多层阻尼复合板常温贮存5年性能研究

目的分析多层阻尼复合板常温贮存5年的性能变化。方法对多层阻尼复合板进行常温下贮存5年的减振性能研究,通过贮存前后的正弦扫描试验和随机振动试验,获得贮存前后多层阻尼复合板的减振性能和模态变化,进行对比分析。结果阻尼复合板常温贮存5年后,径向模态有较大的下降,法向模态变化较少,组件上的加速度响应基本无变化。结论该多层阻尼复合板常温贮存5年后仍然满足要求。     

西北干旱区煤炭基地生态蓄水模式研究

西北干旱区煤炭开采产生的矿井水大多就近排放,利用率低.同时,该地区水资源严重缺乏,尤其是生态用水紧缺,煤炭开采造成地下水资源浪费和生态用水紧缺的矛盾局面.为缓解这一矛盾,提出地面人工湿地及生态储水的设想,构建两种基于生态用水的地面处理储存矿井水的模式,该模式下矿井水通过下渗补给潜水含水层,进而供给地表植被;另一方面,利用干旱区蒸发量大的特点借助低空大气环流输送水份,增加局部降水量,从而实现改善生态环境的目的.     

黑土有机碳、氮及其活性对长期施肥的响应

以长期定位试验为基础,研究不同长期施肥模式对中国东北黑土表层(0～20 cm)及亚表层(20～40 cm)土壤碳、氮的影响.结果表明,有机肥的施入显著提高了表层土壤有机碳(SOC)和全氮(TN)含量,其中以有机无机配施处理最为显著.与不施肥相比,常量和高量有机无机配施分别增加了表层SOC含量24.6%和25.1%,分别增加了表层土壤TN含量29.5%和32.8%,亚表层土壤SOC和TN含量对施肥无响应.尽管常量及高量有机无机配施分别增加了黑土0～40 cm土壤碳储量11.6%和7.6%、氮储量17.3%和12.7%,但各处理之间无显著差异,仅增加了黑土碳、氮储量的变异性.与不施肥相比,有机肥的施用不仅显著增加了表层和亚表层土壤微生物生物量碳、氮(SMBC、SMBN)及可溶性碳、氮(DOC、DN)的含量,且显著提高了这些组分在总有机碳、全氮中所占的比例.有机无机配施处理能使表层土壤SMBC/SOC、SMBN/TN值分别提高0.36～0.59和1.21～1.95个百分点,而DOC/SOC、DN/TN也分别达到0.53%～0.72%和1.41%～1.78%.土壤微生物生物量碳氮、可溶性碳氮及其在总有机碳、氮中所占的比例对于施肥的响应在土壤剖面上表现更为敏感,更能反映土壤肥力对于长期施肥的响应.有机肥的施入尤其是有机无机配施能显著提高黑土表层和亚表层土壤有机碳、氮活性,有利于提升土壤肥力和养分供应能力,但同时也导致了农田系统碳、氮的大量损失,容易引起潜在的环境污染.     

基于可靠性统计分析法的制导弹药储存寿命评估

针对制导弹药价格昂贵而无法采用大规模性能试验和实弹射击方法进行可靠性研究的问题,采用可靠性统计分析法对制导弹药储存寿命进行评估。通过建立制导弹药可靠储存寿命模型,并以制导弹药火工品中的待发程控装置为研究对象,运用Bayes法对试验数据出现的＂倒挂＂现象进行了修正。依据修正后的试验数据进行计算,得到了在一定置信度下待发程控装置的储存寿命。     

呼和浩特市工业料堆扬尘排放清单研究

颗粒物污染是影响中国城市空气质量的首要因素。工业料堆扬尘是城市大气颗粒物污染的主要来源之一。本文通过对呼和浩特市建成区内典型行业风蚀、作业及交通运输扬尘进行采样分析,应用美国AP-42提供的模型,以2006年作为基准年,建立了呼和浩特市工业料堆排放清单。研究结果表明:呼和浩特市建成区内工业料堆扬尘排放量为TSP:5 305 t/a,PM10:1 012 t/a,PM2.5:267 t/a。从空间分布看玉泉区工业料堆扬尘排放量最大,其次是赛罕区。行业分布上排放最大的行业是建材工业,其次是电力热力工业,最少的是化工工业。在各行业类别的工业料堆排放量中,交通运输扬尘排放量是最大的。     

