Achieving an ion-homogenizing and corrosion-resisting interface through nitro-coordination chemistry for stable zinc metal anodes

Suppression of uncontrollable dendrite growth and water-induced side reactions of Zn metal anodes is crucial for achieving long-lasting cycling stability and facilitating the practical implementations of aqueous Zn-metal batteries.To address these challenges,we report in this study a functional nitro-cellulose interfacial layer(NCIL)on the surface of Zn anodes enlightened by a nitro-coordination chemistry strategy.The NCIL exhibits strong zincophilicity and superior coordination capability with Zn^(2+)due to the highly electronegative and highly nucleophilic nature of the nitro functional group.This characteristic facilitates a rapid Zn-ion desolvation process and homogeneous Zn plating,effectively preventing H_(2) evolution and dendrite formation.Additionally,the negatively charged surface of NCIL acts as a shield,repelling SO_(4)^(2-)anions and inhibiting corrosive reactions on the Zn surface.Remarkably,reversible and stable Zn plating/stripping is achieved for over 5100 h at a current density of 1 mA cm^(-2),which is nearly 30 times longer than that of bare Zn anodes.Furthermore,the Zn/V_(2)O_(5) full cells with the functional interface layer deliver a high-capacity retention of 80.3%for over 10,000 cycles at 5 A g^(-1).This research offers valuable insights for the rational development of advanced protective interface layers in order to achieve ultra-long-lifeZnmetal batteries.

Particle Size Optimization of Thermochemical Salt Hydrates for High Energy Density Thermal Storage

Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy sources by time shifting the load,which are critical toward zero energy buildings.Thermochemical materials(TCMs)as a class of TES undergo a solid-gas reversible chemical reaction with water vapor to store and release energy with high storage capacities(600 kWh m^(-3))and negligible self-discharge that makes them uniquely suited as compact,stand-alone units for daily or seasonal storage.However,TCMs suffer from instabilities at the material(salt particles)and reactor level(packed beds of salt),resulting in poor multi-cycle efficiency and high-levelized cost of storage.In this study,a model is developed to predict the pulverization limit or Rcrit of various salt hydrates during thermal cycling.This is critical as it provides design rules to make mechanically stable TCM composites as well as enables the use of more energy-efficient manufacturing process(solid-state mixing)to make the composites.The model is experimentally validated on multiple TCM salt hydrates with different water content,and effect of Rcrit on hydration and dehydration kinetics is also investigated.

Long-term cycles of the Solar System concealed in the Mesozoic sedimentary basin record

Mounting evidence indicates that the orbital period of the solar system’s movement through the Milky Way has had a controlling effect on processes of the Earth’s system throughout the Phanerozoic.To decipher the response of a given terrestrial basin’s rhythms to galactic dynamics,for the first time,we report long-term cycles recorded in the Mesozoic Ordos Basin(Central China).The astronomical time scale(ATS)was established for each successive sedimentary sequence,and the duration of unconformity episodes was estimated based on the chronological constraints.Using this timescale,time-series analysis of the deposition rate is carried out through the Mesozoic Ordos Basin,which reveals compelling periodicities of 93,33,9,3-5,and 2.4Myr.The radial solar system motions around the galactic centre and plate tectonic cycles act cooperatively to impact the magmatic tempo of the Qinling orogenic belt and the 93-Myr depositional cycle of the Mesozoic Ordos Basin.The Mesozoic 33-Myr cycle is a sedimentary response to the half-period of the solar system’s vertical oscillation about the galactic plane.A rational explanation is that galactic oscillation affects mantle convection,which is responsible for periodic asthenospheric upwelling and ultimately controls the vertical crust oscillation of the Ordos Basin.Mesozoic 9-Myr and the higher-frequency 3-5and 2.4-Myr depositional cycles can be sedimentary responses to the Earth’s orbital eccentricity,which affected the temporal variation in depositional environments in the Ordos Basin.Apart from the galactic-geologic correlations,long-term cycles recorded within a sedimentary basin should also consider the tectonically driven mechanisms at these timescales.This framework provides a new perspective for revealing the astronomical origin of Earth’s rhythms.

