The effect of gravity on self-similarity of Worthington jet after water entry of a two-dimensional wedge

The effect of gravity on the self-similarity of jet shape at late stage of Worthington jet development is investigated by experiment in the study.In addition,the particle image velocimetry(PIV)method is introduced to analyze the development of flow field.There is a linear scaling regarding the axial velocity of the jet and the scaling coefficient increases with the Froude number.

Towards machine-learning-driven effective mashup recommendations from big data in mobile networks and the Internet-of-Things

A large number of Web APIs have been released as services in mobile communications,but the service provided by a single Web API is usually limited.To enrich the services in mobile communications,developers have combined Web APIs and developed a new service,which is known as a mashup.The emergence of mashups greatly increases the number of services in mobile communications,especially in mobile networks and the Internet-of-Things(IoT),and has encouraged companies and individuals to develop even more mashups,which has led to the dramatic increase in the number of mashups.Such a trend brings with it big data,such as the massive text data from the mashups themselves and continually-generated usage data.Thus,the question of how to determine the most suitable mashups from big data has become a challenging problem.In this paper,we propose a mashup recommendation framework from big data in mobile networks and the IoT.The proposed framework is driven by machine learning techniques,including neural embedding,clustering,and matrix factorization.We employ neural embedding to learn the distributed representation of mashups and propose to use cluster analysis to learn the relationship among the mashups.We also develop a novel Joint Matrix Factorization(JMF)model to complete the mashup recommendation task,where we design a new objective function and an optimization algorithm.We then crawl through a real-world large mashup dataset and perform experiments.The experimental results demonstrate that our framework achieves high accuracy in mashup recommendation and performs better than all compared baselines.

山羊基因组研究进展

山羊基因组是山羊品种资源保护和利用的研究依据,对培育和改良山羊品种具有重要意义。目前,随着山羊参考基因组的不断完善,在山羊起源、进化和适应性等方面的研究取得了诸多重要成果。本文详细综述了山羊基因组研究进展,主要包括山羊基因组结构、山羊基因组图谱(遗传图谱、物理图谱和比较图谱)、山羊高通量测序和山羊SNP芯片的开发及利用,以期为开展山羊基因组选择(genome selection,GS)奠定理论基础。

聚合物分离膜表面形态及微结构研究进展

聚合物分离膜是分离过程中的核心部件,但传统膜材料存在通量少、易污染的普遍缺点,难以实现高效低阻,为解决这一问题,综述介绍了聚合物分离膜表面形态和微结构的制备方法及应用优势,前者包括制备表面微图案化和增大表面粗糙度的方法,比如仿生及生物启发膜的制备,模板法、刻蚀法、表面改性方法等,后者主要体现在膜表面的超亲水化、减轻膜的污染及抗菌等方面,最后对面向应用过程的微图案膜与表界面构造方法进行展望,未来可通过设计与开发表面微结构膜及相关膜组件推动膜分离过程的发展。

二重粗糙表面乙烯-乙烯醇共聚物超滤膜制备与抗污染性能

在水处理方向,超滤膜表面污染问题是一个解决难点,研究发现提高膜的亲水性能有效解决这一难题。文中提出一种简便制备高度亲水超滤膜的方法——微辊轧协同浸没凝胶法,成功制备了表面具有分层次结构的乙烯-乙烯醇共聚物(EVAL)超滤膜。该方法通过调控半凝胶时间和半凝胶剂组成确保微辊轧工艺的顺利进行。在半凝胶时间为40 s和半凝胶剂质量分数为15%时,膜的亲水角度达到8.9°,去离子水和牛血清蛋白(BSA)的通量分别达到268.09 L/(m^(2)·h)和136.95 L/(m^(2)·h);BSA的截留率、吸附量分别为94%和14.29 mg/m^(2)。与传统EVAL超滤膜相比,辊压EVAL超滤膜的亲水性和抗污染性均得到提升。

Biocontrol potential of Trichoderma asperellum mutants T39 and T45 and their growth promotion of poplar seedlings

