Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Mastering the regional wind sand movement environment and sediment particle size characteristics isthe key to studying wind sand flow, and is of great significance for the prevention and recovery of regional windsand disasters. Based on the wind regime data of Wuzhumuqin Sandy Land, this paper studies the variationcharacteristics of sand driving wind regime and sand transport potential, and reveals the spatial differences ofsand environment in this area by combining with the sediment particle size data. The results show that:（1）Theannual average frequency of sand blowing in the Wuzhumuqin sandy land is 33.8%, with an average wind speedof 3.34-5.40 m·s-1, and an average sand blowing wind speed of 6.46-8.49 m·s-1. The frequency and wind speedof sand blowing in the north of the sandy land are greater than those in the south, and those in the west are greaterthan those in the east.（2）The overall annual frequency and wind speed of sand storms are the highest in spring.The wind direction of sand storms is mainly in the southwest direction, and the frequency in the WSW directionis the highest. （3）The sand transport potential in the sandy land is 19.2-193.7 VU, which is generally a low windenergy environment. The wind conditions are mostly sharp bimodal wind conditions. The sand transport potentialin the north of the sandy land is greater than that in the south, and that in the west is greater than that in the east.Throughout the year, sand material is transported to the east and northeast, and spring is the most importantperiod of wind sand activity.（4）The sandy land is mainly composed of coarse and medium sand components,with soil particle sizes in the south and west being coarser and finer in the east. The sorting of sediment in thenorthern and eastern parts of the sandy land is poor, and the particle size components are greatly influenced byexternal factors. Overall, the sandstorm activity in the northern part of the sandy land is the strongest, making itsuitable for artificial planting or laying sand barriers to fix sand. Protection forest is planted in the east of thesandy land to avoid the continuous eastward movement of sand.
Subjects: Physics >> Atomic and Molecular Physics submitted time 2023-12-03
Abstract： Experimental and theoretical research on X-ray emissions following charge exchange between slow highly charged ions and atomic Hydrogen supply vital atomic data in the study of diagnosing and simulating plasmas in non-equilibrium astrophysical environment. In the present paper, employing the semiclassical multi-channel Landau-Zener (MCLZ) method, we calculated the total cross-section of bare and hydrogenic C, N, O ions charge exchange with hydrogen atoms, and compared it with previously reported experimental results. In C5 + H collision, theoretically calculated cross-sections have large differences with experimental cross-sections. We also compared state-selective cross-sections calculated by classical MCLZ and quantum-mechanical molecular orbital close-coupling(QMOCC) methods in the solar wind ion velocity (or energy) range. For capture to n = 3 shell, MCLZ calculated state-selective cross-section increase with collision energy increasing; For capture to n = 4 shell, MCLZ calculated state-selective cross-section decrease with collision energy increasing; It is lower than two magnitudes as QMOCC method calculated cross-section. Finally, using the Kronos program package developed in the astrophysical field, we calculated the X-ray emission spectrum, line ratio, and hardness ratio of charge exchange of 1000 eV/u O8 by means of recommended cross-section by Janev, and contrast with the MCLZ method calculated results. We consider that the MCLZ calculation has a large uncertainty, which could affect the accuracy of the astrophysical environment simulation. It is required for developing a more accurate full quantum theory.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： Konjac (Amorphophallus konjac) is a horticultural plant with high nutritional and medicinal value. The soft rot is a severe disease in production of konjac and it is also the main factor restricting the development of the konjac industry. It has been reported that the soft rot of konjac is mainly caused by pathogenic bacteria (mainly including Pectobacterium aroidearum, P. carotovorum subsp. carotovorum, P. chrysanthemi and Enterobacter sp.), and rarely reports on pathogenic fungi that cause konjac soft rot. In order to clarify the pathogenic types and infection characteristics of the soft rot in Qujing City, Yunnan province, the diseased corms were collected for fungal isolation by tissue isolation methods. The isolated fungi were identified by morphological and molecular identification methods based on ITS and LSU sequencing analysis, and pathogenicity was determined according to Koch's rule. The infection characteristic was analyzed by mixed inoculation using the identified pathogenic fungi and the pathogenic bacteria of konjac soft rot. The results were as follows: (1) Three species of Fusarium spp. (F. concentricum, F. oxysporum and F. ambrosium), one species of Mucor sp., one species of Rhizopus sp., one species of Penicillium sp. and one species of Clonostachys sp. were identified. (2) Statistics analysis found that F. concentricum had the highest abundance (45.45%). (3) Koch postulates tests showed that inoculation with F. concentricum caused obvious soft rot symptoms of konjac corms within three days. (4) In addition, mixed P. aroidearum and F. concentricum together inoculation promoted the disease development, and the weight of the rotten tissue was significantly higher than that of single inoculation using F. concentricum or P. aroidearum. Overall, these results indicate that konjac soft rot may be caused by a combination of fungus and bacterium infection. This study can provide a theoretical basis for the prevention and management of konjac soft rot.
