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  • Estimation of rock Fe content based on hyperspectral indices

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:Information on the Fe content of bare rocks is needed for implementing geochemical processes and identifying mines. However, the influence of Fe content on the spectra of bare rocks has not been thoroughly analyzed in previous studies. The Saur Mountain region within the Hoboksar of the Russell Hill depression was selected as the study area. Specifically, we analyzed six hyperspectral indices related to rock Fe content based on laboratory measurements (Dataset I) and field measurements (Dataset II). In situ field measurements were acquired to verify the laboratory measurements. Fe content of the rock samples collected from different fresh and weathered rock surfaces were divided into six levels to reveal the spatial distributions of Fe content of these samples. In addition, we clearly displayed wavelengths with obvious characteristics by analyzing the spectra of these samples. The results of this work indicated that Fe content estimation models based on the fresh rock surface measurements in the laboratory can be applied to in situ field or satellite-based measurements of Fe content of the weathered rock surfaces. It is not the best way to use only the single wavelengths reflectance at all absorption wavelengths or the depth of these absorption features to estimate Fe content. Based on sample data analysis, the comparison with other indices revealed that the performance of the modified normalized difference index is the best indicator for estimating rock Fe content, with R2 values of 0.45 and 0.40 corresponding to datasets I and II, respectively. Hence, the modified normalized difference index (the wavelengths of 2220, 2290, and 2370 nm) identified in this study could contribute considerably to improve the identification accuracy of rock Fe content in the bare rock areas. The method proposed in this study can obviously provide an efficient solution for large-scale rock Fe content measurements in the field.

  • Land use/land cover change responses to ecological water conveyance in the lower reaches of Tarim River, China

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin. However, excessive exploitation and over-utilization of natural resources, particularly water resources, have triggered a series of ecological and environmental problems, such as the reduction in the volume of water in the main river, deterioration of water quality, drying up of downstream rivers, degradation of vegetation, and land desertification. In this study, the land use/land cover change (LUCC) responses to ecological water conveyance in the lower reaches of the Tarim River were investigated using ENVI (Environment for Visualizing Images) and GIS (Geographic Information System) data analysis software for the period of 1990–2018. Multi-temporal remote sensing images and ecological water conveyance data from 1990 to 2018 were used. The results indicate that LUCC covered an area of 2644.34 km2 during this period, accounting for 15.79% of the total study area. From 1990 to 2018, wetland, farmland, forestland, and artificial surfaces increased by 533.42 km2 (216.77%), 446.68 km2 (123.66%), 284.55 km2 (5.67%), and 57.51 km2 (217.96%), respectively, whereas areas covered by grassland and other land use/land cover types, such as Gobi, bare soil, and deserts, decreased by 103.34 km2 (14.31%) and 1218.83 km2 (11.75%), respectively. Vegetation area decreased first and then increased, with the order of 2010<2000<1990<2018. LUCC in the overflow and stagnant areas in the lower reaches of the Tarim River was mainly characterized by fragmentation, irregularity, and complexity. By analyzing the LUCC responses to 19 rounds of ecological water conveyance in the lower reaches of the Tarim River from 2000 to the end of 2018, we proposed guidelines for the rational development and utilization of water and soil resources and formulation of strategies for the sustainable development of the lower reaches of the Tarim River. This study provides scientific guidance for optimal scheduling of water resources in the region.

  • Mass balance of saline lakes considering inflow loads of rivers and groundwater: the case of Lake Issyk- Kul, Central Asia

