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The coupled relationship between carrier and phonon scattering severely limits the thermoelectric performance of n-type GeTe materials. Here, we provide an efficient strategy to enlarge grains and induce vacancy clusters for decoupling carrier-phonon scattering through the annealing optimization of n-type GeTe-based materials. Specifically, boundary migration is used to enlarge grains by optimizing the annealing time, while vacancy clusters are induced through the aggregation of Ge vacancies during annealing. Such enlarged grains can weaken carrier scattering, while vacancy clusters can strengthen phonon scattering, leading to decoupled carrier-phonon scattering. As a result, a ratio between carrier mobility and lattice thermal conductivity of ∼492.8 cm3V–1s–1W–1K and a peak ZTof ∼0.4 at 473 K are achieved in Ge0.67Pb0.13Bi0.2Te. This work reveals the critical roles of enlarged grains and induced vacancy clusters in decoupling carrier-phonon scattering and demonstrates the viability of fabricating high-performance n-type GeTe materials via annealing optimization.

Cr(vi) reduction to Cr(iii) with electrochemical technique has been regarded as an effective method for the treatment of toxic Cr(vi) contaminated wastewater. Herein, to promote the reactive sites and electron transfer for improving Cr(vi) reduction, we compositely modified the carbon-fiber felt (CFF) with a tree-like branched structure of polypyrrole (PPy) microwires as the first branch and polyaniline (PANI) nanorods as the secondary branch, which increased the BET surface area from 1.2 m2per each CFF substrate to 89.8 m2per each CFF-PPy–PANI cathode. The flow-through electrochemical reduction device with the CFF-PPy–PANI cathode exhibited 20–70% larger Cr(vi) removal and 20–55% lower energy consumption than that with original CFF, PPy-modified CFF, and PANI-modified CFF cathodes. Electrochemical analyses revealed that the tree-like branched structure of the CFF-PPy–PANI cathode promoted the reactive sites, electron transfer, and interfacial ion diffusion for enhancing Cr(vi) reduction. According to the in situsampling experiments, the Cr(vi) reduction to Cr(iii) on cathode was the major removal mechanism with minor Cr(vi) adsorption on the anode. The CFF-PPy–PANI cathode at 1.4 V and 500 L h−1m−2exhibited excellent durability and stability for almost Cr(vi) reduction and 98.8 ± 0.98% energy efficiency within 5-day continuous operation. These results suggested that the micro-nano PPy/PANI composite modification can be a promising strategy for efficient Cr(vi) reduction.

l Se-alloying induces dense point defects scatter high-frequency phonons. l Se-alloying induce resonant states strengthen Umklapp phonon scattering. l Approaching low lattice thermal conductivity of ∼0.65 W m−1K−1 at 723 K. l Approaching a peak figure of merit value of ∼1.6 at 723 K. High lattice thermal conductivity of intrinsic GeTe limits the wide application of GeTe-based thermoelectrics. Recently, the optimization of GeTe-based thermoelectric materials has been focusing on reducing lattice thermal conductivity via strengthening phonon scattering. In this study, we systematically studied thermoelectric properties of Se-alloyed Ge 0.95 Bi 0.05 Te via theoretical calculations, structural characterizations, and performance evaluations. Our results indicate that Se-alloying can induce dense point defects with mass/strain-field fluctuations and correspondingly enhance point defect phonon scattering of the Ge 0.95 Bi 0.05 Te matrix. Se-alloying might also change chemical bonding strength to introduce resonant states in the base frequency of Ge 0.95 Bi 0.05 Te matrix, which can strengthen Umklapp phonon scattering. Finally, a decreased lattice thermal conductivity from ∼1.02 W m−1 K−1 to ∼0.65 W m−1 K−1 at 723 K is obtained in Ge 0.95 Bi 0.05 Te 1- x Se x pellets with increasing the Se content from 0 to 0.3. A peak figure of merit of ∼1.6 at 723 K is achieved in Ge 0.95 Bi 0.05 Te 0.7 Se 0.3 pellet, which is ∼77% higher than that of pristine GeTe. This study extends the understanding on the thermoelectric performance of GeTe. [ABSTRACT FROM AUTHOR]

Objective: To observe the clinical efficacy of moxibustion therapy plus Liu’s pediatric massage (tuina) for children with recurrent respiratory tract infections due to qi deficiency of spleen and lung. Methods: A total of 60 children who met the inclusion criteria were divided into an observation group and a control group according to the visiting sequence, with 30 cases in each group. Children in the observation group were treated with moxibustion therapy plus Liu’s pediatric massage, and those in the control group were treated with Liu’s pediatric massage alone. The incidence of respiratory tract infections and traditional Chinese medicine (TCM) symptoms score were observed and recorded in both groups before and after treatment. And the clinical efficacy was compared between the two groups. Results: The total effective rate of the observation group was 93.3%, and that of the control group was 83.3%. The difference between the two groups was statistically significant (P<0.05). After treatment, the TCM symptoms score and total times of infections in both groups were all statistically different from those before treatment (all P<0.05). The differences in TCM symptoms score and infection frequency before and after treatment in the observation group were statistically different from those in the control group (both P<0.05). Conclusion: Moxibustion therapy plus Liu’s pediatric massage has a better effect in improving the clinical symptoms and reducing the frequency of respiratory tract infections for children with recurrent respiratory tract infections due to qi deficiency of spleen and lung than the pediatric massage alone.

