EXPERIMENTAL STUDY ON TURBULENT FEATURES IN THE NEGATIVE TRANSPORT REGION OF ASYMMETRIC PLANE CHANNEL FLOW

Turbulent features of streamwise and vertical components of velocity in the negative transport region of asymmetric plane channel flow have been studied experimentally in details. Experiments show that turbulent fluctuations in negative transport region are suppressed, and their probability distributions are far from Gaussian. Besides, the skewness factors attain their negative maxima at the position of the maximum mean velocity, whereas the flatness factors attain their positive maxima at the same position.

Volume transport in the East Taiwan Channel in response to diff erent tracks of typhoons as revealed by HYCOM data

Northward infl ow through the East Taiwan Channel is vital in modulation of water exchange processes off northeastern Taiwan,China.In addition to the eff ects of the Kuroshio Current and westward-propagating oceanic mesoscale eddies,the seas off eastern Taiwan,China,are frequently infl uenced by typhoons.Focusing on extrema of East Taiwan Channel volume transport(ETCVT)that appear within days of typhoon infl uence,this study investigated 124 historical cyclones including 91 typhoons that passed over the study sea area off eastern Taiwan,China.Based on 25-year HYbrid Coordinate Ocean Model(HYCOM)data,71%of short-term(within 10 d)ETCVT absolute values with>5 Sv occurred under the infl uence of typhoons crossing the study sea area,and the maximum short-term ETCVT extrema induced by typhoons were 12.5 and-10.9 Sv.The ETCVT extrema induced by typhoons showed reasonable positive correlation with typhoon wind speed.More importantly,the ETCVT extrema diff ered in response to diff erent typhoon tracks.Three types of typhoon were identifi ed based on their track and impact on ETCVT.Representative typhoon cases were examined to elucidate the specifi cs of each typical response.Based on historical best track data and HYCOM data,it was established that Type I typhoons caused the ETCVT to exhibit a negative extremum followed by a positive extremum.All Type I,II,and III typhoons tended to result in typical ETCVT fl uctuations in the surface mixing layer above the depth of 50-100 m,while Type II typhoons were more likely to induce ETCVT fl uctuations in the subsurface layer.The fi ndings of this study enhance understanding of ETCVT extrema that occur following typhoon passage,which is valuable for short-term physical-biogeochemical studies both in the study region and in areas downstream owing to the large net volume transport changes induced by typhoons.

Semi-interpenetrating-network all-solid-state polymer electrolyte with liquid crystal constructing efficient ion transport channels for flexible solid lithium-metal batteries

The development of the solid-state polymer electrolytes (SPEs) for Li-ion batteries (LIBs) can effectively address the hidden safety issues of commercially used liquid electrolytes.Nevertheless,the unsatisfactory room temperature ion conductivity and inferior mechanical strength for linear PEO-based SPEs are still the immense obstacles impeding the further applications of SPEs for large-scale commercialization.Herein,we fabricate a series of semi-interpenetrating-network (semi-IPN) polymer electrolytes based on a novel liquid crystal (C6M LC) and poly(ethylene glycol) diglycidyl ether (PEGDE) via UV-irradiation at the first time.The LCs not only highly improve the mechanical properties of electrolyte membranes via the construction of network structure with PEGDE,but also create stable ion transport channels for ion conduction.As a result,a free-standing flexible SPE shows outstanding ionic conductivity(5.93×10^(-5) S cm^(-1) at 30℃),a very wide electrochemical stability window of 5.5 V,and excellent thermal stability at thermal decomposition temperatures above 360℃ as well as the capacity of suppressing lithium dendrite growth.Moreover,the LiFePO_(4)/Li battery assembled with the semi-IPN electrolyte membranes exhibits good cycle performance and admirable reversible specific capacity.This work highlights the obvious advantages of LCs applied to the electrolyte for the advanced solid lithium battery.