Subjects: Biology >> Botany submitted time 2022-12-01 Cooperative journals: 《广西植物》
Abstract：
Investigating mechanisms underlying genetic variation and differentiation of wild resources is critical for the utilization and improvement of crop germplasms. Amorphophallus is an important economic crop in Southwest China for its glucomannan production. However, the wild populations of this genus are declining due to human activities. To investigate the genetic diversity and phylogenetic relationship of representative Amorphophallus species in Southwest China, three chloroplast DNA fragments were amplified and used to conduct population genetic and phylogenetic studies. The results were as follows: (1) The genetic diversity of wild Amorphophallus populations was generally low with an average haplotype diversity (Hd) of 0.428. In addition, nearly half of the total populations had only one haplotype. The haplotype diversity of each species varied from 0.704 to 0.983. (2) The genetic differentiation between each pair of six species was relatively high, and the FST values ranged from 0.481 to 0.967. (3) The phylogenetic inference suggested that 27 selected Amorphophallus species should be divided into three clades. A. paeoniifolius belonged to the Southeast Asia clade. The continental Asia A clade included A. konjac and A. krausei, and continental Asia B clade was comprised of A. kiusianus, A. yunnanensis and A. tonkinensis. Geographic isolation and human disturbance could have caused the low genetic diversity in wild populations of Amorphophallus. The divergence of the continental Asia clade may be driven by the rapid radiation and ecological adaptation in species of this clade. These findings provide theoretical guidance for the conservation, utilization and breeding of Amorphophallus species in Southwest China.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-21 Cooperative journals: 《干旱区研究》
Abstract：了揭示沙区建设光伏电站后沙尘运移特征和形态发育及演变过程，本文定量分析了主要风向（光伏板面向正南，风向为W，即光伏设施排布方向与风向夹角为0°）条件下，库布齐沙漠200 MWp光伏电站腹地区域光伏板不同位置输沙特征、地表风蚀状况和流场分布规律。结果显示：① 光伏板不同部位输沙率随风速的增大而增加，不同风速下平均输沙率板间(1.17 g·cm-2·min-1)＞板后(0.86 g·cm-2·min-1)＞板前(0.65 g·cm-2·min-1)。0~30 cm垂直断面上，不同部位90%以上输沙率集中分布在0~8 cm高度范围内，95%以上输沙率集中分布在0~11 cm高度范围内，挟沙气流中输沙率随高度的分布均符合指数规律递减[WTBX]（R2≥0.98）。② 沙粒平均跃移高度表现为板前＞板后＞板间，且与风速正相关。风沙流通量系数分析表明，板间和板后风沙流集中在近地层，而板前风沙流有向高层移动的趋势。③ 光伏板不同位置摩阻风速表现为板前（0.5620~0.596 0 m·s-1）>板后（0.331 2~0.436 0 m·s-1）>板间（0.3252~0.3632 m·s-1）。而且板前干沙层厚度显著高于其他位置，土壤可蚀性增加，综合作用下导致板前发生强烈掏蚀现象，观测期风蚀深度可达12.44 cm。研究可为沙漠地区光伏电站内风沙危害的科学防治提供理论支撑。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-04-26 Cooperative journals: 《干旱区研究》