This study investigates the biocontrol potential of Trichoderma asperellum mutants against Rhizoctonia solani, Alternaria alternata, and Fusarium oxysporum and growth promotion of Populus davidiana 9 P. alba var.pyramidalis(Pd Pap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using Agrobacterium tumefaciens-mediated transformation.Sixty-five positive transformants(T1–T65) were obtained.Growth rates of the mutants T39 and T45 were the same,39.68% faster than the WT. In toxin tolerance tests, only T39 had greater tolerance to A. alternata fermentation broth than the WT, but mutant T45 had the same tolerance as the WT to all fermentation broths. Furthermore, T39 and T45 had a greater antagonistic ability than the WT strain against R. solani and A. alternata. The inhibition rate of the mutants T39 and T45 against A. alternata are 73.92% and80.76%, respectively, and 63.51% and 63.74%, respectively. Furthermore, the three strains increased the activities of superoxide dismutases, peroxidase, catalase(CAT)and phenylalanine ammonia lyase(PAL) in Pd Pap seedling leaves. CAT and PAL activity in the Pd Pap seedling leaveswas 11.25 and 5.50 times higher, respectively, in the presence of T39 than in the control group and 12 and 6.35 times higher, respectively, in the presence of T45 than in the control group. All three strains promoted seedling growth and the root and stem development, especially mutant T45. Mutants T39 and T45 reduced the incidence of pathogenic fungi in poplar and stimulated poplar seedling growth.

The disease resistance potential of Trichoderma asperellum T-Pa2 isolated from Phellodendron amurense rhizosphere soil

To promote the application of Trichoderma,many countries have collected Trichoderma resources.In the present study,nine isolates were isolated from a rhizosphere soil of Phellodendron amurense and were identified as three species:Trichoderma brevicompactum(one isolate),T.asperellum(two isolates),T.atroviride(six isolates).Dual culture experiments showed that T.asperellum T-Pa2 grew fast and produced the best inhibition rates against six tested pathogens(80.25–91.65%)via competition and mycoparasitism.Populus davidiana×P.alba var.pyramidalis Louche(PdPap poplar)was treated with T-Pa2,which increased the catalase activity,nitrate reductase activity,and content of osmosis molecules significantly(P<0.05).Meanwhile,induction by T-Pa2 increased the resistance of PdPap poplar against Alternaria alternata via modulating the expression of salicylic acid,jasmonic acid,and auxin transduction pathway genes.The results will form the basis for the collection and application of biocontrol agents in forestry.

Transcriptomic analysis reveals biocontrol mechanisms of Trichoderma harzianum ACCC30371 under eight culture conditions

A transcriptomic database was constructed to study the biocontrol mechanisms of Trichoderma harzianum ACCC30371 using high quality UniGenes following growth in eight culture media[(1/2PD,minimal medium MM(containing dextrose 10 g L^-1),C starvation medium(derived from MM without dextrose),N starvation medium(derived from MM without ammonium sulphate),and four kinds of phytopathogenic fungi cell wall media].A 4 Gbp transcriptome was generated and 96.7%of the database had a sequencing error rate less than 1%.A total of 25,013 UniGene sequences were obtained with a mean length of 1135 nt.There were 2571 sequences longer than 3000 nt.The National Center for Biotechnology Information Accession number of this transcriptome is SRR8382572.There were 16,360 Unigenes annotated to the Nr protein database,9875 to the SwissProt database,10,266 to the KEGG database,7164 to the COG database,and 1508 to the GO database along with their protein functional annotations.There were 16,723 functional genes identified.We identified 402 bio-control genes,including 14 related to competition,311 to mycoparasitism,76 to antibiosis,and one related to eliciting a plant response.This shows that T.harzianum ACCC30371 has integrated biocontrol mechanisms,and of these mechanisms,mycoparasitism is the most prevalent.Antibiosis and induced systemic resistance also play important roles.These results provide a foundation for further research into the biocontrol mechanisms of Trichoderma,as well as the development and utilization of biological fungicides.

TIPS behavior for IPP/nano-SiO_2 blend membrane formation and its contribution to membrane morphology and performance

In the present work, the TIPS behavior of isotactic polypropylene(iP P)/di-n-butyl phthalate(DBP)/dioctyl phthalate(DOP)/nano-SiO_2 system and the competition relation between liquid–liquid phase separation and polymer crystallization are successfully adjusted by adding nano-SiO_2. The liquid–liquid phase separation temperature of the system increases with increasing nano-SiO_2 content. Besides, iP P crystallization temperature is also changed after adding nano-SiO_2. IPP/nano-SiO_2 blend hollow fiber microporous membrane is prepared via TIPS method. SEM photos show that the membrane exhibits mixed morphology combining cellular structure relating to liquid–liquid phase separation and branch structure originating from polymer crystallization. The relative weight of cellular structure first decreases and then increases with the increase of nano-SiO_2 content. Furthermore, porosity, connectivity among pores and pure water flux of the membrane first increase and then decrease with increasing nano-SiO_2 content. However, mechanical performance of the membrane is improved at all times with increasing nano-SiO_2 content.

