Enabling an Inorganic-Rich Interface via Cationic Surfactant for High-Performance Lithium Metal Batteries

An anion-rich electric double layer(EDL)region is favorable for fabricating an inorganic-rich solid-electrolyte interphase(SEI)towards stable lithium metal anode in ester electrolyte.Herein,cetyltrimethylammonium bromide(CTAB),a cationic surfactant,is adopted to draw more anions into EDL by ionic interactions that shield the repelling force on anions during lithium plating.In situ electrochemical surface-enhanced Raman spectroscopy results combined with molecular dynamics simulations validate the enrichment of NO_(3)^(−)/FSI−anions in the EDL region due to the positively charged CTA^(+).In-depth analysis of SEI structure by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry results confirmed the formation of the inorganic-rich SEI,which helps improve the kinetics of Li^(+)transfer,lower the charge transfer activation energy,and homogenize Li deposition.As a result,the Li||Li symmetric cell in the designed electrolyte displays a prolongated cycling time from 500 to 1300 h compared to that in the blank electrolyte at 0.5 mA cm^(-2) with a capacity of 1 mAh cm^(-2).Moreover,Li||LiFePO_(4) and Li||LiCoO_(2) with a high cathode mass loading of>10 mg cm^(-2) can be stably cycled over 180 cycles.

Recharge processes limit the resource elements of Qarhan Salt Lake in western China and analogues in the evaporite basins

The Qarhan Salt Lake(QSL)in western China is K-Sr-Li-B-Br-Rb multi-resource coexisting Quaternary brine deposits.Significant research efforts have been directed to the origin of K-Li resources and evolutionary history of the QSL.However,the study on the different sources,recharge processes,and differential distribution patterns for these resource elements in brine deposits is still inadequate.Therefore,we measured Li-B concentrations and H-O-Sr-B isotopic compositions of different waters(river,spring,and brine)from the QSL,combined with the reported K-Sr contents and multiple isotopes of waters,to discuss the recharge,source of K-Sr-Li-B and their spatial distributions,by analogy with other evaporite basins in the world.The results show that:(1)the K-Li-B-Sr elemental concentrations of brines and their spatial distribution in the QSL are diverse;(2)high K and Sr values are distributed in Dabuxun and Qarhan sections,respectively,which are controlled by Ca-Cl springs in the northern QSL;on the contrary,Li and B values are enriched in the Bieletan section and are charged by thermal springs in the Kunlun Mountains;(3)the formation and evolution of Ca-Cl and thermal springs constrain fundamentally on the recharge processes of K-Sr and Li-B elements in the terminal salt lakes of the Qaidam Basin(QB);(4)some analogues of recharge processes limit the resource elements of the QSL and other salt lakes(Da Qaidam,Lop Nur,Zhabuye,Atacama,and Guayatayoc)in the world provides a reference for the resource exploration in deep formation waters in the evaporite basins.

Influencing mechanism and hydrogeological implications of water level fluctuation of lakes in the northern Qaidam Basin,Qinghai-Tibet Plateau

The Qaidam Basin(QB)is a concentrated distribution area and chemical industrial bases of salt lakes in China.Lakes in the QB have been expanding during the past 20 years.Rapid lake expansion resulted in some considerable scientific issues on the protection of salt lake resources and infrastructure,and monitoring of hydrological processes at the lake-basin scale.Although the spatial-temporal trends of lake changes on the Qinghai-Tibet Plateau(QTP)have been well documented,the underlying influencing mechanism and hydrogeological implications of rapid lake changes in the QB are not well understood.Three lakes in the northern QB were selected to investigate lake water level fluctuations on different time scales based on extensive in-situ monitoring and satellite observations.The influencing mechanism and hydrogeological implications of rapid changes of terminal lakes were discussed in combination with the reported increasing precipitation rate and mass balance of glaciers in the northern QTP.Results reveal the following:(1)the fluctuation pattern of Sugan Lake was asynchronous and out of phase with that of Xiao Qaidam and Toson lakes during the monitoring period;(2)Sugan Lake water rose gradually,and the rise interval was from late April to early July.In contrast,Xiao Qaidam and Toson lakes took on a rapid and steep rise,and the rise intervalwas from late July to September;(3)the influencing mechanisms for rapid lake fluctuations are controlled by different factors:glacier and snow melting with increasing temperature for Sugan Lake and increasing precipitation for Xiao Qaidam and Toson lakes;(4)in accordance with different intervals and influencing mechanisms of rapid lake expansions in the QB,hydrological risk precaution of lakes and corresponding river catchments was conducted in different parts of the basin.This study provided an important scientific basis for assessing the hydrological process and hydrological risk precaution,and protection of salt lake resources along with rapid lake expansions in the arid area.