Abstract：为了探究西鄂尔多斯地区荒漠灌丛的光合生态适应性，以4种天然荒漠灌丛半日花(Helianthemum songaricum)、红砂(Reaumuria songarica）、沙冬青(Ammopiptanthus mongolicus )、霸王(Sarcozygium xanthoxylon）为研究材料，利用Li-6400便携式光合测定仪野外原位测定荒漠灌丛日光合动态和季节动态规律。结果表明：① 不同季节灌丛光合作用适宜的温度存在差异，高温环境使灌丛净光合速率最适温度升高，低温环境使其降低。② 不同季节4种灌丛的净光合速率、蒸腾速率、水分利用效率和气孔导度日变化曲线趋势为“双峰形”，胞间CO2浓度日变化曲线趋势为“W形”，但不同季节各指标平均日变化趋势表现各异。③ 不同季节灌丛净光合能力表现为：沙冬青>霸王>红砂>半日花，说明沙冬青具有较强的生态适应性。④ 净光合速率和蒸腾速率日变化趋势几乎保持同步状态，表明4种灌丛叶片气孔对外界环境变化反应敏感。⑤ 水分是限制荒漠灌丛生长发育的关键因素。为了保证荒漠植物的群落稳定性和生物多样性，在夏、秋季需对沙冬青、半日花、红砂和霸王进行水分管理。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：通过野外试验探究了流动沙丘中上部导风板板后作用区风速特性和输沙量特征，结果表明：不同角度导风板对板后风速增加的区域有所不同，作用区内最大风速一般出现于板后1.5 m，45°导风板对于板后1.5 m处风速加速效果明显，板后3.0 m处则是25°导风板加速效果较为明显，而在板后4.5 m处影响效果明显的导风板角度为35°。导风板可以有效的提高板后输沙总量，其中30°~45°区间的中等角度导风板对于输沙量的提升具有明显效果，45°导风板对于板后1.5 m处输沙量提升效果较高，而40°导风板对于板后3.0 m处输沙量提升效果较高，在板后4.5 m处则是30°导风板提升效果较高。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：基于自然灾害风险理论，选取森林雪灾相关的气象、林业、基础地理信息和社会经济等数据，从致灾因子危险性、承灾体易损性、孕灾环境敏感性和防灾减灾能力4个方面综合评估内蒙古森林雪灾风险程度的地区差异，利用加权综合评分法、层次分析法建立并计算森林雪灾综合风险评估指标体系及指数，构建出内蒙古森林雪灾风险区划模型。内蒙古森林雪灾高风险区、次高风险区分别占全部森林雪灾风险区的77.18%、0.05%，且均位于内蒙古东北部的呼伦贝尔市。中等风险区占全部森林雪灾风险区的6.01%，主要位于锡林郭勒盟、呼伦贝尔市、赤峰市及兴安盟，分别占中等风险区总面积的0.61%、36.50%、9.11%和5.99%；次低风险区和低风险区占全部森林雪灾风险区的16.76%，主要位于阿拉善盟、鄂尔多斯市、兴安盟等地。内蒙古森林雪灾风险呈现自东北向西南逐渐减轻的趋势，与森林、积雪空间分布规律基本一致。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-10 Cooperative journals: 《干旱区研究》
Abstract：以乌海市晟辉能源技术公司沙区太阳能光伏电场为研究对象，对光伏矩阵内光伏板的前沿、后沿及光伏阵列行道处风沙输移情况进行观测，研究沙区光伏电站的风沙流输移规律。研究表明：① 各观测点输沙量均随着高度的增加呈降低趋势，光伏板前沿、后沿、行道处各观测点输沙量随高度增加的最佳拟合方程均为多项式函数，且R2均大于0.95，拟合结果可信。② 光伏板前沿、后沿处风沙流结构特征值大于1，风沙流呈非饱和状态，地表表现为风蚀。电场矩阵行道处风沙流结构特征值均小于1，风沙流为饱和状态，地表表现为堆积。由于光伏板对风沙流的导向作用，导致光伏板下方形成气流加速区，光伏板下方出现掏蚀现象，因此光伏板下方为场区内部风沙防治的重点区域。③ 光伏矩阵内部各观测点的输沙量均低于旷野处，且随着深入电站内部输沙量逐渐降低。沙区光伏电站控制沙害的关键位置为电站迎风边缘处。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-09 Cooperative journals: 《干旱区研究》
Abstract：积雪融水是干旱区重要的水资源之一，积雪分布变化的监测对区域雪冰资源的合理利用及灾害防治至关重要。基于内蒙古地区2001—2016年MOD10A2积雪数据对研究区进行分带提取，分析不同海拔高度积雪年内年际变化特征，结合气温和降水气象因素，分析其分布变化原因。研究表明：积雪面积、积雪覆盖率年内分布呈单峰形，10个海拔带的积雪期为9月到次年5月，峰值出现在冬季，积雪覆盖率增减的临界高度在952~1 114 m；不同高程带的积雪面积在春季、夏季、秋季整体上呈现出“增加—减少—增加—减少”的年际变化规律，冬季整体上表现出“减少—增加—减少”的变化规律；积雪面积受降水量和气温相互的影响，其中海拔高度可能起到间接作用。内蒙古地区春季、冬季积雪覆盖率均与冬季降水量呈显著正相关，各季节积雪覆盖率基本与温度呈负相关关系。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-06-10 Cooperative journals: 《干旱区研究》
Abstract： 为了进一步厘定西鄂尔多斯高原地区5种天然荒漠灌丛土壤碳排放的主控因子，估算灌丛土壤碳排放量并阐明不同灌丛土壤的碳排放特征，选用5种典型荒漠灌丛林为研究对象，通过土壤碳通量ACE（automated soil CO2exchange station）监测系统分别测定了5种灌丛土壤呼吸速率、土壤温湿度及碳排放量。结果表明：①5种灌丛土壤碳排放速率日动态总体呈现不对称钟形单峰曲线特性，峰值在11:3013:30。5种灌丛生长季土壤碳排放速率均显著高于非生长季，其中半日花灌丛（Helianthemum songaricum Schrenk）比其他灌丛高0.76～1.67倍。土壤年均碳排放量沙冬青灌丛为8090.63 kghm-2a-1、四合木灌丛7868.16 kghm-2a-1、霸王灌丛7287.40 kghm-2a-1、半日花灌丛8375.69 kghm-2a-1和红砂灌丛7618.47 kghm-2a-1；②在3种未来气候情景（低排放情景B1、中等排放情景A1B和高排放情景A2）下，5种灌丛土壤碳排放量将比基准情景高达8.30%，其中霸王灌丛变化最为明显。不同类型灌丛地土壤碳排放对气温变化的响应存在差异，但差异不显著。本研究可为全球环境变化下中国西北干旱、半干旱地区碳平衡估算提供数据基础和参考依据。
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