Paleo-fires and Atmospheric Oxygen Levels in the Latest Permian:Evidence from Maceral Compositions of Coals in Eastern Yunnan,Southern China

Inertinite maceral compositions of the Late Permian coals from three sections in the terrestrial and paralic settings of eastern Yunnan are analyzed in order to reveal the paleo-fire events and the atmospheric oxygen levels in the latest Permian. Although the macerals in the studied sections are generally dominated by vitrinite, the inertinite group makes up a considerable proportion. Its content increases upward from the beginning of the Late Permian to the coal seam near the Permian- Triassic boundary. Based on the microscopic features and the prevailing theory that inertinite is largely a by-product of paleo-fires, we suggest that the increasing upward trend of the inertinite abundance in the latest Permian could imply that the Late Permian peatland had suffered from frequent wildfires. Since ignition and burning depend on sufficient oxygen, a model-based calculation suggests that the 02 levels near the Wuchiapingian/Changhsingian boundary and the Permian-Triassic boundary are 27% and 28% respectively. This output adds supports to other discoveries made in the temporal marine and terrestrial sediments, and challenges the theories advocating hypoxia as a mechanism for the PermianTriassic boundary crisis.

On the Variability of Charleston South Carolina Winds, Atmospheric Temperatures, Water Levels, Waves and Precipitation

Atmospheric winds, air temperatures, water levels, precipitation and oceanic waves in the Charleston South Carolina (SC) coastal zone are evaluated for their intrinsic, internal variability over temporal scales ranging from hours to multi-decades. The purpose of this study was to bring together a plethora of atmospheric and coastal ocean state variable data in a specific locale, to assess temporal variabilities and possible relationships between variables. The questions addressed relate to the concepts of weather and climate. Data comprise the basis of this study. The overall distributions of atmospheric and coastal oceanic state variable variability, including wind speed, direction and kinematic distributions and state variable amplitudes over a variety of time scales are assessed. Annual variability is shown to be highly variable from year to year, making arithmetic means mathematically tractable but physically meaningless. Employing empirical and statistical methodologies, data analyses indicate the same number of intrinsic, internal modes of temporal variability in atmospheric temperatures, coastal wind and coastal water level time series, ranging from hours to days to weeks to seasons, sub-seasons, annual, multi-year, decades, and centennial time scales. This finding demonstrates that the atmosphere and coastal ocean in a southeastern U.S. coastal city are characterized by a set of similar frequency and amplitude modulated phenomena. Kinematic hodograph descriptors of atmospheric winds reveal coherent rotating and rectilinear particle motions. A mathematical statistics-based wind to wave-to-wave algorithm is developed and applied to offshore marine buoy data to create an hour-by-hour forecast capability from 1 to 24 hours;with confidence levels put forward. This affects a different approach to the conventional deterministic model forecasting of waves.

Climate-Induced Variability of Sea Level in Stockholm: Influence of Air Temperature and Atmospheric Circulation

This study is focused on climate-induced variation of sea level in Stockholm during 1873-1995. After the effect of the land uplift, is removed, the residual is characterized and related to large-scale temperature and atmospheric circulation. The residual shows an overall upward trend, although this result depends on the uplift rate used. However, the seasonal distribution of the trend is uneven. There are even two months （June and August） that show a negative trend. The significant trend in August may be linked to fresh water input that is controlled by precipitation. The influence of the atmospheric conditions on the sea level is mainly manifested through zonal winds, vorticity and temperature. While the wind is important in the period January-May, the vorticity plays a main role during June and December. A successful linear multiple-regression model linking the climatic variables （zonal winds, vorticity and mean air temperature during the previous two months） and the sea level is established for each month. An independent verification of the model shows that it has considerable skill in simulating the variability.

