天山乌鲁木齐河源1号冰川雪冰中δ18O的演化过程

2002年9月14日-2005年3月7日,在天山乌鲁小齐河源1号冰川积累区雪坑中连续观测取样,频率为1次/周,分析了其巾的部分表层雪样品和粒雪坑样品中的δ18O.结果表明:表层雪样品的δ18O具有明显的季节变化,且与月平均温度关系密切.粒雪坑样品中的δ18O在9月底至次年6月初变化较小,升华对雪坑1 m以下雪冰中δ18O的影响不超过-2‰,整个雪坑都较好地保持了δ18O的季节变化特征.但6月初-9月底融水对雪冰中δ18O的影响巨大,冬季形成的δ18O低于-30%的中、细粒雪层,经过夏季融水的改造,可成为δ18O-11.6‰的粗粒雪和冰片层.融水可使雩冰中δ18O的改变最>60%.在全球变暖背景下,冬季形成的低δ18O雪层经过夏季融水的改造,其内的δ18O可以完全被平滑.     

高空浮尘对高海拔山地冰川物质平衡的影响——以西昆仑山崇测冰帽为例

西昆仑山位于塔克拉玛干沙漠南缘.从海拔6530m钻取的崇测冰帽冰芯发现,20世纪90年代前的60多年间,沙尘沉积和年积累率存在着一致的下降性趋势变化.结合对沙尘源地、沙尘输送路径及其沉积特征的调查研究,分析源——汇的诸多影响因素,探讨影响高海拔地区降水的主导过程,结果表明:1)在高海拔地区,尘埃可能比低海拔地区对降水起着更为重要的作用,这种作用主要是通过凝结核数量的变化发生的;2)在高海拔地区降水形成过程中,悬浮的尘埃数量会直接影响凝结核的数量;3)对于塔克拉玛干沙漠周边这样的干旱环境,大气水汽供应在高海拔地区相对更为充分些,因此与低海拔地区相比,高海拔山地冰川上的降水过程对大气尘埃微粒浓度的变化似乎更为敏感; 4)在沙漠及其周边地区的盛行气候条件下,冰川冰雪积累呈现出逐渐减少的趋势,与沙漠地区气候和环境变化密切相关——过去几十年间塔克拉玛干低海拔区降水增加,沙尘减少;5)这种行将持续的趋势可能会通过大气尘埃的变化继续影响高海拔冰川的物质平衡.本研究的这一发现可能从一个侧面揭示了一些地区性冰川变化的原因,如中亚地区持续了几十年的冰川消退现象.     

戒毒一号对甲基苯丙胺诱导的小鼠行为敏化的影响

目的探讨戒毒一号对甲基苯丙胺诱导的小鼠行为敏化的影响。方法分别采用单次给予甲基苯丙胺致小鼠高活动性及反复间断甲基苯丙胺处理建立甲基苯丙胺行为敏化小鼠模型,观察戒毒一号对甲基苯丙胺所致小鼠高活动性及其诱导的小鼠行为敏化的影响。结果戒毒一号低、高剂量灌胃给药后,对小鼠自发活动和甲基苯丙胺所致小鼠高活动性均无影响,却能显著抑制甲基苯丙胺诱导的小鼠行为敏化效应的形成、转化和表达。结论戒毒一号对甲基苯丙胺诱导的小鼠行为敏化的形成、转化和表达均有抑制作用,提示戒毒一号对甲基苯丙胺的精神依赖具有治疗作用。     

镉对米荞一号种子萌发与幼苗生长的影响

以米荞一号为对象,探究了不同镉浓度对种子萌发及幼苗生长的影响.结果表明:镉处理对米荞一号种子萌发无显著影响,但对幼苗生长产生差异;低浓度镉(2.5mg/L)对米荞一号幼苗生长无显著抑制作用,部分指标表现出一定的促进作用,芽长和鲜重呈现上升趋势,镉浓度分别达到5.0mg/L和10.0mg/L时,米荞一号鲜重和芽生长出现显著下降;随着镉浓度的增加,对米荞一号种子萌发后幼苗生长的抑制作用逐渐增强,当镉浓度达到80mg/L时,米荞一号幼苗生长几乎完全被抑制,造成无法正常生长.     

