Numerical investigation on the flow and power of small-sized multi-bladed straight Darrieus wind turbine

Straight Darrieus wind turbine has attractive characteristics such as the ability to accept wind from random direction and easy installation and maintenance. But its aerodynamic performance is very complicated,especially for the existence of dynamic stall. How to get better aerodynamic performance arouses lots of interests in the design procedure of a straight Darrieus wind turbine. In this paper,mainly the effects of number of blades and tip speed ratio are discussed. Based on the numerical investigation,an assumed asymmetric straight Darrieus wind turbine is proposed to improve the averaged power coefficient. As to the numerical method,the flow around the turbine is simulated by solving the 2D unsteady Navier-Stokes equation combined with continuous equation. The time marching method on a body-fitted coordinate system based on MAC (Marker-and-Cell) method is used. O-type grid is generated for the whole calculation domain. The characteristics of tangential and normal force are discussed related with dynamic stall of the blade. Averaged power coefficient per period of rotating is calculated to evaluate the eligibility of the turbine.

k_(eff)uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

To benefit from recent advances in modeling and computational algorithms,as well as the availability of new covariance data,sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors(HTGRs).In particular,the contribution of nuclear data to the k_(eff)uncertainty is an important part of the uncertainty analysis of small-sized HTGR physical calculations.In this study,a small-sized HTGR designed by China Nuclear Power Engineering Co.,Ltd.was selected for k_(eff)uncertainty analysis during full lifetime burnup calculations.Models of the cold zero power(CZP)condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation,depletion calculation,and sensitivity and uncertainty analysis.For the sensitivity analysis,the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Track length importance Characterization(CLUTCH)method was applied to obtain sensitive information,and the "sandwich" method was used to quantify the k_(eff)uncertainty.We also compared the k_(eff)uncertainties to other typical reactors.Our results show that ^(235)U is the largest contributor to k_(eff)uncertainty for both the CZP and depletion conditions,while the contribution of ^(239)Pu is not very significant because of the design of low discharge burnup.It is worth noting that the radioactive capture reaction of ^(28)Si significantly contributes to the k_(eff)uncertainty owing to its specific fuel design.However,the k_(eff)uncertainty during the full lifetime depletion process was relatively stable,only increasing by 1.12%owing to the low discharge burnup design of small-sized HTGRs.These numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HTGR.

Assessment for Production and Operation Ability of Medium and Small-sized Enterprises Based on Neural Network

In order to improve production and operation ability of medium and small-sized enterprises, an assessment-index system of production and operation ability was proposed, and a corresponding assessment model was established based on BP neural network. The conjunction weights of the neural network were continuously modified from output layer to input layer in the process of neural network training to reduce the errors between the anticipated and actual outputs. The results from an example show that this method is reliable and feasible. The production and operation abilitv of an enterorise with assessed result of 0.833 is fairly oowerful, and that with assessed result of 0.644 is average.

Study on Contra-Rotating Small-Sized Axial Flow Hydro Turbine

It is thought that small hydropower generation is alternative energy, and the energy potential of small hydropower is large. The efficiency of small hydro turbines is lower than that of large one, and these small hydro turbine’s common problems are out of operation by foreign materials. Then, there are demands for small hydro turbines to keep high per- formance and wide flow passage. Therefore, we adopted contra-rotating rotors which can be expected to achieve high performance and low-solidity rotors with wide flow passage in order to accomplish high performance and stable opera- tion. Final goal on this study is development of an electric appliance type small hydro turbine which has high portability and makes an effective use of the unused small hydro power energy source. In the present paper, the performance and the internal flow conditions in detail of contra-rotating small-sized axial flow hydro turbine are shown as a first step of the research with the numerical flow analysis. Then, a capability adopting contra-rotating rotors to an electric appliance type small hydro turbine was discussed. Furthermore, the high performance design for it was considered by the numeri- cal analysis results.