运输成本、厂商最优规模与长期生产选址

本文研究单中心区域中运输成本对厂商行为的影响机制,探究厂商短期生产规模和长期区位选址策略。通过纳入生产市场自然垄断和消费市场完全竞争的市场结构假设,构建了一个包含原料厂商、生产厂商、消费者、运输部门的多阶段厂商模型,得出了运输部门在不同市场的分别定价策略。本文进一步分析了厂商的短期最优规模和长期最优区位决策。数值模拟发现,代表厂商生产技术的运输依赖程度,是影响最优规模决策的核心。以运输依赖程度将厂商所属产业类别划分为重工业、轻工业、郊区农业、服务业,不同类别的厂商会选择不同的最优规模进行生产。此外,最优区位决策不仅受到厂商运输依赖程度影响,还与原材料和制成品分别的运输难度相关。长期来看,生产技术和运输技术进步改善运输条件,进而影响企业的区位决策,形成区域环状产业带。这对于解释大都市区内部的产业圈层分布有着重要的现实意义,通过运输条件和运输技术的改善促进产业的合理分工,能够更好地推动区域一体化发展。

Soil water repellency and influencing factors of Nitraria tangutorun nebkhas at different succession stages

Abstract： Soil water repellency （WR） is an important physical characteristic of soil surface. It is capable of largely influencing the hydrological and geomorphological processes of soil, as well as affecting the ecological processes of plants, such as growth and seed germination, and has thus been a hot topic in recent research around the world. In this paper, the capillary rise method was used to study the soil WR characteristics of Nitraria tangutorun nebkhas. Soil water repellencies at different succession stages of Nitraria tangutorun were investigated, and the relationships between soil WR and soil organic matter, total N, and total P, soil texture, pH, and concentrations of CO32, HCO3-, CI, SO42-, Na~, K~, Ca2~ and Mg2＋ were discussed. Soil WR may be demonstrated at the following nebkhas dune evolvement stages： extremely degraded〉degraded〉stabilized〉well developed〉newly developed〉quick sand. Apart from some soil at the bottom, the WR of other soils （crest and slope of dune） was found to be largest at the topsoil, and decreased as the soil depth increased. The results showed that multiple factors affected soil WR characteristics e.g. WR increased significantly as the contents of soil organic matter and total N increased, but did not change as the total P content increased. Soil texture was a key factor affecting soil WR; soil WR increased significantly as clay content increased, and decreased significantly as sand content increased. Low pH was shown to be more suitable for the occurrence of soil WR. Four cations （Ca2＋, Mg2＋, K＋ and Na＋） and two anions （CI and SO42） enhanced soil WR, while CO32-decreased it. HCO3- did not show any observable effect. Finally, we established a best-fit general linear model （GLM） between soil-air-water contact angle （CA） and influencing factors （CA=5.606 sand＋6.496 （clay and silt）-2.353 pH＋470.089 CQ2＋11.346 Na＋-407.707 Cl--14.245 SO42-＋0.734 total N-519.521 ）. It was concluded that all soils contain subcritical WR （0°〈CA〈90°）. The development and succession of Nitraria tangutorun nebkhas may improve the formation of soil subcritical WR. There exist significant relationships between soils subcritical WR and soil physical or chemical properties.

Effects of fertilization on population density and productivity of herbaceous plants in desert steppe

In order to investigate the impacts of fertilization on population density and productivity on herbaceous plants in desert steppe, nitrogen （N）, phosphorus （P）, and N-P addition experiments were performed. Each fertilizer treatment included four addition levels, i.e., 0, 5, 10, and 20 g/m2. The results indicated that population density decreased as fertilization levels increased regardless of the sort of fertilizer. More specifically, total density as well as density ofArtemisia capillaris, Allium polyrhizum, and Enneapogon brachystachyus decreased significantly in 20 g/m2 treated plots, as compared with the control plots. Fertilization effects on aboveground and root biomasses were extremely similar to that found in population density; that is, both total aboveground biomass and aboveground biomasses for A. capillaris, A. polyrhizum, and E. brachystachyus were negatively correlated with increasing fertilization levels, with all determination coefficients （R2） greater than 0.80. Therefore, in the case of desert regions （annual precipitation 〈180 mm）, fertilization would inhibit population density and productivity of herbaceous plants.