多源数据结合的高分一号土地利用/覆盖分类方法研究

基于多时相的GF-1数据获取NDVI时序变化、NDWI和MNDVI等指数图像数据,辅以Landsat8卫星OLI影像和数字高程模型(DEM)数据,得到了不同地物在光谱、时相和形状等方面的特征;通过分析各种地物类型在这些特征上的差异和变化规律,总结出不同地物的特征提取规则,构建了一种基于GF-1数据在地物复杂地区的土地利用/覆盖分类方法,并以广州市为实验区,运用该方法、最大似然法和最小距离法进行了土地利用/覆盖分类及其精度评价.结果显示:基于GF-1数据在地物复杂地区的土地利用/覆盖分类方法的总体精度为85.86%(部分地物分类精度达到95%以上),与最大似然法及最小距离法相比,其总体精度分别提高了4.62%和12.24%,说明该方法能够更好地发挥GF-1遥感数据在土地利用/覆盖分类中的实际应用潜力,且有效提高了各种土地利用/覆盖地物类别的分类精度.     

龙宝一号口服液对CCL_4肝损伤脂质过氧化作用的影响

ＣＣＬ４对细胞的损伤作用是通过自由基反应引起的．自由基可通过多种途径造成肝损伤，其直接作用于细胞膜上的不饱和脂肪酸使其过氧化形成脂质过氧化物，从而影响细胞膜的结构造成肝损伤。实验结果表明龙宝一号可降低ＣＣＬ４引起的ＭＤＡ升高的水平。抗组织脂质过氧化自由基在肝炎发病中的重要作用越来越引起了人们的重视。进一步研究龙宝一号的抗氧化机制，将可能为治疗肝炎提供新的药品     

叶面喷施硫酸钾对国庆一号柑橘的影响

以十五年生柑橘作为试验材料,研究了叶面喷施硫酸钾对柑橘叶绿素含量等生理指标的影响。结果表明:可提高叶片相对含水量、叶绿素含量、降低细胞膜透性,过氧化物酶活性,利于叶片光合作用的进行。     

水稻“滇榆一号”不同生育期及不同时期施穗肥后叶片过氧化物酶活性及其同工酶的变化

水稻滇榆一号不同生育期及不同时期施穗肥后,叶片过氧化物酶活性不同,但酶活性曲线都近呈w形。开花期,对照植株叶片的过氧化物酶活性最高,施大量基肥的植株叶片过氧化物酶活性最低,晚期施穗肥的植株叶片的酶活性稍低于对照株,早期和中期施穗肥的植株叶片酶活性介于前两者之间,不同时间施穗肥后,在开花期叶片过氧化物酶同工酶谱中出现两条新酶带。     

基于张衡一号电磁卫星数据对印尼Ms 7.4地震的研究

以2018年9月28日印尼Ms 7.4地震为背景, 利用张衡一号电磁卫星观测的ULF磁场X, Y和Z三分量数据, 采用滑动四分位(IQR)算法、滑动主成分分析算法(PCA)和短时傅里叶变换算法(STFT), 对震中范围的时空电磁数据进行分析, 结果显示 3 种算法都能有效地提取到震前异常。1) X,Y和Z分量均值震前7天开始出现异常, 随着发震时间临近, Y和Z分量的异常程度逐渐增加, 震前2天达到峰值, Y分量最大异常达到0.7 nT, 震后异常慢慢消失; 2) 震前5天主成分出现异常, 第一主成分占比急剧下降, 下降幅度超过15%, 第二、第三主成分占比急剧上升, 异常持续3天; 3) 震前9天, 13和25 Hz功率谱密度占比同时出现大幅异常, 13 Hz占比上升35%, 25 Hz占比下降超过40%, 13 Hz占比出现正异常, 最大正异常达到0.1, 25 Hz占比出现负异常, 最大负异常达到?0.15, 震后异常消失。结合同时段的太阳地磁活动情况, 认为上述电磁异常可以作为印尼地震的前兆。     

