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Monte-Carlo sampling of lattice model Hamiltonians is a well-established technique in statistical mechanics for studying the configurational entropy of crystalline materials. When species to be distributed on the lattice model carry charge, the charge balance constraint on the overall system prohibits single-site Metropolis exchanges in MC. In this article, we propose two methods to perform MC sampling in the grand-canonical ensemble in the presence of a charge-balance constraint. The table-exchange method (TE) constructs small charge-conserving excitations, and the square-charge bias method (SCB) allows the system to temporarily drift away from charge neutrality. We illustrate the effect of internal hyper-parameters on the efficiency of these algorithms and suggest practical strategies on how to apply these algorithms to real applications.

The tremendous improvement in performance and cost of lithium-ion batteries (LIBs) have made them the technology of choice for electrical energy storage. While established battery chemistries and cell architectures for Li-ion batteries achieve good power and energy density, LIBs are unlikely to meet all the performance, cost, and scaling targets required for energy storage, in particular, in large-scale applications such as electrified transportation and grids. The demand to further reduce cost and/or increase energy density, as well as the growing concern related to natural resource needs for Li-ion have accelerated the investigation of so-called "beyond Li-ion" technologies. In this review, we will discuss the recent achievements, challenges, and opportunities of four important "beyond Li-ion" technologies: Na-ion batteries, K-ion batteries, all-solid-state batteries, and multivalent batteries. The fundamental science behind the challenges, and potential solutions toward the goals of a low-cost and/or high-energy-density future, are discussed in detail for each technology. While it is unlikely that any given new technology will fully replace Li-ion in the near future, "beyond Li-ion" technologies should be thought of as opportunities for energy storage to grow into mid/large-scale applications.

In the synthesis of inorganic materials, reactions often yield non-equilibrium kinetic byproducts instead of the thermodynamic equilibrium phase. Understanding the competition between thermodynamics and kinetics is a fundamental step towards the rational synthesis of target materials. Here, we use in situ synchrotron X-ray diffraction to investigate the multistage crystallization pathways of the important two-layer (P2) sodium oxides Na0.67MO2 (M = Co, Mn). We observe a series of fast non-equilibrium phase transformations through metastable three-layer O3, O3' and P3 phases before formation of the equilibrium two-layer P2 polymorph. We present a theoretical framework to rationalize the observed phase progression, demonstrating that even though P2 is the equilibrium phase, compositionally unconstrained reactions between powder precursors favour the formation of non-equilibrium three-layered intermediates. These insights can guide the choice of precursors and parameters employed in the solid-state synthesis of ceramic materials, and constitutes a step forward in unravelling the complex interplay between thermodynamics and kinetics during materials synthesis.

This work investigates the electrochemical Na+/K+ ion exchange mechanism occurring in layered Na3Ni2SbO6. Structural characterizations using X-ray diffraction and transmission electron microscopy uncover a remarkable and rich phase evolution as K is inserted in partially desodiated NaxNi2SbO6. Rather than simple addition of K to the structure, we see significant Na rearrangement, with discrete Na phases traversing the full range of Na compositions, even though the overall Na content in the sample is not changed. At any given time as much as three distinct phases can be present in the sample, consistent with thermodynamic equilibrium rules. Using DFT computations we demonstrate that this remarkable phase behavior during ion exchange is due to the repulsion between Na+ and K+ which creates distinct phases of them. Our analysis should be applicable to other ion-exchange systems where the exchanged ions are not well miscible in the host structure.

Fluorine substitution is a critical enabler for improving the cycle life and energy density of disordered rocksalt (DRX) Li-ion battery cathode materials which offer prospects for high energy density cathodes, without the reliance on limited mineral resources. Due to the strong Li–F interaction, fluorine also is expected to modify the short-range cation order in these materials which is critical for Li-ion transport. In this work, density functional theory and Monte Carlo simulations are combined to investigate the impact of Li–F short-range ordering on the formation of Li percolation and diffusion in DRX materials. The modeling reveals that F substitution is always beneficial at sufficiently high concentrations and can, surprisingly, even facilitate percolation in compounds without Li excess, giving them the ability to incorporate more transition metal redox capacity and thereby higher energy density. It is found that for F levels below 15%, its effect can be beneficial or disadvantageous depending on the intrinsic short-range order in the unfluorinated oxide, while for high fluorination levels the effects are always beneficial. Using extensive simulations, a map is also presented showing the trade-off between transition-metal capacity, Li-transport, and synthetic accessibility, and two of the more extreme predictions are experimentally confirmed.