Transient response of enstrophy transport to opposition control in turbulent channel flow

The transient response of the turbulent enstrophy transport to opposition control in the turbulent channel flow is studied with the aid of direct numerical simulation. It is found that the streamwise enstrophy and the spanwise enstrophy are suppressed by the attenuation of the stretching terms at first, while the vertical enstrophy is reduced by inhibiting the tilt of the mean shear. In the initial period of the control, the streamwise enstrophy evolves much slower than the other two components. The vertical vorticity component exhibits a rapid monotonic decrease and also plays an important role in the attenuation of the other two components.

Bottom Sediment Transport in the Flood and Ebb Channels of the Changjiang Estuary

Nanxiaohong and Nangang main south channel are chosen as the typical flood and ebb channels. Hydrodynamics analysis based on field hydrological and sediment data is conducted with Gao-Collins model to analyse sediment transport trends. Also, the grain size distribution analysis of the bottom sediment sampled in Sep. 2001 is used as the base of the analysis. The result shows that the sediment in Nanxiaohong is from the rive mouth area. The sediment transports upwards with the flood flow which is stronger than the ebb flow, i.e., in the direction of SE-WN. The sediment in main south channel comes from upward. They transport downwards with the ebb flow, which is stronger than the flood flow, i.e., in the direction of WN-SE. The directions, sources and mechanism of sediment transport are identified according to comprehensive analyses of the observed data on hydrodynamics and sediment.

Methodology for Volumetric Measuring Transport of River Sand, in a Laboratory Channel with Mobile Bottom

Most public universities in Latin America and Mexico lack laboratories for measuring sediment transport or to do academic activities. The Research Center of the engineering faculty of Chiapas state university (UNACH by its acronym in Spanish) designed a portable prismatic channel for teaching and researching the sediment transportation in rivers. This paper presents the method to measure river sand transportation in a laboratory channel with a mobile bottom and presents the results of twenty-seven experiments done in the portable channel, using nine different slope inclinations and 27 flow and water speed values. The three main results are the following: 1) The construction of the channel with variable slopes, to experiment and measure sediment transportation. 2) A method developed for measuring the volume of sediment in a laboratory. 3) In a channel with a bottom slope of 0.071, a water flow of 2 l/s and a water speed of 1.77 m/s, the volume of transported sediment was 0.015 m3;in a channel with a bottom slope of 0.44, a water flow of 2 l/s and a water speed of 0.788 m/s, the volume of transported sediment was 0.006 m3;in a channel with the bottom slope of 0.024, a water flow of 2 l/s and a water speed of 0.62 m/s, the transported sediment was 0 m3.

Genome-Wide Identification and Expression Profiling of the Shaker K+ Channel and HAK/KUP/KT Transporter Gene Families in Grape (Vitis vinifera L.)

Potassium(K+)is an essential macronutrient for plants to maintain normal growth and development.Shaker-like K+channels and HAK/KUP/KT transporters are critical components in the K+acquisition and translocation.In this study,we identified 9 Shaker-like K+channel(VvK)and 18 HAK/KUP/KT transporter(VvKUP)genes in grape,which were renamed according to their distributions in the genome and relative linear orders among the distinct chromosomes.Similar structure organizations were found within each group according to the exon/intron structure and protein motif analysis.Chromosomal distribution analysis showed that 9 VvK genes and 18 VvKUP genes were unevenly distributed on 7 or 10 putative grape chromosomes.Three pairs of tandem duplicated genes and one pair of segmental duplicated genes were observed in the expansion of the grape VvKUP genes.Gene expression omnibus(GEO)data analysis showed that VvK and VvKUP genes were expressed differentially in distinct tissues.Various cis-acting regulatory elements pertinent to phytohormone responses and abiotic stresses,including K+deficiency response and drought stress,were detected in the promoter region of VvK and VvKUP genes.This study provides valuable information for further functional studies of VvK and VvKUP genes,and lays a foundation to explore K+uptake and utilization in fruit trees.