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:This study aimed to elucidate the influence of inflow water on the salinity concentration process of a saline lake and the mass balance of Lake Issyk-Kul, a tectonic saltwater lake in Kyrgyzstan. Based on the survey results and meteorological data from 2012 to 2015, we analyzed the dissolved chemical composition loads due to water inflow. Then, we discussed the relationship between the increase in salinity and water inflow into the lake. Through the water quality analysis data, we used the tank model to estimate the river inflow and analyze the loads by the L-Q curve. The groundwater loads were then estimated from the average annual increase in salinity of the lake over a period of 30 a. The results suggest that Lake Issyk-Kul was temporarily freshened between about AD 1500 and 1800 when an outflowing river existed, and thereafter, it became a closed lake in AD 1800 and continued to remain a saline lake until present. The chemical components that cause salinization are supplied from the rivers and groundwater in the catchment area, and when they flow into the lake, Ca2+, HCO3− and Mg2+ precipitate as CaCO3 and MgCO3. These compounds were confirmed to have been left on the lakeshore as evaporite. The model analysis showed that 1.67 mg/L of Ca2+ and Mg2+ supplied from rivers and groundwater are precipitated as evaporite and in other forms per year. On the other hand, salinity continues to remain in the lake water at a rate of 27.5 mg/L per year. These are the main causes of increased salinity in Lake Issyk-Kul. Since Na+ and Cl– are considered to be derived from geothermal water, they will continue to flow in regardless of the effects of human activities. Therefore, as long as these components are accumulated in Lake Issyk-Kul as a closed lake, the salinity will continue to increase in the future.

  • Drought and flood characteristics in the farming- pastoral ecotone of northern China based on the Standardized Precipitation Index

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:The farming-pastoral ecotone of northern China (FPENC) provides an important ecological barrier which restrains the invasion of desert into Northwest China. Studying drought and flood characteristics in the FPENC can provide scientific support and practical basis for the protection of the FPENC. Based on monthly precipitation data from 115 meteorological stations, we determined the changes in climate and the temporal and spatial variations of drought and flood occurrence in the FPENC during 1960–2020 using the Standardized Precipitation Index (SPI), Morlet wavelet transform, and inverse distance weighted interpolation method. Annual precipitation in the FPENC showed a slightly increasing trend from 1960 to 2020, with an increasing rate of about 1.15 mm/a. The interannual SPI exhibited obvious fluctuations, showing an overall non-significant upward trend (increasing rate of 0.02/a). Therefore, the study area showed a wetting trend in recent years. Drought and flood disasters mainly occurred on an interannual change cycle of 2–6 and 9–17 a, respectively. In the future, a tendency towards drought can be expected in the FPENC. The temporal and spatial distribution of drought and flood differed in the northwestern, northern, and northeastern segments of the FPENC, and most of the drought and flood disasters occurred in local areas. Severe and extreme drought disasters were concentrated in the northwestern and northeastern segments, and severe and extreme flood disasters were mainly in the northeastern segment. Drought was most frequent in the northwestern segment, the central part of the northeastern segment, and the northern part of the northern segment. Flood was most frequent in the western part of the northwestern segment, the eastern part of the northeastern segment, and the eastern and western parts of the northern segment. The accurate evaluation of the degrees of drought and flood disasters in the FPENC will provide scientific basis for the regional climate study and critical information on which to base decisions regarding environmental protection and socio-economic development in this region.

  • Characterizing the spatiotemporal variations of evapotranspiration and aridity index in mid-western China from 2001 to 2016

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:Mid-western China is one of the most sensitive and fragile areas on the Earth. Evapotranspiration (ET) is a key part of hydrological cycle in these areas and is affected by both global climate change and human activities. The dynamic changes in ET and potential evapotranspiration (PET), which can reflect water consumption and demand, are still unclear, and there is a lack of predictive capacity on drought severity. In this study, we used global MODIS (moderate-resolution imaging spectroradiometer) terrestrial ET (MOD16) products, Morlet wavelet analysis, and simple linear regression to investigate the spatiotemporal variations of ET, PET, reference ET (ET0), and aridity index (AI) in mid-western pastoral regions of China (including Gansu Province, Qinghai Province, Ningxia Hui Autonomous Region, and part of Inner Mongolia Autonomous Region) from 2001 to 2016. The results showed that the overall ET gradually increased from east to southwest in the study area. Actual ET showed an increasing trend, whereas PET tended to decrease from 2001 to 2016. The change in ET was affected by vegetation types. During the study period, the average annual ET0 and AI tended to decrease. At the monthly scale within a year, AI value decreased from January to July and then increased. The interannual variations of ET0 and AI showed periodicity with a main period of 14 a, and two other periodicities of 11 and 5 a. This study showed that in recent years, drought in these pastoral regions of mid-western China has been alleviated. Therefore, it is foreseeable that the demand for irrigation water for agricultural production in these regions will decrease.

