Analysis of Soil arching effect for Blind sheet-pile wharf based on ABAQUS

Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by ABAQUS sot＇cware to study the impact of cross section type, the pile spacing and soil properties on soil arching effect. We find that cross section type of the pile has a certain influence on soil stress distribution in front of the barrier piles by comparing circular cross section and rectangular cross section. We also find that clear distance between the barrier piles and cohesive force of the soil have a great influence on that impact. We can increase clear distance between the barrier piles appropriately to improve the efficiency of construction and reduce the proiect cost.

Discussion of Construction Related to Sheet-piled Wharf

In this paper, firstly, the characteristics of sheet-piled wharf construction are introduced. And then, six aspects of sheet-piled wharf construction are discussed： sheet pile, anchorage structure, guiding girder, anchor rod, backfilling behind sheet pile wall, superstructure of sheet-piled wharf etc. The construction of sheet pile involves piling on the land or piling？on？the sea, piling methods, piling patterns, guide frame, embedding sheet piles etc.

Possibility of the Application of the Ultra-long Electromagnetic Wave Remote Sensor to Marine Geological Exploration

The ultra-long electromagnetic wave remote sensing technique developed by Peking University is one of new future techniques, which can detect the submarine geological information from the depth of 20 to 10000 m below the surface by receiving natural ultra-long electromagnetic waves (n Hz to n 100 Hz). The new remote sensor is composed of three parts: a main instrument with a portable computer, an antenna with an amplifier and an external power.

Enhanced photocatalytic properties of ultra-long nanofiber synthesized from pure titanium powders

Using Ti powder as reagent,ultra-long TiO2 nanofibers were prepared via hydrothermal method in NaOH solution.The samples were char-acterized respectively by means of field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM) with selected area electron diffraction (SAED),and X-ray diffraction (XRD).The diameter and the length of the ultra-long TiO2 nanofiber were ～100 nm and >200μm,respectively.The ultra-long TiO2 nanofibers were anatase after heat treatment at 450 ?C for 1 h.Moreover,the optical properties of the products were investigated by UV-visible light absorption spectrum.Furthermore,methyl orange was used as a target molecule to estimate the photocatalytic activity of the specimens.Under the same testing conditions,the photocatalytic activity of the ultra-long TiO2 nanofibers was higher than that of P25.Direct electrical pathway and improved light-harvesting efficiency were crucial for the superior photocatalytic activity of the ultra-long TiO2 nanofibers.

Nonlinear Ultra-Long Wave and Its Stability

A stability of a nonlinear ultra-long wave and its solution are discussed in this paper by employing Burger model which is subject to heat resource. It is of interest noted that the wave solution can be described by an equation of KDV or MKDV and that conditions for the existence of the solution are related to characteristic divergences. In addition, a wave velocity expression for nonlinear ultra-long waves and some diagnostic correlations among wave parameters have been obtained.

Synthesis of Ordered Ultra-long Manganite Nanowires via Electrospinning Method

We develop a new electrospinning method to prepare ultra-long ordered La1-xSrxMnO3 （LSMO） nanowires. The length is up to several centimeters and is only limited by the size of the collector. The well-ordered straight-line structure ensures the transport measurement, which is impossible to be carried out for the random nanowires fabricated by the traditional electrospinning method. Magnetic and transport measurements indicate that the physical properties of the LSMO nanowires depend sensitively on the doping concentration. At the optimum doping, the LSMO wires are ferromagnetic at room temperature with a metal-insulator transition temperature close to room temperature. Magnetic force microscopy studies are also performed to provide a microscopic view of these ultra-long nanowires.

New insight into the ultra-long lifetime of excitons in organic-inorganic perovskite： Reverse intersystem crossing

Recently, an effective exciton diffusion length L exceeding 100μm has been reported for organic- inorganic halide perovskites owing to both the high mobility and ultra-long lifetime of the excitons; however, the origin of ultra-long L is still unclear in nature. In some photoelectric materials, reverse intersystem crossing （RISC） from the triplet to the singlet state can enhance the quantum yield of pho- toluminescence greatly. In this study, our theoretical investigation indicated that the energy difference △E_st between the singlet state and the triplet state of CH_3NH_3Pbl_3 was less than 0.1 eV, which represents one crucial prerequisite for the occurrence of RISC. Meanwhile, the experimental results showed that the photoluminescence lifetime increased with the increasing temperature, a typical feature of RISC. Based on this study, we put forward the hypothesis that the ultra-long lifetime of excitons in organic-inorganic halide perovskite might be caused by the RISC process. This may provide a new insight into the important photophysical properties of such novel photovoltaic materials.

Constructing long-cycling crystalline C_(3)N_(4)-based carbonaceous anodes for sodium-ion battery via N configuration control

Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical applications.Coupling carbon nitrides with conductive carbon may relieve these issues.However,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related electrodes.Herein,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt strategy.More importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first time.By elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was obtained.Profiting from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity retention.This work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.