Coastal sea level variability in the Bohai Bay: influence of atmospheric forcing and prediction

The sea level variabilities, especially the atmosphere-driven sea level variabilities, which are diff erent in studies on diverse areas and timescales, need to be further documented in the Bohai Bay. Coastal sea level data and coincident meteorological data collected hourly at two observation stations (E1 and E2) in the Bohai Bay, which is a typical semi-enclosed coastal sea in China, are analyzed for the period from 19 August 2014 to 18 November 2014. The sub-sampled low-pass (<0.8 cpd) sea levels (SLSLs) at E1 and E2 are almost the same as each other, while the winds are not. On the whole, SLSLs at E1 and E2 are dominantly influenced by the across-shore wind;in detail, the dominant wind orientation at E1 is 65° measured clockwise from north, and SLSL at E2 is significantly influenced by the sub-sampled wind (SW) at 55°. Regression of SLSL onto the corresponding SW in dominant orientation and the atmospheric pressure is used to predict SLSL, which make the frequency of occurrences when the predicted total sea level is within 0.15 m from the observed values increase to 66.03% and 58.08% at E1 and E2 from original 36.71% and 34.80% without using it, respectively. The results indicate that for the prediction of the total sea level variability in the coastal shallow waters, the SLSL influenced by the atmospheric forcing, including local wind and atmospheric pressure, can be predicted using the multivariable linear regression model.

A STUDY ON LOW－LEVEL ATMOSPHERIC STRUCTURE ON THE SEASIDE BORDERS TO THE WEST OF HAIKOU

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SST INTRASEASONAL OSCILLATION AND ATMOSPHERIC FORCING SYSTEM OF THE SOUTH CHINA SEA

This study used National Center for Environmental Prediction (NCEP) reanalysis data to confirm that the variance of sea surface temperature (SST) in the South China Sea (SCS) has pronounced intraseasonal oscillations characterized by quasi standing waves; and was aimed to document how intraseasonal time scale SST formed and developed in the SCS. The results derived from the composite analysis indicated the existence of a local low level atmospheric dynamic forcing system over the SCS. The main formation mechanism of SST intraseasonal oscillation is the low level rotational atmospheric circulation forcing over the SCS on intraseasonal time scales and the solar radiation variations caused by cloud amount changes.

一种基于静止卫星的海面风矢量估测方法

参考大气动力学理论中风随高度、纬度的分布特征,提出一种基于静止卫星低层大气导风利用全连接神经网络估测海面风的新思路,构建基于卫星遥感数据的全连接神经网络海面风矢量估测模型,实现基于大气导风的海面风估测。基于GOES-16先进基线成像仪可见光通道0.5 km分辨率大气导风开展试验,并与2021年1月1日—12月31日北美近海岸和海上93个美国国家数据浮标中心浮标数据比对,结果表明:全连接神经网络估算得到基于大气导风的海面风风速均方根误差不大于1.5 m·s^(-1),较传统模型降低0.24 m·s^(-1)。将模型应用于飓风场景,通过与2022年3个北大西洋飓风和3个东太平洋飓风共13个时次的再分析数据比对表明:基于大气导风的海面风风速均方根误差不大于1.1 m·s^(-1),相较于传统经验模型降低0.04 m·s^(-1),在低风速区无系统性偏差。

基于风廓线雷达产品的冰雹过程分析

利用贵州省威宁县气象局的风廓线雷达基础数据及其二次开发产品、雨量站和MICAPS的实况数据,对2019年6月11日发生在威宁本站的一次冰雹大风天气过程进行综合分析。结果表明:水平廓线产品可反映出冷暖平流的时空变化及垂直分布,更早探测冷空气入侵、风场切变情况及低空急流强度;大气折射率结构常数和垂直速度可以指示降水的发生、持续时间及降水强度情况;强降水发生前有较强风垂直切变,降水过程中风垂直切变值整体大于0.2 s^(-1),风垂直切变的增强会引起垂直速度和地面大风的增大;若以大于15 dBZ和小于10 dBZ为降水的起止标志,风廓线雷达反射率因子较其他产品可以更清晰地指示降水的开始和结束。