A Novel Statistical Power Model for Integrated GPU with Optimization

GPUs are of increasing interests in the multi-core era due to their high computing power. However, the power consumption caused by the rising performance of GPUs has been a general concern. As a consequence, it is becoming an imperative demand to optimize the GPU power consumption, among which the power consumption estimation is one of the important and useful solutions. In this work, we present a novel statistical model that is capable of dynamically estimating the power consumption of the AMD's integrated GPU (iGPU). Precisely, we adopt the linear regression for power consumption modeling and propose a mechanism called kernel extension to lengthen the kernel execution time so that we can sample system data for model evaluation. The results show that the median absolute error of our model is less than 3%. Furthermore,to reduce the latency of power consumption estimation, we conduct a study to explore the possibility to simplify our statistical model. The results suggest that the accuracy and stability is still acceptable in the simplified model. This provides a desirable option to reduce our model latency when it is applied to the iGPU power consumption optimization in the real world.

随着邦德数减小球体入水空泡闭合类型的探究

入水空泡的演化在自然界和工程领域中出现了有趣的动态现象.由于很难推动一个小球高速撞击水面,因此空泡的演化和闭合类型在Bo小于10−2时仍未得到解决.在本研究中,进行了一个基于激光驱动原理的实验,可将小球体加速到数百米每秒.在1~7.57×10^(-2)的Bo范围内,空泡闭合类型可分为准静态、浅闭合、深闭合和表面闭合.通过分析空泡颈部的横截面特征,研究了从浅闭合到深闭合的过渡机制.随着Bo值的进一步降低(5.69×10^(-2)~8.41×10^(-3)),浅闭合直接转变为表面闭合,因为颈部横截面的夹断时间随着Bo值的降低而降低,因此,深闭合消失了.最后,通过改变We和Bo进行参数研究,得到了两个边界.We≈64是准静态和浅闭合之间的过渡,We≈326是浅闭合和表面闭合之间的过渡.

The application of CRISPR-Cas in disease diagnosis and treatment

Clustered regularly interspaced short palindromic repeat(CRISPR)has been gaining much attention in the modern medical field and has been widely used for the diagnosis and treatment of diseases in recent years.In this review,we will introduce the application of CRISPR in disease diagnosis and treatment,including its use in detecting pathogens,gene mutations,and genetic diseases,as well as its application in gene therapy for single-gene diseases,cancer,viral infectious diseases,and cardiovascular diseases.Additionally,we will discuss the potential future directions and challenges of CRISPR in the diagnosis and treatment of diseases,and provide a thorough overview of the ways in which CRISPR is used for diagnosing and treating diseases.

Compact Real-time Simulator with Spatial-temporal Parallel Design for Large-scale Wind Farms

Real-time simulation of large-scale wind farms with detailed modeling can provide accurate insights into system transient behaviors,but entails challenges in computing resources.This paper develops a compact real-time simulator based on the field programmable gate array(FPGA)for large-scale wind farms,in which the spatial-temporal parallel design method is proposed to address the huge computation resource demand associated with detailed modeling.The wind farm is decoupled into several subsystems based on model consistency,and the electrical system and control system of each subsystem are solved in parallel.Both the module-level pipeline technique and superscalar pipeline technique are introduced to the wind farms’simulation to effectively improve the utilization of hardware resources.In case studies,real-time simulations of two modified wind farms are separately carried out on a single FPGA,including one with 13 permanent magnet synchronous generators under a time-step of 11µs,and the other with 30 squirrel-cage induction generators under a time-step of 8µs.Simulation tests,under different scenarios,are implemented to validate the numerical performance of the real-time simulator,and a comparison with the commercial tool PSCAD/EMTDC demonstrates the accuracy and effectiveness of the proposed design.