With the development of China's economy, large-scale engineering and complex engineering are emerging. The Engineering Procurement Construction (EPC) project general contracting model is widely used in civil engineering, water conservancy, railway, water treatment, waste incineration plants and other large engineering area. The increasing complexity of construction technology and the risks are facing overwhelming and fragile supply chain. Based on the deep analysis of supply chain operation reference (SCOR) model, which is widely used in various fields of industry, this article puts forward the preliminary index system of supply chain risk of EPC project by analytic hierarchy process (AHP). The risk index system of waste incineration project including 5 first-level risk indicators and 27 second-level risk indicators has been established and determined. The multi-level grey model is used to evaluate the risk index, calculate the grey evaluation coefficient and the grey evaluation weight vector as well as the weight matrix, draw the specific risk evaluation value of the project, and sort the first level index. Finally, an EPC example of a waste incineration in Hubei Province is used to verify the feasibility and reliability of the method.

Differential Evolution Algorithm (DE) is fast and stable, but it’s easy to fall into the local optimal solution and the population diversity reduces fast in the later period. In order to improve the algorithm optimization and convergence capability, this paper proposes an improved DE algorithm based on the new crossover strategy (CMDE). As to the Crossover-factor is decided by the proportion of the variance and the evolution process in each generation, so it can follow the process of evolution and constantly change; the added operation of Second Mutation can improve the capacity of solving problem, which algorithm falls into the local solution easily. With four standard test functions, the results show that the CMDE algorithm is superior to DE in convergence speed, precise and stability of algorithm.

Unsteady cavitation flows in a centrifugal pump operating under off-design conditions are investigated by using a numerical framework combining the re-normalization group k–ɛ turbulence model and the transport equation-based cavitation model. The reliability and accuracy of the numerical model are demonstrated by the satisfactory agreement between the experimental and numerical values of the pump performance. Under partial discharge, the frequency spectra of the pressure fluctuation at the impeller inlet become more complex as the pump inlet pressure decreases. The maximum amplitude of pressure fluctuation at the blade leading edge for cavitation flow is 2.54 times larger than that for non-cavitation flow because of the violent disturbances caused by cavitation shedding and explosion. Under large discharge, the magnification on the maximum pressure amplitude is 1.6. This finding indicates that cavitation has less influence on pressure fluctuations in the impeller under large discharge than under partial discharge. This numerical simulation demonstrates the evolution of cavitation structure inside the impeller.

Nitric-oxide synthase (NOS; EC 1.14.13.39) catalyzes the oxidation of L-arginine to nitric oxide (NO(.)) and L-citrulline via the intermediate N(omega)-hydroxy-L-arginine. Of the three distinct isoforms of NOS that have been characterized, the constitutive neuronal NOS (NOS I) generates NO(.) associated with long-term potentiation (LTP) and early brain development. All of the NOS isoforms contain an N-terminal oxidase and a C-terminal reductase domain connected by a Ca(2+)/calmodulin binding region. To activate NOS I, Ca(2+) has to bind to calmodulin, allowing electron transport through both domains. Calcium ions are tightly regulated in cells. However, a number of other metal ions that bind and activate calmodulin may also activate NOS I. One such metal ion may be Pb(2+), which is associated with neurobehavioral and psychological alterations, including the inhibition of LTP. The effect of various divalent cations on NOS I activity was tested, and the results presented herein demonstrate that Pb(2+) and Sr(2+) can activate NOS I to a level similar to that found for Ca(2+). Finally, there is a synergy between Pb(2+) and Ca(2+) resulting in maximal activation of NOS I using minimal concentrations of both metal ions.

In order to solve the problem of poor robustness of the traditional method of calculating torque in the mechanical model of 7-DOF picking manipulator, this paper proposes a control strategy of calculating torque plus fuzzy compensation by using adaptive fuzzy logic system to compensate the uncertain part of the mechanical model of 7-DOF picking manipulator. By using Lagrange method, the dynamic model of 7-DOF manipulator is established, and the relationship between joint motion and applied torque (force) is obtained. Using ADAMS and MATLAB to establish a co-simulation platform, the manipulator and trajectory tracking control system are simulated. The results show that the trajectory tracking error of each joint in the algorithm is obviously reduced and the convergence trend is obvious. The average trajectory tracking accuracy of joint 1 to joint 7 was improved by 70.22%, 94.78%, 0.62%, 74.23%, 89.78%, 86.45%, and 67.15%, respectively. In this control scheme, the control force (moment) of each joint changes regularly, and the output force (moment) does not appear chattering and mutation when the disturbance signal is added. The research results can provide support for the further study of picking manipulator trajectory tracking control system.