THEORETICAL ANALYSIS AND PRACTICE ON THE SELECTION OF KEY PARAMETERS FOR HORIZONTAL BIAS BURNER

The air flow ratio and the pulverized coal mass flux ratio between the rich and lean sides are the key parameters of horizontal bias burner. In order to realize high combustion efficiency, excellent stability of ignition, low NO x emission and safe operation, six principal demands are presented on the selection of key parameters. An analytical model is established on the basis of the demands, the fundamentals of combustion and the operation results. An improved horizontal bias burner is also presented and applied. The experiment and numerical simulation results show the improved horizontal bias burner can realize proper key parameters, lower NO x emission, high combustion efficiency and excellent performance of part load operation without oil support. It also can reduce the circumfluence and low velocity zone existing at the downstream sections of vanes, and avoid the burnout of the lean primary air nozzle and the jam in the lean primary air channel. The operation and test results verify the reasonableness and feasibility of the analytical model.

Effects of key design parameters of tine furrow opener on soil seedbed properties

The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till conditions.Orthogonal test and single factor test were performed to analyze the effects of different parameters.Results showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk density.Soil types and operating depth had significant effects on soil disturbance caused by tine furrow openers.The concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)increased.The Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,respectively.The tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk density.As the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not significant.The cutting edge thickness(<2 mm)had no significant effects on soil properties of seedbed.This study could provide a reference for optimal design of the tine furrow opener to create more suitable seedbed environment,and promote the application of the light no-till planters.

Mindless Intelligence Method for Solving the Tower of Hanoi Problem

Over the past years, more and more attention has been paid to artificial life research. The main object of artificial life research is to explore how to control the environments in which the digital organisms imitating natural life, under complicated competition and evolutionary conditions, develop their own wisdom, which can then be used to solve the problems in the real world. While most of the current researches applied one or another artificial life method to solve real problems, the fundamental mechanism of the emerging process of artificial life is seldom addressed. The research works on genetic algorithms, although bearing fruitful results, could only be deemed as constituting a basic stage in the process of artificial life development. This study proposes a new method of employing artificial life, to complement the contents of the research of mindless intelligence, which is regarded as a bridge linking genetic algorithms to general artificial life. And two important concepts, key manipulating parameters and contribution function in its context, are proposed to expand the mindless intelligence applications, in order to pave the way for the optimal design of an artificial life method, in an attempt to fill the conceptual gap between genetic algorithms and artificial life, and consequently clarifying the artificial life mechanism. As a case study we applied these innovative methods to solve an open problem： the Tower of Hanoi, to attest to the feasibility of our approach, and we have achieved satisfactory results.

Innovative Design and Development of Simplysupported Tied Arch of Beijing-Shanghai HSR

Simply-supported tied arch is a zero-thrust arch bridge with clear structural force,large stiffness,low height,beautiful appearance and economic efficiency.In Xuzhou-Shanghai section of Beijing-Shanghai HSR,the simply-supported tied arch is systematically studied and widely applied for the first time.A total of 21 simplysupported tied arch bridges with the spans of 96 m,112 m and 128 m respectively are constructed for the route.The simply-supported tied arch is an external static and internal super-static parallel arch or basket arch of Nielsen system in structure;single-box,threechamber and equal-height prestressed concrete box girder is adopted for the tie beam;dumbbell steel pipe concrete section is adopted for the arch rib;PES(FD)low-stress anticorrosion cable body is adopted for the suspender.The rational structural form is determined by comparative study on the key technical parameters such as the layout form of suspender,rise-span ratio and arch axis alignment.This paper summarizes the optimization of simplysupported tied arch structure and looks forward to the development of bridge structure.

