新建交通干线两侧声环境功能区划分问题及对策建议

随着我国交通运输事业的迅速发展,新建交通干线两侧声环境功能区划分时出现了变更程序过于简单和草率,划分标准不符合交通干线噪声的源强特点和衰减规律,两侧群众声环境权益保障范围不合理等问题。提出了规范声环境功能区变更程序,完善相关标准,建立合理可行的补偿机制的对策建议。     

矩形巷道围岩应力解析解

为得出矩形断面巷道围岩应力分布特征,采用复变函数解法对矩形巷道围岩弹性应力进行解析,得出了应力分量的曲线坐标表达式;分析了巷道高宽比和侧压对围岩应力的影响.结果表明,高宽相等时巷道最大应力最小,边界最大应力随侧压系数增大而增大.无论侧压和高宽比如何变化,四角附近区域应力集中系数均最大.同高宽比情况下,随侧压增加,矩形巷道径向应力的峰值近似呈线性增加,环向应力峰值减小,径向应力和环向应力峰值均向围岩内部迁移.相同侧压下,随巷道高宽比增大,径向应力和环向应力峰值均向围岩内部迁移.相同高宽比和侧压下,距离巷道右帮越远,径向应力越大,环向压应力先增后减.     

Aquatic ecological health assessment of Shaying River Basin based on indices of physico-chemistry and aquatic organisms北大核心CSCD

With a variety of ecosystem services, river ecosystem plays an important role in the process of human society development. On the other hand, health condition of most aquatic ecosystems is seriously threatened by human activities. Restoring and maintaining a healthy ecosystem has already become a vital goal of river management. As a basis of river management, river health assessment is therefore particularly important. Based on indices of physics, chemistry and aquatic organisms, this research tried to establish a comprehensive evaluation system of aquatic ecological health suitable for the situation of Shaying River Basin. The system included 6 factors including riparian zone, river morphology, nutrients, oxygen balance, periphyton and benthic macroinvertebrates, which were defined into 19 indices reflecting the aquatic ecological health from different aspects. The assessment results indicated that the health condition of overall basin was normal, varying among different parts of the region, with Shahe River, Lihe River and Beiru River in the upper part sub-healthy, and Jialu River in the same part sub-sick. The middle region was generally in normal or sub-sick level; the health condition of the lower part was comparatively better due to a good condition. Within the indices, the nutrients and benthic macroinvertebrates were the major constraining factors to the health condition of Shaying River Basin for their poor health condition. The health conditions showed significant differences among the rivers (P < 0.01), with Jialu River being the worst. The result indicated that the aquatic ecological health of Shaying River Basin is affected by many factors, with urban and industrial sewage being the main ones, And that different protective measures should be employed for rivers of different conditions. The result can provide theoretical basis for the ecological restoration of Shaying River Basin and reasonable exploitation and conservation of the water resource of the whole Huaihe River Basin.     

Seasonal and Regional Patterns in Performance for a Baltic Sea Drainage Basin Hydrologic Model

This study evaluates the ability of the Catchment SIMulation (CSIM) hydrologic model to describe seasonal and regional variations in river discharge over the entire Baltic Sea drainage basin (BSDB) based on 31 years of monthly simulation from 1970 through 2000. To date, the model has been successfully applied to simulate annual fluxes of water from the catchments draining into the Baltic Sea. Here, we consider spatiotemporal bias in the distribution of monthly modeling errors across the BSDB since it could potentially reduce the fidelity of predictions and negatively affect the design and implementation of land‐management strategies. Within the period considered, the CSIM model accurately reproduced the annual flows across the BSDB; however, it tended to underpredict the proportion of discharge during high‐flow periods (i.e., spring months) and overpredict during the summer low flow periods. While the general overpredictions during summer periods are spread across all the subbasins of the BSDB, the underprediction during spring periods is seen largely in the northern regions. By implementing a genetic algorithm calibration procedure and/or seasonal parameterization of subsurface water flows for a subset of the catchments modeled, we demonstrate that it is possible to improve the model performance albeit at the cost of increased parameterization and potential loss of parsimony.     

Fe(Ⅲ)对海藻酸钙凝胶层过滤特性的影响

为考察饮用水处理膜工艺中Fe(Ⅲ)对多糖污染层过滤特性的影响,本研究以海藻酸钠为模型多糖污染物,分析海藻酸钙在有Fe(Ⅲ)及无Fe(Ⅲ)存在时形成污染层的过滤特性,并用压缩性方程及渗透性方程对凝胶层的过滤特性进行定量描述.研究结果表明,Ca2+的存在会使海藻酸钠分子间结合,形成内部结合紧密的凝胶层,产生较大的过滤阻力;往海藻酸钙溶液中进一步加入Fe(Ⅲ)后,由于可溶性Fe(Ⅲ)较易水解,加入Fe Cl3后溶液中铁离子和铁的氧化物/氢氧化物颗粒同时存在,少量Fe(Ⅲ)对海藻酸钙凝胶层的过滤特性影响不大,较多量Fe(Ⅲ)会形成铁的氧化物/氢氧化物颗粒,一定程度上改变了凝胶层的结构,使过滤性能变好.     