新型整体卸荷式板桩结构在某挖入式港池中的应用

结合某挖入式港池工程,阐述整体卸荷式组合钢板桩结构方案设计及关键技术。该结构形式充分整合了前板桩墙、1 000PHC桩基及卸荷式承台的抗弯能力,以类似于整体刚性承台的形式来抵抗水平及竖向荷载。该新型结构已在某挖入式港池中成功应用,可为以后类似工程的设计提供技术参考。

超长钢板桩围堰施工承台基础计算与应用

以新建宁安铁路安庆长江大桥工程为背景,对高施工水位下超长钢板桩围堰施工承台基础进行了计算分析及其应用研究。首先选取三个典型不利工况,分别采用平面简化模型法和空间整体模型法对钢板桩、圈梁、内支撑的强度和刚度进行了计算,详细介绍了模型的建立和参数的选取,并对两种方法的计算结果进行了比较分析,归纳了相关计算要点。最后根据计算结果和实际工程经验,总结了施工应用过程中的控制重点,从现场实施情况看效果良好,可为相似工程应用提供借鉴。

Hydrogen Bond-Assisted Ultra-Stable and Fast Aqueous NH_(4)^(+)Storage

Aqueous ammonium ion batteries are regarded as eco-friendly and sustainable energy storage systems.And applicable host for NH_(4)^(+)in aqueous solution is always in the process of development.On the basis of density functional theory calcula-tions,the excellent performance of NH_(4)^(+)insertion in Prussian blue analogues(PBAs)is proposed,especially for copper hexacyanoferrate(CuHCF).In this work,we prove the outstanding cycling and rate performance of CuHCF via electrochemical analyses,delivering no capacity fading during ultra-long cycles of 3000 times and high capacity retention of 93.6%at 50 C.One of main contributions to superior performance from highly reversible redox reaction and structural change is verified during the ammoniation/de-ammoniation progresses.More importantly,we propose the NH_(4)^(+)diffusion mechanism in CuHCF based on con-tinuous formation and fracture of hydrogen bonds from a joint theoretical and experimental study,which is another essential reason for rapid charge transfer and superior NH_(4)^(+)storage.Lastly,a full cell by coupling CuHCF cathode and polyaniline anode is constructed to explore the practical application of CuHCF.In brief,the outstanding aqueous NH_(4)^(+)storage in cubic PBAs creates a blueprint for fast and sustainable energy storage.

超长钢板桩围堰施工深水低桩承台技术

结合工程实际情况,介绍了主墩承台钢板桩围堰结构形式和30 m超长钢板桩围堰施工深水低桩承台技术,创造了钢板桩围堰施工深水基础的记录,既加快了施工工期,又保证了工程质量。

Impacts of SST and SST Anomalies on Low-Frequency Oscillation in the Tropical Atmosphere

Considering the multiscale character of LFO effects of SST on LFO in the tropical atmosphere （low-frequency oscillation） in the tropical atmosphere, the are discussed by using an absolute ageostrophic, baroclinic model. Here, SST effects include sea surface heating and forcing of SST anomalies （SSTAs）. Studies of the influences of sea surface heating on LFO frequency and stability show that sea surface heating can slow the speed of waves and lower their frequency when SST is comparatively low; while higher SST leads to unstable waves and less periods of LFO. Since the impact of a SSTA on ultra-long waves is more evident than that on kilometer-scale waves, long-wave approximation is used when we continue to study the effect of SSTAs. Results indicate that SSTAs can lead to a longer period of LFO, and make waves unstable. In other words, positive （negative） SSTAs can make waves decay （grow）.

Building ultra-stable K–Te battery by molecular regulation

Tellurium (Te) is an ideal electrode for potassium ion batteries (PIBs) owing to its excellent electronic conductivity and high volumetric capacity.However,the Te electrode is prone to capacity fading as the shuttle effect.To address this challenge,we propose molecular regulated Se–Te solid solutions on N-doped porous carbon as the PIBs electrode.After optimizing the Se content in Se–Te solid solutions,the resultant SeTe_(6.8) on N-doped porous carbon (SeTe_(6.8)@C) delivered a capacity of over 400 mAh g^(-1) with a flat plateau of 1.0 V at 500 m A g^(-1).It also achieved a superiorly long cycle life,running for more than 1600 cycles (over 7 months with 0.015%degeneration per cycle) at 100 mA g^(-1) and excellent rate performance (179.9 mAh g^(-1) at 10000 mA g^(-1)).This remarkable electrochemical energy storage of the Te electorde likely arises from suppression of the shuttle effect after doping the Te with strongly electronegative Se atoms (forming K_(s)Te_(3) which is not easily soluble in electrolyte).This study presents a fresh approach for designing and developing ultra-stable Te-based electrodes for PIBs and beyond.

