福州仓山工业密集区周边菜地土壤重金属的含量与评价

为研究工业密集区菜地土壤重金属的污染特征,选取福建省福州市仓山工业密集区周边8片菜地为研究对象,分析土壤Zn、Pb、Cr、Ni、Cu的含量特征,以福建省土壤环境背景值和食用农产品产地环境质量标准为评价标准进行菜地土壤重金属污染现状评价和潜在生态风险评价.结果表明:供试菜地土壤中,Ni含量超标最严重,平均含量达297.53 mg·kg-1,其次是Pb和Cr,Cu含量最小,老工业区土壤的Zn、Cr、Ni、Cu污染比新工业区严重.单项污染指数法和多项综合污染指数法与Hakanson潜在生态风险指数法评价的结果基本一致:Ni的污染指数最高、其次是Pb和Cr,Cu污染最轻;壁头村菜地土壤重金属综合污染最严重,其次是梁厝村;潜在生态危害系数大小为:Ni>Pb>Cr>Zn>Cu;潜在生态风险程度大小为:壁头村>梁厝村>浦口村>螺洲>黄山村>云风洲>竹榄洲>盘屿;老工业区周边的菜地土壤重金属综合污染指数和潜在生态危害指数明显高于新工业区.     

景洪市茶园茶叶和土壤中重金属的污染评价

通过野外调查采样和室内分析方法对云南省景洪市茶园茶叶和土壤中重金属元素As、Pb、Cr、Hg和Cd的含量进行研究,并结合茶园茶叶和土壤的卫生质量标准,采用污染指数法对茶叶和土壤进行污染评价.结果表明:景洪市茶园茶叶和土壤中重金属元素的平均含量均较低,其中茶叶重金属含量低于无公害茶叶重金属最低限值,土壤重金属含量达到国家2级标准.茶叶中重金属元素单因子污染指数和综合污染指数均小于0.6,茶叶质量均达到国家1级标准;土壤中除As的综合污染指数为1.11,其余4种重金属元素综合污染指数均小于1.0.土壤处于安全等级或警戒线等级,为清洁水平或尚清洁水平.建议今后在进行无公害茶园的布局和建设时,应对基地适当加以选择.     

基于GIS的城市土壤氡浓度分布规律和健康风险评价

研究城市土壤氡浓度分布特征和健康风险评价,填补城市地质调查放射性领域空白,为城市开发建设提供基础数据。运用GIS分析技术,将研究区划分为特定区域型、线型和区域型三种调查尺度,应用地累积指数法、内梅罗指数法和潜在生态危害指数法进行了土壤氡风险评价。结果表明：1)用地累积指数、内梅罗指数、潜在生态危害指数测算健康风险,全区污染等级和污染指数分别为清洁(-0.287)、轻度污染(2.585)和生态危害高(103.42),各尺度调查对象土壤氡污染程度排序为：全区地质体>全区>秋长构造>沙田构造>秋长社区空地;2)地累积指数、内梅罗指数和潜在生态危害指数测算不同调查尺度的土壤氡健康风险水平基本一致,可作为土壤氡健康风险评价较有效方法。     

有效态与TCLP法评价沉积物重金属生态环境风险

采集了河道沉积物样品,测定了沉积物中重金属的有效态,并采用TCLP法测定了Cd、Pb和Zn的含量,同时开展了生态环境风险评价。结果表明,根据农产品产地土壤重金属污染程度的分级标准,该河段沉积物中Cd超标率为60%,Zn的超标率为20%,Pb的含量都在安全值范围内。沉积物中三种重金属的均为低风险。TCLP提取沉积物中Cd、Pb和Zn含量,与国际标准值对比发现,沉积物中上下游的两个样品Cd含量大于国际标准值;所有沉积物样品中的Pb、Zn的含量均大于国际标准值。内梅罗综合污染指数结果表明,调查区域河段的沉积物为重度污染。根据有效态和TCLP提取的重金属含量评价结果表明,两种评价方法存在一些差异,但综合两种评价结果,该河流流域确实存在污染的风险。     

内梅罗指数法在石油开采区土壤PAHs污染分级评价中的应用

针对内梅罗指数法在土壤质量评价过程中存在的问题,考虑各评价因子的相关性,利用多元线性回归分析各评价因子的浓度,计算其复相关系数,对每种评价因子赋予权重值,通过引入浓度权重对污染指数平均值(P<,1均>)进行修正;同时借鉴化学品评分排序模式对污染物的评分排序,选取危害性较高的评价因子,引入毒性权重对最大污染指数(P<,1最大>)进行修正.通过上述方法对内梅罗指数法进行修正,并将其应用于某石油开采区土壤多环芳烃污染分级评价中.修正后的内梅罗指数法可以在一定程度上消除了最大值的影响,提高了危害性较高评价因子的影响程度,同时兼顾了各评价因子的相关性,能够对土壤质量进行较为合理的反映.     