新型高性能互连技术Hyper Transport研究

HyperTransport(HT)是一种新型用于板级集成电路互连的、高性能、点到点、基于报文交换的互连技术。HyperTransport提供了用途广泛的连接,以减少系统内的总线数,为嵌入系统应用提供高性能的连接,可以实现高度可伸缩的多处理系统。对Hyper Transport的一些关键技术进行了介绍,并设计了一个HT的HOST桥。

植被影响下的弯曲分汊河道水沙特性

弯曲分汊河道由于其特殊的地形和复杂的水沙运动特性,对河势稳定、防洪、航运及沿岸经济发展都有着深远的影响。植被作为河流生态系统的组成部分,对河床演变形态具有重要影响,且植被往往分布在弯曲分汊河道的凸岸淤积段或洲滩。本文基于物理模型试验,开展系列不同来流及不同植被密度影响下的弯曲分汊河道动床非恒定流概化试验,分析植被影响下弯曲分汊河道冲刷与再造过程中的水流和泥沙的输移特性。结果表明:非恒定过程条件下,左汊分流比受植被影响较为显著,且随着支汊植被密度的增加呈现增大的趋势;分流比对右汊有无植被布设较为敏感,但植被布设密度的大小对分流比影响较小。对于推移质输移,支汊植被的存在增大了弯曲分汊河段推移质的输沙率和输沙级配,随着右汊植被覆盖密度的增加,推移质输沙率峰值有所增大,同时推移质输沙波动亦增大,流量较大时波动性表现更为显著。汊道相互影响量化参数的变化表明弯曲分汊河道再造过程中汊道间的影响随着支汊植被密度的增加呈现出较大的增加幅度。研究成果一定程度上可为相关的河道整治、河流生态修复等提供理论支持。

温福高铁运量预测及功能定位分析

温福高铁是国家综合立体交通网主骨架中长三角至粤港澳大湾区主轴的重要组成部分,也是国家“八纵八横”高速铁路网主骨架之沿海高铁通道的关键段落。该文先以“四阶段”预测方法对项目运输需求进行预测,进而分析项目在国民经济、综合交通体系及路网中的作用,综合运量特征及发挥的作用提出本线的功能定位,为项目建设提供参考。

Plant salt tolerance and Na^+ sensing and transport

Salinity is a global challenge to agricultural production. Understanding Na^+ sensing and transport in plants under salt stress will be of benefit for breeding robustly salt-tolerant crop species. In this review, first, possible salt stress sensor candidates and the root meristem zone as a tissue harboring salt stress-sensing components are proposed. Then,the importance of Na^+ exclusion and vacuolar Na^+ sequestration in plant overall salt tolerance is highlighted. Other Na^+ regulation processes, including xylem Na^+ loading and unloading, phloem Na^+ recirculation, and Na^+ secretion, are discussed and summarized.Along with a summary of Na^+ transporters and channels, the molecular regulation of Na^+ transporters and channels in response to salt stress is discussed. Finally, some largely neglected issues in plant salt stress tolerance, including Na^+ concentration in cytosol and the role of Na^+ as a nutrient, are reviewed and discussed.

Research Advance on the Mechanism of Cadmium Transport in Rice

Soils in part of rice production areas have been seriously contaminated by cadmium （Cd）. Rice with high Cd content over allowable limit produced in these areas is widely concerned. Low accumulation varieties can remarkably decrease the Cd content in rice as well as the risk of food safety. The translocation of Cd either from soil to root system or from roots to aboveground parts is identified by a lot of ion transport proteins. Transport efficiency of Cd in some rice varieties is regulated by special metal ionic transporters. However, most varieties transport Cd by cation transporters or universal ionic transporters. Both the expression levels and time of gens controlling ionic transporters directly influence the Cd transport rates inside rice plant and the accumulation amount in different organs. Screening and utilizing specific Cd transport genes are the genetic basis of breeding low accumulation varieties.