Effect of cyclic drying and wetting on engineering properties of heavy metal contaminated soils solidified/stabilized with fly ash

Solidification/stabilization （S/S） is one of the most effective methods of dealing with heavy metal contaminated soils. The effects of cyclic wetting and drying on solidified/stabilized contaminated soils were investigated. A series of test program, unconfined compressive strength （UCS） test, TCLP leaching test and scanning electron microscopy （SEM） test, were performed on lead and zinc contaminated soils solidified/stabilized by fly ash. Test results show that UCS and the leaching characteristics of heavy metal ions of S/S contaminated soils are significantly improved with the increase of fly ash content. UCS of S/S soils firstly increases with the increase of the times of drying and wetting cycles, after reaching the peak, it decreases with it. When the pollutant content is lower （1 000 mg/kg）, the TCLP concentration first slightly decreases under cyclic drying and wetting, then increases, but the change is minor. The TCLP concentration is higher under a high pollutant content of 5 000 mg/kg, and increases with the increase of the times of drying and wetting cycles. The results of scanning electron microscopy （SEM） test are consistent with UCS tests and TCLP leaching tests, which reveals the micro-mechanism of the variations of engineering properties of stabilized contaminated soils after drying and wetting cycles.

Nonlinear Differential Equation of Macroeconomic Dynamics for Long-Term Forecasting of Economic Development

In this article we derive a general differential equation that describes long-term economic growth in terms of cyclical and trend components. Equation is based on the model of non-linear accelerator of induced investment. A scheme is proposed for obtaining approximate solutions of nonlinear differential equation by splitting solution into the rapidly oscillating business cycles and slowly varying trend using Krylov-Bogoliubov-Mitropolsky averaging. Simplest modes of the economic system are described. Characteristics of the bifurcation point are found and bifurcation phenomenon is interpreted as loss of stability making the economic system available to structural change and accepting innovations. System being in a nonequilibrium state has a dynamics with self-sustained undamped oscillations. The model is verified with economic development of the US during the fifth Kondratieff cycle (1982-2010). Model adequately describes real process of economic growth in both quantitative and qualitative aspects. It is one of major results that the model gives a rough estimation of critical points of system stability loss and falling into a crisis recession. The model is used to forecast the macroeconomic dynamics of the US during the sixth Kondratieff cycle (2018-2050). For this forecast we use fixed production capital functional dependence on a long-term Kondratieff cycle and medium-term Juglar and Kuznets cycles. More accurate estimations of the time of crisis and recession are based on the model of accelerating log-periodic oscillations. The explosive growth of the prices of highly liquid commodities such as gold and oil is taken as real predictors of the global financial crisis. The second wave of crisis is expected to come in June 2011.

高超声速发动机不同燃烧模式的性能比较──斜爆轰发动机性能评价

本文采用热力学分析方法，从熵和的概念出发，论证了理想情况下爆轰发动机的有效性，并定量比较了在同样入口压缩条件下，采用爆轰、等压、等Ｍ数等三种燃烧模式的发动机的性能，证明Ｃ─Ｊ斜爆轰是最佳超声速燃烧模式。

东亚大陆边缘的构造格架及其中——新生代演化

燕山运动在亚洲大陆雏形东缘形成2条北东向的剪切带:郯庐断裂带和长乐-南澳-中央构造线断裂带,晚侏罗世—古近纪早期沿之发生地体/地块的拼贴。系统叙述了各移置地体/地块的主要岩石记录和拼贴时代,据起源分为3类:异地的(包括源自冈瓦纳的和源自盘古大洋的)、半异地的和准原地的;据拼贴位置分为2组:拼贴后基本位于原地的(日本海张开以前) 和发生过向北东错移的。新生代内东亚大陆边缘发生解体,可以台湾岛以北的菲律宾海盆断裂为界将东亚大陆边缘弧分为2段,北段仍处于剪切-拉张中,南段已进入剪切挤压-造山阶段。强调该地区中—新生代演化经历了2个里丁旋回, 形成早白垩世的北东向和新近纪的北东东向2期新生构造。