深圳市表层土壤中PBDEs空间分布特征及蓄积量估算

为了解深圳30年快速城市化过程引发的土壤有机污染现状,同时调查城市化过程有机污染历史累积情况,在深圳市收集了110个表层土壤样品,分析了深圳市土壤多溴联苯醚(PBDEs)的空间分布特征,并对其表层土壤PBDEs蓄积总量进行了估算.结果表明,深圳市土壤中∑<,12>PBDEs及BDE209的含量水平范围分别为1.1～85.8 ng/g(dw)和1.2～1931 ng/g(dw).PBDEs总含量在不同土地利用功能分区上表现为工业用地>居住用地>商业用地>城市公园>郊野公园的分布规律.深圳市土壤中PBDEs含量整体表现出从西部的南山区和宝安区向东南方向的龙岗区和盐田区递减的趋势,且PBDEs含量水平与各行政区的城市化水平呈显著的指数函数关系(r=0.98,P<0.01),表明城市化水平是影响深圳市土壤PBDEs污染程度的主要因素.采用基于行政区单元和基于土地利用类型两种估算方法对深圳市表层土壤PBDEs蓄积量进行估算的差异较大,研究认为基于土地利用类型所估算出的数值更为准确,以此估算出深圳市表层土壤中∑<,12>PBDEs和BDE209蓄积量分别为1.51 t和15.9 t.     

五指山茶园表层土壤重金属污染危害评价

[目的]评价五指山茶园表层土壤重金属污染的危害程度.[方法]采样分析五指山茶园表层土壤重金属(Cr、Ni、Cu、Zn、As、Cd、Pb)的平均含量及富集状况,分别以现代工业化以前沉积物中重金属的全球最高背景值和我国<土壤环境质量标准>的一级自然背景值为参比值,采用潜在生态危害指数法对五指山茶园表层土壤重金属的富集系数和生态危害系数以及生态危害指数进行了评价.[结果]以2种背景值为参比得出的重金属污染水平相近,Cd和Pb是对五指山茶园表层土壤生态环境具有潜在影响的主要重金属元素.[结论]五指山茶园表层土壤重金属的潜在危害程度为轻微-中等污染水平.     

汞矿区土壤和农产品重金属污染状况及风险评估

为了解汞矿选冶采矿活动对当地生态环境的影响,以贵州某汞矿区尾矿堆场为研究对象,利用随机布点法采集土壤样品及农产品各60份,利用内梅罗综合指数法、潜在生态风险评价法对土壤重金属污染程度进行评价,利用健康风险评估模型对农产品中重金属的健康危害进行评估。结果表明,研究区土壤复合污染程度为重污染,Hg贡献最大,Cd次之,且A区较B区土壤污染严重。蔬菜、稻米、玉米中Hg的超标率分别为82.8%、46.7%、20%,蔬菜中Cd的超标率为51.7%,其他元素均低于限量标准。食用当地稻米及蔬菜对人群产生的健康危害指数HI1,可能存在潜在健康风险,玉米对人群产生的健康危害指数较小,其潜在健康风险可忽略不计。土壤重金属含量与农产品中重金属含量无明显相关性。     

某冶炼厂周边农田土壤重金属污染状况分析与评价

采用随机布点的方法采取冶炼厂周边农田土壤样品53个,分析了其中Cd、Cu、As、Pb、Zn的含量及部分样品中重金属的赋存形态,结合国家土壤环境质量标准和内梅罗污染指数法对土样进行分级评价.结果表明,该地区农田土壤受重金属综合污染程度依次为:Cd > As > Cu > Zn > Pb,其中水田土壤受Cd、Cu污染较旱地严重,受As污染略轻于旱地.水旱2种类型土壤中各重金属的形态分布规律相似,其中Cd以弱酸态和可还原态为主,Cu、As、Pb、Zn均以残渣态为主.     

基于模糊数学的矿区土壤重金属污染评价——以信丰稀土矿区为例

根据土壤重金属污染评价具有的模糊性和渐变性特点,建立模糊数学污染评价模型分析重金属的污染程度.结果显示单个重金属无污染,矿区综合土壤质量等级为1级,评价分值为97.034,属于安全水平. 在此基础上,与传统的污染指数对比分析,单因子污染指数显示Ni和Pb为轻度污染,地累积指数显示Pb为中度污染,内梅罗指数和潜在生态危害指数显示为无污染和轻微生态危害.研究表明:模糊评价法不仅可以对土壤重金属进行评价,还可以建立隶属度函数描述土壤重金属污染状况的模糊性和渐变性,解决传统污染指数评价法存在的不足,比传统污染指数评价法更为客观、准确,可以作为一种有效的矿区土壤重金属污染程度的评价方法.      

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.