Promotion of structural plasticity in area V2 of visual cortex prevents against object recognition memory deficits in aging and Alzheimer's disease rodents

Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.

Study on the Plugging System of the Lower Ancient High Loss Zone in Changqing Gas Field

At present, in the workover operations of old gas wells in the Changqing Gas Field, due to years of exploitation in the production layer, pressure deficits, and general leakage during the well killing, the well must be plugged before the well can be killed. In particular, the fracture-cavity type fractures of the lower paleocarbonate reservoirs have serious leakage. Traditional plugging materials and traditional plugging materials and methods have some limitations in dealing with leakage problems. Therefore, a composite plugging system using polymer solution as the base carrier fluid, multi-particle size rigid particles, expandable particles and modified fibers is developed. Its formula is: water + 2% polyacrylamide + 0.1% N, N-methylene bisacrylamide polymer gel is the base carrier fluid;the formulation of the particle plugging agent was continuously optimized through the CDL-II high temperature and high pressure dynamic and static plugging ability to plug the core. The final formulation of the plugging agent is: 1) 20% rigid particles (5 mm, 1 mm, 0.5 mm CCP-3 ratio 4:2:1) + 1% 3 mm expanded particles SMK-1 + 1% 1 ~ 2 mm fiber SRXW-10;2) 20% rigid particles (3 mm, 0.1 mm, 0.05 mm CCP-3 ratio 3:2:1) + 1% 3 mm expanded particles SMK-1 + 1% 1 ~ 2 mm fiber SRXW-10. The water swelling multiples of the granular plugging agent in salt water are all above 7 times, which meets the requirements of leak-proof plugging operations under high salinity;3% HCl is selected as the gel breaker, and the plugging system has a gel breaking rate of 95%;through the water plugging and profile control experimental system, the sand-filled pipe is used to simulate the plugging effect under high temperature and high pressure, and the plugging system can be sealed for 5 days at a high temperature of 110°C and a high pressure of 20 MPa to achieve a good plugging of the formation. It is expected that the developed plugging system has a good application prospect in future workover operations.

Performance-Economic and Energy Loss Analysis of 80 KWp Grid Connected Roof Top Transformer Less Photovoltaic Power Plant

In India most part receives 4 - 7 kWh of solar radiation per square meter per day with 200 - 250 sunny days in a year. Tamilnadu state also receives the highest annual radiation in India. In this paper, the grid connected photovoltaic plant has a peak power of 80 KWp supplies electricity requirement of GRT IET campus during day time (7 hrs) and reduces load demand and generates useful data for future implementation of such PV plant projects in the Tamilnadu region. Photovoltaic plant was installed in April 2015, monitored during 6 months, and the performance ratio and the various power losses (power electronics, temperature, soiling, internal, network, grid availability and interconnection) were calculated. The PV plant supplied 64,182.86 KWh to the grid from April to September 2015, ranging from 11,510.900 to 10,200.9 kWh. The final yield ranged from 143.886 (h/d) to 127.51 (y/d), reference yield ranged from 201.6 (h/d) to 155.31 (h/d) and performance ratio ranged from 71.3% to 82.1%, for a duration of six months, it had given a performance ratio of 83.82%, system efficiency was 4.16% and the capacity factor of GRT IET Campus for six months was 18.26%. Payback period in years = 9 years 4 months, energy saving per year = 204,400 KWh, cost reduction per year = 1,737,400, Indian rupee = 26,197.30 USD and total CO2 reductions per year = 102,200 tons CO2/year.

