parvus,Oithona similis,and Acartia bifilosa)stayed above the thermocline and vertically migrated into the upper layer.Calanus sinicus and Aidanosagitta crassa crossed the thermocline and vertically migrated.No species migrated through the stratification in summer,and all of the species were limited above(P.parvus and A.crassa)or below(C.sinicus and Centropages abdominalis)the thermocline.The YSCWM disappeared in winter,and zooplankton species were found throughout the water column.Thus,the existence of thermocline influenced the migration patterns of zooplankton.Cluster analyses showed that the existence of YSCWM resulted in significant differences between zooplankton communities above and below the thermocline.

Study on UV Shielding TiO_2 Thin Film Prepared by Sol-Gel Method

Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm～400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm～400 nm.

DNA methylation and alternative splicing modulate FBXW11 gene expression in Holstein bull testis and are correlated with sperm quality

F-box and WD-40 domain protein 11(FBXW11)is an important component of the E3 ubiquitin-ligase enzyme that plays a key role in the ubiquitin-dependent regulation of spermatogenesis.In our previous research,the mRNA expression of FBXW11 in bull sperm with high motility is significantly higher than that with low motility.In the present study,the protein expression levels of FBXW11 in bull testicular tissues with low-performance sperm quality groups were significantly higher than those in normal performance groups.The immunohistochemistry result demonstrated that FBXW11 protein was located in the periphery of Leydig cells and seminiferous tubules.Three splice variants of the FBXW11 gene,namely,FBXW11-tv1,FBXW11-tv2,and FBXW11-tv3,were identified in testicular tissues.The splicing patterns of the three variants are exon skipping.The transcript FBXW11-tv2 expressions were the highest in each sample.The low-performance groups displayed higher FBXW11-tv1 and FBXW11-tv2 transcript expressions than the normal performance groups.Two CpG islands were located within the 5’UTR and exon 1-2 region of the FBXW11 gene.Bisulfite sequencing PCR results demonstrated that the methylation levels of 11 methylation sites in the CpG island 2 from−99 to−43 in the normal performance groups were significantly lower than those in the low-performance groups.Pearson correlation analysis suggested that the CpG island 2 methylation level was negatively correlated with sperm motility and the transcript FBXW11-tv2 expression level.Our data revealed that alternative splicing and DNA methylation jointly regulated FBXW11 gene expression and were correlated with sperm quality traits during spermatogenesis in Holsteins.

A Coding-Based Incremental Traceback Scheme against DDoS Attacks in MANET

Due to constrained resources, DDoS attack is one of the biggest threats to MANET. IP traceback technique is useful to defend against such type of attacks, since it can identify the attack sources. Several types of traceback schemes have been proposed for wired networks. Among all the existing schemes, probabilistic packet marking (PPM) scheme might be the most promising scheme for MANET. However its performance in MANET is not as good as that in Internet. In this paper, a new scheme based on the codingtechnique (CT) is proposed for traceback in MANET. Furthermore, a new idea of Incremental traceback is raised to cope with the situation of incremental attack (ICT). We present the protocol design and conduct theoretical analysis of this scheme. Additionally, we conduct experiments to compare it with the traditional PPM scheme. The experimental results show that the new coding-based traceback scheme outperforms the PPM scheme in MANET.

Effects of Short-cut Flowering Branches on Harvest Time,Yield and Quality of Guire No.82 Mango

[Objectives]To further study the technology of short-cut flowering branches for Guire No.82 Mango,adjust its harvest time,increase yield and improve fruit quality,and increase the economic benefits of mango production.[Methods]The experiment of short-cut flowering branches was carried out for Guire No.82 Mango.[Results]At the initial flowering stage and full flowering stage of the primary inflorescence,with short-cut flowering branches and corresponding cultivation techniques,Guire No.82 Mango was easy to extract regenerated inflorescences.Compared with the control group,the flowering period of the regenerated inflorescences was delayed by 30-35 d and 40-50 d,respectively;the harvest time was delayed by 30 and 40 d,respectively;the yield significantly increased by 1.63 times and 2.25 times,respectively;compared with the control group,the number of fruits with embryo increased significantly,which were 1.39 and 2.25 times of the control,respectively;there was no significant difference in the fruit quality at the harvest time.[Conclusions]Short-cut flowering branches at the initial flowering stage and full flowering stage of the primary inflorescence is an effective measure to delay the marketing time of Guire No.82 Mango.

Forecasting-Based Adaptive Optimized Dispatch in Smart Grid Online

The power grid is a fusion of technologies in energy systems, and how to adjust and control the output power of each generator to balance the load of the grid is a crucial issue. As a platform, the smart grid is for the convenience of the implementation of adaptive control generators using advanced technologies. In this paper, we are introducing a new approach, the Central Lower Configuration Table, which optimizes dispatch of the generating capacity in a smart grid power system. The dispatch strategy of each generator in the grid is presented in the configuration table, and the scenario consists of two-level agents. A central agent optimizes dispatch calculation to get the configuration table, and a lower agent controls generators according to the tasks of the central level and the work states during generation. The central level is major optimization and adjustment. We used machine learning to predict the power load and address the best optimize cost function to deal with a different control strategy. We designed the items of the cost function, such as operations, maintenances and the effects on the environment. Then, according to the total cost, we got a new second-rank-sort table. As a result, we can resolve generator’s task based on the table, which can also be updated on-line based on the environmental situation. The signs of the driving generator’s controller include active power and system’s f. The lower control level agent carries out the generator control to track f along with the best optimized cost function. Our approach makes optimized dispatch algorithm more convenient to realize, and the numerical simulation indicates the strategy of machine learning forecast of optimized power dispatch is effective.

