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Under the back-side windy condition, the convection and radiation heat transfer characteristics in an iso-flux upward-facing cylindrical cavity were studied by three-dimensional numerical simulation. The impacts of cavity tilt angle, wind incident angle and wind speed on convection and radiation heat transfer Nusselt number Nuc and Nur were analyzed, and the possible explanations for their impacts were presented. Results show that due to the disturbance of wind, the influence of cavity tilt angle becomes more complicated and is related to wind incident angle and wind speed. The variation of Nuc or Nur with wind incident angle is different for different cavity tilt angles. Despite of the changes of cavity tilt angle or wind incident angle, the Nuc increases with the wind speed while the Nur presents a declination with the increasing of wind speed. Hence, compared with cavity tilt angle and wind incident angle, wind speed may be the dominant factor affecting or controlling the convective and radiation heat transfer of cavity.

An experimental investigation was conducted in a 3 MW pilot-scale tangential combustion facility to explore the co-combustion characteristics of bituminous coal mixed with semi-coke. The thermal gravimetric analyzer (TGA) was used to obtained fuel thermal analysis. The results presented effects of semi-coke blending ratio (BR) on average furnace temperature, ignition temperature, NO emission and combustion efficiency. The excess air coefficient in main combustion sections and outlet were fixed at 0.85 and 1.2 while BR increased from 0% to 50 wt%. The temperature profiles of combustion decreases along the height of furnace while average furnace temperature fluctuates slightly with an increasing BR. The concentration of NO has an increasing tendency with the increasing of BR. The ignition temperature obtained from TGA measurement agreed well with experiment result. In addition, combustion efficiency was not sensitive to BR and decreased slightly with the increasing BR.

There is a rising prospective in harvesting energy from water droplets, as microscale energy is required for the distributed sensors in the interconnected human society. However, achieving a sustainable direct-current generating device from water flow is rarely reported, and the quantum polarization principle of the water molecular remains uncovered. Herein, we propose a dynamic water-semiconductor junction with moving water sandwiched between two semiconductors as a moving dielectric medium, which outputs a sustainable direct-current voltage of 0.3 V and current of 0.64 uA with low internal resistance of 390 kilohm. The sustainable direct-current electricity is originating from the dynamic water polarization process in water-semiconductor junction, in which water molecules are continuously polarized and depolarized driven by the mechanical force and Fermi level difference, during the movement of the water on silicon. We further demonstrated an encapsulated portable power-generating device with simple structure and continuous direct-current voltage, which exhibits its promising potential application in the field of wearable electronic generators.

Liquid electricity generator and hydrovoltaic technology have received numerous attentions, which can be divided into horizontal movement generator and vertical movement generator. The horizontal movement generator is limited for powering the integrated and miniaturized energy chip as the current output direction is depending on the moving direction of the water droplet, which means a sustainable and continuous direct-current (DC) electricity output can be hardly achieved because of the film of limited length. On the other hand, the existing vertical movement generators include triboelectricity or humidity gradient-based liquid electricity generator, where the liquid or water resource must be sustainably supplied to ensure continuous current output. Herein, we have designed an integratable vertical generator by sandwiching water droplets with semiconductor and metal, such as graphene or aluminum. This generator, named as polarized liquid molecular generator (PLMG), directly converts the lateral kinetic energy of water droplet into vertical DC electricity with an output voltage of up to ~1.0 V from the dynamic water-semiconductor interface. The fundamental discovery of PLMG is related to the non-symmetric structure of liquid molecules, such as water and alcohols, which can be polarized under the guidance of built-in field caused by the Fermi level difference between metal and semiconductor, while the symmetric liquid molecules cannot produce any electricity on the opposite. Integratable PLMG with a large output power of ~90 nW and voltage of ~2.7 V has been demonstrated, meanwhile its small internal resistance of ~250 kilohm takes a huge advantage in resistance matching with the impedance of electron components. The PLMG shows potential application value in the Internet of Things (IoTs) after proper miniaturization and integration.

