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61.
62.
Evolving from the water immersion sensory deprivation techniques of the 1960s, tank flotation has recently become a popular recreational activity, with commercial manufacturers and facilities available in most major American cities. This paper reviews research using two versions of the technique, and evaluates the responses of 27 customers using one such commercial facility. These customers indicate relaxation and pleasant mood, findings that are compatible with popular treatments and other reports but differ widely from earlier stereotypes about the experience.  相似文献   
63.
The work reported compared the predictive ability of two theories of aesthetic behaviour, using normal, everyday objects. This involved utilizing simulated items of furniture in three experiments in which predictions deduced from the ‘collative-motivation’ model and what has been termed a ‘preference-for-prototypes’ model were made to compete empirically. For each of the five pairs of discrepant expectations formulated in the three experiments the outcomes were inconsistent with Berlyne's model, while supporting the prototypicality model. A number of theoretical implications are drawn from these findings.  相似文献   
64.
Abstract: This research investigates possible impacts of enlarged water body according to dam reconstruction on the hydrodynamics and water quality of the reservoir using a laterally averaged, two‐dimensional hydrodynamic and transport model, CE‐QUAL‐W2. The lake was formed by the artificial dam in 1983 for agricultural water supply and is currently under consideration of reconstruction so as to expand the volume of reservoir for flood control as well as water supply in downstream areas. To calibrate and validate the model, field‐collected data were compared with model predictions for water level fluctuations and water temperature during the years of 2001 (from January to December) and 2003 (from March to November). The model results showed a good agreement with field measurements both in calibration and verification. Utilizing the model, impacts of dam reconstruction on the thermal hydrodynamics and turbid current were predicted. From the model results, dam reconstruction limited the depth of thermal stratification below 10 meter and formed steep temperature gradient between epilimnion and hypolimnion. The restricted thermal stratification persisted up to the end of September. This result indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. In addition, the restricted thermal stratification caused vertical circulation of water mixing lower than 10 meter and isolated the upper water layer from the lower water layer which increased the volume of hypolimnetic water with low temperature. The vertical circulation near the surface also mitigated propagation of density plume within the depth of 10 m which would remain the hypolimnetic water clean.  相似文献   
65.
对氨基苯磺酸降解菌的分离鉴定及降解特性研究   总被引:5,自引:3,他引:2  
王艳青  张劲松  周集体  王竞 《环境科学》2009,30(4):1193-1198
对大连某城市污水处理厂活性污泥进行长期驯化,筛选得到好氧条件下以对氨基苯磺酸(4-aminobenzenesulphonate,4-ABS)为唯一碳源和能源生长的高效降解菌株W1.根据菌株W1的形态特征、生理生化特征及16S rDNA序列分析,初步鉴定为Pannonibacter菌属.通过考察生长条件对降解效果的影响,确定了该菌株降解4-ABS的优化条件为:接种量10%、 30℃、 pH 7、摇床转速150 r/min,并且在有外加碳源的情况下仍保持较高的4-ABS降解活性.在4-ABS的降解过程中,4-ABS自身含有的氨基和磺酸基会以NH+4和SO2-4的形式释放到水体中,但浓度仅为理论释放量的77.6%和91.5%,推测原因是部分释放的NH+4和SO2-4被菌株W1作为氮源和硫源利用;菌株W1可以耐受2 500 mg/L的4-ABS,且在32 h内实现90%的降解率;4-ABS降解率为94.7%时,可以实现84.4%的TOC去除率,且没有检测到其它芳香化合物生成,表明菌株W1可以实现4-ABS的彻底矿化.  相似文献   
66.