The integrated energy system with multi-energy complement and high energy utilization rate as the core has attracted more and more attention. System economy optimization is regarded as the goal based on the multi-time scale optimization model with different time response characteristics of cooling, heating and electricity in the paper. Equipment model constraints and power balance constraints are considered. The branch and bound algorithm is adopted to solve the optimization model. The calculation results show that the system power is balanced, and more time margin is available to regulate system equipment output, and the operating condition of equipment is stable, thereby realizing the purpose of multi-energy complement and efficient utilization.

Due to the coupling of different energy systems, optimization of different energy complementarities, and the realization of the highest overall energy utilization rate and environmental friendliness of the energy system, distributed energy system has become an important way to build a clean and low-carbon energy system. However, the complex topological structure of the system and too many coupling devices bring more uncertain factors to the system which the calculation of the interval power flow of distributed energy system becomes the key problem to be solved urgently. Affine power flow calculation is considered as an important solution to solve uncertain steady power flow problems. In this paper, the distributed energy system coupled with cold, heat, and electricity is taken as the research object, the influence of different uncertain factors such as photovoltaic and wind power output is comprehensively considered, and affine algorithm is adopted to calculate the system power flow of the distributed energy system under high and low load conditions. The results show that the system has larger operating space, more stable bus voltage and more flexible pipeline flow under low load condition than under high load condition. The calculation results of the interval power flow of distributed energy systems can provide theoretical basis and data support for the stability analysis and optimal operation of distributed energy systems.

The potential application of monolayer MS2 (M = Mo, W) as thermoelectric material has been widely studied since the first report of successful fabrication. However, their performances are hindered by the considerable band gap and the large lattice thermal conductivity in the pristine 2H phase. Recent discoveries of polymorphism in MS2s provide new opportunities for materials engineering. In this work, phonon and electron transport properties of both 2H and 1T′ phases were investigated by first-principle calculations. It is found that upon the phase transition from 2H to 1T′ in MS2, the electron transport is greatly enhanced, while the lattice thermal conductivity is reduced by several times. These features lead to a significant enhancement of power factor by one order of magnitude in MoS2 and by three times in WS2. Meanwhile, the figure of merit can reach up to 0.33 for 1T′–MoS2 and 0.68 for 1T′–WS2 at low temperature. These findings indicate that monolayer MS2 in the 1T′ phase can be promising materials for thermoelectric devices application. Meanwhile, this work demonstrates that phase engineering techniques can bring in one important control parameter in materials design.

Objective: To analyze the accuracy and specificity of recent studies to compare the ability of predicting fluid responsiveness with Passive Leg Raising (PLR) by using invasive or non-invasive techniques during passive leg raising. Data Sources: MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews were systematically searched. Study Selection: Clinical trials that reported the sensitivity, specificity and area under the receiver operating characteristic curve (AUC) between the responder and non-responder induced by passive leg raising and Volume Expansion (VE) in critical ill patients were selected. 246 studies were screened, 14 studies were included for data extraction, which met our inclusion criteria. Data Extraction: Data were abstracted on study characteristics, patient population, type and amount of VE, time of VE, definition of responders, position, techniques used for measuring hemodynamic change, number and percentage of responders, the correlation coefficient, sensitivity, specificity, best threshold and area under the ROC curve (AUC). Meta-analytic techniques were used to summarize the data. Data Synthesis: A total of 524 critical ill patients from 14 studies were analyzed. Data are reported as point estimate (95% confidence intervals). The pooled sensitivity and specificity of invasive techniques were 80% (73% - 85%) and 89% (84% - 93%) respectively with the area under the sROC of 0.94. While, the pooled sensitivity and specificity of non-invasive techniques were 88% (84% - 92%) and 91% (86% - 94%) respectively with the area under the sROC of 0.95. The pooled DOR of invasive techniques was 32.2 (13.6 - 76.8), which was much lower than that of non-invasive techniques with the value of 64.3 (33.9 - 121.7). Conclusions: The hemodynamic indexes changes induced by PLR could reliably predict fluid responsiveness. Non-invasive hemodynamic techniques with their accuracy and safety can benefit the daily work in ICUs. Because the number of patients included in the present trials was small, further studies should be undertaken to confirm these findings.