Rapid Ferroelectric‑Photoexcited Bacteria‑Killing of Bi_(4)Ti_(3)O_(12)/Ti_(3)C_(2)T_(x) Nanofiber Membranes

In this study,an antibacterial nanofiber membrane[polyvinylidene fluoride/Bi_(4)Ti_(3)O_(12)/Ti_(3)C_(2)T_(x)(PVDF/BTO/Ti_(3)C_(2)T_(x))]is fabricated using an electrostatic spinning process,in which the self-assembled BTO/Ti_(3)C_(2)T_(x) heterojunction is incorporated into the PVDF matrix.Benefiting from the internal electric field induced by the spontaneously ferroelectric polarization of BTO,the photoexcited electrons and holes are driven to move in the opposite direction inside BTO,and the electrons are transferred to Ti_(3)C_(2)T_(x) across the Schottky interface.Thus,directed charge separation and transfer are realized through the cooperation of the two components.The recombination of electron–hole pairs is maximumly inhibited,which notably improves the yield of reactive oxygen species by enhancing photocatalytic activity.Furthermore,the nanofiber membrane with an optimal doping ratio exhibits outstanding visible light absorption and photothermal conversion performance.Ulti-mately,photothermal effect and ferroelectric polarization enhanced photocatalysis endow the nanofiber membrane with the ability to kill 99.61%±0.28%Staphylococcus aureus and 99.71%±0.16%Escherichia coli under 20 min of light irradiation.This study brings new insights into the design of intelligent antibacterial textiles through a ferroelectric polarization strategy.

Macroscale and microscale analysis of Anammox in anaerobic rotating biological contactor

Inoculated with conventional anaerobic activated sludge, the Anammox process was successfully developed in an anaerobic rotating biological contactor （AnRBC） fed with a low ratio of CfN synthetic wastewater. Operated in a single point feed mode, the AnRBC removed 92.1% （n = 126） of the influent N at the highest surface load of 12 g/（m2.day）. The biomass increased by 25% and 17.1 g/（m2·day） of maximum N removal surface load was achieved by elevating flow rate with another feed point. Fluorescence in situ hybridization and polymerase chain reaction analysis indicated that the Anammox genus Candidatus Kuenenia stuttgartiensis dominated the community. Both Anammox and denitrifying activity were detected in biofilm by the application of microelectrodes. In the outer layer of the biofilm （0-2500 μm）, nitrite and ammonium consumed simultaneously in a ratio of 1.12/1, revealing the occurrence of Anammox. In the inner layer （〉 2500 μm）, a decrease of nitrate was caused by denitrification in the absence of nitrite and ammonium.

Transparent partial page migration between CPU and GPU

Despite the increasing investment in integrated GPU and next-generation interconnect research,discrete GPU connected by PCIe still account for the dominant position of the market,the management of data communication between CPU and GPU continues to evolve.Initially,the programmer explicitly controls the data transfer between CPU and GPU.To simplify programming and enable systemwide atomic memory operations,GPU vendors have developed a programming model that provides a single,virtual address space for accessing all CPU and GPU memories in the system.The page migration engine in this model automatically migrates pages between CPU and GPU on demand.To meet the needs of high-performance workloads,the page size tends to be larger.Limited by low bandwidth and high latency interconnects compared to GDDR,larger page migration has longer delay,which may reduce the overlap of computation and transmission,waste time to migrate unrequested data,block subsequent requests,and cause serious performance decline.In this paper,we propose partial page migration that only migrates the requested part of a page to reduce the migration unit,shorten the migration latency,and avoid the performance degradation of the full page migration when the page becomes larger.We show that partial page migration is possible to largely hide the performance overheads of full page migration.Compared with programmer controlled data transmission,when the page size is 2MB and the PCIe bandwidth is 16GB/sec,full page migration is 72.72×slower,while our partial page migration achieves 1.29×speedup.When the PCIe bandwidth is changed to 96GB/sec,full page migration is 18.85×slower,while our partial page migration provides 1.37×speedup.Additionally,we examine the performance impact that PCIe bandwidth and migration unit size have on execution time,enabling designers to make informed decisions.