Radiationless optical modes in metasurfaces:recent progress and applications

Non-radiative optical modes attracted enormous attention in optics due to strong light confinement and giant Q-factor at its spectral position.The destructive interference of multipoles leads to zero net-radiation and strong field trapping.Such radiationless states disappear in the far-field,localize enhanced near-field and can be excited in nanostructures.On the other hand,the optical modes turn out to be completely confined due to no losses at discrete point in the radiation continuum,such states result in infinite Q-factor and lifetime.The radiationless states provide a suitable platform for enhanced light matter interaction,lasing,and boost nonlinear processes at the state regime.These modes are widely investigated in different material configurations for various applications in both linear and nonlinear metasurfaces which are briefly discussed in this review.

Heating properties of bridge decks using hydronic heating systems with internal or external circulation tubes

A comparison analysis of the heating properties of the hydronic heating system of bridge decks with external(exchange tubes installed at the bottom of the existing bridge deck with voids inside)or internal(exchange tubes embedded in pavement of the newly built bridge deck)tubes was carried out through field tests.Two heating methods(constant heating power and constant inlet fluid temperature)were used to analyze the heat exchange flux and the temperature increments as well as thermally induced stress of the slab.Numerical simulation was conducted to model the bridge deck heating process to analyze the temperature distribution of the bridge surface.The results shows that the heat exchange flux are the same under the same constant heating powers for the two embedded tube position heating systems;the maximum temperature increment of the bridge deck surface obtained by the external heating system is 0.46 times that obtained by the internal heating system;the maximum thermally induced stress caused by the external heating is 20.4%of the concrete strength(19.1 MPa),which is much higher than that caused by the internal heating under the same heating powers.The thermal efficiencies of the external and internal heating systems are approximately 24.4%and 47.9%,respectively.Under the same constant inlet temperatures,the temperature increment of the bridge deck caused by the external heating is 20.4%of that of the internal heating.

在线学习危机精准预警及干预:模型与实证研究

对学生学习行为进行全面的定量化描述、学业诊断、精准预警、处方干预,有助于准确识别学习危机学生,提供精准教学服务。本研究利用数据挖掘和学习分析技术,跟踪分析在线学习中非干预行为数据,包括过程性结构化外显信息(如学习状态、学习交互、学业水平等)和非结构化内隐信息(如学习者情绪),确定在线学习危机预警因素。本研究采用朴素贝叶斯构建精准预警模型,利用准实验设计对处于学习危机的学生进行聚类分组,并提出采用邮件通知人工干预和在线学习支持环境自动干预两种策略,同时通过信誉积分和预警指标干预制度加以保障。研究结果表明,模型能够准确识别学习者学习状态与趋势,发现学习异常者;干预策略能够有效引导学生学习,化解学习危机,促进个性化教学和学生管理。

Chemically synthesizing exchange-coupled SmCo_(5)/Sm_(2)Co_(17) nanocomposites

A new strategy to chemically synthesize exchange-coupled SmCo_(5)/Sm_(2) Co_(17) nanocomposites by in situ decomposition of SmCox(5<x<8.5)is reported in this work.Our synthesis starts with the fabrication of Co/Sm_(2) O_(3)(Sm to Co atomic ratio of Sn/Co=1:4.2),which can be reduced into 40-nm SmCo_(5) single crystal nanoparticles by Ca under the protection of CaO,showing a high coercivity of 2.85 T and saturation magnetization(Ms)of 0.0671 A·m^(2)·g^(-1).By changing the Sm/Co to 1:4.5,1:4.8 and 1:5.2,SmCo_(5)/Sm_(2) Co_(17) nanocomposites with different proportions were acquired using the same process.Owing to the in situ decomposition of SmCo_(x) intermediate,the small size(both of their size less than 10 nm)and uniform phase distribution were achieved in our nanocomposites.Thus,the as-prepared nanocomposites display a strong exchange-coupling interaction.As a consequence,SMCo_(5)/Sm_(2)Co_(17)(Sm/Co=1:5.2)exhibits a coercivity of 1.23 T and enhanced M7 T(magnetization at 7 T)of 0.0812 A·m^(2)·g^(-1),increasing by 21%than pure SmCo_(5).Our synthesis provides a new protocol to prepare exchange-coupled high-performance nanocomposites.

Design of magnet arrays for permanent magnetic linear motor

An iron-less single side permanent magnetic linear motor structure is presented,and two-dimensional analytical formulae for its magnetic field are deduced to design the types of magnetic arrays,the thickness of permanent magnet,and the duty ratio of magnet arrays,etc.With certain design parameters,conventional arrays are used instead of a piecewise Halbach arrays,and the machining and assembling of the motor are greatly simplified.Calculation results coincide with that of ANSYS.The analytical formulae can be used in designing cored linear motors by modifying boundary conditions.A linear motor driven bench with a single degree of freedom is realized,where the travel reaches 27 mm,the mass of the moving parts is 1.4 kg,and the maximum acceleration is 11.5 m/s^(2).