Atmospheric CO2 concentration (Ca) is rising, predicted to cause global warming, and alter precipitation patterns. During 1994, spring barley (Hordeum vulgare L. cv. Alexis) was grown in a strip-split-plot experimental design to determine the effects that the main plot Ca treatments [A: Ambient at 370 μmol (CO2) mol−1; E: Enriched with free-air CO2 enrichment (FACE) at ∼550 μmol (CO2) mol−1] had on several gas exchange properties of fully expanded sunlit primary leaves. The interacting strip-split-plot irrigation treatments were Dry or Wet [50% (D) or 100% (W) replacement of potential evapotranspiration] at ample nitrogen (261 kg N ha−1) and phosphorous (29 kg P ha−1) fertility. Elevated Ca facilitated drought avoidance by reducing stomatal conductance (gs) by 34% that conserved water and enabled stomata to remain open for a longer period into a drought. This resulted in a 28% reduction in drought-induced midafternoon depression in net assimilation rate (A). Elevated Ca increased A by 37% under Dry and 23% under Wet. Any reduction in A under Wet conditions occurred because of nonstomatal limitations, whereas under Dry it occurred because of stomatal limitations. Elevated Ca increased the diurnal integral of A (A′) that resulted in an increase in the seasonal-long integral of A′ (A″) for barley leaves by 12% (P = 0.14) under both Dry and Wet - 650, 730, 905 and 1020 ± 65 g (C) m−2 y−1 for AD, ED, AW and EW treatments, respectively. Elevated Ca increased season-long average dry weight (DWS; crown, shoots) by 14% (P = 0.02), whereas deficit irrigation reduced DWS by 7% (P = 0.06), although these values may have been affected by a short but severe pea aphid [Acyrthosiphon pisum (Harris)] infestation. Hence, an elevated-Ca-based improvement in gas exchange properties enhanced growth of a barley crop.  相似文献   
67.
广州市白云山降水的化学特征及源解析   总被引:3,自引:0,他引:3       下载免费PDF全文
以2006年广州市白云山降水监测资料为基础,对其降水样品的化学特征进行了分析。结果表明,白云山降水样品pH值分布为3.04—6.41,雨量加权pH平均值为4.26,酸雨频率为70.2%,降水中的主要阳离子是Ca^2+和NH^+4分别占阳离子总量的46.4%和17.5%;主要阴离子为SO^2-4和NO^-3,分别占阴离子总量的59.0%和19.9%。相对酸度(FA)和中和因子(NF)计算结果表明,约有84.7%的降水酸度被碱性成分Ca^2+和NH^+4中和。利用富集系数方法,计算结果表明SO^2-4和NO^-3主要来源于人类活动,而Ca^2+和K^+主要来源于岩石/土壤风化。  相似文献   
68.
结晶紫-聚乙烯醇体系分光光度法测定水中溶解氧   总被引:1,自引:0,他引:1       下载免费PDF全文
在碘量法测定水中溶解氧的基础上,利用I3-与结晶紫在聚乙烯醇存在下结合成电中性的离子缔合物,以碘酸钾为标准溶液,与过量碘化钾反应生成碘,加入结晶紫后在550 nm处有最大吸收的原理测定水中溶解氧,优化了试验条件,考察了共存离子的干扰。方法在0.002 7 mg/L~0.55 mg/L范围内符合比尔定律,检出限为0.001 1 mg/L,蒸馏水平行测定的RSD≤0.2%,加标回收率为100%~101%,实际水样测定与碘量法和溶解氧测定仪结果一致。  相似文献   
69.
介绍了江苏省环境质量综合指数的现实意义、定义及在小康社会综合评价中的应用,并提出相应环境质量综合指数达标的对策和建议。  相似文献   
70.
ICP- AES法测定防腐处理后木材中可溶性铜铬砷   总被引:2,自引:1,他引:1       下载免费PDF全文
采用电感耦合等离子发射光谱法同时测定防腐处理后木材中可溶性铜、铬、砷,优化了试验条件,确定了最佳分析线。方法在0.500mg/L—10.0mg/L范围内线性良好,铜、铬、砷的检出限分别为0.003mg/L、0.01mg/L、0.07mg/L.木材样品平行测定的RSD为0.5%—1.2%,加标回收率为97.0%—102%,与原子吸收光谱法的测定结果相吻合。  相似文献   
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