RIDGE REGRESSION TECHNIQUES APPLIED TO LANDSAT INVESTIGATION OF WATER QUALITY IN LAKE OKEECHOBEE1

ABSTRACT: Landsat radiance values were processed at two different (single and double) levels of accuracy to estimate chlorophyll a, turbidity, and suspended sediment in Lake Okeechobee, Florida. Both ordinary least square and ridge regression analyses were used to establish a relationship between water quality parameters and Landsat radiance. Radiance measurements made at greater precision (double level) gave a better solution in this application. The ridge regression analysis for double level not only can reduce the total mean square error about 13–20 percent and confidence interval about 6–28 percent as compared to ordinary least square analysis, but it can also change the interpretation of analysis results.     

THE USE OF MAGNESIUM CARBONATE IN CHLOROPHYLL DETERMINATIONS1

Abstract: Chlorophyll analyses of both laboratory cultures and natural aquatic samples were unaffected by the use of magnesium carbonate. Equal volumes of the samples (at various pH values) were pipetted onto 0.45 micrometer filters with and without magnesium carbonate. Chlorophyll concentrations were determined for each filtered sample and those frozen for specified times. In all samples tested there was no difference either in the retention of algae or in the stability of chlorophyll over the time period and pH range tested.     

PRODUCTION PROCESSES UNDER THE ICE IN LAKE ST. CLAIR: 1. IRRADIATION AND TEMPERATURE1

ABSTRACT: Data from three ice-covered stations in Lake St. Clair were collected to evaluate the effect of ice and related variables on phytoplankton production. Primary production, phytoplankton standing crop, irradiation and temperature were measured from January to April, 1973. Mean production values ranged from 0.74 mgC/m³/h at station 1 near Mitchell Bay to 3.4 mgC/m³/h in waters at stations 2 and 3 below the Thames River mouth. A similar pattern was observed in chlorophyll a concentration, the mean values ranged from 0.63 μg/1 at station 1 to 2.1 and 1.3 μg/1 at stations 2 and 3. Temperature stratification occurred at the three stations. However, the temperatures at station 1 were consistently more than a degree warmer than at the other two stations. Irradiation was low, having a mean value at the sampling depth of .075 ly/min. The data is interpreted to indicate that the ice-bound phytoplankton were adapted to the low irradiation. It is suggested that the variation observed between stations is related to the formation of a plume by the Thames River and differences in nutrient loads carried by the St. Clair and Thames Rivers.     

PROCEDURES FOR THE EVALUATION OF ENGINEERING ALTERNATIVES1

ABSTRACT: This paper describes a method of analyzing the nonquantifiable parameters which should be considered in the evaluation of engineering alternatives. The nonquantifiable parameters can include environmental impact, feasibility of implementation, and performance. The method considers rating all the alternatives on the basis of a set of criteria which reflect these parameters. A procedure is discussed for obtaining review and guidance in the evaluation of engineering alternatives from the local elected officials or governing bodies and for obtaining the views and desires of the local communities. This is achieved through the formation of project review committees and an evaluation procedure which allows for the technical rating of alternatives by the engineer and the weighing of the evaluation criteria by the political and social groups. With the growing environmental concern and the high cost of engineering projects, the involvement of the public during the evaluation of engineering projects is becoming increasingly important to the final success of the project.     

模拟酸雨致酸土壤对小麦幼苗生长发育的影响

用模拟酸雨淋洗土壤,造成土壤酸化和盐基流失,然后播种小麦(Triticumaestivum)。幼苗长至5片叶子时的测定表明:幼苗的生物量、叶片叶绿素含量和光合速率均降低,次生根减少,根系活动下降。酸化土壤对根系生物量和某些生理活动的影响大于对地上部的影响。     

