Mathematical Modeling of a Nickel-Cadmium Battery: Effects of Intercalation and Oxygen Reactions

Extensions are presented for a previously published (1) mathematical model of a nickel-cadmium (Ni-Cd) cell. These extensions consist of intercalation thermodynamics for the nickel electrode and oxygen generation and reduction reactions during charge and overcharge. The simulated results indicate that intercalation may be important in the nickel electrode and that including the oxygen reactions provides a means of predicting the efficiency of the cell on charge and discharge

A Mathematical Model of a Sealed Nickel-Cadmium Battery

A mathematical model for the charge and discharge of a sealed nickel-cadmium (Ni-Cd) battery is presented. The model is used to study the effect of transport properties of the electrolyte and kinetic parameters of the electrode reactions on the cell performance during the charge and discharge period. The model can also be used to demonstrate the changes of cell performance during cycling. Some comparisons between model predictions and experimental results indicate that the model predictions appear to fit the experimental data well. Sensitivity analyses illustrate that the sealed nickel-cadmium battery operates under activation control. It is also shown theoretically that oxygen generated on the positive electrode during charge is reduced electrochemically on the negative electrode

SiCP: Simultaneous Individual and Cooperative Perception for 3D Object Detection in Connected and Automated Vehicles

Cooperative perception for connected and automated vehicles is traditionally achieved through the fusion of feature maps from two or more vehicles. However, the absence of feature maps shared from other vehicles can lead to a significant decline in object detection performance for cooperative perception models compared to standalone 3D detection models. This drawback impedes the adoption of cooperative perception as vehicle resources are often insufficient to concurrently employ two perception models. To tackle this issue, we present Simultaneous Individual and Cooperative Perception (SiCP), a generic framework that supports a wide range of the state-of-the-art standalone perception backbones and enhances them with a novel Dual-Perception Network (DP-Net) designed to facilitate both individual and cooperative perception. In addition to its lightweight nature with only 0.13M parameters, DP-Net is robust and retains crucial gradient information during feature map fusion. As demonstrated in a comprehensive evaluation on the OPV2V dataset, thanks to DP-Net, SiCP surpasses state-of-the-art cooperative perception solutions while preserving the performance of standalone perception solutions

Widely wavelength-tunable mid-infrared fluoride fiber lasers

We demonstrate widely wavelength-tunable continuous-wave (CW) and Q-switched Er3+-doped ZBLAN fluoride fiber lasers operating around 3 μm enabled by a volume Bragg grating (VBG). In the CW operation regime, a total wavelength tuning range of over 160-nm spanning from 2694 to 2854 nm has been achieved. For the Q-switched mode of operation, a slightly modified resonator configuration, incorporating a passive Q-switcher, topological insulator Bi2Te3 nanosheets, can produce stable pulse trains with a pulse width of 880 ns at a repetition rate of 81 kHz, while maintaining a wavelength tuning range of 62 nm from 2762 to 2824 nm through adjusting the VBG. In both operation regimes, the output spectral width is measured to be <;0.3 nm (full-width at half-maximum) over the whole tuning range. Our work both demonstrates the great wavelength-tuning potential of the Er3+ -doped fluoride fiber laser, and also paves a way for the development of a range of high-performance midinfrared laser sources

Main control factors of rock burst and its disaster evolution mechanism

With the gradual transfer of shallow coal mining to deep coal mining in China, the rock burst disasters are becoming an increasingly serious problem. In the process of rock burst mechanism cognition to rock burst prevention engineering, the primary task is to clarify the main factors of rock burst and to identify its risk level. In this paper, four kinds of objective factors i.e., coal rock impact tendency, mining depth, hard roof and geological structure, and three kinds of human factors i.e., coal pillar, goaf and mining unloading effect, were proposed. And the disaster evolution mechanism of each factor was discussed in detail. In terms of objective controlling factors, the impact tendency is the inherent attribute of coal/rock to accumulate deformation energy and induce impact failure. The mining depth is positively correlated with the deformation energy accumulated in the surrounding rock of the roadway, which is an essential condition for the occurrence of rock burst. The impact dynamic load and kinetic energy formed by large-scale hard roof periodic fracture are the 'fuse' to rock burst. The influence of geological structure on rock burst is significant. For fault structure, the two walls will relatively ‘rebound’ under the sudden unloading caused by mining disturbance. And the equivalent elastic modulus of the thinning area of the coal seam becomes larger, and the advanced abutment pressure is distributed in a 'double peak' pattern, which expands the impact influence range. In terms of subjective controlling factors, coal pillar is a high stress concentration area, and its size, dip angle and relative position will directly affect the probability and strength of rock burst. The goaf will induce a sudden release of energy accumulated in the stress concentration area, especially under large mining height and insufficient roof collapse conditions. Mining unloading will lead to the rapid “migration” of the stress concentration area and release a large amount of energy stored in the coal/rock, which is an important external inducement of rock burst. On this basis, the differences of main control factors of rock burst disaster in the main rock burst mining area, such as Xinwen, Luxi, Erdos, Binchang, Xinjiang and Gansu were compared and analyzed. The study emphasized the importance of identifying the main control factors and their influence degree of rock burst from an entire mine, a panel to a working face. Also, it constructed the engineering management path of rock burst from energy-reducing, energy-releasing, energy-damping to energy-resisting