Purpose: To investigate the dosimetric characteristics of a low energy photon intra-operative radiotherapy (IORT) system and explore its potential limitation in clinical application. Methods: A special water phantom, a parallel-plate ionization chamber and an electrometer were used to measure the depth dose rate, isotropy of dose distribution in X/Y plane, dosimetry reproducibility of bare probe and spherical applicators of different size which were used in comparison with the system data. Results: The difference in depth dose rate between the measurement and system data for bare probe is -2.16% ± 1.36%, the range of the relative deviation for isotropy in the X/Y plane is between -1.9% and 2.1%. The difference in depth dose rate, transfer coefficient, isotropy in X/Y plane between the measurement and system data for the whole set of spherical applicators is -10.0% - 2.3%, -8.9% - 4.2% and -1.6% - 2.6%, respectively. Higher surface dose rate and steeper gradient depth dose are observed in smaller spherical applicators. The depth dose rate and isotropy for bare probe and spherical applicators have been shown good reproducibility. The uncertainty of measurement is associated with the positioning accuracy, energy response, noise current and correction function f’(R). Conclusions: Thorough commissioning of the low energy photon IORT system helps us better understand the dosimetry characteristics, verify the system data, obtain adequate data for clinical application and routine quality assurance. The steep gradient depth dose and limited treatment range may restrain its potential in clinical application.

The grid-connected operation of the distributed generation (DG) via the direct current (DC) microgrid is the operation mode of the DC power distribution system in the future. Considering the grid-connected operation of multiple DC microgrids, we have proposed a new type of DC power distribution management system aiming at the lowest operating cost of the entire DC power distribution system. Our proposed DC power distribution management system can be used to carry out the optimized dispatching for the connected DC microgrids, thereby achieving the economic, safe, and stable operation of DC power distribution management systems. At the same time, through the different nodes where the modular multilevel converter (MMC) is connected to the alternating current (AC) distribution network, a DC power distribution management system can control the active and reactive power generated by the MMC, achieving the control of the load flow of the upper-stage AC grids in real time. The example simulation shows that the method proposed in this paper has a great role in reducing the transmission losses of the power distribution network, achieving electric power peak-load shifting, and utilizing renewable energy. Thus, it can not only maximize the use of distributed renewable resources, but also enable mutual support and optimal scheduling between a DC power distribution system and multiple microgrids.

The integrated energy system coupling multi-type energy production terminal to realize multi-energy complementarity and energy ladder utilization is of great significance to alleviate the existing energy production crisis and reduce environmental pollution. In this paper, the topology of the cold-thermal-electricity integrated energy system is built, and the decoupling method is adopted to analyze the feasible interval of load rate under the strong coupling condition, so as to ensure the “source-load” power balance of the system. Establishing a multi-objective optimization function with the lowest system economic operation and pollution gas emission, considering the attribute differences and energy scheduling characteristics of different energy sources of cold, heat and electricity, and adopting different time scales to optimize the operation of the three energy sources of cold, heat and electricity, wherein the operation periods of electric energy, heat energy and cold energy are respectively 15 min, 30 min and 1 h; The multi-objective problem is solved by standard linear weighting method. Finally, the mixed integer nonlinear programming model is calculated by LINGO solver. In the numerical simulation, the hotel summer front load parameters of Zhangjiakou, China are selected for simulation and compared with a single time scale system. The simulation results show that the multi-time scale system reduces the economic operation cost by 15.6% and the pollution gas emission by 22.3% compared with the single time scale system, it also has a wider feasible range of load rate, flexible time allocation, and complementary energy selection.