New Development of Port Structures Design and Construction

Some new innovative constructions and technologies for improvement of port structures are worked out and discussed. The aims of innovations are to increase structures＇ reliability, to decrease cost of construction and maintenance, to simplify technology and cost of building. For these purposes either some main bearing elements or structures in whole are modified or improved. In particular different improved waterfront constructions as well as retaining walls and coastal protection （gravity, piled, sheet piling, etc.） for use in various soil conditions are outlined. One of them incorporates trapezoidal blocks forming columns, each block in the column contacts the others either with smaller or larger bases. Another design incorporates blocks that are constructed with holes ran through the centres of gravity of the blocks. Rigid cylinder element running through the holes of several adjacent blocks allows them to be joined forming large size units, The structure consisting of wedge form retaining wall is original but simple to construct, Some new designs based on perfection of sheet-piling walls （sheet piles with curvilinear cross-section having a form of semi-rings） are proposed for different applications. Proposals on modernization of some traditional structures and technologies are discussed.

瓯飞一期围垦工程海上超长钢板桩插打施工质量控制

海上插打超长钢板桩围堰是水闸工程的起始阶段,也是水闸工程的薄弱环节,其质量的好坏直接影响着后续工程进度与质量安全等。以温州市瓯飞一期围垦工程规模最大的北1~#、北2~#水闸钢板桩围堰为例,提出钢板桩插打各种施工质量问题,并对问题原因进行分析,采取合理质量控制措施,施工中取得良好成效,可为类似工程借鉴。

Enabling Extraordinary Rate Performance for Poorly Conductive Oxide Pseudocapacitors

Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate performance,which in turn deteriorates cyclic stability at high current levels.Using the example of spinel manganese oxide,herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites,which are derived based on a novel solution chemistry,and carbon additive(CA)nanoparticles with highly uniform of size distributions.Precisely controlling the particle morphology and size distribution of the active material and conductive additive(CA)in the nanometer range can maximize the density of active material-CA-electrolyte three-phase contact points,thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions.The resultant Mn3O4 pseudocapacitive electrode exhibits rate capability and cycle stability,including 60%capacity retention at 60 A g-1 and no capacity fade over 100000 cycles under dynamic current densities,far superior to the state-of-the-art PTMO electrodes.The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials.

罗源湾鲁能码头超长钢板桩施工技术

某码头工程结构采用前板桩高桩梁板形式,前板桩墙采用BOX桩和AZ板桩,为国内罕见。以BOX桩、AZ板桩的施打工艺的开发研究为主线,在无相应成熟工艺可供借鉴的情况下,对该桩型的制作(焊接工艺)、出运(吊点设置)、施打工艺进行试验比较和改进,采取相应技术措施,总结了沉桩过程的质量控制措施,既节约了施工成本,加快了施工进度,又确保了工程质量。

Some Innovations for Offshore and Harbor Berths Construction

Some new innovative constructions and piling technologies for improvement of offshore and port berthing structures are worked out and discussed. The aims of innovations are to decrease required power of construction （in particular, piling） equipment and, correspondingly, to improve environmental situation at the construction site. Another achieved goal is providing long tubular piles installation in hard soils conditions without application of very heavy and powerful driving machines. Worked out solutions are based on two approaches. One of them provides separate loading of driving force on pile＇s shaft and pile＇s tip concentrating the whole driving force on one of the mentioned parts of the pile. Another approach is focused on prevention of soil plug formation inside of the tubular pile tip facilitating the pile installation process. Also improved anchorage system for sheet piling seafront walls is presented and discussed. All considered innovations are patented and can be used in wide range of marine, offshore, coastal and harbor structures.

A simplified model for unsteady airflow analysis in ultra-long tunnels based on the resistance compensation method

With the expansion of tunnel construction scale,accurate modeling of 3D unsteady flow fields in ultra-long tunnels requires high computational resources.In this study,a resistance compensation method based on the St and Eu similarity criterion is proposed to construct the simplified model to rapidly and precisely replicate the train-driven unstable airflow.A 6000 m ultra-long tunnel is utilized as a reference model and simplified models with the scale ratio varying from 80%to 10%are developed to assess the method performance.The multi-region dynamic mesh model is employed to simulate train tracking motion.After weighing the computational accuracy and efficiency,the results show that 20%is the optimal scale ratio.The unsteady wind speed of the simplified model deviates 6.96%from the reference model,while the simulation computation time is reduced by 85.01%.On this basis,the simplified model is applied to analyze the impacts of tunnel friction coefficients,blockage rates,train lengths and speeds,and departure intervals.The mean bias error(MBE)and Pearson correlation coefficient(PCC)are within 10%and over 0.8 respectively,confirming the reliability of the simplified model.The resistance compensation method is a crucial technique to improve the accuracy and efficiency of the unsteady flow field in ultra-long tunnels.