Characterization of two monoclonal antibodies, 38F10 and 44D11, against the major envelope fusion protein of Helicoverpa armigera nucleopolyhedrovirus

The envelope fusion protein F of baculoviruses is a class I viral fusion protein which play a significant role during virus entry into insect cells. F is initially synthesized as a precursor（F_0） and then cleaved into a disulfide-linked F_1 and F_2 subunits during the process of protein maturation and secretion. To facilitate further investigation into the structure and function of F protein during virus infection, monoclonal antibodies（mAbs） against the F_2 subunit of Helicoverpa armigera nucleopolyhedrovirus（HearNPV）（Ha F） were generated. Two kinds of mAbs were obtained according to their different recognition epitopes： one kind of mAbs, as represented by 38F10,recognizes amino acid（aa） 85 to 123 of F_2 and the other kind, represented by 44D11, recognizes aa148 to 173 of F_2. Western blot and immunofluorescence assay confirmed that both of the mAbs recognized the F protein expressed in HearNPV infected cells, however, only 44D11 could neutralize HearNPV infection. The results further showed that 44D11 may not interact with a receptor binding epitope, rather it was demonstrated to inhibit syncytium formation in cells expressing the Ha F protein. The results imply that the monoclonal antibody 44D11 recognizes a region within HaF_2 that may be involved in the F-mediated membrane fusion process. 基金

Si-doping bone composite based on protein template- mediated assembly for enhancing bone regeneration

Bio-inspired hybrid materials that contain organic and inorganic networks interpenetration at the molecular level have been a particular focus of interest on designing novel nanoscale composites. Here we firstly synthesized a series of hybrid bone composites, silicon-hydroxyapatites/silk fibroin/collagen, based on a specific molecular assembled strategy. Results of material characterization confirmed that silicate had been successfully doped into nano-hydroxyapatite lattice. In vitro evaluation at the cellular level clearly showed that these Si-doped composites were capable of promoting the adhesion and proliferation of rat mesenchymal stem cells （rMSCs）, extremely enhancing osteoblastic differentiation of rMSCs compared with silicon-free composite. More interestingly, we found there was a critical point of silicon content in the composition on regulating multiple cell behaviors. In vivo animal evaluation further demonstrated that Si-doped composites enabled to significantly improve the repair of cranial bone defect. Consequently, our current work not only suggests fabricating a potential bone repair materials by integrating element-doping and molecular assembled strategy in one system, but also paves a new way for constructing multi-functional composite materials in the future.

Understanding co-run performance on CPU-GPU integrated processors： observations, insights, directions

Recent years have witnessed a processor develop- ment trend that integrates central processing unit （CPU） and graphic processing unit （GPU） into a single chip. The inte- gration helps to save some host-device data copying that a discrete GPU usually requires, but also introduces deep re- source sharing and possible interference between CPU and GPU. This work investigates the performance implications of independently co-running CPU and GPU programs on these platforms. First, we perform a comprehensive measurement that covers a wide variety of factors, including processor ar- chitectures, operating systems, benchmarks, timing mecha- nisms, inputs, and power management schemes. These mea- surements reveal a number of surprising observations. We an- alyze these observations and produce a list of novel insights, including the important roles of operating system （OS） con- text switching and power management in determining the program performance, and the subtle effect of CPU-GPU data copying. Finally, we confirm those insights through case studies, and point out some promising directions to mitigate anomalous performance degradation on integrated heteroge- neous processors.

Research on the autonomous system of the quadruped robot with a manipulator to realize leader-following,object recognition,navigation and operation

A systematic solution is developed to improve the autonomous capability of the quadruped robot with a manipulator,such as navigation,recognition and operation.The developed system adopts novel software,hardware system and system architecture,including a specially designed environment awareness system(EAS).Based on the camera and LiDAR on the EAS,the recognition of multiple common targets,such as the leader,door,window and bag,is achieved.In terms of navigation,a location method is built,that combines the laser odometer and global positioning system.A mapping and path planning module is designed by the Robot-centric Elevation Mapping algorithm and the rapidly exploring rand tree algorithm.For operation,a real-time target grasp detection system is proposed based on the You Only Look Once v5 algorithm to improve the success rate of tasks.The whole system is integrated based on the task relevance scheduling strategy to reduce the computational complexity.The tightly integrated system and the subsystems are evaluated by conducting simulations and physical experiments in robot recognition,navigation and operation.Extensive experiments show that the proposed framework can better achieve the autonomous navigation and operation of the quadruped robot with a manipulator.Notably,the proposed framework is still effective when facing dynamic objects.In addition,the system can be easily extended to other forms of mobile robot.