  • Contribution of underlying terrain to sand dunes: evidence from the Qaidam Basin, Northwest China

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:Underlying terrain strongly influences dune formation. However, the impacts of underlying terrain on the dune formation are poorly studied. In the present research, we focused on dunes that formed in the alluvial fans and dry salt flats in the Qaidam Basin, Northwest China. We quantified the dunes' sediment characteristics on different types of underlying terrain and the terrain' effects on the surface quartz grains by analyzing grain-size distribution, soluble salt contents and grain surface micro-textures. Results showed that barchan dunes were dominated by medium sands with a unimodal frequency distribution, whose peak corresponded to the saltation load. Linear dunes were mainly composed of fine sands with a bimodal frequency distribution, whose main peak represented the saltation load, and whose secondary peak represented the modified saltation or suspension load. Sand was transported from source area by running water (inland rivers) over short distances and by wind over relatively longer distances. Thus, quartz grains had poor roundness and were dominated by sub-angular and angular shapes. Surface micro-textures indicated that dune sands were successively transported by exogenic agents (glaciation, fluviation and wind). Soluble salt contents were low in dunes that developed in the alluvial fans, which represented a low-energy chemical environment, so the grain surface micro-textures mainly resulted from mechanical erosion, with weak micro-textures formed by SiO2 solution and precipitation. However, soluble salt contents were much higher in dunes that developed in the dry salt flats, which indicated a high-energy chemical environment. Therefore, in addition to micro-structures caused by mechanical erosion, micro-textures formed by SiO2 solution and precipitation also well developed. Our results improve understanding of the sediment characteristics of dune sands and the effects of underlying terrain on dune development in the Qaidam Basin, China.

  • Effects of restoration modes on the spatial distribu¬tion of soil physical properties after land consolida¬tion: a multifractal analysis

    分类: 地球科学 >> 地理学 提交时间: 2021-12-30 合作期刊: 《干旱区科学》

    摘要:soil physical properties (SPP) are considered to be important indices that reflect soil structure, hydrological conditions and soil quality. It is of substantial interest to study the spatial distribution of SPP owing to the high spatial variability caused by land consolidation under various land restoration modes in excavated farmland in the loess hilly area of China. In our study, three land restoration modes were selected including natural restoration land (NR), alfalfa land (AL) and maize land (ML). Soil texture composition, including the contents of clay, silt and sand, field capacity (FC), saturated conductivity (Ks) and bulk density (BD) were determined using a multifractal analysis. SPP were found to possess variable characteristics, although land consolidation destroyed the soil structure and decreased the spatial autocorrelation. Furthermore, SPP varied with land restoration and could be illustrated by the multifractal parameters of D1, ∆D, ∆α and ∆f in different modes of land restoration. Owing to multiple compaction from large machinery in the surface soil, soil particles were fine-grained and increased the spatial variability in soil texture composition under all the land restoration modes. Plough numbers and vegetative root characteristics had the most significant impacts on the improvement in SPP, which resulted in the best spatial distribution characteristics of SPP found in ML compared with those in AL and NR. In addition, compared with ML, ∆α values of NR and AL were 4.9- and 3.0-fold that of FC, respectively, and ∆α values of NR and AL were 2.3- and 1.5-fold higher than those of Ks, respectively. These results indicate that SPP can be rapidly improved by increasing plough numbers and planting vegetation types after land consolidation. Thus, we conclude that ML is an optimal land restoration mode that results in favorable conditions to rapidly improve SPP.