Performance-based seismic financial risk assessment of reinforced concrete frame structures

Engineering facilities subjected to natural hazards(such as winds and earthquakes) will result in risk when any designed system(i.e.capacity) will not be able to meet the performance required(i.e.demand).Risk might be expressed either as a likelihood of damage or potential financial loss.Engineers tend to make use of the former(i.e.damage).Nevertheless,other non-technical stakeholders cannot get useful information from damage.However,if financial risk is expressed on the basis of probable monetary loss,it will be easily understood by all.Therefore,it is necessary to develop methodologies which communicate the system capacity and demand to financial risk,Incremental dynamic analysis(IDA) was applied in a performance-based earthquake engineering context to do hazard analysis,structural analysis,damage analysis and loss analysis of a reinforced concrete(RC) frame structure.And the financial implications of risk were expressed by expected annual loss(EAL).The quantitative risk analysis proposed is applicable to any engineering facilities and any natural hazards.It is shown that the results from the IDA can be used to assess the overall financial risk exposure to earthquake hazard for a given constructed facility.The computational IDA-EAL method will enable engineers to take into account the long-term financial implications in addition to the construction cost.Consequently,it will help stakeholders make decisions.

Exergy Analysis and Thermal Optimization of a Double-Turbine Regeneration System in a Ultra-Supercritical Double-Reheat Unit

Improving the primary steam parameters is one of the most direct ways to improve the cycle efficiency of a powergeneration system. In the present study, the typical problem connected to the excessively high superheat degree ofextraction steam in an ultra-supercritical (USC) double-reheat unit is considered. Using a 1000 MW power plantas an example, two systems (case 1 and case 2) are proposed, both working in combination with a regenerativesteam turbine. The thermal performances of these two systems are compared with that of the original systemthrough a heat balance method and an exergy balance strategy. The results reveal that the two coupled systemscan significantly reduce the superheat degree of extraction steam, turbine heat rate, and coal consumption of theunit and improve the energy utilization efficiency. These results will provide useful theoretical guidance to futureinvestigators wishing to address the general problem relating to energy conservation and modelling of the coupledextraction steam regenerative system of USC double-reheat units.

A Comparison and Performance of Different Optical Switching Architectures

Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.

A Fully Adaptive Active Queue Management Method for Congestion Prevention at the Router Buffer

Active queue management(AQM)methods manage the queued packets at the router buffer,prevent buffer congestion,and stabilize the network performance.The bursty nature of the traffic passing by the network routers and the slake behavior of the existing AQM methods leads to unnecessary packet dropping.This paper proposes a fully adaptive active queue management(AAQM)method to maintain stable network performance,avoid congestion and packet loss,and eliminate unnecessary packet dropping.The proposed AAQM method is based on load and queue length indicators and uses an adaptive mechanism to adjust the dropping probability based on the buffer status.The proposed AAQM method adapts to single and multiclass traffic models.Extensive simulation results over two types of traffic showed that the proposed method achieved the best results compared to the existing methods,including Random Early Detection(RED),BLUE,Effective RED(ERED),Fuzzy RED(FRED),Fuzzy Gentle RED(FGRED),and Fuzzy BLUE(FBLUE).The proposed and compared methods achieved similar results with low or moderate traffic load.However,under high traffic load,the proposed AAQM method achieved the best rate of zero loss,similar to BLUE,compared to 0.01 for RED,0.27 for ERED,0.04 for FRED,0.12 for FGRED,and 0.44 for FBLUE.For throughput,the proposed AAQM method achieved the highest rate of 0.54,surpassing the BLUE method’s throughput of 0.43.For delay,the proposed AAQM method achieved the second-best delay of 28.51,while the BLUE method achieved the best delay of 13.18;however,the BLUE results are insufficient because of the low throughput.Consequently,the proposed AAQM method outperformed the compared methods with its superior throughput and acceptable delay.

