高烈度地震区隧道软硬围岩交接段刚柔并济抗减震技术研究*

为提高高烈度地震区隧道抗震性能，以某铁路隧道为研究背景，分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数，通过对比分析得到最优抗减震措施。结果表明:相比于工况1，工况2隧道拱顶沉降减小10.54%~81.10%，边墙收敛减小13.92%~78.77%，衬砌结构PGA减小31.42%~72.02%，最小安全系数增加18.04%~66.13%；相比于工况1，工况3结构拱顶沉降减小3.04%~18.02%，边墙收敛减小4.70%~32.00%，PGA增加13.95%~27.48%，最小安全系数增加7.49%~30.99%；工况4即“减震层+SFRC衬砌”刚柔并济法，相比于工况1，隧道拱顶沉降减小18.46%~83.98%，结构边墙收敛减小17.54%~85.47%，PGA减小30.00%~69.98%，最小安全系数增加47.95%~83.56%；4种工况抗减震性能由高到低依次为:工况4＞工况2＞工况3＞工况1。研究结果可为隧道软硬围岩交接段抗震设防提供理论参考。     

淮河支流污染物综合降解系数动态测算

确定河流污染物综合降解系数动态变化规律对提高水环境容量测算精度和水环境管理具有重要意义。通过现场模拟法,采用一维稳态模型测算了淮河支流洪河五沟营-塔桥乡河段COD、氨氮和总磷在枯水期、平水期和丰水期的综合降解系数,COD、氨氮和总磷降解系数在各水期的关系为枯水期平水期丰水期,提出了建议值并利用实测浓度对计算结果进行了检验,结果表明,不同水期综合降解系数吻合情况较好。     

The Impact of Agriculture On Dissolved Nitrogen and Phosphorus Cycling in Temperate Ecosystems

Although most research has focussed on inorganic nutrient forms of nitrate (NO^-₃) and phosphorus (PO³₄) in runoff and receiving waters, nitrogen loss from agricultural land can also occur in organic and ammonium-nitrogen form; phosphorus losses, although often dominated by particulate transport, may occur in soluble organic and inorganic form. Furthermore, fluxes between different species may take place during transport from the land to the stream and as a result of in-stream, in-river or in-lake transformations. Knowledge of the spatial and temporal variation in all nitrogen species and phosphorus fractions in a drainage basin is therefore essential if the wider environmental significance of elevated nutrient concentrations in natural waters are to be assessed. This paper reviews recent work on N and P losses from agricultural land and presents some results from two intensive agricultural catchments: Slapton, Devon and the river Windrush catchment in the Cotswolds.     

母岩的风化剥蚀速率与土壤允许流失量的关系 --以长江三峡坝区风化花岗岩土壤为例

土壤允许流失量的确定是一个非常复杂而又必须解决的问题，它关系到水土保持措施的布设和土壤的可持续利用。然而，发育在不同母质上的土壤，其土壤的最大允许流失量差异很大，确定这一值的依据也各不相同。在岩成土壤地区，母岩风化剥蚀速率的大小直接影响土壤的发育。是确定土壤允许流失量、分析人类加速水土流失的重要依据之一。选长江三峡黄陵背斜段风化花岗岩土壤为研究对象，根据剥蚀沉积相关原理，通过恢复古地理环境及时代，计算出新生代以来本区花岗岩的平均风化剥蚀速率为16．97mm／ka．最大剥蚀速率为49．56。又根据区内太平溪流域的泥沙资料，算出了当地现代的剥蚀速率，多年平均为297．7mm／ka，最小值为31．5mm／ka，而水利部颁布的当地土壤允许流失量为200t／km^2,a，折合为76．9mm／ka，二者相差近1．5—4．5倍。基于此。提出了确定土壤允许流失量必须参考母岩风化剥蚀速率的新观点。     

The Influence of Chironomus plumosus Larvae on Nutrient Fluxes and Phosphorus Fractions in Aluminum Treated Lake Sediment

One of the methods to diminish the internal phosphorus (P) loading is inactivation of P by aluminum (Al). After addition of Al to lake water an Al(OH)₃ floc is formed, which settles to the bottom and initially form a lid on the sediment surface. The effects of Chironomus plumosus larvae on sediment nutrient fluxes and P binding-sites in the sediment after addition of Al were tested. C. plumosus larvae were added to sediment cores in which sediment–water fluxes of nutrients were measured four times. After one month, the sediment was sectioned with depth and P fractions were measured by sequential chemical extraction. The chironomids created burrows through the Al layer which caused a significantly increased efflux of P from the Al treated sediment, because the P had only limited contact to the added Al. The chironomids also affected the P fractions in the sediment by their bioturbating activity. Thus, they caused increased Al concentrations in the upper part of the Al treated sediment. This created an enhanced contact between Al and P in the upper 7 cm of the sediment and, as a result, an increased binding of P to Al and a lowered porewater P. The DIP efflux is therefore expected to be lowered after the initial phase. Al had no effects on the nitrogen fluxes, but the chironomids enhanced the release, and decreased the release or increased the uptake by the sediments.     