Random pore model was employed to calculate the reaction kinetics parameters of SH bituminous coal and Shenmu semi-coke blended fuels under high-temperature entrained flow combustion, and the reaction kinetics parameters was modified by the intrinsic reaction Arrhenius curve obtained from low temperature thermogravimetric experiments. Then the combustion reaction rate and intrinsic reaction order at different blending ratios of semi-coke were determined. The reaction kinetics parameters and carbon conversion rate of blended fuels were investigated based on the pore structure of fuel, the effects of blending ratio of semi-coke, initial partial pressure of oxygen and reaction temperature. The reaction order decreases with the increasing of semi-coke blended ratio except 100% semi-coke combustion has higher reaction order approximately as char pure burning. The distribution of oxygen alone the radius of particle was also calculated in this study. In the low oxygen reduction zone, the blending ratio of semi-coke has little effect on the carbon conversion of blended fuel, and the blending effect is enhanced with the increasing of oxygen content. Carbon conversion rate decreases with the increasing of blending ratio and increases with reaction temperature.

In this paper, the low load steady combustion test of a single burner was carried out on the 30MW thermal test bench of the State Key Laboratory of efficient and clean coal-fired power plant boiler. Combined with numerical simulation, the lower limit of the minimum stable combustion load of the burner was tried to find out, which provided the basic test data for the furnace combustion stability during the deep peak load regulation of the boiler. The experimental and numerical simulation results show that under 40% rated load, the outlet flame is stable and bright, and the negative pressure in the furnace is stable, which can realize the stable combustion of a single burner.

The fuel cell is a device which can convert chemical energy from fuel into electrical and thermal energy directly. It has advantages like high power density, fast start-up and high conversion efficiency. Its prospects of application in transportation, fixed power supply and standby power generation are great. Fuel cell is a dynamic complex system with multi-phase, multi-scale and multi-physical fields. Based on the working mechanism of fuel cell, this paper establishes a mathematical model to simulate the electrochemical reaction, material and energy transfer process in fuel cell. The parameters such as temperature, pressure, concentration, current and potential, which are difficult to measure, are visualized to deepen the transfer and counter-reaction in fuel cell. In order to provide important scientific basis for the optimal design and system control of the stack, the mechanism should be understood and the optimum reaction conditions should be found.

Traditionally, Schottky diodes are used statically in the electronic information industry but dynamic state Schottky diodes based applications have been rarely explored. Herein, a novel Schottky diode named moving Schottky diode generator has been designed, which can convert mechanical energy into electrical energy with voltage output as high as 0.6V, by means of lateral movement between graphene/metal film and semiconductor, where the semiconductor can be non-piezoelectric materials. The mechanism is based on the built-in electric field separation of drifting electrons in moving van der Waals Schottky diode. The power output can be further increased in future through optimizing the Schottky diode. The graphene film/silicon moving van der Waals Schottky diode based generator behaves better stability. This direct-current generator has the potential of converting mechanical efficiently and vibrational energy into electricity and enables many promising applications.

For most of the AGV superior control system is planar two-dimensional, poor visibility and lack of equipment operating efficiency statistics, A three-dimensional AGV simulation control system based on wireless communication and Flexsim logistics simulation software is proposed.. Through the socket socket connection zigbee wireless transmission module serial port and Flexsim software completes the data communication between the processes, thus establishes AGV and Flexsim data communication. Build the 3D system simulation model of AGV and write the control algorithm through Flexsim. At the same time, call the SQL database data to complete the real-time simulation and analyze the running status in real time. Mainly studied the data communication interaction between the AGV wireless communication module and Flexsim, using the AGV of the college laboratory to conduct field tests. The results show that the design program basically achieves the expected functions and effects.

Polar lattices, which are constructed from polar codes, are provably good for the additive white Gaussian noise (AWGN) channel. In this work, we propose a new polar lattice construction that achieves the secrecy capacity under the strong secrecy criterion over the mod-$\Lambda$ Gaussian wiretap channel. This construction leads to an AWGN-good lattice and a secrecy-good lattice simultaneously. The design methodology is mainly based on the equivalence in terms of polarization between the $\Lambda/\Lambda'$ channel in lattice coding and the equivalent channel derived from the chain rule of mutual information in multilevel coding., Comment: 7 pages, 2 figures, extended version of a paper submitted to ISIT'14