ARTP诱变灰葡萄孢霉筛选高产脱落酸菌株

目的:利用常压室温等离子体(Atmospheric Room Temperature Plasma,ARTP)技术对生产脱落菌的潜力宿主灰葡萄孢霉进行诱变,以获得遗传稳定性好的高产脱落酸的突变菌种。方法:利用酶解法去除灰葡萄孢霉细胞壁,从而获得灰葡萄孢霉原生质体。接着将灰葡萄孢霉原生质体在输出功率120 W,工作气流10 L/min,照射距离2 mm,照射时间120 s的条件下进行ARTP诱变处理。检测突变菌株的脱落酸产量,并对最佳突变菌株进行发酵优化。结果:与野生型相比,突变菌株的脱落酸生产能力有了不同程度的提高,其中突变菌株A4和A7的脱落酸生产能力显著提高,分别提高了26.3%和30.5%。进一步通过单因素实验,确定突变菌株A7的最佳发酵碳源和氮源成分为葡萄糖和黄豆粉,最佳接种量为8%。结论:采用ARTP诱变技术能够有效获得高产脱落酸的突变菌株,为脱落酸的工业化生产提供了有利支撑。

浅析环境监测在当前水污染及大气污染防治工作中的作用

本文旨在研究环境监测在水污染及大气污染防治工作中的作用。首先介绍了水污染和大气污染的背景和重要性;然后阐述了环境监测的定义、作用和关键作用,包括保障水质安全、提升污水处理技术和降低水污染隐患发生率;最后介绍了环境监测技术的创新与发展,包括传统技术的局限性、新型技术的应用和智能化监测系统的建设。研究认为环境监测在水污染及大气污染防治中起着重要作用,为环境保护和人民健康提供了科学依据。

金融集聚对高技术产业创新韧性的影响机制分析

创新驱动发展战略实施过程中,需要创新链、产业链、资金链、人才链深度融合,进而提高创新效能。然而高技术产业创新具有高风险、高投入等特性,因此提升其持续创新能力、增强其韧性尤为重要。文章基于省份面板数据,运用动态面板广义矩阵(GMM)考察金融集聚对高技术产业创新韧性的影响机制。研究结果表明:金融集聚显著提升了地区高技术产业的创新韧性;人力资本水平在金融集聚影响高技术产业创新韧性过程中发挥中介效应;创新氛围正向调节了金融集聚提升高技术产业创新韧性。

防爆仪表的温度组别选型难题解决办法

化工装置中存在多种爆炸性气体。防爆仪表在进行防爆选型设计时,仪表的温度组别必须满足爆炸危险区域的要求。项目中工艺介质温度过高,使防爆证书中认证的温度组别低于所在爆炸危险区域要求的组别,无法选到可以使用的音叉液位开关产品。针对此问题,深入分析温度组别防爆的基本原理,结合项目具体爆炸危险区域划分图和工艺介质特性等实际情况,提出了应对不同情形的三种解决思路:合理调整仪表位置、精细划分爆炸危险区域和对仪表防爆保温。最终使选择出的音叉液位开关符合爆炸危险区域温度组别的要求,解决了特殊工况下防爆仪表温度组别选型难题。

昌平地震台井水位观测资料质量评价与数据分析

对2002—2023年昌平地震台地下流体数字化井水位观测资料进行系统整理,对数据的连续率、完整率、内在质量进行评估,同时,对水位资料的长期动态变化等进行了分析。结果表明,昌平地震台井水位观测资料连续、可靠,观测仪器稳定。井水位日变特征明显,具有清晰的固体潮效应,长期动态特征与昌平区地下水位动态特征一致,主要受到农业灌溉用水及水库生态补水的影响。井水位与气压间具有明显的负相关性,此外,井水位经一阶差分处理后的变化速率曲线与地震间具有相关性。

