碳中和的缘起、实现路径与关键科学问题：气候变化与可持续城市化

碳中和是我国应对气候变化的新目标,提出以来引起国内外广泛关注。碳中和目标实现是一个复杂系统科学问题,涉及大气圈、岩石圈、水圈、生物圈、人类圈等多圈层耦合过程与作用机制,需要跨学科交叉、综合与协同研究。简要梳理碳中和提出的气候变化和温控目标缘起,归纳碳中和实现的碳源、碳汇的多元路径,强调从碳源的需求侧推动可持续城市化对于碳中和目标实现的重要作用,并且可能是成本低、潜力大、更直接有效的方案途径。提出适应与减缓气候变化下碳中和与可持续城市化研究领域8个方面的科学问题：气候变化—碳中和—可持续城市化关联关系、中国及各地区碳中和实现的路线图与时间表、城市区域尺度碳排放的精准核算、绿色生活方式与低碳社会、绿色生产方式与低碳经济、能源结构优化、风险与不确定性和碳中和长效机制的治理创新等,以及该领域当前研究面临的机遇和挑战。     

新的污染物环境危害评价指标——超标强度

污染物的危害程度不仅与超标率和超标倍数有关,而且与污染物超标持续时间有关。同样高的污染物浓度,如果其持续时间长短不同,其对环境的生态效应是不同的。为此,在充分分析超标率、超标倍数所存在缺陷的基础上,通过实例分析对比,以直观图解的方式提出了一套新的污染物环境危害评价指标体系——超标强度指标体系。超标强度指标体系中涉及的主要概念和指标有标准面积、超标面积、超标持续时间、超标强度和综合超标强度。在阐述了各指标的概念含义和计算方法后,以同一组监测数据为例,用超标率和超标倍数与超标强度指标进行了对比评价。结果表明,用超标强度及其指标体系可以科学、准确区分和评判超标率、超标倍数指标体系所不能区分和评判的真实存在的客观事实,而且非常精确地给出了污染物超标持续时间。超标强度指标所涵盖的内容比超标率和超标倍数更丰富,评价的结果更准确,所反映的生态环境质量状况更客观准确、科学真实。超标持续时间表明了污染物超标状态的持续时间。     

磁铁矿纳米颗粒与Pb~(2+)复合物对大鼠肾细胞的毒性研究

磁铁矿纳米颗粒(magnetite nanoparticles, MNPs)是一种环境友好型吸附剂,广泛应用于废水中Pb~(2+)的处理。目前,有不少关于MNPs毒性的研究,但对MNPs处理Pb~(2+)形成的复合物的毒性却鲜有报道,其复合毒性亟待深入研究。本文以大鼠肾细胞(NRK)作为细胞模型,系统研究不同Pb含量的MNPs-Pb复合物,以及相应浓度的MNPs和Pb~(2+),对大鼠肾细胞活性、细胞形态和密度的影响,考察细胞对纳米颗粒的摄取以及细胞凋亡的作用机制,评估MNPs-Pb的毒性效应。结果表明,在本实验浓度和暴露时间(12 h)条件下,Pb~(2+)能够显著抑制细胞活性,改变细胞形态,促进细胞凋亡,对细胞有显著的毒性效应,并且呈现剂量相关性;利用MNPs吸附水环境中Pb~(2+)形成的复合物MNPs-Pb对大鼠肾细胞没有显著的毒性作用(P<0.05),MNPs对Pb~(2+)的吸附可能是Pb~(2+)的细胞毒性降低的原因。     

Prioritizing Agricultural Lands for Conservation Buffer Placement Using Multiple Criteria1

Qiu, Zeyuan, 2010. Prioritizing Agricultural Lands for Conservation Buffer Placement Using Multiple Criteria. Journal of the American Water Resources Association (JAWRA) 1-13. DOI: 10.1111/j.1752-1688.2010.00466.x Abstract: Although conservation buffers are multifunctional, the current conservation buffer planning strategies tend to use a single criterion, most frequently a hydrological or soil condition indicator, to guide conservation buffer placement. This study presents a watershed planning approach that prioritizes agricultural lands for conservation buffers based on multiple selection criteria and applies the approach to Raritan Basin in central New Jersey. The multiple selection criteria include soil erodibility, hydrological sensitivity, wildlife habitat, and impervious surface rate. These criteria capture the conservation buffers’ benefits in reducing soil erosion, controlling runoff generation, enhancing wildlife habitat, and mitigating stormwater impacts, respectively. An expert panel was used to identify and define the section criteria, review the measured values of those criteria, and develop the classification scales that assign the class score to each criterion. The prioritization is based on the summation of the criteria class scores. About one-third of agricultural lands are prioritized for conservation buffers in Raritan Basin. The total program cost of converting those prioritized agricultural lands to conservation buffers in Raritan Basin is estimated to be between $54.8 and 102.9 million depending on the composition of installed conservation buffer practices.     

