Research on the Development of Smart Animal Husbandry in Beijing

With the rapid development of agricultural science and technology,animal husbandry,as an important pillar in the field of agriculture,is gradually moving towards a new era of smart animal husbandry with the deep integration of informatization and digitalization.This transformation not only breaks through the traditional production mode of animal husbandry,but also promotes it to a new form under the Internet ecology,draws a new blueprint for the development of agriculture and animal husbandry,and gives birth to numerous potential business opportunities for the development of new agriculture.However,the practice and promotion of smart animal husbandry is not a smooth road,and many challenges and problems need to be solved urgently.On the basis of an in-depth investigation of the development status of smart animal husbandry in Beijing,this paper comprehensively analyzes the current problems,including the difficulty of technology integration,the lack of talent reserve,and the need to improve the policy environment.In view of these problems,it puts forward a series of practical suggestions,in order to speed up the development of animal husbandry in Beijing to the direction of smart development,and realize the sustainable development of animal husbandry.

多学科协作模式的护理对阿尔茨海默病患者认知功能下降的影响研究

目的:多学科协作模式的护理干预对阿尔茨海默病患者认知功能下降的影响。方法:临床纳入2019年12月至2020年12月期间我院收治的88例阿尔茨海默病患者作为研究对象,按随机数字表法将所有患者分为两组各44例。其中44例患者采用常规护理作为对照组,另44例患者采用基于多学科协作模式的综合护理干预作为干预组。观察两组患者生活质量、认知功能以及心理状态情况。结果:护理前两组患者ADL评分无差异,P> 0.05;护理后干预组ADL评分高于对照组,P <0.05。护理前两组患者MoCA、CDR以及CASI评分无差异,P> 0.05;护理后干预组MoCA和CASI评分均大于对照组,CDR评分小于对照组,P <0.05。护理前两组患者HAMA和HAMD评分对比无差异,P> 0.05;护理后干预组HAMA和HAMD评分均低于对照组,P <0.05。结论:多学科协作模式的综合护理干预能明显提高阿尔茨海默病患者的认知功能下降情况,改善患者心理状态和生活质量,值得临床应用及推广。

Enabling Argyrodite Sulfides as Superb Solid-State Electrolyte with Remarkable Interfacial Stability Against Electrodes

While argyrodite sulfides are getting more and more attention as highly promising solid-state electrolytes(SSEs)for solid batteries,they also suffer from the typical sulfide setbacks such as poor electrochemical compatibility with Li anode and high-voltage cathodes and serious sensitivity to humid air,which hinders their practical applications.Herein,we have devised an effective strategy to overcome these challenging shortcomings through modification of chalcogen chemistry under the guidance of theoretical modeling.The resultant Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)delivered excellent electrochemical compatibility with both pure Li anode and high-voltage LiCoO_(2)cathode,without compromising the superb ionic conductivity of the pristine sulfide.Furthermore,the current SSE also exhibited highly improved stability to oxygen and humidity,with further advantage being more insulating to electrons.The remarkably enhanced compatibility with electrodes is attributed to in situ formation of helpful electrolyte–electrode interphases.The formation of in situ anode–electrolyte interphase(AEI)enabled stable Li plating/stripping in the Li|Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)|Li symmetric cells at a high current density up to 1 mA cm^(-2)over 200 h and 2 mA cm^(-2)for another 100 h.The in situ amorphous nano-film cathode–electrolyte interphase(CEI)facilitated protection of the SSE from decomposition at elevated voltage.Consequently,the synergistic effect of AEI and CEI helped the LiCoO_(2)|Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)|Li full-battery cell to achieve markedly better cycling stability than that using the pristine Li_(6)PS_(5)Cl as SSE,at a high area loading of the active cathode material(4 mg cm^(-2))in type-2032 coin cells.This work is to add a desirable SSE in the argyrodite sulfide family,so that high-performance solid battery cells could be fabricated without the usual need of strict control of the ambient atmosphere.