大角度旋转开采技术在晓南矿的应用

为解决晓南煤矿西三采区北部的备采区域原设计布置的4个工作面造成的回采巷道布置困难,搬家倒面频繁,综采效率低下的问题,根据工作面开采煤层赋存特点,在理论分析的基础上,将原设计的4个工作面简化为一个工作面(W3707),实行了大角度旋转联合开采。为确保该技术成功实施,将75°开采弧线被改造成6道短弦,经过2次确定旋转中心,实行机头多进,机尾割通不进的调采原则,采用长、短刀穿插割煤的工艺解决了综采工作面3次搬家倒面等技术难题,提高了工作面采出率5%左右。

酸雨-干湿耦合作用下树脂-水泥界面腐蚀特性

为探究酸雨环境下树脂-水泥界面劣化对树脂导光水泥基材料(RLCCM)力学性能及界面微观结构的影响,以透明树脂和水泥基体为载体,通过酸雨-干湿耦合作用加速试验,测试树脂-水泥界面斜剪黏结强度、表面外观特征变化,并通过环境扫描电子显微镜-能谱仪(ESEM-EDS)分析树脂-水泥界面在酸雨环境下的劣化机理.结果表明:树脂-水泥基试样的斜剪破坏均从树脂-水泥界面处开始;在酸雨-干湿耦合作用下,界面斜剪黏结强度呈先升后降趋势,水泥基体自靠近界面的位置处开始腐蚀,随着龄期的增长,破坏由表及里逐渐发生;在酸雨-干湿耦合作用下,试样中的氢氧化钙(CH)在早期被逐渐消耗,部分生成石膏,体积膨胀填充部分界面空隙,使树脂-水泥界面结合更为紧密;随着腐蚀时间的延长,试样中的C-S-H被逐渐消耗,石膏越来越多,树脂-水泥界面附近覆盖了1层白色黏稠状的石膏,导致界面出现裂缝.

基于BIM快速生成高精度三维模型的方法研究及其应用探索

BIM技术的发展推动了建筑业的一场新的革命,随着绿色建筑、智能建筑以及城市可持续发展概念的不断深化,现有的建模方式已经无法满足新时代模型的要求。三维实景建模技术在近年来广泛用于既有建筑的模型重建,如何实现高精度、快速率、低成本的实景模型是广大技术人员面临的重要问题,本文利用倾斜摄影技术实现三维实景建模并结合实际工程案例提出可实施性参考方案,并提出用实景建模的方法监测隧道洞口沉降量。

Strongly Anchoring Polysulfides by Hierarchical Fe3O4/C3N4 Nanostructures for Advanced Lithium-Sulfur Batteries

Li-S batteries have attracted considerable interest as nextgeneration energy storage devices owing to high energy density and the natural abundance of sulfur.However,the practical applications of Li-S batteries are hampered by the shuttle effect of soluble lithium polysulfides(LPS),which results in low cycle stability.Herein,a functional interlayer has been developed to efficiently regulate the LPS and enhance the sulfur utilization using hierarchical nanostructure of C3 N4(t-C3 N4)embedded with Fe304 nanospheres.t-C3 N4 exhibits high surface area and strong anchoring of LPS,and the Fe3 O4/t-C3 N4 accelerates the anchoring of LPS and improves the electronic pathways.The combination of these materials leads to remarkable battery performance with 400%improvement in a specific capacity and a low capacity decay per cycle of 0.02%at 2 C over 1000 cycles,and stable cycling at 6.4 mg cm-2 for high-sulfur-loading cathode.

3D skeleton nanostructured Ni_3S_2/Ni foam@RGO composite anode for high-performance dual-ion battery

The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ～90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ～85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.

Using geophysical logs to identify Milankovitch cycles and to calculate net primary productivity(NPP) of the Late Permian coals,western Guizhou,China

