Draft genome sequence of the Tibetan antelope

The Tibetan antelope (Pantholops hodgsonii) is endemic to the extremely inhospitable high-altitude environment of the Qinghai-Tibetan Plateau, a region that has a low partial pressure of oxygen and high ultraviolet radiation. Here we generate a draft genome of this artiodactyl and use it to detect the potential genetic bases of highland adaptation. Compared with other plain-dwelling mammals, the genome of the Tibetan antelope shows signals of adaptive evolution and gene-family expansion in genes associated with energy metabolism and oxygen transmission. Both the highland American pika, and the Tibetan antelope have signals of positive selection for genes involved in DNA repair and the production of ATPase. Genes associated with hypoxia seem to have experienced convergent evolution. Thus, our study suggests that common genetic mechanisms might have been utilized to enable high-altitude adaptation

An improved battery pack equalizer based on a DC/DC converter with fuzzy logic controller

This paper presents an improved battery pack equalizer (BPE) based on a DC/DC converter using fuzzy logic controller (FLC). This BPE can be designed without the necessity of a cell model in the pack. It is simple and robust. The simulation results have demonstrated that the BPE with the FLC has better performance than the BPE with the PI controller in terms of the balancing speed and efficiency

Mechanisms during Strain Rate-Dependent Crack Propagation of Copper Nanowires Containing Edge Cracks

The crack propagation mechanism of Cu nanowires is investigated by using molecular dynamics methods. The microstructural evolution of crack propagation at different strain rates and crack depths is analyzed. Meanwhile, the stress intensity factor at the crack tip during crack propagation is calculated to describe the crack propagation process of Cu nanowires under each condition. The simulation results show that the competition between lattice recovery and dislocation multiplication determines the crack propagation mode. Lattice recovery dominates the plastic deformation of Cu nanowires at low strain rates, and the crack propagation mode is shear fracture. With the increase in strain rate, the plastic deformation mechanism gradually changes from lattice recovery to dislocation multiplication, which makes the crack propagation change from shear fracture to ductile fracture. Interestingly, the crack propagation mechanism varies with crack depth. The deeper the preset crack of Cu nanowires, the weaker the deformation resistance, and the more likely the crack propagation is accompanied

New on-line approach for lithium iron phosphate battery pack balancing based on state of charge

Lithium iron phosphate batteries (LiFePO4) are becoming one of the main power resources for electric vehicles (EVs), and the non-uniformity of cells in a battery pack has become the bottleneck to improve battery usable capacity. Many active balancing approaches are proposed to transfer charge among the cells to achieve the uniformity based on terminal voltage. This paper proposes a new balancing approach based on the battery state of charge (SOC) to equalize the cells in the LiFePO4 battery pack in charging process. The hybrid extended Kalman filter is adopted to dynamically estimate the cell SOCs which serve as a balancing criterion. A current sensor is added to detect balancing current for the SOC estimation. Simulations are carried out to compare the proposed approach with terminal voltage approaches and show that the proposed approach has charged more capacity into the pack in charging process

The refinement of the crystal structure of carboborite MgCa2[CO3]2[B(OH)4]2 • 4H2O

Carboborite is a new hydro-bearing multiplex carbonate and borate mineral discovered in China. Its space group is P2₁/n with the lattice parameters a = 11.011 Å (3), b = 6.674 Å (1), c = 10.692 Å (5), ß = 116.64° (3). The structure was refined to a R value of 0.043 for 1964 independent reflections with |F₀| ⩾ 3(σ|F₀|) (MoKα radiation). The correct structural model was obtained using Patterson method. In the structure, the Mg atom is octahedrally coordinated. The octahedron MgO₆ is connected with 2 B(OH)₄ and 2 [CO₃] to form a basic structure unit. The Ca atom is eight-fold coordinated. These structural sheets are connected with each other by hydrogen bond. Based on the crystal structure, its optical and physical properties could be explained very well.La carboborite, découverte en Chine, est un nouveau composé multiple dérivé du sel contenant principalement du carbonate et du borate, ainsi que de l'eau. Son groupe spatial est P2₁/n, avec des paramètres réticulaires : a = 11.011 Å, b = 6.674 Å, c = 10.692 Å, ß = 116.64°. La structure a été affinée jusqu'à une valeur de R de 0.043 pour 1964 réflexions indépendantes avec F₀ ⩾ 3σ|F₀| obtenues pour la radiation de MoKα. Le modèle de la structure exacte fut obtenu par la méthode de Patterson. Dans la structure, l'atome Mg occupe un site octaédrique ; l'octaèdre MgO₆ lié aux entités [B(OH)₄] et [CO₃] forme une unité structurale de base. L'atome de calcium est octacoordiné. Les lamelles de la structure sont reliées les unes aux autres par une liaison hydrogène. Selon la structure du cristal, ses propriétés optique et physique peuvent être très bien expliquées.Ma Zhesheng, Shi Nicheng, Shen Jinchuan, Peng Zhizhong. The refinement of the crystal structure of carboborite MgCa2[CO3]2[B(OH)4]2 • 4H2O. In: Bulletin de Minéralogie, volume 104, 4, 1981. 12e assemblée générale de l'I.M.A. - Orléans – Juillet 1980. Deuxième partie : inclusions magmatiques / silicates / gemmes / « open session »

Fuzzy Sliding Mode Control for logitudinal motion of underground mining electric vehicles

Cost and safety are always the most important factors for personnel transport and mining vehicles in mining industry. That is why the development of underground mining electrical vehicles (UMEVs) becomes more and more attractive in undergrounds mines. However, a stable, reliable and robust controller for the UMEV is also a critical condition due to the safety requirements. Sliding Mode Control (SMC) is able to deal with system uncertainties and external disturbances, but it cannot achieve smooth performance during the transition between different subspaces in the state space. This paper first presents the modeling of an UMEV for acceleration, braking and speed maintenance, and a global fuzzy model will be developed based on that. Then, a Fuzzy Sliding Mode Controller (FSMC) of the UMEV will be proposed. The comparison of the simulation results for both the proposed FSMC controller and an SMC controller shows that the proposed FSMC controller has a better performance when the system switches in different subspaces in the state space

Sliding mode control for longitudinal motion of underground mining electric vehicles

Nowadays, zero-emission electric vehicles (EVs) become more and more attractive personnel transport vehicles for mining industry. However, underground mining electric vehicles (UMEVs) require more stable, reliable and robust vehicle system compared with traditional EVs due to their special working conditions and the complex road conditions. Thus, a proper controller needs to be designed. This paper first presents the modeling of an UMEV for both acceleration and braking. Then, the controller based on the sliding mode control (SMC) is designed to track the longitudinal velocity and keep the longitudinal slip ratio in a desired stable region in the presence of the bounded system uncertainties. The comparison of the simulation results for both the proposed SMC controller and a traditional PID controller shows that the proposed SMC controller has a better performance for the long-distance up/down slopes with varying rolling resistance coefficients