Dissection of Pleiotropic QTL Regions Controlling Wheat Spike Characteristics Under Different Nitrogen Treatments Using Traditional and Conditional QTL Mapping

Optimal spike characteristics are critical in improving the sink capacity and yield potential of wheat even in harsh environments. However, the genetic basis of their response to nitrogen deficiency is still unclear. In this study, quantitative trait loci (QTL) for six spike-related traits, including heading date (HD), spike length (SL), spikelet number (SN), spike compactness (SC), fertile spikelet number (FSN), and sterile spikelet number (SSN), were detected under two different nitrogen (N) supplies, based on a high-density genetic linkage map constructed by PCR markers, DArTs, and Affymetrix Wheat 660 K SNP chips. A total of 157 traditional QTLand 54 conditional loci were detected by inclusive composite interval mapping, among which three completely low N-stress induced QTL for SN and FSN (qSn-1A.1, qFsn-1B, and qFsn-7D) were found to maintain the desired spikelet fertility and kernel numbers even under N deficiency through pyramiding elite alleles. Twenty-eight stable QTL showing significant differencet in QTL detection model were found and seven genomic regions (R2D, R4A, R4B, R5A, R7A, R7B, and R7D) clustered by these stable QTL were highlighted. Among them, the effect of R4B on controlling spike characteristics might be contributed from Rht-B1. R7A harboring three major stable QTL (qSn-7A.2, qSc-7A, and qFsn-7A.3) might be one of the valuable candidate regions for further genetic improvement. In addition, the R7A was found to show syntenic with R7B, indicating the possibly exsting homoeologous candidate genes in both regions. The SNP markers involved with the above highlighted regions will eventually facilitate positional cloning or marker-assisted selection for the optimal spike characteristics under various N input conditions

Roof Cutting Parameters Design for Gob-Side Entry in Deep Coal Mine: A Case Study

Roof cutting is an effective technique for controlling the deformation and failure of the surrounding rock in deep gob-side entry. The determination of the roof cutting parameters has become a popular research subject. Initially, two mechanical models are established for the non-roof-cutting and roof-cutting of gob-side entry in deep mining conditions. On this basis, the necessity and significance of roof cutting is revealed by analysing the stress and displacement of roadside prop. The Universal Distinct Element Code numerical simulation model is established to determine the key roof-cutting parameters (cutting angle and cutting height) according to the on-site situation of No. 2415 headentry of the Suncun coal mine, China. The numerical simulation results show that with the cutting angle and height increase, the vertical stress and horizontal displacement of the coal wall first increase and then decrease, as in the case of the vertical stress and displacement of roadside prop. Therefore, the optimum roof cutting parameters are determined as a cutting angle of 70° and cutting height of 8 m. Finally, a field application was performed at the No. 2415 headentry of the Suncun coal mine. In situ investigations show that after 10 m lagged the working face, the stress and displacement of roadside prop are obviously reduced with the hanging roof smoothly cut down, and they are stable at 19 MPa and 145 mm at 32 m behind the working face, respectively. This indicates that the stability of the surrounding rock was effectively controlled. This research demonstrates that the key parameters determined through a numerical simulation satisfactorily meet the production requirements and provide a reference for ensuring safe production in deep mining conditions

Global Attitude Synchronization of Networked Rigid Bodies Under Directed Topologies

The global attitude synchronization problem is studied for networked rigid bodies under directed topologies. To avoid the asynchronous pitfall where only vector parts converge to some identical value but scalar parts do not, multiplicative quaternion errors are leveraged to develop attitude synchronization protocols for rigid bodies with the absolute measurements. It is shown that global synchronization of networked rigid bodies can be achieved if and only if the directed topology is quasi-strongly connected. Simultaneously, a novel double-energy-function analysis method, equipped with an ordering permutation technique about scalar parts and a coordinate transformation mechanism, is constructed for the quaternion behavior analysis of networked rigid bodies. In particular, global synchronization is achieved with our analysis method regardless of the highly nonlinear and strongly coupling problems resulting from multiplicative quaternion errors, which seriously hinder the traditional analysis of global synchronization for networked rigid bodies. Simulations for networked spacecraft are presented to show the global synchronization performances under different directed topologies.Comment: 26 pages, 6 figure