Milankovitch periodicities of 123 kyr(eccentricity), 35.6 kyr(obliquity), and 21.2 kyr(precession) were identified in geophysical logs of three Late Permian coals: 17#, 18#, and 17 + 18#, from the Songhe mining area in western Guizhou Province. Based on the astronomic temporal framework, the periods of deposition of the 17#(5.6 m), 18#(6.4 m), and 17 + 18#(5.4 m) coals were constrained to 140.8–119.8 kyr, 160–136.2 kyr, and 135–114.9 kyr,respectively. The overall depositional period of the 18# coal of 160–136.2 kyr was further subdivided using the wavelet analysis method, into short and precise periods corresponding to the Milankovitch periodicities. It includes one eccentricity periodicity(123 kyr), three obliquity periodicities(35.6 kyr), and five precession periodicities(21.2 kyr). Different thicknesses of the subdivided coal sections, equivalent to the same time span of deposition, indicate different rates of coal deposition, i.e., thicker sections imply higher rates while the thinner sections represent lower rates. The combination of the measured average carbon concentration with the density of the coals gave rise to long-term average values of carbon accumulation rates for the Late Permian coals, in the range of 42.4–50.6 g?C?m^(-2)?a^(-1). This range corresponds to the long-term average carbon accumulation rates for the initial peat in the range of 60.6–72.3 g?C?m^(-2)?a^(-1). Based on the known quantitative relation between net primary productivity(NPP)values and long-term average carbon accumulation rates for the Holocene tropical peatlands, the range of NPP values for the Late Permian tropical peatlands was estimated as 242.4–433.8 g?C?m^(-2)?a^(-1).A comparison of existing information about peatland NPP levels of various ages and latitudes indicated that when conditions of high rain and high humidity prevail in the palaeo-peatland at given latitude, the NPP rates will vary with changes in atmospheric concentration of CO_2 and O_2. This relationship may lead to the use of coals as an indicator for the concentration of these gases(CO_2 and O_2) in the contemporaneous atmosphere encompassing the long records of coal deposition.

Conductivity and Oxidation Behavior of Fe-16Cr Alloy as Solid Oxide Fuel Cell Interconnect Under Long-Stability and Thermal Cycles

Conductivity and oxidation behavior of Fe-16Cr alloy were investigated under long-term stability operation at 750℃and thermal cycles from room temperature to 750℃.The results showed that the area specific resistance(ASR)of Fe-16Cr alloy increased over time and reached about 56.29 mΩcm~(2)after 40,000 h of long-term stability operation at 750℃by theoretical calculation.The ASR of Fe-16Cr remained about 11 mΩcm~(2)after 52 thermal cycles from room temperature to750℃.The analysis of structure showed that the oxidized phase on the surface of Fe-16Cr was mainly composed of Cr_(2)O_3and Fe Cr_(2)O_(4)spinel phase under long-term stability operation at 750℃.While the Cr_(2)O_(3)phase was mainly observed on the surface of Fe-16Cr alloy after 52 thermal cycles,the oxidation rates of Fe-16Cr alloy were 0.0142μm h~(-1)and 0.06μm cycle~(-1)under long-term stability operation and under thermal cycle,respectively.The property of Fe-16Cr alloy with 2.6 mm thickness met the lifespan requirement of interconnect for solid oxide fuel cell(SOFC)stacks.The Cr element all diff used onto oxidation surface,indicating that it was necessary to spray a coating on the surface to avoid poisoning cell cathode of SOFCs.Two 2-cell stacks were assembled and tested to verify the properties of Fe-16Cr alloy as SOFC interconnect under long-term stability operation and thermal cycle condition.

白赤交角的周期在川滇地区M≥6.7级地震预测中的应用

基于对20世纪以来川滇地区M≥6.7级以上大地震年份与月亮白赤交角的两个极值的变化周期18.6年的关系,建立了1个预测模型,用于对未来川滇地区地震的发生时间进行预测。分析结果表明,20世纪以来川滇地区的39个M≥6.7级强震与月亮白赤交角的两个极值的变化周期18.6年有着密切的关系。通过分析,认为川滇地区未来19年内有可能发生4次M≥6.7级地震的危险,另一方面,2012～2017年有强烈的地震灾害信号,并且未来几次M≥6.7地震可能发生在2014/2015/2019/2027年。

Combined application of organic manure and chemical fertilizers stabilizes soil N-cycling microflora

