寻找阅读教学中的奇妙支点——切入点

找准文本的切入点,可以激发学生学习语文的兴趣,深入文本,自主探究,陶冶情操,让语文课堂魅力四射,反之则会使语文课堂枯燥无味,让学生厌恶阅读,甚至讨厌语文课,那么,如何选择合适的切入点,激发学生自主阅读文本的兴趣,文本的切入途径有很多,可以根据不同的课文选择不同的切入点。     

蚂蚁有爱

我喜欢各种各样的小动物,昆虫,天上的飞鸟,以及四季的更替,无论刮风,下雨,晴天,雪天,只要在自然的环境里,我就会感到很幸福。 这与我的童年有关,那时候没有玩伴,一切不会讲话的事物都是我的朋友,他们教给我许多做人的道理,他们很忠诚,如果让我选择,我更喜欢他们。     

available的用法及其汉译举例

available在英语中相当活跃,用法也颇为多样,在地质地球化学等科技文献中经常遇到,在日常生活、社会科学中也比较常见。这里根据手头掌握的资料,将available的主要用法及其汉译加以整理,以供参考。 available是由avail派生而来的形容词。其基本意思是可以得到的;可以利用的;有效的。在这些基本意思的基础上,扩大、引伸、转意,中文还可译为:1.可以获得的,可以买到的,可以提供的,可以达到的;2.可用的,自由的,可采用的,合用的,适合于……的,有希望当选的,有可能……的,有能力……的;3.通用的,     

云东海——一颗生态明珠

青山孕绿水,绿水生奇景。从拥挤烦嚣的大都市步入三水云东海,一种绿的色彩,绿的空气,绿的气氛向我们袭来,浑身顿觉清爽和快慰,一种自得其乐的心情油然而生,使我们感到绿的温馨,绿的情怀,绿的快感。踏羊肠小道,穿深山密林,我们置身于“曲径通幽”的诗境中,抬头望天,天高云淡;举目远眺,群山逶迤,古木参天;俯视碧湖,清澈见底。一畦畦桑林,一间间茅舍。一派田园风光,一片诗情画意。攀树枝,跨小溪,翻小丘,终于,“大塱涡之水天上来”美景呈现在我们面前。大塱涡舒展柔情,以妩媚、清丽、温柔、纯朴的姿容展示着大自然的神功造化。湖里的水剔透玲珑,纤尘不染,湖中倒影,树影婆娑相映成趣。碧水上欢游的小鸭,“呷呷呷”地唱着自己的歌,     

乐中施教提高历史教学的质量

<正>历史是人生的圭臬,回放往昔,荟萃文明,昭示不朽,鉴往知来,掌握做人处事的真谛,懂得自己与社会的关系,达到学习历史的目的。然而,传统的历史教学往往被学生忽视其价值,知识得不到应有的巩固。因此,教师必须知机识变,教学生面别开。下面略述心得,期待同仁指正。一、利用历史人物教给学生为人处世讲解历史,教师照本宣科,必然枯燥干瘪。教学中,教师要根据青少年的特点,结合教材内容,找到最佳的教学方法,必使传     

浦东新区环境保护政策初探

浦东新区的开发目标,是“面向世界,面向21世纪,面向现代化”,将新区建设成世界一流的社会主义现代化城市。因而,浦东新区的环境保护,也应以这一目标为基础,在发展经济的同时,保持良好的自然生态环境,使之成为布局合理,基础设施完善,空气新鲜,水清质优,安静舒适,绿树成荫的花园式新城。为此,必须根据《中华人民共和国环境保护法》和国务院颁发的《对外经济开放地区环境管理暂行规定》,以及党中央关于浦东开发一开始就要注意生态环境保护的重要指示,设定浦东新区的环境保护政策。     

基本建设与环境保护

<正> 解放以来,我国基本建设事业突飞猛进,为国民经济的发展,人民生活水平的提高,以及环境面貌的改善,创造了良好的物质条件,同时为今后完成四个现代化的目标,奠定了坚实的基础。目前,对于如何在基本建设中搞好环境保护,维护自然界生态系统的平衡,达到经济效果与环境效果的统一,并且在环境保护工作中,加速对旧城的改建,污染严重企业的改造,以及工业“三废”治     