  • 节律在听觉言语理解中的作用

    分类: 心理学 >> 认知心理学 提交时间: 2021-12-29

    摘要: 言语理解是听者接受外部语音输入并且获得意义的心理过程。日常交流中,听觉言语理解受多尺度节律信息的影响,常见有韵律结构节律、语境节律、和说话者身体语言节律三方面外部节律。它们改变听者在言语理解中的音素判别、词汇感知以及言语可懂度等过程。内部节律表现为大脑内神经振荡,其能够表征外部言语输入在不同时间尺度下的层级特征。外部节律性刺激与内部神经活动的神经夹带能够优化大脑对言语刺激的处理,并受到听者自上而下的认知过程的调节进一步增强目标言语的内在表征。我们认为它可能是实现内外节律相互联系并共同影响言语理解的关键机制。对内外节律及其联系机制的揭示能够为理解言语这种在多层级时间尺度上具有结构规律的复杂序列提供了一个研究窗口。

  • 补偿他人还是保护自己?内疚与羞耻情绪对合作行为的影响差异

    分类: 心理学 >> 发展心理学 分类: 心理学 >> 社会心理学 提交时间: 2021-12-28

    摘要:作为两种常见且易混淆的自我意识情绪, 内疚和羞耻对合作行为的影响及其机制存在差异, 内疚的影响更为稳定及具有普适性, 羞耻的影响更为复杂。两种情绪的影响可从动机机制和调节机制方面进行解释, 包括内疚对他人的补偿、修复动机, 羞耻对自我的保护、修复动机, 以及个体因素和情境因素对情绪影响的调节作用。未来研究可进一步关注内疚和羞耻诱发与测量方法的有效性, 情绪作用发生的内在过程和生理机制, 情绪影响的个体和文化差异。

  • 智力运动专家领域内知觉与记忆的加工特点及其机制

    分类: 心理学 >> 认知心理学 提交时间: 2021-12-26

    摘要:智力运动是以开发智力为目的且涉及到较多认知活动的竞技运动。研究表明,长期的智力运动经验会影响专家在领域内任务中知觉及记忆的行为表现及其大脑活动。智力运动经验使专家知觉广度增大的同时,促进专家对棋子关系进行整体性知觉加工,且这一过程与颞顶联合区、缘上回、压后皮质、侧副沟、梭状回等区域有关;在长时记忆中存储的具体(空间位置)及抽象信息(知识、策略、棋子关系等)是专家记忆优势发生的基础,该过程与内侧颞叶、额叶和顶叶有关。未来研究可以从智力运动类型、创新实验范式,结合测量设备及认知特点,深入探讨智力运动专家整体知觉优势及记忆优势的神经机制,为人工智能和技能训练等提供理论依据。

  • 用CSHINE重建重离子反应中的裂变事件

    分类: 物理学 >> 核物理学 提交时间: 2021-12-25

    摘要: 我们研究了在CSHINE上重建$ 25 MeV/u ^{86}Kr +^{208}Pb$ 反应中快裂变事件的方法。裂变碎片由三个大面积平行板雪崩计数器进行探测,它可以提供碎片的位置和到达的时间信息。起始时间信息由回旋加速器的高频信号给出。我们利用两个裂变碎片的速度,重建了裂变事件。裂变碎片的速度分布和方位差的展宽均随折叠角的增大而减小,这与快速裂变发生的图像一致。同时,裂变轴的各向异性角分布也一致地揭示了裂变事件的动力学特征。

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  • 人心难读:冲突中的预测偏差及其心理机制

    分类: 心理学 >> 社会心理学 提交时间: 2021-12-25

    摘要:广泛存在的预测偏差严重妨碍了冲突管理,因此,欲解决冲突管理的难题,必须探究人类在冲突中的预测偏差。然而现有研究多着眼于非冲突中的预测偏差,未考虑冲突的独特性。本项目旨在突破当前的理论困境,探讨冲突事件中预测偏差的独特规律及其心理机制与后果,具体而言包括四大目标:(1)聚焦冲突事件中的预测偏差,并以对应的非冲突事件作为对照,揭示预测偏差在冲突中独特的表现形式,提出冲突事件的“偏差放大效应”;(2)从动机性认知视角探讨“偏差放大效应”的心理成因,揭示“负性驱动机制”;(3)考察“负性驱动机制”下预测偏差导致的后果;(4)设计有效的去偏差方案。本项目最终将构建冲突事件中预测偏差的理论模型,推动对预测偏差的全面理解,发展行为决策理论,帮助公众和社会治理者准确预测他人,提升冲突管理能力,提高决策质量。

