桂林市酸雨污染特征及防治对策研究

为促进桂林市酸雨污染防控,利用2013—2017年桂林市3个监测站点采集的共1 147个降雨样品,分析了降雨pH、电导率和水溶性离子成分,结合气态污染物的变化特征和气象因素影响分析,探讨了桂林市酸雨污染成因,并提出了桂林市酸雨污染防治对策建议.结果表明:①2013—2017年桂林市降雨的pH年均值范围为4.85~5.23.酸雨频率范围为42.5%~74.9%,2017年酸雨频率达74.9%.虽然近年来桂林市环境空气质量明显改善,但是酸雨污染却没有明显减轻,反而在2015年后出现恶化.降雨的离子组成中,SO₄2-和NO₃-是主要的阴离子成分,分别占总离子当量浓度的28.19%和10.82%;Ca2+和NH₄+是主要的阳离子成分,分别占总离子当量浓度的23.46%和17.64%.酸中和效应分析显示,Ca2+和NH₄+为降雨中主要的中和物质.②降雨中碱性离子当量浓度的降幅比酸性离子当量浓度的降幅大,这是导致桂林市近年酸雨恶化的重要因素;此外,来自西部和东南部方向的气流对应了较高的降雨酸度和总离子当量浓度,因此污染物的远距离传输对降雨酸度和离子当量浓度也有一定影响.研究显示,桂林市SO₂和NO_x排放的持续管控将有利于酸雨污染防治,但桂林市目前实施的削减大气粗颗粒物和NH₃排放的大气污染控制策略对于降雨酸度的影响还需要开展进一步评估.      

Highly time-resolved aerosol characteristics during springtime in Weizhou Island

A single particle aerosol mass spectrometer was deployed to measure the changes of single particle species and sizes during March 2015 in Weizhou Island of the Beibu Gulf, Guangxi province, South China. In this campaign, a total of 3,100,597 particles were sized, and 25.8%particles with both positive and negative mass spectrum were collected and 24.8%characterized in combination with the ART-2 a neural network algorithm. The distribution of sized particles was mainly in from 520 to 600 nm, and the diameters ranging from 340 to1000 nm accounted for above 90%. Eight types of particles were classified: Elemental Carbon containing(EC), Organic Carbon containing(OC), EC and OC combined containing particles,Na containing particles, K containing particles(K), Levoglucosan containing particles,mineral containing particles, and Heavy Metal containing particles(HM). EC, OC and K were the major containing particles, which accounted for 84.3% in the eight types particles. The relative ratio and size distribution of the three types were EC(48.1%, 620 nm), OC(12.7%,440 nm), and K(23.5%, 600 nm), respectively. The three types of particles were a bit increasing ratios compared with those in clean periods during haze pollution periods.Combined with the back-trajectory results from the Hysplit-4 model and local pollution sources revealed that the ambient air quality on the Weizhou Island may be influenced by biomass burning in the Indochina Peninsula(biomass burning in the Indochina Peninsula)from the transportation on higher level atmospheric layer and by mainland of south China located northeast of Weizhou Island on the ground.     

建设海峡西岸高效持续农业示范区的基本思路与技术对策——以福建省龙海市为例

本文以福建省龙海市为例,分析了龙海市农业发展优势与存在的问题,提出了建设海峡西岸高效持续农业示范区的基本思路与技术对策     

B级钢侧架圆角细节耐久性力学模型研究

根据Paris公式推导出适用于B级钢圆角细节耐久性分析的 ,在一定裂纹尺寸范围内的裂纹扩展速率公式及其检验方法 ,笔者模拟货车B级钢转 8A侧架的导框弯角内侧 (A区 )的圆角细部进行耐久性实验 ;以试验数据的检验证明 ,在 0 .4～ 4mm的尺寸范围内 ,选用的断裂力学模型是合理的 ;同时为建立合理的检修周期和寿命体系提供理论模型和安全评价基础。     