确立全新的阅读观念势在必行

语文教师要克服传统语文阅读教学的弊端,确立全新的阅读观念,引导学生学会阅读的方法,逐步提高自己的阅读能力,因势利导,利用学生的特点和爱好,引发学生兴趣点,让学生自主阅读,感知作者的情感,在阅读中寻求读书的快乐和体验,拓宽阅读渠道,开阔阅读视野,提升语文素养。     

一“朵”花，一“辆”车

一朵花,漂亮。一辆车,精密。那一朵花就不精密吗？它的每一片花瓣,每一叶花萼,花瓣上的条条纹络,花蕊上襄的粉球,不精密吗？雪花,六角的,均匀的,细致的,     

农药污染的生物降解与生物修复分析

生物降解的研究,始于20世纪40年代,起初人们认为,生物降解是指土壤、水体和废水生物处理系统中需氧微生物对天然和合成有机物质的破坏或者矿化作用。但是,在长久的研究和总结中,发现生物降解的目的,是为了更好的处理各种污染物质,以此来实现自然界的良性循环,避免造成更大的问题。在现阶段的污染中,农药污染引起了社会上的注意。目前,我国的农业发展迅速,农药污染在很大程度上,对土地、水源、空气等,都造成了极大的影响,因此,今后必须在农药污染的生物降解与生物修复分析上努力,减少对自然界造成的损害,为我国的可持续发展,做出更大的贡献。     

Gaseous elemental mercury concentration in atmosphere at urban and remote sites in China

An investigation of gaseous elemental mercury concentration in atmosphere was conducted at Beijing and Guangzhou urban, Yangtze Delta regional sites and China Global Atmosphere Watch Baseline Observatory (CGAWBO) in Mt. Waliguan of remote continental area of China. High temporal resolved data were obtained using automated mercury analyzer RA-915 . Results showed that the overall hourly mean Hg0 concentrations in Mt. Waliguan were 1.7± 1.1 ng/m3 in summer and 0.6±0.08 ng/m3 in winter. The concentration in Yangtze Delta regional site was 5.4±4.1 ng/m3, which was much higher than those in Waliguan continental background area and also higher than that found in North America and Europe rural areas. In Beijing urban area the overall hourly mean Hg0 concentrations were 8.3±3.6 ng/m3 in winter, 6.5±5.2 ng/m3 in spring, 4.9±3.3 ng/m3 in summer, and 6.7±3.5 ng/m3 in autumn, respectively, and the concentration was 13.5±7.1 ng/m3 in Guangzhou site. The mean concentration reached the lowest value at 14:00 and the highest at 02:00 or 20:00 in all monitoring campaigns in Beijing and Guangzhou urban areas, which contrasted with the results measured in Yangtze Delta regional site and Mt. Waliguan. The features of concentration and diurnal variation of Hg0 in Beijing and Guangzhou implied the importance of local anthropogenic sources in contributing to the high Hg0 concentration in urban areas of China. Contrary seasonal variation patterns of Hg0 concentration were found between urban and remote sites. In Beijing the highest Hg0concentration was in winter and the lowest in summer, while in Mt. Waliguan the Hg0 concentration in summer was higher than that in winter. These indicated that different processes and factors controlled Hg0 concentration in urban, regional and remote areas.     

胶州湾水体重金属HgⅠ.分布和迁移

根据1979年5月,8月,11月胶州湾水域调查资料,并且与近几十年来的调查资料进行对比分析,探讨和研究胶州湾重金属Hg的平面分布、垂直分布、季节分布以及发展趋势.结果表明:胶州湾东北部海域春季污染较为严重,西南部的污染程度相对较轻;春季和夏季的表层含量大于底层含量,秋季时底层含量高于表层含量;而且春季Hg污染较为严重,秋季水质状况最好.从历史资料来看,1979年到1982年,Hg污染在加剧;1982年到1997年,从污染严重到缓和,在1997年就达到了一类水质的要求;1997年到1999年,水质更加清洁.     

