地质学野外教学基地建设的几点思考

综合考虑地质学实践课的特点及野外地质实习基地应具备的功能,根据目前我校地质学野外实习基地的现状,提出了合理选择及建设地质学野外教学基地的几点思考.依照吉林大学地球科学院野外地质实习基地建设经验,制定了我校地质野外实习基地的建设原则和初步构想.     

许昌市环境空气质量变化趋势及规律分析

“九五”期间 ,许昌市环境空气监测主要因子有二氧化硫、氮氧化物、总悬浮颗粒物、降尘和硫酸盐化速率。市区空气中主要污染物排序依次为 :降尘量 ,总悬浮颗粒物、氮氧化物、二氧化硫。其季变化规律一般为冬 >春 >秋 >夏。主要污染物年变化为二氧化硫、氮氧化物、总悬浮颗粒物、降尘量。“九五”期间均为波动下降趋势 ,除降尘量下降明显外 ,其余 3项均不明显     

高校学生干部应具备的能力及培养途径与方法

高校学生干部在党团组织、老师和广大同学中起着桥梁纽带与助手作用,他们所具备的意识和能力,直接关系到学校及各项学生活动的开展.本篇文章首先列举了学生干部应具备的六个基本意识和基本能力,进而结合实践经验从选拔、培训、实践、总结四个方面提出学生干部的培养途径和方法.     

DEHP在土壤和白菜中的残留及毒性分析

用聚氯乙烯（ＰＶＣ）塑膜覆盖白菜地，收获期土壤和白菜植株中ＤＥＨＰ的残留量分别为２．７３ｍｇ．ｋｇ＾－１和３．０５ｍｇ．ｋｇ＾－１。借鉴国外的评价指标，对人体食用白菜后的潜在危害进行了分析认为，人每天摄入干白菜中ＤＥＨＰ的量〈０．０５ｍｇ．ｋｇ＾－１，远低于人每天可接受ＤＥＨＰ的安全摄入量１ｍｇ．ｋｇ＾－１。     

海洋硅藻细胞表面物理化学特性对镉累积的影响

硅藻是海洋生态系统中主要的初级生产者,在全球碳循环中扮演重要角色。硅藻在镉(Cd)的生物地球化学循环中同样发挥了关键的作用。营养盐、盐度、pH、光照、温度等因子可改变Cd在硅藻中的累积,但其关键过程尚未清楚。借助多功能原子力显微镜(AFM)、X射线光电子能谱(XPS)、非损伤微测(NMT)等先进表征手段,可定量研究硅藻细胞的表面物理化学特性。本综述讨论环境因子对细胞表面粗糙度的影响,探索粗糙度-表面功能基团-电势之间的联系,从微观层次揭示硅藻细胞与Cd之间的相互作用,诠释硅藻吸附金属Cd的过程。     

Atmospheric aerosol concentration level and chemical characteristics of water-soluble ionic species in wintertime in Beijing,China

Total suspended particulate (TSP) samples were collected during wintertime from November 24, 1998 to February 12, 1999 in Beijing. Ionic species including Cl-, NO3(-), SO4(2-), Na+, NH4(+), K+, Mg2+ and Ca2+ were determined by Ion Chromatography (IC). The sum average concentration of all the determined ions accounted for 18.9% of the TSP concentration, and SO4(2-) appeared the dominant ion with an average concentration of 30.84 microg m(-3); the sum mass concentration of SO4(2-), NO3(-), Ca2+ and NH4(+) accounted for about 83.2% of all the eight ions measured. The study indicated that the chemical form of sulfate and ammonium varies with TSP concentration levels. During heavy pollution periods, the average TSP concentration was 0.66 mg m(-3), and the NH4(+)/SO4(2-) molar ratio was low (0.58). It indicated that sulfate may present as CaSO4 and (NH4)2SO4 x CaSO4 x 2H2O. When TSP concentration (average 0.186 mg m(-3)) was relatively low, the NH4(+)/SO4(2-) molar ratio was 1.94, close to the theoretical ratio of 2 of (NH4)2SO4. Under this condition (NH4)2SO4 is expected to exist as the major form of sulfate. When the TSP concentration level was medium (average 0.35 mg m(-3)), the NH4+/SO4(2-) molar ratio appeared an average value (1.27), (NH4)2SO4, (NH4)2SO4 x CaSO4 x 2H2O and CaSO4 are expected to be present in those aerosol particles. Meteorological conditions including wind speed and wind direction were related to the TSP concentration level.     

