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Peripheral nerve injury not only affects the site of the injury, but can also induce neuronal apoptosis at the spinal cord. However, many acupuncture clinicians still focus only on the injury site, selecting acupoints entirely along the injured nerve trunk and neglecting other regions; this may delay onset of treatment efficacy and rehabilitation. Therefore, in the present study, we compared the clinical efficacy of acupuncture at Governor vessel and local meridian acupoints combined (GV/LM group) with acupuncture at local meridian acupoints alone (LM group) in the treatment of patients with peripheral nerve injury. In the GV/LM group (n = 15), in addition to meridian acupoints at the injury site, the following acupoints on the Governor vessel were stimulated: Baihui (GV20), Fengfu (GV16), Dazhui (GV14), and Shenzhu (GV12), selected to treat nerve injury of the upper limb, and Jizhong (GV6), Mingmen (GV4), Yaoyangguan (GV3), and Yaoshu (GV2) to treat nerve injury of the lower limb. In the LM group (n = 15), only meridian acupoints along the injured nerve were selected. Both groups had electroacupuncture treatment for 30 minutes, once a day, 5 times per week, for 6 weeks. Two cases dropped out of the LM group. A good or excellent clinical response was obtained in 80% of the patients in the GV/LM group and 38.5% of the LM group. In a second study, an additional 20 patients underwent acupuncture with the same prescription as the GV/LM group. Electomyographic nerve conduction tests were performed before and after acupuncture to explore the mechanism of action of the treatment. An effective response was observed in 80.0% of the patients, with greater motor nerve conduction velocity and amplitude after treatment, indicating that electroacupuncture on specific Governor vessel acupoints promotes functional motor nerve repair after peripheral nerve injury. In addition, electromyography was performed before, during and after electroacupuncture in one patient with radial nerve injury. After a single session, the patient's motor nerve conduction velocity increased by 23.2%, indicating that electroacupuncture at Governor vessel acupoints has an immediate therapeutic effect on peripheral nerve injury. Our results indicate that Governor vessel and local meridian acupoints used simultaneously promote functional repair after peripheral nerve injury. The mechanism of action may arise from an improvement of the local microenvironment in injured nervous tissue, as well as immediate effects of Governor vessel and local meridian acupoint stimulation to ensure the continuity between the peripheral and central nervous systems

Due to the increasing concern on environmental sustainability, many efforts have been made to improve the energy efficiency and reduce carbon emissions of manufacturing processes, including abrasive machining processes. Oilstones, as the abrasive tool of honing machines, are the key parts to remove material. However, the theoretical models and methods that can be used to support the selection of oilstone parameters for reduced carbon emissions are lacking. To fill this gap, this paper proposes a method to optimize shape and distribution of abrasive grains for minimized carbon emissions while maintaining surface quality. First, the carbon emissions boundary is defined, and a carbon emissions calculation model is established from a macroperspective. As each grain contributes to the total carbon emissions, the behavior of grains during honing is then described and analyzed to obtain the carbon emissions model from a microperspective. Surface area of oilstones and the required total volume of material removal are kept constant to meet the physical size limit of oilstones and machining requirement of workpiece. Third, a shape and distribution optimization model is developed to minimize carbon emissions. A modified particle swarm optimization (PSO) algorithm is adopted to solve this problem. Finally, the proposed method is applied to a case study to validate its effectiveness. Results show that carbon emissions can be reduced by up to 30% using the proposed model. The proposed method provides a new green manufacturing strategy for the honing process and a possibility to customize abrasive tools to meet the environmental challenges. [ABSTRACT FROM AUTHOR]

Key parts refer to the problematic parts which have higher carbon emissions and need to be further optimized in low-carbon design. However, it is difficult to pick them out for designers because the quantitative relationship and unified connection between product life cycle stages and carbon emissions are hard to determine. To efficiently and effectively select the key parts of equipment products, this paper presents a selection methodology based on the characteristic of carbon emissions for low-carbon design. First, a low-carbon design framework is constructed to guide the low-carbon design process. Second, an embodied carbon-energy field (ECEF)-based selection method is proposed to help product designers make a decision. The ECEF denotes the carbon emissions distribution on product structures. Based on the temperature field of products, the ECEF can be constructed by integrating the main life cycle stages of products. The definition of ECEF is given initially. Then, the mapping mechanism and process between the temperature field and ECEF are studied. Meanwhile, the mathematical model of the ECEF is also presented to support the mapping process. Thus, the total carbon emissions distribution of every part and every point can be achieved by the ECEF of products and also seen by product designers visually. Therefore, the key parts could be selected easily. Finally, the proposed method is applied to a CNC gantry type honing machine to validate its feasibility and correctness. The result shows the selection method can be used to identify the problematic parts and points effectively and easily. [ABSTRACT FROM AUTHOR]

In order to solve problems arising in ordinary heat pump system for pure electric vehicles at ultra-low temperature, a low pressure gas-injection scroll compressor is designed, and a mathematical model is established. Comparison with the experimental results shows good accuracy of the theoretical prediction. [ABSTRACT FROM AUTHOR]

When the ordinary heat pump air conditioning system of a pure electric vehicle runs at ultra-low temperature, the discharge temperature of compressor will be too high and the heating capacity of the system will decay seriously, it will lead to inactivity of the heating system. In order to solve this problem, a modification is put forward, and an experiment is also designed. The experimental results show that in the same conditions, this new heating system increases more than 20% of the heating capacity; when the outside environment temperature is negative 20 degrees, the discharge temperature of compressor is below 60 degrees. [ABSTRACT FROM AUTHOR]