Modeling OH transport phenomena in cold plasma discharges using the level set method

Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma medicine.Generated reactive species such as hydroxyl(OH)species play an important role in applications of CAPs.Transportation of OH species towards the target and distribution of these OH species in the plasma plume play an important role in the applications of plasma medicine.In the present work,a computational model was built to simulate the transportation and distribution of OH species in CAP discharges,which was based on the level set method to dynamically track the propagation of plasma carrier gas in air.A reaction term was incorporated for the OH species.The OH species tended to diffuse around the main stream of the carrier gas,and thus covered larger radial and axial distances.A CAP discharge onto a skin layer led to the largest accumulation of OH species at the central part of the exposed area.The distribution of OH species on the skin was asymmetric,which agreed with experiments.The computational model itself and the obtained results would be useful for future development of plasma medicine.

THE PRELIMINARY DESIGN OF LOW-LEVEL WINDSHEAR SIMULATION SYSTEM ON GROUND

Infrared windshear prediction is one of airborne LLWS remote sensing methods.Before it is applied,the prediction system should be tested on ground to prove it’s feasibility.The LLWS simulation system isused to check whether the infrared windshear prediction system operate properly.In this paper,according tothe requirement of the LLWS detection and the characteristic of LLWS＂source＂,we will analyze the theoryof the LLWS simulation and give a basic description of the system construction in which we pay more atten-tion to optical simulation and flight simulation.The optical simulation is used to simulate the atmospherc in-frared radiation as a LLWS occurs.The flight simulation is used to simulate the aircraft airspeed,pitch,alti-tude etc..The works presented here are necessary for the LLWS infrared prediction system.

北京4种典型林分水质效应分析

以北京松山国家森林公园4种典型林分类型为研究对象,通过收集它们各空间层次(林冠层、枯落物层和土壤层)水样以及溪水、地下水和库区水的水样,并带回实验室检测分析各水样中水质离子浓度,探讨降雨输入-输出过程中离子浓度变化趋势,验证松山国家森林公园4种林分对水质效应的影响程度。结果表明:林冠层到土壤层,Na^(+)、Mg^(2+)和Ca^(2+)的浓度变化呈现出逐渐升高的趋势,K^(+)、NH_(4)^(+)和Cl-浓度变化呈现出先升高后下降的趋势,转折点分别为0~20 cm土壤层、林冠层和枯落物层,NO_(3)^(-)、NO_(2)-、SO_(4)^(2-)和F-的浓度变化呈现出先下降再升高又下降的趋势,转折点分别为枯落物层和0~20 cm土壤层。4种林分对溪水净化作用明显,溪水中Na^(+)、K^(+)、NH_(4)^(+)、NO^(3)^(-)、NO_(2)-和SO_(4)^(2-)浓度较壤中流降幅为13.54%~86.81%,对地下水和库区水影响较小。根据《地表水环境质量标准》和《地下水质量标准》综合评价结果显示,20~60 cm土壤层对降雨水质起到关键的净化作用,以蒙古栎纯林的净化效果最佳。4种林分中蒙古栎纯林对水质净化效果最佳,其次为油松+毛白杨混交林、油松纯林、山杨纯林。

城市群网络空间结构对大气污染的减排效应研究

探究城市群网络化空间结构演化及减排效应是提升城市群环境质量的重要支撑.本文基于2004−2020年中国14个城市群的动态面板数据,采用社会网络分析方法总结城市群网络空间结构及多重嵌套特征,进而构建实证模型纠偏最小二乘法(LSDVC)检验城市群网络空间结构的大气污染减排效应,并引入嵌套型与非嵌套型城市群的异质性分析,最后探讨了城市群产业分工水平的中介影响机制.结果表明:①我国城市群空间结构具有明显的网络化趋势,但各城市群之间存在显著差距,其中长三角城市群、长江中游城市群和珠三角城市群的网络空间结构已经出现了多重嵌套特征.②城市群网络空间结构具有显著的大气污染减排效应,且相对于非嵌套型城市群,嵌套型城市群的减排效应更显著.③产业分工水平对于城市群的大气污染减排效应存在中介影响机制,优化城市群产业分工布局有利于大气污染减排.研究显示,发展多重嵌套、分工明确、联系紧密、功能互补的城市群网络空间结构有助于强化区域协同合作,提升环境污染治理能力,推动城市群绿色发展.