利用废酸液制备脱硫剂

以废酸液为原料制备脱硫剂，具有原料来源广、价廉、工艺简单等优点，所制备的脱硫剂 主要理化标能达到商品脱硫剂的水平，脱硫剂可以再生，转适宜的再生温度为２０－５０℃，再生后，脱硫剂的脱硫能力有所下降。     

液相色谱测定土壤中氟磺胺草醚残留量方法研究

采用甲醇／浓盐酸浸渍振荡提取，二氯甲烷萃取，经弗罗里硅土柱层析净化，用液相色谱法测定。方法的最低检出含量为０．０２ｍｇ／ｋｇ，添加回收率在９５．８％￣９６．６％之间。     

Characteristics of carbonaceous aerosols in Beijing, China

Carbonaceous aerosols and PM10 were monitored from September 8 to November 30, 2002, in a semi-urban site (Tsinghua University) in Beijing. Daily concentrations of OC and EC ranged from 7.1 to 65.9 microgCm(-3) and from 1.3 to 26.1 microgCm(-3), with the overall average concentrations of 21.2 microgCm(-3) and 7.3 microgCm(-3), respectively. The diurnal variation of carbonaceous concentrations on 2 h basis presented two-peak trend, which was attributed to the cooperative effect of local meteorological conditions and anthropogenic sources such as traffic exhaust and human outdoor activities. Daily average OC/EC ratio varied between 1.5 and 5.3 with an average of 3.0. Strong correlation between OC and EC (R2=0.8) indicated that their main sources were common. The frequency of OC/EC ratio presented Gaussian normal distribution trend in fall, of which the peak value appeared in the range of 2.8-5. In winter, it presented bi-peak mode, with the first peak near 1.4-1.6, and the second between 2.8 and 5. The high value (2.8-5) implied the SOC formation in both seasons, and the low one probably suggested the primary OC/EC ratio from coal burning in winter. Averagely, PM10 and carbonaceous species exhibited higher concentrations in Wednesday than in other weekdays, which could be ascribed to the low wind speed (1.6 ms(-1)) and high humidity (62.9%). OC was the abundant component accounting for 76% of TC. OC and EC contributed 15% and 5% to PM10, respectively. The estimation on a minimum OC/EC ratio (1.5) basis showed that SOC accounted more than 50% for the total organic carbon. Even in winter, the SOC contribution to OC was also significant, as high as 40%.     

Balancing China’s climate damage risk against emission control costs

In this study, we incorporate a three-reservoir climate module into our energy-economy-environmental integrated (3E-integrated) system model, in order to estimate the effect of China’s contribution of unilateral emissions on global warming and to weigh the macro-mitigation cost against the risk of damage, and we also explore the role of adaptation in reducing climate change risk. Our results suggest that China’s unilateral emission-control action plays a relatively limited role in mitigating global warming and is not particularly cost-effective, given that the macro-reduction cost is much larger than the benefit in the corresponding climate damage mitigation. Adaptation plays a large role in curbing China’s climate damages and improving the economics of China’s unilateral emission-control actions, and it is little affected by the introduction and option mitigation strategies. To prevent global warming from exceeding critical thresholds, more international collaborations and cooperative efforts are therefore anxiously needed; as for China, bolstering a low-carbon economy and installing an effective mechanism for improving the adaptation level are two feasible options for controlling climate damage risks, given the great uncertainty on the present situation of international cooperation mitigation.