刁江水体多相介质中As,Zn和Pb的空间和季

调查了广西刁江河水中As,Zn和Pb的溶解态、悬浮颗粒态分布情况及季节变化,以及3种重金属在不同粒级沉积物中的分布情况. 结果表明:刁江流域河水与沉积物中3种重金属污染在流域尺度上的分布存在差异,沉积物污染更为严重. 与土壤污染一致,沉积物中3种重金属的污染范围扩散延伸到距离污染源近200 km的下游区域,其中车河矿区对As污染的贡献率明显高于大厂矿区,而对Pb污染的贡献率明显小于大厂矿区;不同重金属在水体中的赋存形态存在差异,河水中悬浮颗粒态Pb所占比例远高于As和Zn,这与3种重金属矿物的稳定性以及在不同粒级沉积物中的富集特征有关;河水中重金属的赋存形态存在季节差别,丰水期悬浮颗粒态重金属所占比例明显高于枯水期.      

Oxidative stress and DNA damages induced by cadmium accumulation

Experimental evidence shows that cadmium （Cd） could induce oxidative stress and then causes DNA damage in animal cells, however, whether such effect exists in plants is still unclear. In the present study, Vicia faba plants was exposed to 5 and 10 mg/L Cd for 4 d to investigate the distribution of Cd in plant, the metal effects on the cell lipids, antioxidative enzymes and DNA damages in leaves. Cd induced an increase in Cd concentrations in plants. An enhanced level of lipid peroxidation in leaves and an enhanced concentration of H2O2 in root tissues suggested that Cd caused oxidative stress in Vicia faba. Compared with control, Cd-induced enhancement in superoxide dismutase activity was significant at 5 mg/L than at 10 mg/kg in leaves, by contrast, catalase and peroxidaseactivities were significantly suppressed by Cd addition. DNA damage was detected by neutral/neutral, alkaline/neutral and alkaline/alkaline Comet assay. Increased levels of DNA damages induced by Cd occurred with reference to oxidative stress in leaves, therefore, oxidative stress induced by Cd accumulation in plants contributed to DNA damages and was possibly an important mechanism of Cd-phytotoxicity in Vicia faba plants.     

Contribution of additives Cu to its accumulation in pig feces： study in Beijing and Fuxin of China

Massive amounts of pig manure are produced by intensive pig farm in China, and the composition of pig manure has changed much due to the use of feed additives. However, little is known about the exact Cu （copper） feed as additives or present as contaminants in pig feed and the residues in feces. One hundred and thirty-seven feeds and one hundred and forty-two fecal samples from 48 pig farms were collected in Beijing and Fuxin cities in 1999 and 2005, respectively. The concentrations of Cu were in the range of 6.86-395.19 mg/kg in the feed samples, and the mean values were in the order of weaner〉 grower-finisher〉 sow＇s feeds. The high concentrations over EU recommendations implied that excessive levels of Cu are fed on many pig farms in Beijing and Fuxin. Cu was also present in high concentrations in feces, and concentrations were highly variable. Cu concentrations in the feces from grower-finisher and weaner pigs were significantly greater than feces of sows. The super-intensive and small-scale farms had higher levels of Cu in feces than the middle farms. Cu concentrations in pig feces were approximately 5-times greater than in pig feeds. Feed management in grower-finisher pigs on super-intensive and small-scale pig farms is needed to reduce high Cu concentrations in feces and risks to soil contamination while feces are land-applied.     

Distribution of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area in China

ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｒａｚｉｎｅ(2ｃｈｌｏｒｏ4ｅｔｈｙｌａｍｉｎｏ6ｉｓｏｐｒｏｐｙｌａｍｉｎｏｓｔｒｉａｚｉｎｅ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｓｅｌｅｃｔｉｖｅｐｒｅａｎｄｐｏｓｔｅｍｅｒｇｅｎｃｅｈｅｒｂｉｃｉｄｅｓｆｏｒｔｈｅｃｏｎｔｒｏｌｏｆｂｒｏａｄｌｅａｆａｎｄｇｒａｓｓｙｗｅｅｄｓ.ＴｈｉｓｈｅｒｂｉｃｉｄｅｉｓｐｒｉｍａｒｉｌｙｕｓｅｄｉｎｃｏｒｎｃｒｏｐｐｉｎｇｓｙｓｔｅｍｉｎＮｏｒｔｈｅａｓｔａｎｄＮｏｒｔｈｏｆＣｈｉｎａ,ａｎｄａｓｏｆｔｅｎｔｉｍ…     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