Self-consistent assessment of Li^(+) ion cathodes:Theory vs.experiments

Transition metal oxide cathodes such as layered Li Co O_(2),spinel Li Mn_(2)O_(4) and olivine Li Fe PO4 have been commercialized for several decades and widely used in the rechargeable Li-ion batteries(LIBs).While great theoretical efforts have been made using the density functional theory(DFT)method,leading to insightful understanding covering materials stability and functional properties,the lack of consistency in choices of functionals and/or convergence criteria makes it somewhat difficult to compare results.It is therefore highly useful to assess these established systems towards self-consistency,thus offering a reliable working basis for theoretical formulation of novel cathodes.Here in this work,we have carried out systematic DFT calculations on the basis of recently established framework covering both thermodynamic stability,functional properties and associated mechanisms.Efforts have been made in selfconsistent selection of exchange-correlation(XC)functionals in terms of dependable accuracy with affordable computational cost,which is essential for high-throughput first-principles calculations.The outcome of the current work on three established cathode systems is in very good agreement with experimental data,and the methodology is to provide a solid basis for designing novel cathode materials without using costing non-local exchange-correlation functionals for structure-energy calculations.

Stable all-solid-state battery enabled with Li_(6.25)PS_(5.25)Cl_(0.75) as fast ion-conducting electrolyte

All-solid-state batteries(ASSB) with lithium anode have attracted ever-increasing attention towards developing safer batteries with high energy densities.While great advancement has been achieved in developing solid electrolytes(SE) with superb ionic conductivity rivalling that of the current liquid technology,it has yet been very difficult in their successful application to ASSBs with sustaining rate and cyclic performances.Here in this work,we have realized a stable ASSB using the Li_(6.25)PS_(5.25)Cl_(0.75) fast ionconducting electrolyte together with LiNbO_3 coated LiCoO_2 as cathode and lithium foil as the anode.The effective diffusion coefficient of Li-ions in the battery is higher than 10^(-12) cm~2 s^(-1),and the significantly enhanced electrochemical matching at the cathode-electrolyte interface was essential to enable long-term stability against high oxidation potential,with the LCO@LNO/Li_(6.25)PS_(5.25)Cl_(0.75)/Li battery to retain 74.12% capacity after 430 cycles at 100 μA cm-2 and 59.7% of capacity after 800 cycles at 50 μA cm^(-2),at a high charging cut-off voltage of 4.2 V.This demonstrates that the Li_(6.25)PS_(5.25)Cl_(0.75) can be an excellent electrolyte for the realization of stable ASSBs with high-voltage cathodes and metallic lithium as anode,once the electrochemical compatibility between cathode and electrolyte can be addressed with a suitable buffer coating.

First Principle Material Genome Approach for All Solid-State Batteries

Due to ever-increasing concern about safety issues in using alkali metal ionic batteries, all solid-state batteries (ASSBs) have attracted tremendous attention. The foundation to enable high-performance ASSBs lies in delivering ultra-fast ionic conductors that are compatible with both alkali anodes and high-voltage cathodes. Such a challenging task cannot be fulfilled, without solid understanding covering materials stability and properties, interfacial reactions, structural integrity, and electrochemical windows. Here in this work, we will review recent advances on fundamental modeling in the framework of material genome initiative based on the density functional theory (DFT), focusing on solid alkali batteries. Efforts are made in offering a dependable road chart to formulate competitive materials and construct "better" batteries.

Theoretical and experimental design in the study of sulfide-based solid-state battery and interfaces

In recent years,due to the increasing demand for portable electronic devices,rechargeable solid-state battery technology has developed rapidly.Lithium-ion batteries are the systems of choice,offering high energy density,flexible and lightweight design,and longer lifespan than comparable battery technologies.Therefore,a better understanding of the relationship between electrochemical mechanism and structural properties from theory and experiment will enable us to accelerate the development of high-performance and security batteries.This review discusses the interplay between theoretical calculation and experiment in the study of lithium ion battery materials.We introduce the application of theoretical calculation method in solid-state batteries through the combination of theory and experiment.We present the concept and assembly technology of solid-state batteries are reviewed.The basic parameters of solid-state electrolytes,especially sulfide-based solid-state electrolytes and their interface mechanisms with high-voltage cathode materials,are analyzed by theoretical methods.We present an overview on the scientific challenges,fundamental mechanisms,and design strategies for solid-state batteries,especially focusing on the issues of stability on solid-state electrolytes and the associated interfaces with both cathode and electrolyte.Owing to the theoretical models,we can not only reveal the unprecedented mechanism from the atomic scale,but also analyze the interface problems in the battery thoroughly,thus effectively designing more promising electrolyte and interface coating materials.It blazed a new trial for engineering an interphase with improved interfacial compatibility for a long-term cyclability.

