Multiple Effects of Environmental Factors on Algal Growth and Nutrient Thresholds for Harmful Algal Blooms: Application of Response Surface Methodology

Systematic understanding of the co-effects of environmental factors on phytoplankton proliferation can enable more effective control of harmful algal blooms in eutrophic lakes and reservoirs. A batch of statistically designed experiments using response surface methodology was recently conducted on mixed algae samples collected from Changtan Reservoir. The central composite designed response surface model was established to evaluate multiple effects of various physical and chemical factors (total nitrogen, total phosphorus, temperature, and light intensity) on algal density and chlorophyll a content. Analysis of variance indicated an excellent correlation between modeling results and experimental responses. Among the selected environmental variables, promotion of the interactive effects of nitrogen and phosphorus together with the optimum total nitrogen/phosphorus mass ratio (between 7.9 and 10.1) was determined to be the most significant stimulating parameter associated with algal blooming development dominated by non-nitrogen-fixing species. The favorable effects of strong illumination were shown to be greater than those of high temperature. The border values of total nitrogen and phosphorus concentrations leading to a critical value of algal density under different water temperatures and light intensities could be predicted as nutrient loading thresholds for harmful algal blooms by our second-order polynomial regression model.     

多色强光手电筒在森林防火应用中的试验研究

论述了多色强光手电筒发出的求助信号及应答联络信号在林区野外应用试验过程,进一步证实了多色强光手电筒在求助信号测试、点对点应答联络测试及露营光源测试的有效性。该工具的推广应用,是林区通信的必要补充,具有广阔的应用前景。     

试论劳动保护法规建设

探讨了劳动保护法规的特性、作用和现状，并就劳动保护法规建设提出了建议。力图引起劳动保护立法界人士和工作者的注意，推动劳动保护法规建设与市场经济同步发展。     

Prenatal diagnosis of congenital mesoblastic nephroma in mid-second trimester by sonography and magnetic resonance imaging

Although congenital mesoblastic nephroma (CMN) is a rare benign congenital renal tumor, it is the most common solid renal tumor in the newborn period. The most common presentation of congenital mesoblastic nephroma is polyhydramnios, and only one case with prenatal fetal hydrops has been previously reported. Prenatal diagnosis of CMN has previously been made on the basis of the findings of sonography in the third trimester, and magnetic resonance imaging (MRI)–based diagnosis has been reported recently. Here we report a case of prenatally diagnosed classical type CMN diagnosed at 22 + 3 weeks of gestation based on the findings of sonography and magnetic resonance imaging. The characteristic imaging findings in this case were fetal hydrops and polyhydramnios. To our knowledge, this is the youngest reported gestational age for prenatal diagnosis of CMN and it is the second case of CMN associated with fetal hydrops detected prenatally. Copyright © 2003 John Wiley & Sons, Ltd.     

平原河网地区非点源污染分析

在流域水环境中，非点源污染已成为首要污染源，其研究正成为业内人士关注的重要课题。文中分析了平源河网地区非点源污染研究的现状、进展和防治途径。     

Chlorination of water containing bromide and formationof the bromine - substituted trihalomethanes

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双组分VOCs在吸附树脂上的吸附穿透特性

选取超高交联吸附树脂（H-resin）和大孔吸附树脂（M-resin）作为吸附剂，采用固定床吸附法研究了单、双组分的正戊烷和环己烷在2种不同孔结构吸附树脂上的吸附穿透特性.结果表明：2种吸附树脂对正戊烷和环己烷的吸附主要依靠色散力作用，吸附树脂对摩尔极化率大的环己烷有更优秀的吸附能力.双组分吸附实验中，由于富含微孔的H-resin对不同组分VOCs的吸附作用力差别大，发生环己烷取代正戊烷的现象，并且取代随环己烷浓度升高而更加显著，但吸附温度由30升至50℃过程中，取代现象减弱.M-resin的孔主要分布在中、大孔区，对环己烷和正戊烷的吸附作用力相近，因而正戊烷和环己烷在M-resin上始终为共同吸附.     

固定化细胞技术在废水处理中的应用

固定化（主要为固定化微生物）技术，由于降解效率高，抗逆性强等优点，在废水处理中应用广泛。按作用方式不同，固定化技术可分为4类，其中吸附法与包埋法应用较多。为提高机械强度与处理效率，包埋剂常与交联剂和吸附剂联用。结合90年代以来，固定化方法的研究成果和应用实例对化技术作了较全面的论述。     

基于卫星遥感的甘肃省吸收性气溶胶的研究

基于OMAERUV数据日产品，对甘肃省2008~2017年吸收性气溶胶指数（UVAI）的时空分布进行了分析，并对其相关因素进行了探讨，结果表明：该省近10a UVAI空间格局为由西北向东南区域逐步递减，UVAI的高值区域一直分布在酒泉市及邻近区域，为吸收性气溶胶污染源中心；甘肃省UVAI的稳定性呈现从东北向西南区域逐渐降低的规律；UVAI月均值呈现出明显的规律性，每年的月变化均呈现"V"型；四季UVAI水平为：冬季 > 春季 > 秋季 > 夏季，四季变化规律基本同步，十年来四季的UVAI呈逐渐上升趋势，且四季中主导的吸收性气溶胶来源不同.基于PM_2.5的UVAI指示的空气质量等级分析，甘肃省空气质量以良为主；从气象因素与UVAI相关性分析来看，降水量、气温均与UVAI之间呈现显著正相关，风向也对其空间分布有重要影响；植被覆盖度与UVAI呈现正相关的区域主要分布在甘肃省西北部、武威市中部区域，呈现负相关的甘肃南部天水、陇南等区域为较高的植被覆盖区域.从人类活动因子与UVAI相关性来看，地区生产总值、各产业产值与UVAI有着明显的正相关性，尤其以第二产业与UVAI相关性最高；UVAI与汽车保有量、能源消耗总量及人口密度均存在较强的正相关，说明汽车尾气和工业排放及建筑粉尘也是吸收性气溶胶的重要来源.针对甘肃省UVAI时空分布特点、自然及人类活动因素分析情况，提出了减少人类活动强度等建议.