Soft-bottom benthic community in the estuarine waters of East Java

During the Snellius-II Expedition, both in the period July–August and in the period November–December 1984, the structure of the macrobenthic communities in the estuaries of the rivers Porong, Wonokromo and Solo was investigated. The numerical densities of the benthic organisms (>0.5 mm) from the Porong, Wonokromo, and Bengawan Solo estuaries during the Snellius-II Expedition varied between 87 and 5787 ind·m⁻²; biomasses between 0.4 and 602 g DW·m⁻². The high numerical density (1573 ind·m⁻²) found at st.2 of the Porong estuary in period I (July–August 1984) was attributed to the dense population of the bivalve Varicorbula rotalis. Consequently a very high biomass (602 g DW·m⁻²) was measured at this station.The mollusc Theora lata and the polychaetes Ancistrosyllis parva, Nepthys dibranchis, Paraprionospio pinnata, and Sternaspis laevis occurred at almost every station during the investigation periods.Paraprionospio pinnata and Theora lata, which are considered indicator species of disharmonic environments, were found at almost every station of the study areas in both periods. Species diversity at all the stations was low, ranging form 0.1 to 1.6.     

Values and beliefs about urban forests from diverse urban contexts and populations in the Greater Toronto area

Cities around the world are diverse. People’s perceptions of urban forests may vary according to urban contexts and people’s diverse identities. A better understanding of these diverse perceptions is critical to support stewardship initiatives, inform urban tree decisions, and guide community engagement, among other key management and governance processes in urban forestry. This study examines the values and beliefs that diverse people living in a variety of urban contexts associate with urban trees. Using an urban gradient approach, 2009 responses were collected through an online panel survey conducted in the Greater Toronto Area (GTA) to understand variations in values and beliefs of urban forests across municipal types (inner core, suburban, peri-urban, and regional cities). The GTA has an ethnoculturally diverse population, allowing us to also explore perceptions held by people with various identities. The study uses analytical techniques, such as means differences and linear regression models, to segment the diverse meanings people attribute to urban trees by municipal types and people’s identities. The results show that, while people value the urban forest very highly, people’s value orientations vary depending on their context and identities. For example, respondents who speak European or South Asian languages tend to hold value orientations related to cultural, social, and identity issues. Respondents living in inner municipal types tend to hold values related to identity issues, whereas respondents living in outer municipal types and regional cities tend to hold values related to natural issues. The results also show that people’s beliefs about urban forests are primarily positive. Urban forests managers and stewardship initiatives should recognize the diverse set of values and beliefs that people associate with urban forests, incorporating these perceptions into policy and programs. Additionally, since specific value and belief orientations may depend on personal identity and urban contexts, tailored messaging may also help generate support for policy or stewardship initiatives across different communities and in varied urban contexts.     

穿斗式木结构直榫边节点承载性能试验研究

以传统民居穿斗式木结构直榫边节点为研究对象,分析节点承载机制,并设计制作3套杉木结构直榫边节点足尺试件(对照组1套、扒钉加固1套、角钢加固1套),进行低周往复加载试验。研究结果表明:直榫边节点破坏模式主要表现为节点木材横纹压屈变形和节点拔榫,滞回曲线轮廓均呈反“Z”形状,且呈现较明显的捏缩现象。与未加固节点相比,加固节点的承载性能均有所提高;扒钉加固节点在扒钉脱落失效前提高了节点刚度、累积耗能及变形能力,角钢加固节点在穿枋断裂前显著提高了节点刚度、累积耗能及变形能力。     

再生水灌溉对果菜类蔬菜产量及品质的影响

为推动再生水灌溉作物的适宜性分类，该文研究了再生水灌溉对果菜类蔬菜产量与品质的影响。结果表明，再生水处理与对照处理相比可显著增加果菜类蔬菜产量，其中，西红柿、黄瓜平均增产15.1%、23.6%。茄子、豆角增产60.7%、7.4%。再生水灌溉对果实含水率、粗蛋白、氨基酸含量、可溶性总糖、维生素C、粗灰分、硝酸盐、亚硝酸盐等品质或营养指标无显著影响，再生水灌溉处理硝酸盐、亚硝酸盐含量低于标准限值。研究为再生水适宜灌溉的作物筛选提供了技术依据。     