  • 即兴演奏的心理模型及其神经机制

    分类: 心理学 >> 认知心理学 提交时间: 2021-12-24

    摘要:即兴演奏是一个复杂的认知过程,其目标是为了创造出流畅并具有美感的音乐序列。即兴演奏需要使用大量的大脑网络来设计、产生和监控新的音乐输出,受到艺术表演者水平、创作条件要求等因素的影响,即兴演奏会出现两种不同的模式——认知控制模式和自动化加工模式。聚焦于两种不同的即兴演奏模式和其主要激活大脑区域,综述了即兴演奏的神经机制的研究,并提出了即兴演奏的双模式的心理模型。未来的研究可以重点关注即兴演奏的研究方法、即兴演奏两种模式的转换、即兴演奏和机器学习,以及即兴演奏对教育的启发意义等方面。

  • 随机排列集的信息熵度量

    分类: 数学 >> 数学(综合) 提交时间: 2021-12-24

    摘要:最近,一种全新的集合被提出,名为随机排列集(Random Permutation Set RPS)。随机排列集考虑了某一集合的所有可能的排列,并可以看作是证据理论的一种推广。不确定性是随机排列集的一个重要特征。一个简单的问题是如何测量随机排列集的不确定度。为了解决这一问题,本文提出了随机排列集的信息熵(Entropy of Random Permutation Set)。当忽略排列事件(Permutation Event)中元素的顺序时,随机排列集的信息熵退化为证据理论中的邓熵。当每个排列事件只包含一个元素时,随机排列集的信息熵退化为概率论中的香农熵。因此,随机排列集的信息熵可以看作是邓熵和香农熵的推广。 本文用数值算例说明了随机排列集的信息熵的有效性。

  • 消费者新产品采纳的特征及其影响因素

    分类: 管理学 >> 管理学其他学科 提交时间: 2021-12-23

    摘要:成功的新产品开发是企业获取竞争优势的重要因素,但创新产品并非总能得到市场的接受,大多数的新产品扩散往往以失败告终。因此,业界和学界对新产品采纳问题进行了诸多探索。新产品采纳过程是指创新产品从被设计制造出来,到最终被消费者或潜在消费者认识和采用的过程。对相关研究综述发现:以Rogers创新扩散模型为依据,按采纳时间和特征的不同,新产品采纳者可以系统分为早期采纳者和晚期采纳者,二者之间主要从创新性、产品理解和易感性三个维度进行区分。具体来说,早期采纳者具有高创新性、高产品理解和低易感性;晚期采纳者具有低创新性、低产品理解和高易感性。在此基础上,我们探究了各维度下影响消费者新产品采纳的具体因素。未来研究可以从这三个维度出发,结合已有研究的不足以及当前环境、消费特点等进行拓展。

  • A Player-like Agent Reinforcement Learning Method For Automatic Evaluation of Game Map

    分类: 计算机科学 >> 计算机科学技术其他学科 分类: 心理学 >> 心理学其他学科 提交时间: 2021-12-21

    摘要: Game map is an important human-computer interactive content-bearing platform in major games. With the application of cellular automata(CA) and Procedural Content Generation (PCG)in map generation, the spatial scale and data volume of current game maps are increasing greatly, while in game map test procedure, automatic methods such as interactive test script are inadequate both in depth and application breadth, especially in the lack of game map evaluation from player experience perspective. This research proposes an automatic game map test method based on agent reinforcement learning. By establishing agents’ interactive action models standing for different types of players’ behaviors in the map, universal evaluation of the map environment is enhanced through agent actions, which can optimize game map design from the perspective of player experience with quantitative value of inferiority. Finally, our campus scenes in Minecraft were used as the experimental environments to verify the effectiveness of the method.