Effect of Organic and Chemical Fertilizer Application on Growth, Yield, and Quality of Small-Sized Tomatoes

Tomatoes in Japan are generally cultivated under management systems that use chemical fertilizers and synthetic chemical pesticides. However, the continuous use of these fertilizers and pesticides damages the soil environment and reduces the number of soil microorganisms. Organic farming has a relatively low environmental impact compared to conventional farming techniques, but typically has lower and more unstable yields. In this study, we investigated the effect of organic and chemical fertilizer application on growth, yield, and quality of small-sized (cherry) tomatoes. Cherry tomatoes were cultivated using organic and chemical organic fertilizers. Average weight and lateral diameter were significantly higher under organic fertilizer than under chemical fertilizer. In addition, shoot dry weight was significantly higher under organic fertilizer than chemical fertilizer. Lycopene content was significantly higher under organic fertilizer than chemical fertilizer. The total carbon (TC), total phosphorus (TP), total potassium (TK), available phosphoric (SP) and exchangeable potassium (SK) contents, C/N ratio, and pH were significantly higher under organic fertilizer than chemical fertilizer. Bacterial biomass, nitrite (NO? 2-N) oxidation activity, nitrification (N) circulation activity, and phosphoric (P) circulation were higher under organic fertilizer than chemical fertilizer. From these results, the study indicates that appropriate controls such as TC, total nitrogen (TN), and C/N ratio of organic fertilizer increased microbial biomass and enhanced nutrient circulation such as N circulation activity and P circulation activity. These results can be used to improve current organic farming practices and promote soil conservation.

猪三维点云体尺自动计算模型Pig Back Transformer

[目的/意义]为了提高体尺关键点定位准确率,猪三维点云体尺自动测量方法会采用点云分割,在各个分割后局部点云定位测量关键点,以减少点云之间相互干扰。然而点云分割网络通常需要消耗较大计算资源,且现有测量点定位效果仍有待提升空间。本研究旨在通过设计关键点生成网络从猪体点云中提取出各体尺测量所需关键点。在降低显存资源需求的同时提高测量关键点定位效果,提高体尺测量的效率和精度。[方法]针对猪三维表面点云进行体尺测量,提出了一种定位猪体尺关键点的模型Pig Back Transformer。模型分为两个模块,分别设计了两种改进的Transformer自注意力编码器,第一模块为全局关键点模块,首先设计了一种猪背部边缘点提取算法用于获取边缘点,再使用edge encoder编码器以边缘点集合作为输入,edge encoder的edge attention中加入了边缘点和质点的偏移距离信息;第二模块为关键点生成模块,使用了back attention机制的back encoder,其中加入了与质心和第一模块生成的全局关键点的偏移量,并将偏移量与点云注意力通过按位max pooling操作结合,最后通过生成猪的体尺测量关键点和背脊走向点。最后设计了使用关键点和背脊走向点作为输入的体尺算法。[结果和讨论]对比关键点和背脊走向点生成任务上Pig Back Transformer表现最佳,并对比体尺计算结果与人工测量结果,体长相对误差为0.63%,相对PointNet++、Point Transformer V2、Point Cloud Transforme、OctFormer PointTr等模型有较大提升。[结论] Pig Back Transformer能相对准确地生成猪体尺关键点,提高体尺测量数据准确度,并且通过点云特征定位体尺关键点节省了计算资源,为无接触牲畜体尺测量提供了新思路。

Influence of Small-Size Contaminations on Thin Film Structural Properties

An approach for studying the influence of nano-particles on the structural properties of deposited thin films is proposed. It is based on the molecular dynamic modeling of the deposition process in the presence of contaminating nano-particles. The nano-particle is assumed to be immobile and its interaction with film atoms is described by a spherically symmetric potential. The approach is applied to the investigation of properties of silicon dioxide films. Visualization tools are used to investigate the porosity associated with nano-particles. The structure of the film near the nano-particle is studied using the radial distribution function. It is found that fluctuations of film density near the nano-particles are essentially different in the cases of low-energy and high-energy deposition processes.