农地资源不同价值属性的产权结构设计实证

农地是农业的基础、国民经济的基础,也是社会稳定的基础。农地资源具有经济价值属性、生态价值属性和社会价值属性,而社会价值属性包括社会保障功能价值、社会稳定功能价值及其他社会功能价值。本文针对农地资源不同的价值属性进行了产权结构设计,经济价值属性对应于农地农用产权,社会保障功能价值对应的是农地发展权,其他的价值属性构成了农地的公共产权。通过建立农地资源不同形态的价值属性与产权、价格之间的关系框架,为农地产权价格的衡量提供了依据。江都市的实证研究表明:农地发展权价格和公共产权价格在农地完全价格中的比重高达81.85%,其中,发展权价格的比重最大,达到63.02%,是农用产权价格的3.47倍;而公共产权价格的比重也达到18.83%,高出农用产权价格4%。在征地过程中如果考虑农地发展权和公共产权,并将其权益分配给农民,那么农民的土地财产权益可以增加4倍多。     

基于二级近似的航天器结构的模型修正方法

目的基于航天器结构自由度数大且结构复杂,直接对有限元模型修正计算效率低的问题,利用二级近似方法来提高有限元模型修正的计算效率。方法根据特征向量建立Ritz空间推导出频率响应及其敏度的一级近似计算公式,利用近似函数二级近似计算结构参数变化后的动刚度矩阵,通过多重优化流程消除近似计算引入的误差。结果通过两个数值算例进行验证,该方法提高了结构模型修正的计算效率。结论该方法适用于航天器结构的模型修正。     

多能源设备隔离流程措施的探讨

分析了2起因能量的意外释放导致的伤害事故,提出了具备多能源设备的锁定和挂牌的安全流程,并附有能源隔离安全检查表和流程图.     

关于大气中PM2.5浓度的综合预测

鉴于PM2.5对人体的危害，为了提前预测PM2.5浓度值并及时通过降雨方法降低其浓度，开展了PM2.5浓度综合预测研究。通过对西安市一个空气质量监测点收集到观测数据分析与PM2.5浓度强相关的因素，随后综合考虑天气、温度、风力风向对PM2.5浓度观测值的影响，通过添加虚拟变量及因子分析提取因子的方法，将强相关因素、提取的天气、温度、风力风向因子与PM2.5浓度观测值进行回归预测，最终得到较好预测效果。     

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers

This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0–1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0–1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7–1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6–1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.     

Conserving tigers in working landscapes

Tiger (Panthera tigris) conservation efforts in Asia are focused on protected areas embedded in human‐dominated landscapes. A system of protected areas is an effective conservation strategy for many endangered species if the network is large enough to support stable metapopulations. The long‐term conservation of tigers requires that the species be able to meet some of its life‐history needs beyond the boundaries of small protected areas and within the working landscape, including multiple‐use forests with logging and high human use. However, understanding of factors that promote or limit the occurrence of tigers in working landscapes is incomplete. We assessed the relative influence of protection status, prey occurrence, extent of grasslands, intensity of human use, and patch connectivity on tiger occurrence in the 5400 km² Central Terai Landscape of India, adjacent to Nepal. Two observer teams independently surveyed 1009 km of forest trails and water courses distributed across 60 166‐km² cells. In each cell, the teams recorded detection of tiger signs along evenly spaced trail segments. We used occupancy models that permitted multiscale analysis of spatially correlated data to estimate cell‐scale occupancy and segment‐scale habitat use by tigers as a function of management and environmental covariates. Prey availability and habitat quality, rather than protected‐area designation, influenced tiger occupancy. Tiger occupancy was low in some protected areas in India that were connected to extensive areas of tiger habitat in Nepal, which brings into question the efficacy of current protection and management strategies in both India and Nepal. At a finer spatial scale, tiger habitat use was high in trail segments associated with abundant prey and large grasslands, but it declined as human and livestock use increased. We speculate that riparian grasslands may provide tigers with critical refugia from human activity in the daytime and thereby promote tiger occurrence in some multiple‐use forests. Restrictions on human‐use in high‐quality tiger habitat in multiple‐use forests may complement existing protected areas and collectively promote the persistence of tiger populations in working landscapes.