Diffusion pollution from livestock and poultry rearing in the Yangtze Delta,China

BACKGROUND: The Yangtze Delta is one of the most developed regions in China and includes Shanghai, eight cities in Jiangsu province and eight cities in Zhejiang province. Meat consumption in this region has increased with economic growth, and most of the consumed meat is produced locally. The water quality of surface waters has deteriorated in recent years. An example was the huge blue-green algae bloom in Tai Lake in late May 2007, which affected millions of people's daily drinking water. However, animal husbandry is considered to be one of the main pollution sources. METHODS: Pollutants (NH3-N, total phosphorus (TP), and total nitrogen (TN)) excreted by livestock and poultry, and the resultant COD (chemical oxygen demand) and BOD (biochemical oxygen demand), were estimated using two different methods based on different data sets. RESULTS: The number of livestock and poultry has remained stable in the Yangtze Delta over the four years from 1999 to 2002, with the average number of pigs, cattle, sheep and poultry being 21.1 M, 0.4 M, 7.7 M and 597.6 M, respectively. Pollutants in livestock and poultry excreta estimated by Method I were: 0.12 Mt NH3-N, 0.11 Mt TP and 0.29 Mt TN, resulting in COD and BOD of 1.34 Mt and 1.30 Mt, respectively, while the estimations based on Method II were: 0.18 Mt NH3-N, 0.15 Mt TP and 0.40 Mt TN, resulting in COD and BOD of 1.95 Mt and 1.80 Mt, respectively. DISCUSSION: Pollutants excreted annually by livestock and poultry in the Yangtze Delta are estimated to be: 0.17 Mt NH3-N, 0.16 Mt TP and 0.42 Mt TN, giving rise to a COD of 1.86 Mt and a BOD of 1.72 Mt. Approximately 25% of this pollution was estimated to enter water bodies, which means that the annual pollutant load is 43,700 t NH3-N, 39,400 tTP, 104,600t TN with a COD of 465,000 tand a BOD of 430,100 t. Pollutants from animal husbandry were similar in magnitude to those from industrial wastewater. Pigs produced the most pollution, followed by poultry, cattle and sheep. The pollution load from animal husbandry in the Yangtze Delta is about twice the average level of the whole of China. CONCLUSIONS: Domestic wastewater was the main pollution source in the Yangtze Delta, followed by pollution from raising livestock and poultry and from industrial wastewater. The pollution load in Shanghai and Jiaxing were the greatest, followed by 7 cities of Jiangsu province (except Suzhou) and other cities of Zhejiang province and Suzhou. Pigs and poultry produced about 90% of the total pollutants from animal husbandry. RECOMMENDATIONS AND PERSPECTIVES: The local governments, especially in Shanghai and Jiaxing, should focus their attention on the pollution produced by livestock and poulrry. Controlling pollution from pigs and poultry will have the greatest impact in this region. Control of pollution will be facilitated by the development of large-scale livestock and poultry farming units and a shift away from small scale husbandry.     

降水空间异质性对非点源关键源区识别面积变化的影响

针对地形起伏和降水空间差异较大的农业区非点源污染问题,基于SWAT模型评估了阿什河流域在异质性降水和均匀降水两种情景下总氮、总磷关键源区空间变化规律,统计了两种情景下识别的关键源区面积变化,并分析其与降水特征参数的关系.结果表明,降水量一定时,两种情景下识别的总氮、总磷关键源区面积变化趋势大致相同,且总磷关键源区面积不易受降水空间异质性的影响,但总氮关键源区面积却明显受到其影响.对各年份总氮和总磷关键源区面积与降水特征参数的相关分析表明,总磷关键源区面积与当年降水量呈显著正相关,而总氮关键源区面积却与前一年降水量呈显著正相关.研究结果对进一步探讨降水这一重要驱动因子的不确定性对非点源污染关键源区的影响,以及农业非点源污染的治理具有重要意义.     