The heat exchanger is a devise used for transferring thermal energy between two or more different temperatures. The widespreadly used heat exchanger can only achieve heat exchange between two substances. In this paper, a coupled heat exchanger is proposed, which includes a finned heat exchanger and a double pipe heat exchanger, for multiple heat exchange simultaneously. An experiment is conducted, showing that the average heating capacity increases more than 35%, and the average heating efficiency increases more than 55%, compared with the ordinary air-source heat pump. [ABSTRACT FROM AUTHOR]

A single-phase iron oxide Ba0.8Sr0.2FeO3-δ with a simple cubic perovskite structure in Pm-3m symmetry is successfully synthesized by a solid-state reaction method in O2 flow. The oxygen content is determined to be about 2.81, indicating the formation of mixed Fe3+ and Fe4+ charge states with a disorder fashion. As a result, the compound shows small-polaron conductivity behavior, as well as spin glassy features arising from the competition between the ferromagnetic interaction and the antiferromagnetic interaction. Moreover, the competing interactions also give rise to a remarkable exchange bias effect in Ba0.8Sr0.2FeO2.81, providing an opportunity to use it in spin devices. [ABSTRACT FROM AUTHOR]

A new oxide CaCr0.5Fe0.5O3 was prepared under high pressure and temperature conditions. It crystallizes in a B-site disordered Pbnm perovskite structure. The charge combination is determined to be Cr5+/Fe3+ with the presence of unusual Cr5+ state in octahedral coordination, although Cr4+ and Fe4+ occur in the related perovskites CaCrO3 and CaFeO3. The randomly distributed Cr5+ and Fe3+ spins lead to short-range ferromagnetic coupling, whereas an antiferromagnetic phase transition takes place near 50 K due to the Fe3+–O–Fe3+ interaction. In spite of the B-site Cr5+/Fe3+ disorder, the compound exhibits electrical insulating behavior. First-principles calculations further demonstrate the formation of charge combination, and the electron correlation effect of Fe3+ plays an important role for the insulting ground state. CaCr0.5Fe0.5O3 provides the first Cr5+ perovskite system with octahedral coordination, opening a new avenue to explore novel transition-metal oxides with exotic charge states. [ABSTRACT FROM AUTHOR]

The transport property of electrons tunneling through arrays of magnetic and electric barriers is studied in silicene. In the tunneling transmission spectrum, the spin-valley-dependent filtered states can be achieved in an incident energy range which can be controlled by the electric gate voltage. For the parallel magnetization configuration, the transmission is asymmetric with respect to the incident angle θ, and electrons with a very large negative incident angle can always transmit in propagating modes for one of the spin-valley filtered states under a certain electromagnetic condition. But for the antiparallel configuration, the transmission is symmetric about θ and there is no such transmission channel. The difference of the transmission between the two configurations leads to a giant tunneling magnetoresistance (TMR) effect. The TMR can reach to 100% in a certain Fermi energy interval around the electrostatic potential. This energy interval can be adjusted significantly by the magnetic field and/or electric gate voltage. The results obtained may be useful for future valleytronic and spintronic applications, as well as magnetoresistance device based on silicene. [ABSTRACT FROM AUTHOR]

A heat pump for heat recovery is designed to produce hot water through recovering the heat from the superheated vapor and hot refrigerant in the condenser. The experimental results show that performance of the heat pump system with superheated vapor heat exchanger has obvious superiority over the regular condenser for hot water production. [ABSTRACT FROM AUTHOR]

We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junction with local variation of Fermi velocity, where the properties of charge, valley, and spin transport through the junction are investigated. By matching the wavefunctions at the normal-ferromagnetic interfaces, it is demonstrated that the variation of Fermi velocity in a small range can largely enhance the total conductance while keeping the current nearly fully valley- and spin-polarized. Further, the variation of Fermi velocity in ferromagnetic silicene has significant influence on the valley and spin polarization, especially in the low-energy regime. It may drastically reduce the high polarizations, which can be realized by adjusting the local application of a gate voltage and exchange field on the junction. [ABSTRACT FROM AUTHOR]

This paper investigates theoretically the electronic structure and transport of a two-level quantum dot irradiated under a strong laser field at low temperatures. Using the method of Keldysh equation of motion for nonequilibrium Green functions, it examines the time-averaged density of states and conductance for the system with photon polarization parallel with and perpendicular to the tunnelling current direction respectively. It is demonstrated that, by analysing some numerical examples, more photon sidebands resonance states and multi- and single-photon transitions are found when diagonal matrix elements dominate the interaction, while the electronic transitions due to multiphoton absorption are more or less suppressed when off-diagonal interaction dominates. [ABSTRACT FROM AUTHOR]

We investigate theoretically the electron transport for a two-level quantum channel (wire) with Rashba spin-orbit coupling under the irradiation of a longitudinally-polarized external laser field at low temperatures. Using the method of equation of motion for Keldysh nonequilibrium Green function, we examine the time-averaged spin polarized conductance for the system with photon polarization parallel to the wire direction. By analytical analysis and a few numerical examples, the interplay effects of the external laser field and the Rashba spin–orbit coupling on the spin-polarized conductance for the system are demonstrated and discussed. It is found that the longitudinally-polarized laser field can adjust the spin polarization rate and produce some photon sideband resonances of the conductance for the system. [ABSTRACT FROM AUTHOR]