In view of the enterprise ecological apple manor a variety of problems of existence, put forward to the enterprise management transformation, achieve enterprise, collective, individual integrated operation management and the use of regression mathematical model on apple professional cooperation organization analysis. Through the example, Apple professional economic cooperation organization innovation model of the input output ratio than the rural economic cooperation organization is much higher, the conclusion and the utility of the marginal analysis theory is contrary to. Conclusion the apple professional economic cooperation organization of research and development has a certain reference value.

To assess the value of passive leg raising (PLR) test in predicting fluid responsiveness in patients with sepsis-induced cardiac dysfunction.A prospective observational cohort study was conducted. Thirty-eight patients under mechanical ventilation suffering from sepsis-induced cardiac dysfunction admitted to Department of Surgical Intensive Care Unit of First Affiliated Hospital of Sun Yat-Sen University from September 2013 to July 2014 were enrolled. The patients were studied in four phases: before PLR (semi-recumbent position with the trunk in 45°), PLR (the lower limbs were raised to a 45° angle while the trunk was in a supine position), before volume expansion (VE, return to the semi-recumbent position), and VE with infusing of 250 mL 5% albumin within 30 minutes. Hemodynamic parameters were recorded in every phase. The patients were classified into two groups according to their response to VE: responders (at least a 15% increase in stroke volume, A SV(VE) ≥ 15%), and non-responders. The correlations among all changes in hemodynamic parameters were analyzed by linear correlation analysis, and the receiver operating characteristic curve (ROC) was plotted to assess the value of hemodynamic parameters before and after PLR in predicting fluid responsiveness.Of 38 patients, 25 patients were responders, and 13 non-responders. There was no significant difference in the baseline and hemodynamic parameters at semi-recumbent position between the two groups. The changes in SV and cardiac output (CO) after PLR (Δ SV(PLR) and Δ CO(PLR)) were significantly higher in responders than those of non-responders [ Δ SV(PLR): (14.7 ± 5.7)% vs. (6.4 ± 5.3)%, t = 4.304, P = 0.000; ΔCO(PLR): (11.2 ± 7.5)% vs. (3.4 ± 2.3)%, t = 3.454, P = 0.001], but there was no significant difference in the changes in systolic blood pressure, mean arterial pressure, pulse pressure, and heart rate after PLR (Δ SBP(PLR), Δ MAP(PLR), Δ PP(PLR) and Δ HR(PLR)) between two groups. Δ SV(VE) in responders was significantly higher than that of the non-responders [(20.8 ± 5.5) % vs. (5.0 ± 3.7) %, t = 8.347, P = 0.000]. It was shown by correlation analysis that ΔSV(PLR) was positively correlated with Δ SV(VE) (r = 0.593, P = 0.000), Δ CO(PLR) was positively correlated with ΔSV(VE) (r = 0.494, P = 0.002). The area under ROC curve (AUC) of Δ SV(PLR) ≥ 8.1% for predicting fluid responsiveness was 0.860 ± 0.062 (P = 0.000), with sensitivity of 92.0% and specificity of 70.0%; the AUC of Δ CO(PLR) ≥ 5.6% for predicting fluid responsiveness was 0.840 ± 0.070 (P = 0.000), with sensitivity of 84.0% and specificity of 76.9%; the AUC of Δ MAP(PLR) ≥ 6.9% for predicting fluid responsiveness was 0.662 ± 0.089, with sensitivity of 68.0% and specificity of 76.9%; the AUC of Δ SBP(PLR) ≥ 6.4% for predicting fluid responsiveness was 0.628 ± 0.098, with sensitivity of 76.0% and specificity of 61.5%; the AUC of Δ PP(PLR) ≥ 6.2% for predicting fluid responsiveness was 0.502 ± 0.094, with sensitivity of 56.0% and specificity of 53.8%; the AUC of Δ HR(PLR) ≥ -1.7% for predicting fluid responsiveness was 0.457 ± 0.100, with sensitivity of 56.0% and specificity of 46.2%.In patients with sepsis-induced cardiac dysfunction, changes in SV and CO induced by PLR are accurate indices for predicting fluid responsiveness, but the changes in HR, MAP, SBP and PP cannot predict the fluid responsiveness.