Mass transport deposits and processes in the north slope of the Xisha Trough,northern South China Sea

Triple mass-transport deposits （MTDs） with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic reflection data and multi-beam bathymetric data, the Quaternary MTDs are characterized by typical geometric shapes and internal structures. Results of slope analysis showed that they are developed in a steep slope ranging from 5° to 35°. The head wall scarps of the MTDs arrived to 50 km in length （from headwall to termination）. Their inner structures include well developed basal shear surface, growth faults, stepping lateral scarps, erosion grooves, and frontal thrust deformation. From seismic images, the central deepwater channel system of the Xisha Trough has been filled by interbedded channel-levee deposits and thick MTDs. Therefore, we inferred that the MTDs in the deepwater channel system could be dominated by far-travelled slope failure deposits even though there are local collapses of the trough walls. And then, we drew the two-dimensional process model and three- dimensional structure model diagram af the MTDs. Combined with the regional geological setting and previous studies, we discussed the trigger mechanisms of the triple MTDs.

Animal secretory endolysosome channel discovery

Secretory pore-forming proteins(PFPs) have been identified in organisms from all kingdoms of life. Our studies with the toad species Bombina maxima found an interaction network among aerolysin family PFPs(af-PFPs) and trefoil factors(TFFs). As a toad af-PFP, Bm ALP1 can be reversibly regulated between active and inactive forms, with its paralog Bm ALP3 acting as a negative regulator. Bm ALP1 interacts with Bm TFF3 to form a cellular active complex called βγ-CAT. This PFP complex is characterized by acting on endocytic pathways and forming pores on endolysosomes, including stimulating cell macropinocytosis. In addition, cell exocytosis can be induced and/or modulated in the presence of βγ-CAT. Depending on cell contexts and surroundings, these effects can facilitate the toad in material uptake and vesicular transport, while maintaining mucosal barrier function as well as immune defense. Based on experimental evidence,we hereby propose a secretory endolysosome channel(SELC) pathway conducted by a secreted PFP in cell endocytic and exocytic systems, with βγ-CAT being the first example of a SELC protein. With essential roles in cell interactions and environmental adaptations, the proposed SELC protein pathway should be conserved in other living organisms.

Mechanism of back siltation in navigation channel in Dinh An Estuary, Vietnam

The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Vietnam and then to Phnom Penh, Cambodia. The morphological evolution of the navigation channel is complicated and unstable. The back siltation intensity in the navigation channel has largely increased and been concentrated in the curvature segments of the channel since 1980. In this study, based on simulation results and measured data, five key factors that influence the back siltation in the navigation channel were systematically analyzed. These factors included the increasing elevation gap between the channel and the nearby seabed, the disadvantageous hydrodynamic conditions, sediment transport, mixing of saltwater and freshwater, and wave effects in the navigation channel. It is shown that the back siltation to a large extent results from the low current velocity of the secondary ocean circulation, which often occurs in the curvature segments of the channel. Suspended sediment also settles in the channel due to the decrease of the current velocity and the sediment transport capacity when flow passes through the channel. The changes of hydrodynamic conditions are responsible for the majority of the severe siltation in the curvature segments of the navigation channel.

Comment on: Cloning and characterization of porcine aquaporin 1 water channel expressed extensively in the gastrointestinal system

TO THE EDITOR Sir, I read with great interest the recently published article in the World Journal of Gastroenterology by Jin and co-workers on the cloning and characterization of porcine aquaporin 1 water channel from the pig liver and studies on its expression in the porcine gastrointestinal system. The authors should be congratulated for making this important and valuable contribution to the field of aquaporin biology and porcine gastrointestinal physiology. However, there are a number of unresolved issues and controversies concerning the expression of aquaporins （especially aquaporin 1） in the gastrointestinal system that are worthy of additional comment and discussion by Jin and co-workers.