Polar lattices, which are constructed from polar codes, are provably good for the additive white Gaussian noise (AWGN) channel. In this work, we propose a new polar lattice construction that achieves the secrecy capacity under the strong secrecy criterion over the mod-$��$ Gaussian wiretap channel. This construction leads to an AWGN-good lattice and a secrecy-good lattice simultaneously. The design methodology is mainly based on the equivalence in terms of polarization between the $��/��'$ channel in lattice coding and the equivalent channel derived from the chain rule of mutual information in multilevel coding., 7 pages, 2 figures, extended version of a paper submitted to ISIT'14

In this thesis, we propose a new class of lattices based on polar codes, namely polar lattices. Polar lattices enjoy explicit construction and provable goodness for the additive white Gaussian noise (AWGN) channel, \textit{i.e.}, they are \emph{AWGN-good} lattices, in the sense that the error probability (for infinite lattice coding) vanishes for any fixed volume-to-noise ratio (VNR) greater than $2\pi e$. Our construction is based on the multilevel approach of Forney \textit{et al.}, where on each level we construct a capacity-achieving polar code. We show the component polar codes are naturally nested, thereby fulfilling the requirement of the multilevel lattice construction. We present a more precise analysis of the VNR of the resultant lattice, which is upper-bounded in terms of the flatness factor and the capacity losses of the component codes. The proposed polar lattices are efficiently decodable by using multi-stage decoding. Design examples are presented to demonstrate the superior performance of polar lattices. However, there is no infinite lattice coding in the practical applications. We need to apply the power constraint on the polar lattices which generates the polar lattice codes. We prove polar lattice codes can achieve the capacity $\frac{1}{2}\log(1+\SNR)$ of the power-constrained AWGN channel with a novel shaping scheme. The main idea is that by implementing the lattice Gaussian distribution over the AWGN-good polar lattices, the maximum error-free transmission rate of the resultant coding scheme can be arbitrarily close to the capacity $\frac{1}{2}\log(1+\SNR)$. The shaping technique is based on discrete lattice Gaussian distribution, which leads to a binary asymmetric channel at each level for the multilevel lattice codes. Then it is straightforward to employ multilevel asymmetric polar codes which is a combination of polar lossless source coding and polar channel coding. The construction of polar codes for an asymmetric channel can be converted to that for a related symmetric channel, and it turns out that this symmetric channel is equivalent to an minimum mean-square error (MMSE) scaled $\Lambda/\Lambda'$ channel in lattice coding in terms of polarization, which eventually simplifies our coding design. Finally, we investigate the application of polar lattices in physical layer security. Polar lattice codes are proved to be able to achieve the strong secrecy capacity of the Mod-$\Lambda$ AWGN wiretap channel. The Mod-$\Lambda$ assumption was due to the fact that a practical shaping scheme aiming to achieve the optimum shaping gain was missing. In this thesis, we use our shaping scheme and extend polar lattice coding to the Gaussian wiretap channel. By employing the polar coding technique for asymmetric channels, we manage to construct an AWGN-good lattice and a secrecy-good lattice with optimal shaping simultaneously. Then we prove the resultant wiretap coding scheme can achieve the strong secrecy capacity for the Gaussian wiretap channel. Open Access

In this paper, we propose the explicit construction of a new class of lattices based on polar codes, which are provably good for the additive white Gaussian noise (AWGN) channel. We follow the multilevel construction of Forney \textit{et al.} (i.e., Construction D), where the code on each level is a capacity-achieving polar code for that level. The proposed polar lattices are efficiently decodable by using multistage decoding. Computable performance bounds are derived to measure the gap to the generalized capacity at given error probability. A design example is presented to demonstrate the performance of polar lattices., Comment: ISIT 2013. This is the authors' version with the correct "lattice formula"

In this paper, we propose the explicit construction of a new class of lattices based on polar codes, which are provably good for the additive white Gaussian noise (AWGN) channel. We follow the multilevel construction of Forney \textit{et al.} (i.e., Construction D), where the code on each level is a capacity-achieving polar code for that level. The proposed polar lattices are efficiently decodable by using multistage decoding. Computable performance bounds are derived to measure the gap to the generalized capacity at given error probability. A design example is presented to demonstrate the performance of polar lattices., ISIT 2013. This is the authors' version with the correct "lattice formula"