黄浦江江水和沉积物中汞的分布和形态特征

黄浦江江水的总汞、溶解态汞和颗粒汞含量变化较大,其平均值分别为(0.4±0.44)ng/mL、(0.27±0.42)ng/mL和(0.13±0.10)ng/mL,江水中汞以溶解态汞为主.黄浦江沉积物的总汞含量为70.52ng/g～387.30ng/g,平均汞含量为(204.03±97.41)ng/g.江水和沉积物中汞的沿江分布具有中游高,上游和下游低的特征,西渡—南浦大桥江段汞含量为整个黄浦江最高的江段,汞的分布特征与两岸工农业布局相一致.沉积物总汞与有机质显著相关,沉积物中高汞含量的地点都在高水汞点的下游,与河流的动力沉积特点一致.沉积物中汞以可交换态、腐殖酸结合态、残渣态为主,少量为碳酸盐结合态.从上游到下游,沉积物中可交换态汞具有两端高中间低的特点,而残渣态汞与此相反.在剖面方向上,沉积物中的汞主要集中在残渣态,少量为腐殖酸结合态,可交换态及碳酸盐结合态,随着深度增加残渣态所占比例不规则增加.愈接近长江口,沉积物中的重金属愈容易被重新激活.     

青岛大气气溶胶水溶性无机离子的粒径分布特征

为了解大气颗粒物中水溶性离子的来源及环境效应,利用安德森采样器连续采集青岛近海2008年1~12月大气颗粒物分级样品,用离子色谱法分析其中主要的水溶性离子,并讨论其粒径分布特征.结果表明, NH4+、K+、Cl-、NO3-、PO43-、SO42-主要存在于粒径小于2.1μm的细粒子中,Na+、Mg2+、Ca2+、F-则主要存在于粒径大于2.1μm的粗粒子中.各离子的粒径分布存在明显的季节变化.NH4+、K+和SO42-四季均主要分布于细粒子中,而Mg2+和Ca2+则主要分布在粗粒子中,两者均在3.3~4.7μm出现峰值;Na+在春、夏、秋3个季节主要存在于粗粒子中,集中分布在3.3~7.0μm粒径范围内,而在冬季则集中分布于0.43~1.1μm且细粒子含量高于粗粒子;春季Cl-在粗粒子中分布较多,尤以2.1~3.3μm范围内的最为突出,而其他3个季节均是细粒子比例明显偏高;NO3-春、夏两季在粗、细粒子中的含量各占50%,秋、冬季节均为细粒子占多数;PO43-夏季只出现在0.65~1.1μm以及>11μm的粒径范围内,粗粒子占95%,其他3个季节则是细粒子含量较高;春季F-在3.3~4.7μm出现峰值,夏季各粒径均未检出,而秋、冬两季粗、细粒子各占50%.K+、NH4+、F-、Cl-、NO3-、SO42-和PO43-受供暖期燃煤取暖的影响较大.K+和NH4+在供暖期和非供暖期峰值均出现在0.43~0.65μm粒径范围;F-供暖期在0.43~0.65μm和3.3~4.7μm粒径段出现峰值;供暖期Cl-的峰值出现在0.43~0.65μm粒径段,而在非供暖期,则出现在2.1~3.3μm的粗粒径段;SO42-和NO3-在供暖期和非供暖期的峰值均出现在0.43~0.65μm和3.3~4.7μm粒径段;供暖期PO43-的最大峰值出现在0.43~0.65μm粒径段,而在非供暖期其最大峰值出现在3.3~4.7μm粒径段.     

环渤海湿地芦苇对TC、TN、TP吸收通量的研究

主要调查研究环渤海湿地芦苇对TC、TN、TP的吸收通量。调查表明,2008年环渤海湿地的芦苇面积为20.08×104hm2。2009年,芦苇总生物量在7月、10月和11月的调查结果分别为267.2×104t、183.4×104t和138.0×104t。7月、10月和11月,芦苇对TC的吸收通量分别为115.58×104t、80.68×104t、64.23×104t;对TN的吸收通量分别为4.03×104t、1.45×104t、0.84×104t;对TP的吸收通量分别为0.37×104t、0.10×104t、0.031×104t。