Coxsackievirus B3 HFMD animal models in Syrian hamster and rhesus monkey

Coxsackievirus B3(CVB3)is the pathogen causing hand,foot and mouth disease(HFMD),which manifests across a spectrum of clinical severity from mild to severe.However,CVB3-infected mouse models mainly demonstrate viral myocarditis and pancreatitis,failing to replicate human HFMD symptoms.Although several enteroviruses have been evaluated in Syrian hamsters and rhesus monkeys,there is no comprehensive data on CVB3.In this study,we have first tested the susceptibility of Syrian hamsters to CVB3 infection via different routes.The results showed that Syrian hamsters were successfully infected with CVB3 by intraperitoneal injection or nasal drip,leading to nasopharyngeal colonization,acute severe pathological injury,and typical HFMD symptoms.Notably,the nasal drip group exhibited a longer viral excretion cycle and more severe pathological damage.In the subsequent study,rhesus monkeys infected with CVB3 through nasal drips also presented signs of HFMD symptoms,viral excretion,serum antibody conversion,viral nucleic acids and antigens,and the specific organ damages,particularly in the heart.Surprisingly,there were no significant differences in myocardial enzyme levels,and the clinical symptoms resembled those often associated with common,mild infections.In summary,the study successfully developed severe Syrian hamsters and mild rhesus monkey models for CVB3-induced HFMD.These models could serve as a basis for understanding the disease pathogenesis,conducting pre-trial prevention and evaluation,and implementing post-exposure intervention.

“双碳”背景下新能源固态电池材料理论设计与电池技术开发进展

由于可充电锂金属电池(LMBs)具有较高理论能量密度,在便携式电子设备、电动汽车和智能电网等方面有重要应用。以固态电解质和锂金属负极组装的固态电池(ASSBs)具有高安全性,被认为是可提高电池能量密度和有效解决安全问题的一种有前景的电池技术。然而,LMBs在实际实施过程中仍面临许多挑战,如库仑效率低、循环性能差和界面反应复杂等。深入分析ASSBs的物理基础和化学科学问题对电池开发具有重要意义。为了证实和补充实验研究机理,理论计算为探索电池材料及其界面的热力学和动力学行为提供了一种强有力的支撑,为设计综合性能更好的电池奠定了理论基础。本工作论述了理论计算方法在电池关键材料计算中的应用和研究意义;综述了硫化物固态电解质中Li_(10)GeP_(2)S_(12)(LGPS)及银硫锗矿体系的理论和结构设计思路,包括锂离子的输运机理和扩散路径。分析了新型反钙钛矿Li_(3)OCl和双反钙钛矿Li_(6)OSI_(2)电解质体系的理论设计思路。综述了氧化物固态电解质体系在缺陷调控下锂离子的输运机理。此外,本工作针对新型卤化物电解质体系的理论设计也进行了介绍。介绍了计算材料学在电池材料性能研究中的作用:借助理论手段分析离子传输机制、相稳定性、电压平台、化学和电化学稳定性、界面缓冲层和电极/电解质界面等关键问题;理解原子尺度下的充放电机制,并为电极材料和电解质提供合理的设计策略。总结了固态电解质和ASSBs电极与电解质间界面的理论计算的最新进展。最后,对ASSBs理论计算的不足、挑战和机遇进行了展望。

简单易得的自氧化纳米泡沫镍用于高性能析氢和析氧催化

开发组成简单、无贵金属、制备简洁的自支撑析氢、析氧催化反应(HER和OER)催化剂是电解水的关键需求之一.本文以Mg_(80)Ni_(20)非晶合金薄带为前驱体,采用一步脱合金法制备了具有自支撑结构的自氧化纳米泡沫镍,在电流密度为10 mA cm^(-2)时HER和OER的过电位仅分别为33.1和330 mV,且均具有长达100 h的长期稳定性.基于纳米泡沫镍的水电解槽达到10 mA cm^(-2)的外加电压仅为1.58 V.纳米泡沫镍独特的三维超细多孔结构显著促进了其表观活性,同时其Ni/NiO复合结构显著提高了本征HER活性.本工作验证了纳米泡沫金属是一种有潜力的高性能催化材料.