  • 越富有越不支持再分配?社会阶层与再分配偏向的关系及其心理机制

    分类: 心理学 >> 社会心理学 提交时间: 2021-12-21

    摘要:社会阶层是影响再分配偏向的重要因素。研究发现,与低阶层者相比,高阶层者再分配偏向更低。基于以往研究,提出高社会阶层者低再分配偏向的作用机制及干预模型。依据该模型,动机方面的经济自利与系统合理信念,认知方面的经济不平等感知、贫富差距归因与刻板印象,情感方面的同情心与地位焦虑是影响高阶层者再分配偏向的中介因素;培育谦卑心态、进行反刻板印象干预、利用不平等框架效应、提高同情心、改变阶层文化价值观有助于提升高阶层者的再分配偏向。未来研究可对高阶层者的慈善行为及部分低阶层者拒绝再分配的现象加以关注,深入考察和完善该模型的作用机制,探索提升高阶层者再分配偏向的策略。

  • 多感觉整合范式中潜在的跨通道转换效应

    分类: 心理学 >> 认知心理学 提交时间: 2021-12-20

    摘要:大脑可以对来自不同感觉通道的信息进行处理与整合。与单一感觉通道相比,个体对同时呈现在不同感觉通道的目标信号的响应会更快。对于这种现象的一种主要理论解释是共同激活模型,该模型认为来自不同通道的刺激在特定的脑区汇聚整合,比如顶叶内沟、颞上沟和前额叶皮层区域。整合后的信号强度更大,可以更快地触发反应,但是信号的整合发生在认知加工的哪一阶段目前尚未有明确结论。当个体对出现在不同感觉通道之间的任务转换进行加工时,产生与感觉通道相关的任务转换的损失小于跨感觉通道转换损失与任务转换损失的总和,这为与感觉通道相关的转换代价来源于任务设置的惯性和干扰提供了证据。而在单通道和多通道之间发生转换时,跨通道转换代价会减小甚至消失,这是由于同时发生的多感觉整合抵消了一部分损失,这种现象支持了共同激活模型理论。然而,多感觉信号整合对任务转换的神经加工过程产生怎样的影响并不清楚,在未来的研究中可以把多感觉整合范式同经典的任务转换范式结合改进,进而确定跨通道转换的加工机制和多感觉信号整合的发生阶段。

  • Spectrum Broadening due to Nonselective Linear Absorption

    分类: 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 提交时间: 2021-12-20

    摘要:The position and linewidth of emission spectrum reflect the physical information inside an object observed. So keeping them from distortion is very important in the measurement of spectrum. However, the emission spectra are not always kept their forms. We let the near-infrared emission of a sodium lamp pass through a nonselective linear absorbing filter and then observe the emission spectrum. It is found that the spectral lines will be broadened when the power of the emission just after the filter becomes low enough, and the lower the transmittance of the filter is, the more obvious the effect is. This is another broadening effect different from the known ones and is likely to be another independent evidence for discrete wavelet structure of classical plane light waves.

  • MonTTS: 完全非自回归的实时、高保真蒙古语语音合成模型

    分类: 计算机科学 >> 计算机科学技术其他学科 提交时间: 2021-12-20

    摘要: 针对现有基于Tacotron模型的蒙古语语音合成系统存在的两个问题:1)难以实时合成;2)合成语音保真度较低,该文基于FastSpeech2模型提出了完全非自回归的实时、高保真蒙古语语音合成模型MonTTS。为了提高MonTTS模型合成蒙古语语音的韵律自然度/保真度,根据蒙古语声学特点提出以下三点创新改进:1)使用蒙古文音素序列来表征蒙古文发音信息;2)提出音素级的声学调节器以学习长时韵律变化;3)提出基于蒙古语语音识别和自回归语音合成两种时长对齐方法。同时,该文构建了一个当前最大规模的蒙古语语音合成数据库:MonSpeech。实验结果表明MonTTS在韵律自然度方面的主观平均意见分数(Mean Opinion Score,MOS)达到4.53,显著优于当前最优的基于Tacotron的蒙古语语音合成基线系统和基线FastSpeech2模型;MonTTS合成实时率达3.63×10-3,满足实时高保真合成要求。最后,文中涉及的训练脚本和预训练模型全部开源(https://github.com/ttslr/MonTTS)。