应用蚕豆根尖细胞微核技术监测太湖水质的研究

应用蚕豆根尖细胞微核技术对太湖水质进行监测,测定太湖各样点水样的蚕豆根尖细胞微核千分率（MCN‰）及污染指数（PI）,并进行F检验。结果表明,各样点MCN‰有显著性差异,39个样点中有6个采样点的PI在2以上,和对照组相比有显著差异（p＜0.05）,表明太湖部分区域水质受到不同程度的污染。     

蚕豆SCE检测环境诱变剂的方法学研究

通过大量探索性试验,对蚕豆根尖细胞ＳＣＥ的Ｂｒｄｕ－Ｆｅｕｌｇｅｎ法的试验条件,如Ｂｒｄｕ浓度、Ｂｒｄｕ标记时间及其长短、稀酸水解浓度、时间和温度等对分色的影响进行了详尽的研究,获得了最佳的实验条件及程序、克服了ＳＣＥ研究沿用的ＦＰＧ法程序复杂,难以普及的缺点。此外,还用其他遗传毒理学民本方法进行了比较研究,探索利用该技术检测环境诱变因素的可能性。     

综合评定苯并（a）芘低浓度污染有毒危险性的研究

在细胞遗传损伤和免疫功能综合指标中,观察对苯并（a）芘（BaP）敏感并适用于人群检测的指标。结果显示外周血淋巴细胞姐妹染色单体交换（SCE）率与尿中BaP含量呈正相关;并在BP低于10μg/100M³的接触人群中观察到SCE率增高;血清IgG和补体C³与血中BaP含量呈负相关。以SCE率增高、IgG降低和尿中BaP负荷量增高综合评定BaP污染的有危毒险性有应用前景,饮用中华猕猴桃饮料,有助于SCE率增高的恢复和体内BaP的排出。     

China＇s Land Carrying Capacity Based on Man-grain Relationships

With population growth and increasing pressure on land resources, land carrying capacity （LCC） and food safety have been attracting great attention worldwide. From the point of man-grain relationship and by establishing LCC and land carrying capacity index （LCCI） models, this article firstly analyzes the spatial-temporal dynamics of LCC of China from 1949 to 2005 at county, provincial and national levels. Choosing 2005 as a representative year, this article then evaluates the LCC of 264 pastoral regions （semipastoral regions）, 663 urban regions and 592 poverty stricken regions of the country. The results show that： （1） from 1949 to 2005, with the increase of grain production, the LCC of China has been improved conspicuously, but due to the rapid population growth, the production can only maintain a low level grain consumption; （2） over the past 25 years （1980-2005）, the number of population overloading provinces decreased from 23 to 15 and the mangrain relationship has been improved gradually, but there were more overloading provinces than surplus provinces in China; （3） at county level, there were 1572 overloading counties in 1980 accounting for 68.26% of the total counties of the country and where were 649 million people lived, while in 1990, 2000 and 2005, the number of overloading counties were 1066, 1133 and 1087 respectively, which shows that the man-grain relationship has been improved obviously during the past 25 years; as for spatial distribution, the surplus counties were mainly concentrated in agriculture developed regions, such as Northeast Plain, North China Plain, middle and lower Reaches of the Yangtze River Plain, and overloading counties were mainly located in regions with poor natural environment and low grain production capacity, such as Northwest China, Tibetan Plateau and Loess Plateau and economically developed urban regions, such as Beijing, Tianjin and Shanghai; （4） animal husbandry improved greatly the LCC of pastoral and semi-pastoral regions, while urban regions were overloading for increasing population pressure and more than half of poverty stricken regions were overloading due to critical natural environment and poor economic conditions.     

城市地表灰尘颗粒体积分形特征及其吸附性

以地表灰尘颗粒分析数据为基础,运用分形模型,分析了芜湖市高新技术开发区地表灰尘颗粒的分维数.结果表明:19个地表灰尘样品的粒径较粗,粒径的平均值多出现在140～230 gm之间,峰值多出现在200～400 μm之间;分维数为2.5392～2.7408.平均值为2.665 7,pH值为7.97～12.36,平均值为10.22,呈较强的碱性.分维数与pH值之间的相关系数r=-0.221 0,相关性不明显;地表灰尘分维数对吸附性的影响效果不明显.