长江口海域近50a来营养盐的变化及其对浮游植物群落演替的影响

本文根据收集到的1960s到2000s年间东海长江口附近海域(30.5～32°N,122～123°E)的营养盐数据,分析了长江口海域营养盐的季节变化及历史变化趋势。其中根据1959～1960年,1985～1986年和2002～2003年长江口海域营养盐的季节变化数据,发现50 a来,营养盐的季节变化差异不大,均呈现出春夏低,秋冬高的季节变化趋势,其中2002～2003年四个季节之间营养盐含量的变化幅度较其它两年略小。从1960s～2000s年的历史变化可以看出,调查海域的DIN含量呈现出显著上升的趋势,但是在2000年以后,DIN的年平均含量略有降低但变化不大,基本保持在18μmol/L。DIP年平均浓度变化不明显,浓度范围维持在0.39～0.60μmol/L之间。SiO3-Si的年平均含量呈现出明显的降低趋势。就营养盐组成变化来说,DIN/P比例和Si/DIN比值的变化趋势相反,DIN/P比例呈现出升高的趋势而Si/DIN呈现出降低的趋势。生物数据表明从1980s以后该海域赤潮优势种有从硅藻演变为甲藻的趋势,结合营养盐的变化分析认为过量的DIN和持续升高的DIN/P是造成这一藻种长期演变现象的主要原因。     

Leaching of styrene and other aromatic compounds in drinking water from PS bottles

Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene （PS） bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as ＂purge and trap＂ and analysed by gas chromatograph-mass spectrometer （GC/MS）. Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 μg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 μg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.     

Nitrogen cycling of atmosphere-plant-soil system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China

The nitrogen (N) distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW) and marsh meadow Calamagrostis angustifolia wetland (MMCW) in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/(m2·a), and total inorganic N (TIN) was the main body (0.640 gN/(m2·a)). The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m2·a) and the values of aboveground were 11.31 and 6.08 gN/(m2·a), the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m2·a), the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m2·a), the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m2·a), the translocation amounts from root to soil were 14.90 and 13.17 gN/(m2·a), and the soil (0-15cm) N net mineralization amounts were 1.94 and 0.55 gN/(m2·a), respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.     

V_2O_5-TiO_2离子存储电极薄膜的溶胶-凝胶法制备与性能研究

利用无机溶胶-凝胶技术制备了V2O5-（TiO2）x离子存储电极薄膜。采用X射线衍射（XRD）、原子力显微镜（AFM）、Raman光谱、循环伏安法（CV）和紫外-可见光透射光谱分别研究了复合薄膜的微观结构、化学计量、锂离子注入性能以及光学性能。结果表明复合薄膜具有V2O5的层状结构,其c轴方向的结构取向性有所降低;颗粒尺寸和表面粗糙度显著减小;同时TiO2的复合导致薄膜中V2O5的化学计量发生偏移,氧空位数量增多。当x=0.2时,薄膜具有相对较高的离子存储容量及循环稳定性,并且在离子注入/脱出状态均获得相当高的可见光透过性。     

Interspecific competition effects on phosphorus accumulation by Hydrilla verticillata and Vallisneria natans

The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes. The ability of different species to take up and store nutrients from the surrounding ambience varies, and hence plant community structure might be expected to affect the cycling of nutrients in lake ecosystems. In this study, the uptake of phosphorus by Hydrilla verticillata and Vallisneria natans was studied and compared in monoculture and competitive mixed-culture plantings. Results showed that for both studied species the phosphorus concentrations of different tissues and of whole plants was unaffected by competition. However, the quantity of phosphorus accumulated by whole plants of H. verticillata was significantly higher in mixture culture than in monoculture, while that of V. natans was lower in the mixed culture. The results indicated that H. verticillata has a competitive advantage over V. natans, when the two species are grown in competition, and is able to accumulate a greater quantity of phosphorus.