Detrital zircon geochronology and provenance of sediments within the Mesozoic basins:New insights into tectonic evolution of the Qinling Orogen

Mesozoic sedimentary units within the Nanzhao and Mashiping basins record the paleogeographic and tectonic evolution of the Qinling Orogen(QO).This study uses new detrital zircon U-Pb ages and Hf isotopic data to constrain the timing of deposition and provenance of the Taishanmiao,Taizishan,Nanzhao,and Mashiping formations of the North Qinling Orogen(NQO).The detrital zircons can be split by age peaks into five major groups,including Early Cretaceous,Late Triassic,Early Paleozoic,Neoproterozoic and Paleoproterozoic age peaks.On the basis of the youngest zircon ages and age-diagnostic fossils,we conclude that the Taishanmiao(youngest age of 234 Ma)and Taizishan(216 Ma)formations were deposited during the Late Triassic,whereas the Nanzhao Formation(110 Ma)was deposited during the Early Cretaceous rather than the Late Jurassic as previously thought.The Mashiping Formation(110 Ma)was also deposited during the Early Cretaceous.Combined with zircon Hf isotopic compositions,zircons from Late Triassic units were generally derived from the NQO,South Qinling Orogen(SQO),and North China Craton(NCC),with minor amounts derived from the Xing-Meng Orogenic Belt.The sediments within the Nanzhao Formation were mainly derived from the QO,with a minor contribution from the NCC.The Early Cretaceous conglomerates of the Mashiping Formation were generally derived from recycled earlier detritus.This implies that Late Triassic deposition was related to the final closure of the Mianlue Ocean,whereas Early Cretaceous deposition was correlated to the continued intercontinental subduction of the Yangtze Craton beneath the QO.The change in provenance within these Mesozoic sediments suggests the QO underwent two periods of significant uplift,which was a process generated sediments that were deposited in a series of basins of this area.

Design and modification of metal sulfide-based catalysts for lithiumsulfur batteries

Metal sulfide(MS)have good conductivity,strong adsorption ability,and excellent catalytic activity for the conversion of sulfur species,and thus,show great promise as the catalysts in LieS batteries.However,the relationship between their properties and electrochemical performance is still unclear.Thus,further in-depth discussions are required to improve their design in Li-S batteries.This review systematically summarizes the basic structural and electrochemical properties of MSs and highlights the advantages that guarantee them as high-performance catalysts in Li-S batteries.Then,various modification strategies for MSs to enhance the catalytic activity,efficiency,and stability are also reviewed.At last,future opportunities for MS catalysts in Li-S batteries are proposed.

陆生蜗牛壳体日分辨率氧同位记录定量重建"千年一遇"超级暴雨

A"once-in-a-millennium"super rainstorm battered Zhengzhou,central China,from 07/17/2021 to 07/22/2021(named"7.20"Zhengzhou rainstorm).It killed 398 people and caused billions of dollars in damage.A pressing question is whether rainstorms of this intensity can be effectively documented by geological archives to understand better their historical variabilities beyond the range of meteorological data.Here,four land snail shells were collected from Zhengzhou,and weekly to daily resolved snail shellδ^(18)O records from June to September of 2021 were obtained by gas-source mass spectrometry and secondary ion mass spectrometry.The daily resolved records show a dramatic negative shift between 06/18/2021 and 09/18/2021,which has been attributed to the"7.20"Zhengzhou rainstorm.Moreover,the measured amplitude of this shift is consistent with the theoretical value estimated from the flux balance model and instrumental data for the"7.20"Zhengzhou rainstorm.Our results suggest that the ultra-high resolutionδ^(18)O of land snail shells have the potential to reconstruct local synoptic scale rainstorms quantitatively,and thus fossil snail shells in sedimentary strata can be valuable material for investigating the historical variability of local rainstorms under different climate backgrounds.