Global parameter estimation of the Cochlodinium polykrikoides model using bioassay data

Cochlodinium polykrikoides is a notoriously harmful algal species that inflicts severe damage on the aquacultures of the coastal seas of Korea and Japan. Information on their expected movement tracks and boundaries of influence is very useful and important for the effective establishment of a reduction plan. In general, the information is supported by a red-tide(a.k.a algal bloom) model. The performance of the model is highly dependent on the accuracy of parameters, which are the coefficients of functions approximating the biological growth and loss patterns of the C. polykrikoides. These parameters have been estimated using the bioassay data composed of growth-limiting factor and net growth rate value pairs. In the case of the C. polykrikoides, the parameters are different from each other in accordance with the used data because the bioassay data are sufficient compared to the other algal species. The parameters estimated by one specific dataset can be viewed as locally-optimized because they are adjusted only by that dataset. In cases where the other one data set is used, the estimation error might be considerable. In this study, the parameters are estimated by all available data sets without the use of only one specific data set and thus can be considered globally optimized. The cost function for the optimization is defined as the integrated mean squared estimation error, i.e., the difference between the values of the experimental and estimated rates. Based on quantitative error analysis, the root-mean squared errors of the global parameters show smaller values, approximately 25%–50%, than the values of the local parameters. In addition, bias is removed completely in the case of the globally estimated parameters. The parameter sets can be used as the reference default values of a red-tide model because they are optimal and representative. However, additional tuning of the parameters using the in-situ monitoring data is highly required.As opposed to the bioassay data, it is necessary because the bioassay data have limitations in terms of the in-situ coastal conditions.

Off-Design Performance Analysis of Axial Flow Fan in Helicopter

A theoretical calculation method of off-design performance is developed for an axial flow fan of oil cooling system in helicopter,including calculation of aerodynamic parameters and performance parameters.When calculating inlet shock loss,the shock loss coefficient is obtained by comparing results of theoretical calculation,experimental and numerical calculation.The theoretical results and numerical results show that all air velocity components increase from hub to shroud in main flow area at rated condition.Tip leakage vortex moves downstream as flow rate increases.When flow rate decreases,Re decreases,and boundary layer thickness from hub to shroud area all increases gradually.Tip leakage vortex moves upstream,and secondary loss increases.Low speed area in the passage is widened along with high speed area moving to hub area,influenced by boundary layer separation.Consequently wake area and jet area at fan outlet are both larger than rated condition.Therefore optimization design for off-design performance of the fan is required on aerodynamic parameters influencing fan loss.A reliable method is supplied for estimating altitude performance of lubricating system in helicopter.

Design and Numerical Analysis of Ultra-High Negative Dispersion, Highly Birefringent Nonlinear Single Mode Core-Tune Photonic Crystal Fiber (CT-PCF) over Communication Bands

This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10-2 at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 104 at 1550 nm. Furthermore, at 1550 nm, the CT-PCF exhibits exceptional nonlinear characteristics, featuring a high nonlinearity of 50.74 W-1⋅Km-1 for y polarization. In comparison to existing designs, the proposed CT-PCF exhibits superior performance metrics and optical characteristics. Additionally, the y polarization dispersion coefficient of the CT-PCF at 1550 nm is measured at -3534 ps/(nm⋅km). Overall, the CT-PCF represents a significant advancement, outperforming established systems in terms of performance metrics and optical properties.

Performance-Based Design through Implementation of FEMA P-58 Methodology in Developing Countries

This paper investigates a simple approach proposed towards performance-based earthquake engineering (PBEE) which has potential applications to the performance-based design (PBD) and performance-based assessment (PBA) fields. The simple method of PBEE encompasses three areas of seismic risk which include seismic hazard, structural analysis, and loss models. The aim of the PBEE process, entitled as FEMA P-58, is to present essential data needed to make a rational decision regarding predicted performance, where various sources of uncertainties are involved. In developing countries, the lack of suitable real ground motions corresponding to site characteristics and seismicity particularly for larger intensities and the scarcity of demands, which makes it hard to identify the seismic capacity of a structure, is the main our motivation of using the FEMA method. In this paper, the method of FEMA P-58 is investigated, in terms of available tools and required data, in such a way that it will be applicable for developing countries which are located in high seismic hazard zones. To achieve this goal, three steel moment-resisting buildings with low and high ductility, and three steel braced-frame buildings are selected as case studies. The mean annual loss is estimated by the available software, Performance Assessment Calculation Tool (PACT). The achieved results, i.e. the loss curves, will provide a simple means by which the engineers can quantify and communicate seismic performance to other stakeholders. In the case study buildings, the braced one has less annual losses in comparison with other investigated cases, and the structure with high ductility can be considered as the next ones. Execution cost of each building should be considered by contractors. Also, seismic fragility curves of structures for various limit states, as well, the corresponding loss models are identified as the most essential data towards application of the investigated PBEE process.