Comparative analysis of primate and pig cells reveals primate-specific PINK1 expression and phosphorylation

PTEN-induced putative kinase 1(PINK1),a mitochondrial kinase that phosphorylates Parkin and other proteins,plays a crucial role in mitophagy and protection against neurodegeneration.Mutations in PINK1 and Parkin can lead to loss of function and early onset Parkinson's disease.However,there is a lack of strong in vivo evidence in rodent models to support the theory that loss of PINK1 affects mitophagy and induces neurodegeneration.Additionally,PINK1 knockout pigs(Sus scrofa)do not appear to exhibit neurodegeneration.In our recent work involving non-human primates,we found that PINK1 is selectively expressed in primate brains,while absent in rodent brains.To extend this to other species,we used multiple antibodies to examine the expression of PINK1 in pig tissues.In contrast to tissues from cynomolgus monkeys(Macaca fascicularis),our data did not convincingly demonstrate detectable PINK1expression in pig tissues.Knockdown of PINK1 in cultured pig cells did not result in altered Parkin and BAD phosphorylation,as observed in cultured monkey cells.A comparison of monkey and pig striatum revealed more PINK1-phosphorylated substrates in the monkey brain.Consistently,PINK1 knockout in pigs did not lead to obvious changes in the phosphorylation of Parkin and BAD.These findings provide new evidence that PINK1expression is specific to primates,underscoring the importance of non-human primates in investigating PINK1function and pathology related to PINK1 deficiency.

Associations of genome-wide structural variations with phenotypic differences in cross-bred Eurasian pigs

Background During approximately 10,000 years of domestication and selection,a large number of structural variations(SVs)have emerged in the genome of pig breeds,profoundly influencing their phenotypes and the ability to adapt to the local environment.SVs(≥50 bp)are widely distributed in the genome,mainly in the form of insertion(INS),mobile element insertion(MEI),deletion(DEL),duplication(DUP),inversion(INV),and translocation(TRA).While studies have investigated the SVs in pig genomes,genome-wide association studies(GWAS)-based on SVs have been rarely conducted.Results Here,we obtained a high-quality SV map containing 123,151 SVs from 15 Large White and 15 Min pigs through integrating the power of several SV tools,with 53.95%of the SVs being reported for the first time.These high-quality SVs were used to recover the population genetic structure,confirming the accuracy of genotyping.Potential functional SV loci were then identified based on positional effects and breed stratification.Finally,GWAS were performed for 36 traits by genotyping the screened potential causal loci in the F2 population according to their corresponding genomic positions.We identified a large number of loci involved in 8 carcass traits and 6 skeletal traits on chromosome 7,with FKBP5 containing the most significant SV locus for almost all traits.In addition,we found several significant loci in intramuscular fat,abdominal circumference,heart weight,and liver weight,etc.Conclusions We constructed a high-quality SV map using high-coverage sequencing data and then analyzed them by performing GWAS for 25 carcass traits,7 skeletal traits,and 4 meat quality traits to determine that SVs may affect body size between European and Chinese pig breeds.

Genetically modified pigs:Emerging animal models for hereditary hearing loss

Hereditary hearing loss(HHL),a genetic disorder that impairs auditory function,significantly affects quality of life and incurs substantial economic losses for society.To investigate the underlying causes of HHL and evaluate therapeutic outcomes,appropriate animal models are necessary.Pigs have been extensively used as valuable large animal models in biomedical research.In this review,we highlight the advantages of pig models in terms of ear anatomy,inner ear morphology,and electrophysiological characteristics,as well as recent advancements in the development of distinct genetically modified porcine models of hearing loss.Additionally,we discuss the prospects,challenges,and recommendations regarding the use pig models in HHL research.Overall,this review provides insights and perspectives for future studies on HHL using porcine models.

Performance and Internal Flow of Contra-Rotating Small-Sized Cooling Fan

High pressure and large flow rate small-sized cooling fans are used for servers in data centers and there is a strong demand to increase its performance because of increase of quantity of heat from servers. Contra-rotating rotors have been adopted for some of high pressure and large flow rate cooling fans to meet the demand. The performance curve of the contra-rotating small-sized cooling fan with 40 mm square casing was investigated by an experimental apparatus and its internal flow condition was clarified by the numerical analysis. The fan static pressure of the front rotor was extremely low and it increased significantly at the rear rotor. The uniform flow was achieved at the inlet of the rear rotor because of the special shape of the casing between the front and rear rotors. On the other hand, the tip leakage flow was large enough to influence on the main flow of the test cooling fan by the design specification of high pressure with compact rotor diameter.