Characterization of individual fly ash particles in surface snow at Urumqi Glacier No. 1, Eastern Tianshan

This research aimed to identify and characterize individual spherical fly ash particles extracted from surface snow at Urumqi Glacier No.1 (UG1), Eastern Tien Shan, central Asia. Characterization of the spherical particles (i.e. morphology, chemical composition and genesis) was obtained by scanning electron microscopy coupled with energy dispersive X-ray spectrometer (SEM-EDX). This method enabled the characterization of submicroscopic spherical particles, which were present in very small quantities. Spherical particles and agglomerates were identified according to their morphology in five snow samples. Prevalent particle types in all samples were granular spherical particles, hollow spherical particles, irregularly shaped carbonaceous particles and agglomerates. The vast majority of spherical particles in our samples had mostly smooth and glossy surfaces, although these particles varied in diameter and elemental composition. The diameter of fly ash particles ranged from 0.76 to 16.7 m, with an average of 3.79 m (median: 3.21 m). Individual particle analyses of elemental composition showed that particles formed in combustion were mainly composed of carbon, silicon, aluminum and trace elements (e.g. Na, K, Ca, Fe). Some spherical fly ash particles contained toxic heavy metals (e.g. Pb, Cr, As, Zn), and indicated that fly ash particles acted as the main possible carriers of toxic heavy metals deposited in snow and ice of glaciers in high altitudes of central Asia. On the basis of chemical information obtained from EDX, the fly ash particles deposited in the snow could be classified into four types. Namely, Si-dominant particles, with average diameters of 3.24 m were formed by industrial coal combustion via high temperature processes in typical coal-fired heating stations and thermal power plants. Moreover, Fe-dominant particles, with average diameters of 3.82 m, and Ti-dominant spherical particles formed by lower temperature processes in foundry and iron or steel plants. In addition, C-dominant particles, with average diameters of 8.43 m, formed from unburned coal. Fe-dominant particles had larger average diameters than Sidominant particles, indicating that the former were easier to form and developed earlier in the furnace because of their differential melting points of compositional oxide. Backward air mass trajectory analysis suggests that the developed urban regions of central Asia contributed the primary fly ash particles from industrial combustion to the study site through the high-level westerlies jet steam.     

Changes in physical features of Glacier No. 1 of the Tianshan Mountains in response to climate change

This study analyzes the changes in glacier zones and snow composition of Glacier No.1 in the Tianshan Mountains of China since 1961,and their possible relations with climate.It is found that precipitation dominated the snow composition and that air temperature and precipitation controlled the distribution of glacier zones,but interannual change in precipitation had a relatively large effect on glacier zones and snow composition during 1963–1981 (P10) and 1963–1989 (P11).However,during 1982–2007 (P20) and 19...     

Glacier changes during the last forty years in the Tarim Interior River basin, northwest China

By comparing digitized glacier outlines from the Chinese Glacier Inventory (CGI) during the 1960s–1970s and Landsat Enhance Thematic Mapper (ETM+) images from 1999 to 2001, we investigated changes for about 7665 alpine glaciers among 11665 glaciers in seven sub-basins of the Tarim Interior River basin (TIRB). The results showed that the total glacier area was reduced by 3.3% from the 1960s/ 1970s to 1999/2001 and area losses for 1–5 km2 glaciers accounted for 48.3% of the total glacier area loss in the TIRB. However, the glacier area reductions varied from 0.7% to 7.9% among the seven sub-basins of the TIRB during the study period. The glacier area changing with altitude showed that the maximum contribution of area shrinkage occurred at 4900–5400 m. Data from 25 meteorological stations in the TIRB showed increases in both the annual mean air temperature and annual precipitation during 1960–2000. This indicates that the glacier shrinkage in the TIRB over the last 40 years was largely due to regional climate warming that enhanced glacier ablation and overcame the effects of increased precipitation on the glacier mass balance.     