Efficient three-dimensional characterization of C/C composite reinforced with densely distributed fibers via X-ray phase-contrast microtomography

Carbon fiber(CF)/pyrolytic graphite(PG) composites are promising structural materials for molten salt reactors because of their superior performance.Due to the minor density difference between CF and PG, existing methods are impractical for efficient three-dimensional characterization of CF/PG composites.Therefore, in this study, a method based on in-line phasecontrast X-ray microtomography was developed to solve the aforementioned problem.Experimental results demonstrate that the method is suitable for comprehensive characterization of CF/PG composites.The relationship between the microporous defects and fiber orientations of such composites was also elucidated.The findings can be useful for improving the manufacturing process of CF/PG composites.

3D reconstruction of coal pore network and its application in CO_(2)-ECBM process simulation at laboratory scale

Three-dimensional(3D)reconstruction of the equivalent pore network model(PNM)using X-ray computed tomography(CT)data are of significance for studying the CO_(2)-enhanced coalbed methane recovery(CO_(2)-ECBM).The docking among X-ray CT technology,MATLAB,with COMSOL software not only can realize the 3D reconstruction of PNM,but also the CO_(2)-ECBM process simulation.The results show that the Median filtering algorithm enabled the de-noising of the original 2D CT slices,the image segmentation of all slices was realized based on the selected threshold,and the PNM can be constructed based on the Maximum Sphere algorithm.The mathematical model of CO_(2)-ECBM process fully coupled the expanded Langmuir equation.At the same time for CO_(2)injection,CH_(4)pressure tends to decrease with the increase of CO_(2)pressure,but its difference is not obvious.The CH_(4)pressure in the slice center changed a lot,while at the edge it changed a little under different CO_(2)pressures.The injected CO_(2)was transported to matrix along the macro and micro-fractures with continuous flow.The injected CO_(2)first replaced the adsorbed CH_(4)by covering the inner surface of macro-pores and meso-pores to form the single molecular layer adsorption of CO_(2).Then they migrated to micro-pores by Fick’s diffusion,sliding flow,and surface diffusion.Furthermore,the CO_(2)replaced CH_(4)adsorbed by volumetric filling in micro-pores,and formed the multi-molecular layer adsorption of CO_(2).The gas pressure and migration path between CO_(2)and CH_(4)are opposite.This study can provide a theoretical basis for studying digital rock physics technology and enrich the development of CO_(2)-ECBM technology.

Structural characterization of SiC nanoparticles

The structure and size of SiC nanoparticles were studied by different characterization methods including small angle X-ray scattering（SAXS）,transmission electron microscope（TEM）,and X-ray diffraction（XRD）.The results showed that particle size distributions determined respectively from SAXS and TEM are comparable and follow the log-normal function.The size distribution of the particles is between 10 to 100nm with most of them being in the range of 20-50nm.The average particle size is around 42nm.XRD identifies the phase of the SiC nanoparticles and suggests the average size of the single crystalline domain to be around 21nm.The combined results from XRD and SAXS suggest the existence of many polycrystals,which is confirmed by the HRTEM observation of particles with twins and stacking faults.The material synthesis methods leading to various particle sizes are also discussed.

Hyperbranched poly(ether amine)(hPEA)as novel backbone for amphiphilic one-component type-Ⅱ polymeric photoinitiators

To make photoinitiators （PI） to be polymeric and water-soluble is an effective approach to develop the high efficient photoinitiator systems with low-migration, low-toxic and environment-friend. We developed a series of novel amphiphilic hyperhranched polymeric photoinitiators （hPEA-TXs, and hPEA- BPs） by introducing thioxanthone （TX） or benzophenone （BP） moieties into the periphery of the hyperbranched poly（ether amine） （hPEA） comprised of the hydrophilic poly（ethylene oxide） （PEO） short chain and coinitiator amine moieties in the backbone. Compared with their water-soluble low-molecular weight analogues, the resulting hyperbranched polymeric photoinitiators hPEA101-TX, hPEA211-TX, hPEA101-BP and hPEA211-BP could be dissolved very well not only in many organic systems including acrylate monomers, but also in water with high solubility of 10 wt~. The photopolymerization kinetics of water-soluble monomer acrylamide （AM） and three hydrophobic multifunctional acrylate monomers initiated by these hyperbranched photoinitiators were investigated in detail by photo-differential scanning calorimetric （photo-DSC）. Both hPEA-TXs and hPEA-BPs can initiate photopolymerization of AM as efficiently as their low-molecular weight analogues MGA-TX and MGA-BP, respectively. The final double bond conversion （DBC） of oil-soluble monomer hexanediol diacrylate （HDDA） photoinitiated by these hyperbranched photoinitiators can reach as high as 99%. Especially for photopolymerization of multifunctional monomers initiated by these hyperbranched polymeric photoinitiators, the final DBC of trimethylolpropane triacrylate （TMPTA） and pentaerythritol tetraacrylate （PETTA） can reach 80% and 60%, respectively, which is much higher than that of low-molecular weight photoinitiators.