基于PPR和NSGA-Ⅱ的泵前微压过滤器水力与过滤性能研究

【目的】探究泵前微压过滤器的性能。【方法】开展5组流量(2~8m^(3)/h)、5组含沙量(0.5~2.0g/L)、3组滤网过滤面积(1 105、1 582、2 060 cm^(2))和4组分水器型式(不加、1型、2型、3型)的物理模型试验,采用投影寻踪回归分析法(PPR)、多目标遗传算法(NSGA-Ⅱ),建立水头损失、截沙质量和总过滤效率的预测模型,探究各指标的影响因素排序,确定泵前微压过滤器的最佳运行工况。【结果】影响泵前微压过滤器水头损失的因素排序为进水流量?含沙量?滤网过滤面积;影响截沙质量的因素排序为含沙量?滤网过滤面积?进水流量;影响总过滤效率的因素排序为滤网过滤面积?含沙量?进水流量;以相对误差≤10%作为判定标准,建立的截沙质量和总过滤效率PPR预测模型合格率为100%,模型精度较高,但水头损失PPR预测模型合格率仅为70%,模型不可靠。本试验范围下泵前微压过滤器的最佳运行工况为:含沙量2 g/L、进水流量7 m^(3)/h、滤网过滤面积2 060 cm^(2)。【结论】PPR预测模型对截沙质量和总过滤效率的预测精度较高,对水头损失的预测误差较大,在后期可用量纲分析与多元回归相结合预测水头损失、截沙质量和总过滤效率。

活化调控的龙眼壳多孔碳材料结构和吸波性能

生物质材料是一种来源丰富、廉价易得的可再生资源,通过在生物质材料中构筑多层级结构制备生物质碳材料是目前吸波材料领域研究的热点。为制备轻质、宽频、高效的生物碳基吸波材料,以龙眼壳为原料,通过活化碳化的方式制备龙眼壳多孔碳材料(LSPC),通过X-射线衍射、拉曼光谱、扫描电镜等表征多孔碳材料的微观结构,并采用矢量网络分析仪对其吸波性能进行分析,考察了磷酸(H3PO4)、氢氧化钾(KOH)和氧化锌(ZnCl_(2))对龙眼壳多孔碳材料结构和吸波性能的影响。结果表明:活化使得龙眼壳多孔碳结晶度下降、缺陷增多,形成了较多的异质界面和活化中心,增强了材料的极化损耗。与未活化的龙眼壳多孔碳相比,H3PO4活化处理使得多孔碳材料的孔壁变薄、孔结构更为明显;KOH活化多孔碳材料不仅保留了龙眼壳连续的孔结构,而且孔壁出现了类似脊椎的波浪起伏结构;ZnCl_(2)活化制得的龙眼壳多孔碳材料仅在原有的光滑截面形成许多小孔;综合分析表明,活化处理改善了龙眼壳多孔碳材料的吸波性能,其中以氢氧化钾活化制备的龙眼壳多孔碳材料吸波性能最佳,其反射损耗达到-43.57 dB,分别是LSPC-H3PO4的2.03倍和LSPC-ZnCl_(2)的3.02倍;活化处理不同程度地改善了龙眼壳多孔碳材料的有效吸收带宽。对微观形貌关联的电磁损耗行为分析表明,活化促进了龙眼壳多孔碳材料中多层级孔结构的生成,有效降低了龙眼壳多孔碳材料的有效介电常数,改善了材料的阻抗匹配;同时,龙眼壳多孔碳材料可通过传导损耗、偶极极化、界面极化、多重反射等多重损耗机制衰减电磁波。