遮阴和盐分对银叶树幼苗光合特性与叶绿素荧光参数的影响

通过比较不同光和盐水平下银叶树(Heritiera littoralis)幼苗的叶绿素含量、光合光响应参数及叶绿素荧光参数的差异,探讨了遮阴和施盐处理下银叶树幼苗的光合生理及适应能力。以银叶树盆栽幼苗为研究对象,以全光无盐为对照,设置遮阴(遮光率为80%)与2.5%盐水处理,经60 d的处理,测定其光合光响应参数、叶绿素荧光参数及叶绿素含量。结果表明,在正常环境下,银叶树光饱和点(LSP)、光补偿点(LCP)及Chla/b分别为1023、28.8μmol·m^?2·s^?1及3.65,属阳性树种。在无盐条件下,遮阴处理导致了叶片叶绿素含量、表观量子效率(AQY)、PSⅡ潜在活性(Fv/Fo)、PSII最大光化学效率(Fv/Fm)及PSⅡ有效光化学量子产量(Fv'/Fm')的升高,却降低了Chl a/b、最大净光合速率(P′max)、LSP、LCP、暗呼吸速率(Rd)、初始荧光(Fo)、PSⅡ实际光合效率(ΦPSⅡ)、表观光合量子传递效率(ETR)、光化学猝灭系数(qP)及非光化学淬灭系数(NPQ)。在全光照或80%的遮阴环境下,盐胁迫均使得叶片叶绿素含量、光合光响应参数(AQY、P′max、LSP)及叶绿素荧光参数(Fm、Fv/Fo)显著下降(P<0.05);而在全光环境下,盐胁迫同样显著降低了Fv/Fm、ΦPSⅡ、ETR(P<0.05),但在遮阴环境下,盐胁迫并没有显著降低叶片Fv/Fm、Fv′/Fm′、ΦPSⅡ及ETR(P>0.05)。盐分对叶片叶绿素含量、光合光响应参数(AQY、P′max及LSP)及叶绿素荧光参数(Fo、Fm、Fv、Fv/Fo、ΦPSⅡ、ETR及NPQ)的影响高于光照,光和盐对叶绿素含量、光合光响应参数(AQY、P′max及LSP)及叶绿素荧光参数的影响没有交互作用。研究表明,银叶树幼苗表现出较高的耐阴性及对弱光的利用能力;盐胁迫使银叶树幼苗发生了明显的光抑制,PSII的光化学活性降低,过剩光能对光系统的破坏的风险增加,光能转换效率与电子传递能力下降,光合作用效率大幅降低。     

Fe2+EDTA溶液络合-铁还原脱除烟气中NO

提出了“Fe2 螯合剂络合-铁粉还原-酸吸收”回收法脱除烟气中NO的新工艺,重点研究了模拟烟气中O2体积分数对NO络合量的影响,以及铁粉用量、铁粉粒径、搅拌速度对NO脱除效率的影响,确定了最佳的铁粉脱氮工艺条件,并对铁粉和铁屑的脱氮效果进行了比较。结果表明,烟气中O2的体积分数从0%增加到4.2%,NO络合量下降90.2%;NO脱除效率随铁粉用量和反应器搅拌速度的增加而增加,随铁粉粒径的增加而降低;过程的最佳工艺参数为,铁粉用量0.8g,铁粉粒径≤0.077mm,搅拌速度900r·min-1,在此条件下,对O2体积分数为5%的模拟烟气在搅拌反应器中可取得90%以上的NO脱除效率;用铁粉在1台搅拌反应器中取得的NO脱除效率和用铁屑在2个鼓泡反应器串联时所取得的效率相当。     

37个含硫芳香族化合物理化参数的相关性分析

本文对37个含硫(S,SO,SO_2)芳香族化合物的理化参数作了统计分析,在水解速率常数k与取代基常数之间建立了几个多元回归方程,并根据各化合物的因子得分和实验设计方法为生物试验挑选出了8个有代表性的化合物。     

微波、毫米波电磁材料特性及参数宽频带测试方法

讨论一种微波、毫米波电磁材料特性和参数宽频带测量方法——自由空间法。给出了该测量方法的测试原理和基于国产AV3630幅相接收机为基础的测试系统构成及系统扩频方法,论述了自由空间测试法需注意的关键技术问题。     

Hg2+胁迫下玉米生理生态变化的研究

通过砂培实验,研究汞胁迫下玉米的生理生态指标包括叶绿素含量、根系活力、游离脯氨酸含量的变化.结果表明,汞对玉米的胁迫是浓度和时间双重因子的作用在低汞浓度、短时间内,叶绿素含量、根系活力及游离脯氨酸含量均有上升的趋势;在高汞浓度、长时间内,各生理指标均严重下降.各生理指标对汞的敏感度略有差异游离脯氨酸含量>根系活力>叶绿素含量;其中脯氨酸含量可以作为汞污染的一个监测指标.