Determination of representative elementary volume of digital coal based on fractal theory with X-ray CT data and its application in fractal permeability predication model

Representative elementary volume(REV)is the key to study the heterogeneity of digital coal and characterize its macroscopic and microscopic properties.The permeability evolution law of digital coal based on REV analysis can provide theoretical support for the application of permeability prediction model in multi-scale reservoirs.This study takes typical coal samples from Bofang and Sihe coal mines in Qinshui Basin as research object.First,the nondestructive information of two samples is scanned and visualized.Secondly,the calculation methods of two-dimensional(2D)and threedimensional(3D)fractal dimensions of pores and fractures are illustrated.Then,the determination methods of REV based on porosity and fractal dimension are compared.Finally,the distribution pattern of fractal dimension and porosity curves is studied,the relationship between 2D and 3D fractal dimension is characterized,and the application of fractal permeability model in permeability analysis of multi-scale reservoir is further discussed.The REV size varies greatly in different vertex directions of the same sample and between samples,so REV analysis can only be performed in specific directions.When the REV based on fractal dimension is determined,the porosity curve continues to maintain a downward trend and then tends to be stable.The 2D fractal dimension has a positive linear correlation with the 3D fractal dimension,and the porosity can be expressed as a linear function of the fractal dimension.The permeability through REV analysis domain is mainly affected by fractal dimension,dip angle,azimuth angle and maximum fracture length,which is of great significance for exploring permeability evolution law of coal reservoir at different scales.This study is of great significance for enriching the determination methods of REV in digital coal and exploring the permeability evolution law of multi-scale reservoirs.

Planar Li growth on Li_(21)Si_(5)modified Li metal for the stabilization of anode

Lithium(Li)metal is widely considered the ultimate anode for future rechargeable batteries.However,dendritic growth and related parasitic reactions during long-term cycling often lead to severe safety hazards and catastrophic failure.Herein,we fabricate a hybrid anode by coating single-phase Li_(21)Si_(5)on lithium metal.The resultant electrodes show a stable cycle and depressed polarization in symmetric and half cells.A planar plating/stripping behavior is observed on the modified anode.The investigation of the interplay of Li and Li_(21)Si_(5)shows relatively large adsorption energy in the Li-Si system.The deposition and stripping are surface processes,and Li_(21)Si_(5)maintains its intrinsic phase structure.The deposited Li layer around Li_(21)Si_(5)also has the advantage of diminished preferred orientation,which also contributes to the planar growth of Li.Both LiFePO4(LFP)and LiNi1/3Co1/3 Mn1/3O2(NCM)cathodes were applied to further demonstrate the enhanced rate and cycle performance.

Mechanism of oxide thickness and temperature dependent current conduction in n^+-polySi/SiO_2/p-Si structures—a new analysis

The conduction mechanism of gate leakage current through thermally grown silicon dioxide（Si02）films on（100） p-type silicon has been investigated in detail under negative bias on the degenerately doped n-type polysilicon（n^＋-polySi） gate.The analysis utilizes the measured gate current density JG at high oxide fields Eox in5.4 to 12 nm thick Si02 films between 25 and 300 ℃.The leakage current measured up to 300 ℃ was due to Fowler-Nordheim（FN） tunneling of electrons from the accumulated n^＋-polySi gate in conjunction with Poole Frenkel（PF） emission of trapped-electrons from the electron traps located at energy levels ranging from 0.6 to 1.12 eV（depending on the oxide thickness） below the Si02 conduction band（CB）.It was observed that PF emission current IPF dominates FN electron tunneling current IFN at oxide electric fields EOX between 6 and 10 MV/cm and throughout the temperature range studied here.Understanding of the mechanism of leakage current conduction through Si02 films plays a crucial role in simulation of time-dependent dielectric breakdown（TDDB） of metaloxide-semiconductor（MOS） devices and to precisely predict the normal operating field or applied gate voltage for lifetime projection of the MOS integrated circuits.