飞轮储能用永磁同步电机温度场分析

针对飞轮储能用永磁同步电机散热困难的问题,以某额定功率为300 kW、转速为10000 r/min的永磁同步电机为研究对象,利用磁热耦合的方法,对永磁同步电机的损耗和温度场进行模拟及测试分析,研究永磁同步电机的损耗及电机热分布;利用热仿真模型,研究电机关键部件散热的影响因素。结果表明:高温主要集中于永磁体及绕组区域;减小流道宽度、增大流道数目以及增大流道圆角半径可有效提高定子散热性能;辐射率越高,永磁体散热性能越好;改进电机结构后,永磁体最高温度下降10.5%。研究结果可为永磁同步电机的设计及散热优化提供参考。

晚间授课会导致大学生课程成绩的“无谓损失”吗?

课程成绩是学生学习和个人发展的重要风向标。优化课堂教学安排减少课程成绩无谓损失是目前高校教务部门关注的热点问题。本文从排课时间视角实证讨论了课堂教学安排对大学生课程成绩的影响。研究表明:(1)晚上进行课堂教学会导致学生课程成绩下降。(2)对于同一教学班而言,所有课堂教学均在晚上进行,将带来严重的课程成绩损失。(3)晚上进行必修课程教学和采用多位教师协同教学能够缓释晚上教学带来的课程成绩损失。据此,为缓释晚上教学带来的课程成绩损失,应当深入推进教学范式改革,尽量避免晚上教学;完善教学安排系统,妥善考虑课程性质差异;推动课程组深度教学合作,施行同课师资交叉授课。

江汉水牛生产性能及经济效益研究

[目的]研究江汉水牛的主要体尺指标和生产性能,为江汉水牛保种和开发利用提供理论依据。[方法]测定20头2.5岁左右、平均体质量(360±59)kg江汉水牛(公牛10头、母牛10头)的主要体尺指标,并进行134d的强度育肥试验。育肥结束后,选取12头江汉水牛(公牛6头、母牛6头)进行屠宰和肉质性能测定。[结果]江汉水牛育肥期平均日增质量为(818±189) g,平均日采食量为26.87 kg。江汉水牛屠宰率为45.4%,净肉率37.6%,眼肌面积85.7 cm^(2),肌肉嫩度平均为80.35 kg/cm^(2),肌肉肉色评分7.83,滴水损失1.17%,江汉水牛产肉成本为27.57元/kg。[结论]江汉水牛躯体高大,骨骼粗壮,肉质优良,是培育乳肉兼用水牛新品种的良好遗传素材。

(Si_(0.2)Ti_(0.2)Nb_(0.2)Ta_(0.2)V_(0.2))C高熵陶瓷的低温制备及吸波性能

寻求具有良好耐高温及力学性能的新型陶瓷材料是吸波材料领域的研究热点之一。高熵碳化物陶瓷具有高温热稳定性及抗氧化性好等优点,但合成温度高且吸波性能研究较少,限制了其在高温吸波材料领域的应用。本工作采用熔盐法合成了多晶岩盐晶型(Si_(0.2)Ti_(0.2)Nb_(0.2)Ta_(0.2)V_(0.2))C高熵碳化物陶瓷,研究了其物相组成、微观形貌及吸波特性。结果表明:随着反应温度的升高,样品的衍射峰逐渐锐化,吸波性能明显提高。当反应温度为1500℃时,3.72 GHz时最低反射损耗达-34.68 dB;与已报道的高熵碳化物陶瓷相比,在相同的有效吸收带宽(2.3 GHz)下,涂层厚度减少了13.3%(1.5 mm降低到1.3 mm),其介电损耗主要来源于极化损耗和导电损耗。本工作制备的高熵碳化物陶瓷可以为研究制备新型环境适应、耐高温、抗冲击的高性能单相吸波材料提供新途径。