The Markov chain empirical prediction results of economic models based on agricultural enterprises, so as to avoid investment risks. Venture capital investment as a new investment tool, its earnings forecast method is better than the traditional finance investment prediction, which is more complex, more professional. This study constructs a risk investment based on Markov chain prediction of economic model, the fitting matrix method to estimate one-step transfer probability matrix. Finally taking Shaanxi Huasheng Group's actual earnings data as an example, a calculating example is given, which shows the effectiveness of the method. This study presents the economic model for the development of the venture capital industry has certain positive role.

Pulmonary microvascular endothelial cell(PMVEC) is a very important tool to study acute respiratory distress syndrome. Several methods for in vitro cultivation of PMVEC have been established, but all the methods damage PMVECs either by use of proteolytic emzymes or by mechanical trauma. This study was to improve the method for primary cultivation of rat pulmonary microvascular endothelial cells and identify the primary cultivated cells.

In Fig. 1 we give the diagram of this compact short pulse high power laser facility with variablepulsewidth. The laser facility consists of an actively-passively mode-locked (APM) Nd : YAG oscillatoroperating in coffiding pulse scheme, a series of laser amplifiers (except two stages, they are two- passamplifiers), a double Pockels-Cell (PC) as single pulse selector, two spatial filters and one PC isolator.The whole system is fixed on an antivibration optical table with the area of 10 m2. The output of beamfrom last main amplifier with diameter of 40 mm is guided to the experimental target chamber.

We report here the preliminary experimental results of a gain-switched Ti:sapphire laser in which some characteristics of the output pulses were investigated. In these experiments the minimum laser pulsewidth of 1.2 ns has been obtained and pulsewidth can be varied from 5 ns to 27.5 ns continuously under certain experimental conditions.

We have carried out a series of experiments on a gain-switched Ti:sapphire laser to investigate the temporal characteristics of the output pulses. In these experiments the minimum laser pulsewidth of shorter than 2 ns has been obtained and pulsewidth can be varied from 5 ns to 27.5 ns continuously under our experimental condition. Using only one output coupler the laser tunable range was greater than 2.1 X 103 cm-1 (from 720 nm to 850 nm). A maximum output pulse energy of 4.65 mJ at 780 nm was obtained. The spectral content of the output from the laser with three intracavity prisms was less than 0.14 nm (FWHM).© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An active-passive mode-locked solid state laser cavity configuration operating in colliding pulse scheme and some experimental results of Nd:doped lasers are reported.

This paper reports the experimental results on an active-passive colliding pulse mode-locked (APCPM) Nd:YAG laser with variable pulsewidths of 15-20ps and 0.15-2ns. The amplitude fluctuations of the pulse train were less than ± 4%.

To find out homogeneous line-shaped plasma as a gain mediuni of soft Xray lasers produced by linefocused lasers the hydrodynamic characteristics and forms of harmonic and X-ray emission profiles of the plasma colunu-is have been studied with optical diagnostic equipments such as the five-frame laser probing diagnostic system the micrographic diagnostic systems and the spectral resolved Xray pinhole camera. Some experimental results are given and the emphasis is put on those of the halfcylindricalgroove shell targets. The results show that the halfcylindrical groove shell target may be favorable for soft X-ray laser research. 1 .

An X-ray preionized discharge-pumped XeCl laser with two flat electrodes and a variable active volume of up to 1 1 is described. A charge-transfer circuit is employed with low-inductance water capacitors. The laser beam width is determined by X-ray collimators. Beam cross-sections up to 4x5 cm2 have been achieved. The laser pulse energy exceeds 3 J in a 40 ns pulse (FWHM). The dependence of output energy on gas pressure, charging voltage and beam width as well as the X-ray preionizer performance are presented.

We have studied the interaction between the 1010 W Nd glass laser pulses with a leading edge of about 1ns and several planar targets made of deuterium-contained materials. In our experiments, the neutron yields, electron temperature and various characteristics (such as reflectivity, temporal, spatial and spectral structure) of the backward-reflected laser light from the plasmas have been mainly measured.

This paper reports the results of the investigation on six-beam ns laser symmetrically irradiating (CD2)n mierospherical targets.