Internal Flow Condition between Front and Rear Rotor of Contra-Rotating Small-Sized Axial Fan at Low Flow Rate

Contra-rotating small-sized fans are used as cooling fans for electric equipment. The internal flow condition between the front and rear rotors of the contra-rotating small-sized fan is not known well especially at the low flow rate. Furthermore, the blade row distance between the front and rear rotors is an important parameter for the contra-rotating small-sized fan and its influence on the internal flow condition is not clarified at the low flow rate. Therefore, the internal flow condition of the contra-rotating small-sized fan at the low flow rate is investigated by the numerical analysis in this research. The numerical analysis results are validated by comparing the fan static pressure curves of the numerical results to the experimental results. The internal flow condition at the low flow rate is clarified using the numerical models of the different blade row distance L = 10 mm and 30 mm. In the present paper, pressure fluctuations phase locked each front and rear rotor’s rotation are shown and the influences of the wake and the potential interference are discussed by the unsteady numerical analysis results at the low flow rate.

Study on Construction and Countermeasures of Technological Innovation Environment within Medium and Small-sized Enterprises in Hubei Province

Based on the application of the latest technological innovation theory and the successful experience generated by the domestic and overseas medium and small-sized enterprises, this thesis proposes a theoretical framework, strategic proposition and some secure measures for the regional technological innovation to promote the technological innovation within medium and small-sized enterprises in Hubei Province. In addition, the author also provides some tactics concerning the original motivation, technological market, innovation talents and innovation system, which aim at offering some consultation for the government decision, optimize industrial structure, implement the innovation strategy and propel to the medium and small-sized enterprises＇ development.

Space-to-Ground Quantum Key Distribution Using a Small-Sized Payload on Tiangong-2 Space Lab

Quantum technology establishes a foundation for secure communication via quantum key distribution （QKD）. In the last two decades, the rapid development of QKD makes a global quantum communication network feasible. In order to construct this network, it is economical to consider small-sized and low-cost QKD payloads, which can be assembled on satellites with different sizes, such as space stations. Here we report an experimental demonstration of space-to-ground QKD using a small-sized payload, from Tiangong-2 space lab to Nanshan ground station. The 57.9-kg payload integrates a tracking system, a QKD transmitter along with modules for synchronization, and a laser communication transmitter. In the space lab, a 50MHz vacuum＋weak decoy-state optical source is sent through a reflective telescope with an aperture of 200mm. On the ground station, a telescope with an aperture of 1200mm collects the signal photons. A stable and high-transmittance communication channel is set up with a high-precision bidirectional tracking system, a polarization compensation module, and a synchronization system. When the quantum link is successfully established, we obtain a key rate over 100bps with a communication distance up to 719km. Together with our recent development of QKD in daylight, the present demonstration paves the way towards a practical satellite-constellation-based global quantum secure network with small-sized QKD payloads.

Study on Virtual Training Management in Small-sized Enterprises

This paper firstly analyses the necessity of virtual management in small-sized enterprises, then presents two main modes to implement virtual training management in small-sized enterprises. The paper also points out the best mode for the small-sized enterprises＇ training to implement virtual management.

A Study on USA Promoting the Development of Middle and Small-sized Enterprises and Its Revelation

The middle and small-sized enterprises of USA develop very well, and they are the pillars of American economy. The long-term development of middle and small-sized enterprises lies in suitable supporting countermeasures and clear economic function of the government. The development of middle and small-sized enterprises of USA brings China many useful revelations.

Peers Small-sized Group Work-A Beneficial Form of Classroom Interaction

Classroom interaction plays a critical role in language teaching and learning process.It involves both the teacher-students,and students-students.This article is intended to explore the vital significance of classroom interaction in language learning process with the emphasis placed on the students' involvement in the classroom activities,furthermore,to discover whether the peers small-sized group work is a beneficial and irreplaceable form of classroom interaction.