Discovering the ultralow thermal conductive A_(2)B_(2)O_(7)-type high-entropy oxides through the hybrid knowle dge-assiste d data-driven machine learning

Lattice engineering and distortion have been considered one kind of effective strategies for discovering advanced materials.The instinct chemical flexibility of high-entropy oxides(HEOs)motivates/accelerates to tailor the target properties through phase transformations and lattice distortion.Here,a hybrid knowledge-assisted data-driven machine learning(ML)strategy is utilized to discover the A_(2)B_(2)O_(7)-type HEOs with low thermal conductivity(κ)through 17 rare-earth(RE=Sc,Y,La-Lu)solutes optimized A-site.A designing routine integrating the ML and high throughput first principles has been proposed to predict the key physical parameter(KPPs)correlated to the targetedκof advanced HEOs.Among the smart-designed 6188(5RE_(0.2))_(2)Zr_(2)O_(7)HEOs,the best candidates are addressed and validated by the princi-ples of severe lattice distortion and local phase transformation,which effectively reduceκby the strong multi-phonon scattering and weak interatomic interactions.Particularly,(Sc_(0.2)Y_(0.2)La_(0.2)Ce_(0.2)Pr_(0.2))_(2)Zr_(2)O_(7)with predictedκbelow 1.59 Wm^(−1)K^(−1)is selected to be verified,which matches well with the ex-perimentalκ=1.69 Wm^(−1)K^(−1)at 300 K and could be further decreased to 0.14 Wm^(−1)K^(−1)at 1473 K.Moreover,the coupling effects of lattice vibrations and charges on heat transfer are revealed by the cross-validations of various models,indicating that the weak bonds with low electronegativity and few bond-ing charge density and the lattice distortion(r∗)identified by cation radius ratio(r A/r B)should be the KPPs to decreaseκefficiently.This work supports an intelligent designing strategy with limited atomic and electronic KPPs to accelerate the development of advanced multi-component HEOs with proper-ties/performance at multi-scales.

Status and trends in the stability of the three largest ice shelves in Antarctica

The Ross,Filchner-Ronne,and Amery ice shelves are the three largest ice shelves in Antarctica,playing a crucial role in supporting the Antarctic ice sheet.However,current studies on the stability of the three largest ice shelves primarily focus on singular or limited factors,lacking a comprehensive assessment of multiple parameters.To systematically and in-depth study the stability and trend of the three largest ice shelves,we comprehensively collected and analyzed key parameters,including elevation changes,basal melting,surface meltwater,major rifts propagation rate,suture zones,ice front area change rate,grounding lines,ice velocity,and mass balance.Additionally,we selected the collapsed Larsen B Ice Shelf(LBIS),the rapidly changing and structurally weakened Pine Island Ice Shelf(PIIS),and the accelerating Totten Ice Shelf(TIS)as reference ice shelves.By comparing and analyzing the key parameters between these reference ice shelves and the three largest ice shelves,we find the status and trends in the stability of the latter.Our findings reveal that most key parameters of the three largest ice shelves present relatively minor variations compared to those of the reference ice shelves.Specifically,50%of the parameters are smaller than those of the accelerating TIS,88%are smaller than those of the rapidly changing PIIS,and all parameters are smaller than those of the collapsed LBIS.Furthermore,after analyzing parameters that are not smaller than those of the TIS,it is observed that they remain in a stable state.Hence,the three largest ice shelves are currently undergoing natural changes that do not threaten their stability in the short term.Nevertheless,the evolution of the ice shelves under global climate change remains uncertain,making long-term observation and monitoring essential to assess their impact on sea level rise.

Numerical analysis of non-Newtonian rheology effect on hydrocyclone flow field

In view of the limitations of the existing Newton fluid effects on the vortex flow mechanism study,numerical analysis of non Newton fluid effects was presented.Using Reynolds stress turbulence model(RSM)and mixed multiphase flow model(Mixture)of FLUENT(fluid calculation software)and combined with the constitutive equation of apparent viscosity of non-Newtonian fluid,the typical non-Newtonian fluid(drilling fluid,polymer flooding sewage and crude oil as medium)and Newton flow field(water as medium)were compared by quantitative analysis.Based on the research results of water,the effects of non-Newtonian rheology on the key parameters including the combined vortex motion index n and tangential velocity were analyzed.The study shows that:non-Newtonian rheology has a great effect on tangential velocity and n value,and tangential velocity decreases with non-Newtonian increasing.The three kinds of n values(constant segment)are:0.564(water),0.769(polymer flooding sewage),0.708(drilling fluid)and their variation amplitudes are larger than Newtonian fluid.The same time,non-Newtonian rheology will lead to the phenomenon of turbulent drag reduction in the vortex flow field.Compared with the existing formula calculation results shown,the calculation result of non-Newtonian rheology is most consistent with the simulation result,and the original theory has large deviations.The study provides reference for theory research of non-Newtonian cyclone separation flow field.