Straw and manure are widely applied to agricultural systems,and greatly shape soil N-cycling microflora.However,we still lack a comprehensive understanding of how these organic materials structure soil N-cycling microbial communities.In this study,metagenomic analysis was performed to investigate the compositional variation in N-cycling microbial communities in a 30-year long-term experiment under five fertilization regimes:no fertilization(Control),chemical fertilization only(NPK),and NPK with wheat straw(NPK+HS),pig manure(NPK+PM),and cow manure(NPK+CM).Long-term NPK application differentially changed N-cycling gene abundance and greatly altered N-cycling microbial community structure.NPK+HS resulted in a similar pattern to NPK in terms of gene abundance and community structure.However,NPK+PM and NPK+CM significantly increased most genes and resulted in a community similar to that of the Control.Further analysis revealed that serious soil acidification caused by long-term NPK fertilization was a major factor for the variation in N-cycling microbial communities.The addition of alkaline manure,rather than wheat straw,stabilized the N-cycling microbial community structure presumably by alleviating soil acidification.These results revealed the strong impact of soil acidification on microbial N-cycling communities and illustrated the possibility of resolving nitrogen-related environmental problems by manipulating pH in acidified agricultural soils.

月球运动规律的数值模拟

从牛顿定律出发,在太阳-地球-月球三质点的简单模型下,用Mathematica求动力学微分方程组的数值解,对月球在太阳参照系和地心参照系中的运动轨迹进行动画模拟,计算出朔望月和近点月以及黄白交角的变化幅度和周期.

Multiple transition metals modulated hierarchical networks for high performance of metal-ion batteries

Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 m Ah g^(-1)(vs. Li/Li^(+)) and 454 m Ah g^(-1)(vs. Na/Na^(+)), respectively, after 100 cycles.Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.

An efficient molten-salt electro-deoxidation strategy enabling fast-kinetics and long-life aluminum-selenium batteries

Aluminum-selenium(Al-Se)batteries have been considered as one of the most promising energy storage systems owing to their high capacity,energy density,and cost effectiveness,but Se falls challenges in addressing the shuttle effect of soluble intermediate product and sluggish reaction kinetics in the solid-solid conversion process during cycling.Herein,we propose an unprecedented design concept for fabricating uniform Se/C hollow microspheres with controllable morphologies through low-temperature electro-deoxidation in neutral NaCl-AlCl_(3) molten salt system.Such Se/C hollow microspheres are demonstrated to hold a favorable hollow structure for hosting Se,which can not only suppress the dissolution of soluble intermediate products into the electrolyte,thereby maintaining the structural integrity and maximizing Se utilization of the active material,but also promote the electrical/ionic conductivity,thus facilitating the rapid reaction kinetics during cycling.Accordingly,the as-prepared Se/C hollow microspheres exhibit a high reversible capacity of 720.1 mAh g^(−1)at 500 mA g^(−1).Even at the high current density of 1000 mA g^(−1),Se/C delivers a high discharge capacity of 564.0 mAh g^(−1),long-term stability over 1100 cycles and high Coulombic efficiency of 98.6%.This present work provides valuable insights into short-process recovery of advanced Se-containingmaterials and value-added utilization for energy storage.

Diffusion-Free All-Solid-State Batteries Enabled by an Ionic/Electronic Dual-Conductive Anode

Silicon(Si)is one of the most promising anodes for enabling all-solid-state batteries(ASSBs)with high energy density and safety.However,the tremendous volume change and sluggish kinetics result in poor electrochemical performance.Herein,we proposed an ionic/electronic dual-conductive material of Li_(x)Si as a diffusion-rapid and all-active anode for ASSBs.Compared with pure Si anode,the as-fabricated Li_(x)Si showed dramatic promotions of 35 times electronic and 400 times ionic conductivities.The three-dimensional(3D)ionic-electronic transport system of Li_(x)Si enabled rapid kinetics and uniform volume change of electrode materials in the whole electrode,corresponding to a lower volumechange rate.As a result,the ASSBs with LiCoO_(2)cathode exhibited a reversible discharge capacity of 154.4 mAh g−1,corresponding to an initial Coulombic efficiency of 97.3%.Besides,the batteries delivered a high rate capacity of 99.3 mAh g^(−1)at 2 C and long-term cycle stability of 94.0%after 800 cycles at 1 C,which was much better than the pure Si anode.This study sheds light on a new understanding of the importance of ionic conductivity for Si-based anode and might help inspire the design of advanced anode materials for ASSBs.