Evaluation of the Pharmacological Potential of Strychnos camptoneura Trunk Bark Hydroethanol Extract on Reproductive Functions in Male Guinea Pigs (Cavia porcellus) Exposed to Cypermethrin

The main objective of this study was to evaluate the pharmacological potential of the hydroethanol extract of Strychnos camptoneura trunk bark on reproductive functions in male guinea pigs exposed to cypermethrin. The results showed that administration of the hydroethanolic extract (100 and 250 mg/kg) of Strychnos camptoneura trunk bark after exposure of the animals to cypermethrin induced a highly significant (p Strychnos camptoneura trunk bark produced a highly significant (p Strychnos camptoneura trunk bark may have protective effects against cypermethrin-induced male infertility due to its androgenic, spermatogenic and antiradical properties.

In‑depth proteome characterization of endometrium and extraembryonic membranes during implantation in pig

Background Proteome characterization of the porcine endometrium and extraembryonic membranes is important to understand mother-embryo cross-communication.In this study,the proteome of the endometrium and cho-rioallantoic membrane was characterized in pregnant sows(PS)during early gestation(d 18 and 24 of gestation)and in the endometrium of non-pregnant sows(NPS)during the same days using LC-MS/MS analysis.The UniProtKB database and ClueGO were used to obtain functional Gene Ontology annotations and biological and functional networks,respectively.Results Our analysis yielded 3,254 and 3,457 proteins identified in the endometrium of PS and NPS,respectively;of these,1,753 being common while 1,501 and 1,704 were exclusive to PS and NPS,respectively.In addition,we iden-tified 3,968 proteins in the extraembryonic membranes of PS.Further analyses of function revealed some proteins had relevance for the immune system process and biological adhesion in endometrium while the embryonic chorion displayed abundance of proteins related to cell adhesion and cytoskeletal organization,suggesting they dominated the moment of endometrial remodeling,implantation and adhesion of the lining epithelia.Data are available via Pro-teomeXchange with identifier PXD042565.Conclusion This is the first in-depth proteomic characterization of the endometrium and extraembryonic mem-branes during weeks 3 to 4 of gestation;data that contribute to the molecular understanding of the dynamic environ-ment during this critical period,associated with the majority of pregnancy losses.

Preliminary study of metabonomic changes during the progression of atherosclerosis in miniature pigs

Background:To explore potential biomarkers for early diagnosis of atherosclerosis(AS)and provide basic data for further research on AS,the characteristics of serum metabolomics during the progression of AS in mini-pigs were observed dynamically.Methods:An AS model in Bama miniature pigs was established by a high-cholesterol and high-fat diet.Fasting serum samples were collected monthly for metabolomics and serum lipid detection.At the end of the treatment period,pathological analysis of the abdominal aorta and coronary artery was performed to evaluate the lesions of AS,thereby distinguishing the susceptibility of mini-pigs to AS.The metabolomics was de-tected using a high-resolution untargeted metabolomic approach.Statistical analysis was used to identify metabolites associated with AS susceptibility.Results:Based on pathological analysis,mini-pigs were divided into two groups:a susceptible group(n=3)and a non-susceptible group(n=6).A total of 1318 metabo-lites were identified,with significant shifting of metabolic profiles over time in both groups.Dynamic monitoring analysis highlighted 57 metabolites that exhibited an ob-vious trend of differential changes between two groups with the advance of time.The KEGG(Kyoto Encyclopedia of Genes and Genomes)pathway enrichment analysis in-dicated significant disorders in cholesterol metabolism,primary bile acid metabolism,histidine metabolism,as well as taurine and hypotaurine metabolism.Conclusions:During the progression of AS in mini-pigs induced by high-cholesterol/high-fat diet,the alterations in serum metabolic profile exhibited a time-dependent pattern,accompanied by notable disturbances in lipid metabolism,cholesterol me-tabolism,and amino acid metabolism.These metabolites may become potential bio-markers for early diagnosis of AS.