不同碳源模式下酵母菌PNY2013同步脱氮除磷的应用研究

针对首次分离得到的一株具有同步脱氮除磷新功能的热带假丝酵母（Candida tropicalis） PNY2013,通过生理及动力学特征,连续流运行操作及其在含糖类工业废水中的应用3个环节,探讨了不同碳源模式下PNY2013同步脱氮除磷的特性.结果表明：PNY2013以葡萄糖、乙醇及乙酸为唯一碳源时均生长良好,其最大比增长速率μ_max分别为0.1327、0.1252及0.1115 h^-1,其同步脱氮除磷率分别可达100%、80%、100%（NH₄⁺-N）及93%、95%、98%（PO₄^3--P）.3种碳源下PNY2013同步脱氮除磷的最佳条件基本接近为：温度30℃,pH=8.0,溶解氧0~2 mg·L^-1,C/N=200∶5左右.PNY2013同步脱氮除磷的长期连续运行条件下的实验进一步表明,以葡萄糖为碳源条件下,进水NH₄⁺-N及PO₄^3--P浓度分别达400及80 mg·L^-1时,两者去除率均接近100%.与这种超强能力相比,以乙醇及乙酸为碳源条件下,进水NH₄⁺-N及PO₄^3--P浓度分别达100及20 mg·L^-1时,两者的去除率也可达60%~80%（NH₄⁺-N）及40%（PO₄^3--P）,显示出相当的同步脱氮除磷能力.在以模拟制糖废水、淀粉加工废水、啤酒废水、味精废水这4种典型含糖工业废水为碳源条件下,除淀粉加工废水外PNY2013均能有效去除COD、NH₄⁺-N和PO₄^3--P,其中,制糖、啤酒、制药废水中的COD去除率分别可达40%、89%、96%,NH₄⁺-N去除率分别为85%、94%、76%,PO₄^3--P去除率均为90%.即使在40000 mg·L^-1（制糖）及12500 mg·L^-1（啤酒）的高COD条件下,PNY2013也均具有稳定的NH₄⁺-N和PO₄^3--P去除效果,显示出良好的同步脱氮除磷应用前景.     

黄海麻坑群沉积物磷的保存与转化及环境效应

基于对北黄海典型麻坑群海域某单位麻坑内部和外缘沉积物中不同赋存形态的磷、甲烷（CH₄）和硫化物等参数的分析,探讨了麻坑独特的环境中磷的转化与埋藏机制、沉积物-水体系磷的释放及对区域磷循环的影响.研究表明,沉积物中碎屑态磷（Det-P）是磷主要的赋存形态（>50%）,其次是有机磷（Org-P）、铁结合态磷（Fe-P）和自生态磷（Auth-P）,交换态磷（Exch-P）对总磷的贡献较小;麻坑内部与麻坑外缘处沉积物中溶解态活性磷（DRP）向水体的释放通量分别为2.84μmol/（cm²·a）和1.03μmol/（cm²·a）,对上层水体的贡献依次为19.6%和3.03%,是上层水体磷的重要来源.麻坑内外磷的埋藏速率与转化过程存在不同;研究区地下水的渗漏是磷的沉积速率和释放通量都普遍高的原因.北黄海麻坑区沉积物中磷的保存与转化还与浅层CH₄的逸出相关,潜在提高黄铁矿的生成速率.较高的沉积物-水界面磷通量必然对区域富营养化等生态环境问题产生深远影响,值得关注.     

红树林土壤解磷菌的分离鉴定及解磷特性

从罗源湾红树林根际土壤中分离解磷菌,筛选出洋葱伯克霍尔德菌（Burkholderia cepacia, NR 113645.1）和短小芽孢杆菌（Bacillus pumilus, NR 043242.1）,研究它们的解磷特性和动态解磷过程. HPLC结果表明, B. cepacia菌液上清中含葡萄糖酸、丙酮酸、乳酸、乙酸、丁二酸, 这些有机酸的产生导致磷酸盐溶解. B.pumilus菌液上清中仅检测到少量的葡萄糖酸, 因此该菌溶磷效果不佳. 在细菌动态溶磷过程中发现, 经B. cepacia菌处理的磷酸钙, 其X射线衍射（XRD）特征峰强度随时间的增长降低, 显微镜图像显示磷酸钙颗粒随时间增长变小, 甚至消失. 而经B.pumilus菌处理的结果表明, 在试验期间内磷酸钙峰强度和颗粒大小没有明显变化. 细菌产生有机酸是溶解磷酸盐的重要前提, 这是解决板结土壤中难溶性磷源转化为生物可利用磷源问题的关键.