Characteristics of U-pattern distribution of highconcentration ^210pb in surface air at central Guizhou, China

In recent thirty years, with deep-going studies of the problems of regional environmental quality and global climate change, 210Pb has been found to have wide appli-cations in tracing the aquatic sedimentation, catchment’s erosion and the path of atmospheric transfer. 222Rn pro-duced from decay of the U-Ra series in surface rocks and soils diffuses in the atmosphere and continues to decay into 210Pb. This part of the 210Pb, due to separation from its parent 226Ra, is generally referred to a…     

Personality and neurochemicals in the human brain： A preliminary study using ^1H MRS

To investigate the neuro-biological bases of introversion-extraversion personality traits, the concentration of four neuroehemieals （Cho, mI, α-Glx and NAA） in anterior eigulate gyrus between normal extroverts and introverts were examined using non-invasive ^1H MRS technique. Our study revealed that introverts have significantly higher level of α-Glx, Cho and mI in the anterior eingulate gyrus than extroverts. This result provides new evidence that the anterior eingulate gyrus is related to personality traits partly in support of Eysenek＇s supposition that introverts have higher arousal level than extroverts. Moreover, this result offers neuroehemieal data for psychobiological theories of personality.     

^7Be and ^210pb radioactivity and implications on sources of surface ozone at Mt. Waliguan

Beryllium-7 (^7Be) and lead-210 (^210Pb) radioactivity in aerosols collected, from October 2002 to January 2004 at Mt. Waliguan, by the Global Atmospheric Watch (GAW) Station, Qinghai Province is presented. The data were analyzed together with simultaneously measured surface ozone concentrations. We found that short time variations of ^7Be and ^210Pb were linked to alternations of synoptic weather around the Mt. Waliguan region. ^210Pb showed the lowest concentration in summer while ^7Be showed no obvious seasonal changes. Relatively high ^7Be and ^210Pb radioactivity was observed at Mt. Waliguan when compared with the observations at other mountain sites in other parts of the world. Surface ozone and ^7Be showed a consistent seasonal variation. Surface ozone correlated fairly well with ^7Be/^210Pb ratio. This suggested that vertical transport from higher altitudes of the atmosphere has predominant effects on the budget of surface ozone at Mt. Waliguan.     

210国道对牛背梁保护区羚牛东西扩散影响的研究(Ⅰ)——210国道两侧羚牛东西扩散特征

2000年10月～2001年10月,采用样带法,并结合访问调查,对210国道牛背梁保护区段公路两侧羚牛扩散情况进行了监测.在监测样带内总计发现羚牛82头次,主要集中在西平沟一秦岭梁—干沟一带,以西平沟—秦岭梁段活动最为频繁;有64.64%的羚牛活动在相距公路10～100 m处;在国道两侧的活动时间以下午和傍晚为主,主要集中在17:00～19:00时.仅有7头次羚牛(占总数的8.53%)穿越公路完成了扩散.     

Sediment source identification by using ^137Cs and ^210pb radionuclides in a small catchment of the Hilly Sichuan Basin, China

The Hilly Sichuan Basin is one of the most populous agricultural regions in the Upper Yangtze River Basin and has an area of about 105000 km2. Cropland ratios and population densities vary between 0.3 and 0.7 and be-tween 400 and 800 people/km2, respectively, in the Si-chuan basin. The basin is considered as one of the most severely eroded regions in the Upper Yangtze River Basin as well in China. Soil erosion rates were reported mostly to be greater than 5000 t·km-2·a-1 by the first st…     

高效液相色谱法( HPLC) 测定中成药保济丸中木香挥发油的含量

采用高效液相色谱（HPLC）法测定羊城和香港保济丸中木香挥发油的含量，色谱柱为ODS柱（4．6≌150mm），流动相为甲醇－水（40：60），检测波长为275nm，在0．008％至0．022％的范围内呈良好的线性关系，回归方程为Y＝0．2581＋100．92X，r=0.9867.羊城药厂保济丸中木香挥发油的含量为0．016％，而香港李众胜堂保济丸中木香挥发油的含量为0．059％，此方法简便，快速，准确，可用于控制保济丸产品的质量。     

CD4^＋CD25^＋调节性T细胞在肺癌患者外周血中的表达

目的探讨肺癌患者外周血中CD4^＋CD25^＋调节性T细胞的变化及其与临床病理因素的关系。方法用流式细胞术检测60例肺癌患者和60例健康对照者的CD4^＋CD25^＋调节性T细胞数量变化。结果肺癌患者外周血中CD4^＋CD25^＋调节性T细胞水平明显高于正常组（P〈0．05）,其变化与病理分期和是否有转移有关（P〈0．05）,而和性别、家族史、病理类型和肿瘤体积等无关。结论CD4^＋CD25^＋调节性T细胞可能在肿瘤免疫中发挥重要作用,导致和促进肺癌的发生和转移。     

SO_4~(2-)改性锆交联蒙脱土的表面酸中心及催化活性

研制SO42-改性的锆交联蒙脱土(SO42-/Zr-CLM)固体酸催化剂,采用IR、Py-TPD和Py-IR等方法研究其表面酸中心的结构特征,并以柠檬酸和正丁醇的酯化反应为探针反应,研究其表面酸中心与催化活性的关系.实验结果表明:SO42-/Zr-CLM表面同时具有Bronsted(B)酸和Lewis(L)酸,L酸为弱酸中心,B酸为强酸中心;B酸中心是主要催化活性中心;催化剂经过500℃焙烧后,B酸的酸量显著增加,这可能是由于Zr与SO42-形成了螯合状配位结构,有利于形成更多的B酸中心并且提高其酸强度.     

La添加对S_2O_8~(2-)/ZrO_2-Al_2O_3固体超强酸催化剂性能的影响

柠檬酸三丁酯(TBC)是绿色环保无毒的增塑剂,其传统合成工艺采用浓硫酸作催化剂,设备腐蚀、三废问题严重,开发高效、绿色的替代催化剂是当前研究的重点。本文采用共沉淀-浸渍法向S2O82-/ZrO2-Al2O3催化剂中引入适量的La元素,制备出具有较高催化活性和稳定性的固体超强酸催化剂;以柠檬酸三丁酯的合成为探针反应评价催化剂的活性,并通过红外光谱、X射线衍射、NH3程序升温脱附,吡啶红外光谱等表征方法考察了La的添加对催化剂结构和性能的影响,结果表明:La的加入能够阻止催化剂中过硫酸根的分解,增强S和O之间的相互作用;少量的La不仅能增加催化剂的比表面积、酸强度和酸量,且能提高催化剂的活性和稳定性,当La的加载量为1%时,制得的催化剂活性最高,柠檬酸的转化率达到93.69%。这表明La的引入可提高固体超强酸催化剂的活性和稳定性,所制备的催化剂可用于传统催化剂浓硫酸的替代品,并有效降低设备的损耗,提高产品TBC的品质,优化TBC合成工艺,具有良好的经济价值。