一种改进的微光夜视系统视距探测方程

视距是评估微光夜视成像系统性能的一个重要参数。随着微光夜视探测技术的发展,经典视距模型的视距仿真结果与实测结果出现了一些偏差,特别是在10-3 lx低照度条件下视距仿真结果不甚理想,这对微光夜视仪在实际应用中造成了很大的阻碍。针对这一问题,从微光成像系统成像链路的三个环节对经典视距模型进行修正:考虑大气透过率对微光夜视系统视距的影响并对经典视距模型中的大气透过率因子进行修正;基于像增强器噪声因子对视距模型进行修正;考虑人眼视觉传递特性对微光夜视系统视距的影响,在系统的传递函数模型中加入了简化的人眼视觉模型。进而推导出改进的视距模型。结合野外试验数据,验证了改进视距模型的有效性和实用性,这对于微光夜视系统的设计、评估和应用具有一定的指导性意义。

土壤和河流沉积物吸附三价铬过程中的铬同位素分馏

沉积岩的铬同位素组成已被广泛应用于重建地质历史时期大气氧气含量的波动。这一指标的一个基本前提是自然环境中铬同位素分馏只发生在六价铬与三价铬的氧化还原转化过程中。但是,对非氧化还原过程中的铬同位素分馏行为目前仍然不清楚。本文通过模拟实验发现三价铬被土壤和河流沉积物吸附这一非氧化还原过程也会造成明显的铬同位素分馏。这一过程的铬同位素分馏系数(-0.06‰至-0.95‰,表示为103lnα)要小于氧化还原过程中的。结合前人对于有机配体溶解三价铬过程伴随的非氧化还原铬同位素分馏的研究结果,本文认为沉积岩中观测到的系统性的非常偏正的铬同位素记录可以被解释为大气氧化事件,但是在某些地质时代观测到的较弱的偏正铬同位素记录可能是由于非氧化还原过程造成的,应谨慎解译数据。

WRF 4.0模式陆气耦合对不同物理参数化方案的敏感性初探

模式的不同参数化方案会对模拟的天气和气候产生影响,但如何影响陆气耦合还不是很清楚。利用WRF 4.0模式设计了一组16种不同参数化方案组合的集合试验,对华北地区2013年夏季气候进行模拟。结果表明,不同积云对流参数化方案对模拟的降水平均态影响较大,其次是短波辐射方案,而微物理方案影响较小。进一步利用潜热通量(LH,Latent Heat flux)和土壤湿度(SM,Soil Moisture)、抬升凝结高度(LCL,Lifting Condensation Level)的相关系数R(SM,LH)和R(LH,LCL)表征陆气耦合过程,评估了陆气耦合对不同参数化方案的敏感性。模式模拟的R(SM,LH)在不同区域随着平均降水、相对湿度的增加以及平均短波辐射的减少而减小,而R(LH,LCL)的变化正好相反。它们内在的物理机制类似,与气候态的干湿变化密切相关,即随着土壤湿度趋于饱和,蒸散发过程逐渐受太阳辐射的限制,陆面对大气的影响减弱。另外,陆气耦合强度受积云对流方案、微物理方案和短波辐射方案的影响而产生差别,这与不同参数化方案模拟的气候态的不同密切相关,因此本研究对于WRF 4.0模式中参数化方案特别是积云对流方案的选择同样有着重要的指导意义。