腾格里沙漠人工固沙植被区藓类植物形态演变特征

形态演变特征能够反映植物体对环境变化的适应策略。为了解藓类植物适应干旱沙区环境演变的形态变化特征,以腾格里沙漠东南缘人工固沙植被区内的真藓(Bryum argenteum)、土生对齿藓(Didymodon vinealis)和齿肋赤藓(Syntrichia caninervis)为研究对象,采用空间代时间的方法,解析了不同植被年龄区(35、41、66年)的藓类植物在叶片、个体、种群和群落水平的形态特征和数量特征的变化规律。结果表明:随着植被年龄的增加,3种藓的形态性状呈现出一定的差异性。突出体现在土生对齿藓的叶面积、叶尖长和株高不断下降,而真藓和齿肋赤藓表现出非持续性变化,这可能与种内和种间的资源竞争有关。尽管如此,从整体特征来看,腾格里沙漠人工固沙植被区藓类植物在生态系统修复过程中普遍经历了由茎叶体小、密度大向茎叶体大、密度小的演变趋势。

Passive devices at 2 μm wavelength on 200 mm CMOS-compatible silicon photonics platform [Invited]

As a promising spectral window for optical communication and sensing, it is of great significance to realize on-chip devices at the 2 μm waveband.The development of the 2 μm silicon photonic platform mainly depends on the performance of passive devices.In this work, the passive devices were fabricated in the silicon photonic multi-project wafer process.The designed micro-ring resonator with a 0.6 μm wide silicon ridge waveguide based on a 220 nm silicon-on-insulator platform achieves a high intrinsic quality factor of 3.0 × 105.The propagation loss is calculated as 1.62 d B/cm.In addition,the waveguide crossing, multimode interferometer, and Mach–Zehnder interferometer were demonstrated at 2 μm with good performances.

Accurate attitude estimation of HB2 standard model based on QNCF in hypersonic wind tunnel test

The accuracy of the HB2 standard model attitude measurement has an important impact on the hypersonic wind tunnel data assessment.The limited size of the model and the existence of external vibrations make it challenging to obtain real-time reliable attitude measurement.To reduce the influence of attitude errors on test results,this paper proposes a Quaternion Nonlinear Complementary Filter(QNCF)attitude determination algorithm based on Microelectromechanical Inertial Measurement Unit(MEMS-IMU).Firstly,the threshold-based PI control strategy is adopted to eliminate noise effect according to the Acceleration Magnitude Detector(AMD).Then,the flexible quaternion method is updated to carry out attitude estimation which is operational and easy to be embedded in the Field Programmable Gate Array(FPGA).Finally,a high-precision three-axis turntable test and a hypersonic wind tunnel test are performed.The results show that the pitchroll attitude errors are within 0.05°and 0.08°in the high-precision three-axis turntable test in a calculation time of 100 s respectively,and the attitude error is within 0.3°after the elastic angle correction in the hypersonic wind tunnel test.The proposed method can provide accurate real-time attitude reference for the analysis of the actual movement of the model,exhibiting certain engineering application value with robustness and simplicity.

Electro-optomechanical cooperative cooling of nanomechanical oscillator beyond resolved sideband regime

We propose a ground-state cooling scheme for a nanomechanical oscillator(NMO)that interacts with an optical cavity via radiation pressure at one side and with a superconducting microwave cavity via a capacitor at the other side.By driving these two cavities on their respective red sidebands with extra laser and microwave fields,the NMO’s dual cooling channel is created through electro-optomechanical cooperation.Differing from the conventional optomechanical system with a single optical cavity wherein ground-state cooling is limited in the resolved sideband,the proposed scheme allows the optical cavity to function in an unresolved sideband regime under the cooperation of a microwave cavity with a high quality factor,or vice versa.In a weak coupling regime we demonstrate that the NMO can be cooled to near its ground-state from a finite temperature with a cooling rate that is significantly faster than that of the single-cavity optomechanical system.The heating process can be completely suppressed by the cooperation of the dual cooling channel by appropriately selecting the system’s parameters.With a decreasing thermal phonon number,the numerical results of final mechanical occupancy gradually approach the analytical cooling limit.

A Monochromophoric Approach to Succinct Ratiometric Fluorescent Probes without Probe-Product Crosstalk

Ratiometric probes facilitate quantitative studies via self-calibration and are cherished for bioimaging.Often,a small probe-product spectral separation leads to crosstalk,but the rational development of ratiometric probes with zero probe-product crosstalk remains challenging.Harnessing the recent progress on photophysical modulation of xanthenoid fluorochromes,we propose a powerful and versatile probe design principle,that is,“bridging-group modification,”and developed totalROX,a robust probe for monitoring the total cellular oxidative capacity.