Migration-associated secretion of melanoma inhibitory activity at the cell rear is supported by KCa3.1 potassium channels

Malignant melanoma, characterized by invasive local growth and early formation of metastases, is the most aggressive type of skin cancer. Melanoma inhibitory activity （MIA）, secreted by malignant melanoma cells, interacts with the cell adhesion receptors, integrins a4131 and 05131, facilitating cell detachment and promoting formation of me- tastases. In the present study, we demonstrate that MIA secretion is confined to the rear end of migrating cells, while in non-migrating cells MIA accumulates in the actin cortex. MIA protein takes a conventional secretory pathway including coat protein complex I （COPI）- and coat protein complex II （COPII）-dependent protein transport to the cell periphery, where its final release depends on intracellular Ca2＋ ions. Interestingly, the Ca2＋-activated K＋-channel, subfamily N, member 4 （KCa3.1）, known to be active at the rear end of migrating cells, was found to support MIA secretion. Secretion was diminished by the specific KCa3.1 channel inhibitor TRAM-34 and by expression of dominant- negative mutants of the channel. In summary, we have elucidated the migration-associated transport of MIA protein to the cell rear and also disclosed a new mechanism by which KCa3.1 potassium channels promote cell migration.

Control of Halo-Chaos in Beam Transport Network via Neural Network Adaptation with Time-Delayed Feedback

Subject of the halo-chaos control in beam transport networks （channels） has become a key concerned issue for many important applications of high-current proton beam since 1990＇. In this paper, the magnetic field adaptive control based on the neural network with time-delayed feedback is proposed for suppressing beam halo-chaos in the beam transport network with periodic focusing channels. The envelope radius of high-current proton beam is controlled to reach the matched beam radius by suitably selecting the control structure and parameter of the neural network, adjusting the delayed-time and control coefficient of the neural network.

Potassium nutrition of maize:Uptake,transport,utilization,and role in stress tolerance

Potassium(K) is an essential macronutrient for plant growth and development and influences yield and quality of agricultural crops.Maize(Zea mays) is one of the most widely distributed crops worldwide.In China,although maize consumes a large amount of K fertilizer,the K uptake/utilization efficiency(KUE)of maize cultivars is relatively low.Elucidation of KUE mechanisms and development of maize cultivars with higher KUE are needed.Maize KUE is determined by K+uptake,transport,and remobilization,which depend on a variety of K+channels and transporters.We review basic information about K+channels and transporters in maize,their functions and regulation,and the roles of K+in nitrogen transport,sugar transport,and salt tolerance.We discuss challenges and prospects for maize KUE improvement.

Elucidating Ion Transport Phenomena in Sulfide/Polymer Composite Electrolytes for Practical Solid-State Batteries

Despite the enormous interest in inorganic/polymer composite solid-state electrolytes(CSEs)for solid-state batteries(SSBs),the underlying ion transport phenomena in CSEs have not yet been elucidated.Here,we address this issue by formulating a mechanistic understanding of bi-percolating ion channels formation and ion conduction across inorganic-polymer electrolyte interfaces in CSEs.A model CSE is composed of argyrodite-type Li_6PS_5Cl(LPSCl)and gel polymer electrolyte(GPE,including Li~+-glyme complex as an ion-conducting medium).The percolation threshold of the LPSCl phase in the CSE strongly depends on the elasticity of the GPE phase.Additionally,manipulating the solvation/desolvation behavior of the Li~+-glyme complex in the GPE facilitates ion conduction across the LPSCl-GPE interface.The resulting scalable CSE(area=8×6(cm×cm),thickness~40μm)can be assembled with a high-mass-loading LiNi_(0.7)Co_(0.15)Mn_(0.15)O_(2)cathode(areal-mass-loading=39 mg cm~(-2))and a graphite anode(negative(N)/positive(P)capacity ratio=1.1)in order to fabricate an SSB full cell with bi-cell configuration.Under this constrained cell condition,the SSB full cell exhibits high volumetric energy density(480 Wh L_(cell)~(-1))and stable cyclability at 25℃,far exceeding the values reported by previous CSE-based SSBs.