探索C5级程控端局No.1与No.7信令的接口

作者在本文研究了我国本地网中端局至端局的Ｎｏ．７信令系统基础上，探索了一种Ｃ５级程控端局Ｎｏ．１与Ｎｏ．７信令接口的设计方法。     

Numerical simulation of Urumqi Glacier No. 1 in the eastern Tianshan, central Asia from 2005 to 2070

Due to climate changes, most of the alpine glaciers have retreated dramatically during the past decades. Thus it is significant to predict the alpine glacier variability in the future for a better understanding of the impact of climate changes on water resource. In this paper, we perform the numerical simulation on Urumqi Glacier No.1 in the eastern Tianshan, central Asia (hereafter Glacier No.1 for short) by considering both the mass balance and ice flow. Given the shape of the Glacier No.1, the velocity of the glacier is obtained by solving a two-dimensional nonlinear Stokes equation and simulated result is in agreement with the observation. In order to predict the variability of Glacier No.1 in the next decades, a climatic scenario is constructed with a temperature rise rate as 0.17°C/10 a and precipitation as constant during the period of 2005-2070. The simulation shows that, the glacier terminus will retreat slowly and the glacier will thin dramatically before 2040, while after year 2040, the glacier terminus retreat will accelerate. This study confirms the increasing retreat rate of alpine glaciers under global warming.     

Variations in the equilibrium line altitude of Urumqi Glacier No.1, Tianshan Mountains, over the past 50 years

The glacier ELA is one of the important parameters reflecting climate change.Based on observations of the equilibrium line altitude(ELA) of Urumqi Glacier No.1 in the Tianshan Mountains,we established a statistical model between ELA and its major influencing factors,warm season air temperature(air temperature averages for May,June,July and August) and annual precipitation.Result showed that,warm season air temperature was the leading climatic factor influencing ELA variations.The glacier ELA ascends(descends) 61.7 m when warm season air temperature increases(decreases) by 1°C,and ascends(descends) 13.1 m when cold season precipitation decreases(increases) by 10%.In the period 1959-2008,the glacier ELA showed a general increasing trend,ascending108 m and reaching its highest altitude in 2008 at 4168 m a.s.l.,close to the glacier summit.If future climate is similar to that in the past 50 years,the ELA of Urumqi Glacier No.1 will still ascend with a speed of 2.16 m/a.However,If future climate is similar to that in the period 2000-2008,the ELA will still ascend with a speed of 6.5 m/a before it is stable.As a result of ELA variation,the accumulation area ratio(AAR) of the glacier showed a decreasing trend during the past 50 years.     

Environmental changes in the upper-reaches of Thurumqi River in the past 10,000 years, Tianshan Mountains, China

The sediments, at bore-hole T-3 in the upper reaches of the Urumqi River, are 10.7 m thick, and are composed mainly of till, slope-washed materials, solifluction and glacial-water deposits. The borehole can be divided into six sections based on the pollen distribution, magnetic susceptibility , δ~(13)C determinations and the diatoms distribution. There were three cold and dry periods during the past 10.0 Ka (10~3 years): before 9.3 KaBP, from 8.1 to 5.6 KaBP and 3.0 to 1.0 KaBP. The three warmer periods were from 9.3 to 8.1 KaBP, 5.6 to 3.0 KaBP and since 1.0 KaBP. The Holocene maximum was between 5.6 and 3 KaBP. However, the vegetation compositions, mainly C_3 plants, the magnetic susceptibility and the δ~(13)C were little changed in the study region in the past 10 Ka. Indications are that the climate was relatively cold and stable during the past 10 Ka.     

输水线路一干郭河与沙坡河倒虹吸工程地质评价

经过张峰水库输水线路一干工程地质勘测,就输水线路一干郭河与沙坡河倒虹吸工程地质条件进行了分析与评价。