Modeling and optimization of activated sludge bulking for a real wastewater treatment plant using hybrid artificial neural networks-genetic algorithm approach

Prediction of sludge bulking is a matter of growing importance around the world. Sludge volume index (SVI) should be monitored to predict sludge bulking for a wastewater treatment plant. This study was an effort to develop hybrid artificial neural network-genetic algorithm models (MLPANN-GA and RBFANN-GA) to accurately predict SVI. Operating parameters, including MLVSS, pH, DO, temperature, TSS, COD and total nitrogen were the inputs of neural networks. Genetic algorithm was utilized in order to optimize weights and thresholds of the MLPANN and RFBANN models. Training procedures for SVI estimation were successful for both the MLPANN-GA and RBFANN-GA models. The training and validation models showed an almost perfect match between experimental and predicted values of SVI. The results indicated that with low experimental values of input data to train ANNs, the MLPANN-GA compared with the RBFANN-GA is more accurate due to higher coefficient of determination (R²) and lower root mean squared error (RMSE) values. The values of RMSE and R² for the optimal models approached 0 and 1, respectively. The mean average error for the ANN models did not exceed 3% of the input values of the measured SVI. The GA increased the accuracy of all the MLPANN and RBFANN models.     

科尔沁沙地水资源投入对粮食生产的影响定量研究 ——以奈曼旗为例

借鉴Cobb-Douglas全要素生产函数,以粮食总产量为因变量,以包括年降水量等气候要素、 耕地面积等经济要素和化肥施用量等技术要素在内的10项投入为自变量,构建1987年至2008年期间奈曼旗农业生产投入产出模型。结果表明:①影响奈曼旗粮食总产量的关键因素为农业劳动力(t=9.44,P/=0.00)、 年降水量(t=8.33,P=0.00)和灌溉用水量(t=6.89,P=0.00)。 除农业劳动力外,其他两项因子均与水资源有关;年降水量和灌溉用水量的弹性系数均大于1,说明粮食总产量的增长倍数高于水资源投入的增长倍数,水资源的继续投入将导致粮食产出快速增长。②根据模型,农业劳动力、 灌溉用水量、 年降水量的回归系数分别为5.13、 1.55和1.46,显示当地劳动力投入及水资源投入均存在不足,单独增加某个投入要素即会导致粮食产出以更快速度增长;随着奈曼旗农业劳动力不断减少,且年降水量波动性增强且呈下降趋势,粗放式的灌溉明显加强。根据模型,其他投入要素不变、农业劳动力减少1%时,灌溉用水量增加3.31%;其他投入要素不变、 年降水量减少1%时,灌溉用水量增加0.94%。③降水的波动会导致粮食单产量的波动,而灌溉用水量在很大程度上影响了粮食单产量水平(R²=0.543);降水量的减少导致农民通过扩大播种面积来获得增产,因此降水量的年际变化和播种面积的年际变化之间呈现明显的反向变动关系。总体来讲,奈曼旗农业生产对灌溉用水的依赖程度不断加大。随着灌溉用水的持续投入,其增产作用将逐渐降低,并且对当地脆弱生态系统带来进一步的压力。     

基于地域功能的土地利用协调研究——以长株潭生态绿心暮云镇为例

论文以长株潭生态绿心暮云镇为例,基于地域功能及其格局视角,采用整体协调性(C₁)和有效协调性(C₂)等指标,分析土地利用现状态势与地域功能规划的数量协调性、 空间协调性、 主要协调问题及效应。研究结果表明:暮云镇生态空间C₁为54%,C₂为69.81%,存在较大缺口,应新增面积高达802.95 hm²,绿心建设任重道远,需重点加强东北部-东部山林生态和北部绿带建设;农业空间C₁为38.08%,C₂为91.28%,转换潜力较大,但应加强区内土地整理和村庄整治,提升生产效能和生态服务功能;建设空间C₁为36.11%,C₂为82.94%,增长速度过快,威胁生态绿心功能定位及格局形成,扩展速度与空间布局亟需优化调整。研究区应实行功能空间三重保障、 统筹城乡人口与用地、 建设适度复合功能空间及构建区域协调长效机制,促进土地利用与地域功能协调发展。     

基于未确知测度的岩体稳定性多元联系度评价模型*

为准确评定岩体稳定性等级,引入未确知测度理论、多元联系度理论和同异反确定不确定体系,建立基于未确知测度的岩体稳定性多元联系度评价模型。该模型通过指标组合权重值和单指标测度矩阵,得出多指标综合测度矩阵、同异反联系度矩阵和模糊评价矩阵。并借助多元联系度定量计算待评岩体的评价等级、定性分析及准确预判岩体稳定性的发展趋势,较好地优化置信度评价过程,克服传统模型不能定量表达不确定性因素的缺陷,而且拓展指标隶属等级交叉的特性。以1号岩体为例,研究结果表明:岩体的稳定性等级为Ⅲ级,处于基本稳定状态,但有着向不稳定状态（Ⅳ级）移动的趋势。模型的评价结果与实际结果相吻合,说明应用该模型评判岩体稳定性等级是有效可行的。     

Red-list status and extinction risk of the world's whales,dolphins, and porpoises

To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2–3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.