果园有机肥机械化环沟施肥方法及其实现

环状沟施肥在传统上被认为是一种果园精准施肥方法，但其高肥效的机理尚不明确，且其机械化作业依然是个巨大的挑战。针对上述问题，该研究分析了果园机械化环沟施肥技术的相关农艺要求，并提出有机肥机械化环沟施肥方法及其实现装备。通过分析矮砧密植苹果树根系分布、肥料养分迁移与吸收、肥-土混合的农艺机理，阐明了果园环沟施肥机械化技术的优势和必要性，并确定环沟轨迹基圆半径。提出密植苹果园有机肥机械化环沟施肥方法，在树行单侧以连续曲线沟对根区形成包围，并同步施肥和混肥。研制了履带自走式果园有机肥环沟施肥机。该施肥机借助检测到的树干定位信号，通过电液式环沟轨迹控制系统控制开沟混肥器横向运动。由开沟混肥器的横向运动与施肥机的纵向运动合成曲线轨迹，一体化完成曲线开沟、施肥和混肥。田间试验表明，研制的施肥机能够精准识别果树树干，并围绕树干进行连续的环沟施肥，且肥料与全层土壤混合分布。环沟宽度210±6.3 mm，施肥深度300±19.5 mm，平均开沟阻力矩127.32 N·m，开沟混肥器平均功耗5.84 kW，工况稳定。基圆半径为0.7 m时，环沟轨迹和施肥轨迹平均误差分别为0.05和0.03 m。本研究首次实现了矮砧苹果园有机肥机械化环沟施肥方法，对旱区果园有机肥精准、高效施肥新技术具有促进作用。     

Experimental Investigation of Biofouling Mechanism of RO Membrane for Wastewater Advanced Reuse

Biofouling has become the focus of RO in water and wastewater treatment. Experimental investigation of RO biofouling mechanism and characteristics in wastewater advanced reuse was carried out by static test and cross-flow dynamic test on a lab-scale membrane fouling simulator(MFS).The experimental results show that the major contributors to biofouling are coli and filamentous bacteria; there usually is no biofouling on the RO membrane surface with the absence of microbial source and nutrient composition; it is easy to cause biofouling on the fouled membrane; the germicidal treatment and the protection in the shut-down period are important for RO. Guidance for the analysis and reduction of biofouling in the practical engineering is provided.     

乡村产业振兴背景下资源依托型特色村乡村旅游发展路径研究——以祁杨村为例

乡村旅游是乡村产业振兴的重要途径,这在资源依托型特色村表现更为突出。以祁杨村为例,在乡村产业振兴视角下研究了乡村旅游发展的策略。基于该村的现状,分析了其产业发展存在的问题与差距。在深入发掘该村乡村旅游资源、市场优势的基础上,提出了祁杨村乡村旅游的发展策略,可通过整合提升旅游产品、丰富完善乡村旅游吸引物、优化空间布局、完善旅游设施与服务等措施促进乡村旅游发展,助力乡村产业振兴。     

白羊草种子脱绒技术初探

白羊草(Bothriochloa ischaemum)种子上的散发性簇状绒毛致使其相互粘连,严重影响了机械化播种。本研究采用H₂SO₄和NaOH对白羊草种子进行脱绒处理,探究两种化学试剂对白羊草种子的脱绒效果。结果表明:当NaOH的浓度在30%以上时对种子的脱绒产生了明显的效果,但随着NaOH的浓度和处理时间的增加,种子的发芽指数和种子活力显著降低;而以浓度60%的H₂SO₄处理10 min的方式可有效地脱去白羊草表面绒毛,并且对脱绒后的白羊草种子发芽指数和种子活力指数没有显著影响。综上所述,用浓度60%的H₂SO₄处理10 min,是白羊草种子脱绒处理的最优方案。     

中国乡村现代化治理中的关键问题及政策导向

以乡村现代化治理推进国家治理体系和治理能力现代化，全面促成农业农村发展取得历史性成果，是满足人民日益增长的美好生活需要和解决我国发展不平衡不充分问题的要求。基于此，在推进乡村现代化治理过程中，需明确当下乡村治理中的“纵向”与“横向”结构问题，廓清农村承包土地中确权不清和分权不当的问题，认识外出农民返乡与乡村现代化治理之间的内在关联。只有通过城乡融合发展破除城乡二元差异，坚持自治、德治、法治“三治合一”，推动农村土地制度变革，吸引外出农民返乡参与建设，才能更好地从政策导向上推进乡村现代化治理取得重大成效。     

冷弯卷边槽钢轴压屈曲机理试验与数值研究

对6根冷弯卷边槽钢进行了轴力加载试验.其中4根试件用以研究截面高宽比和长细比对试件屈曲行为、承载力等参数的影响；另2根组合试件用以对比分析组合作用以及组合形式对试件静力性能的改善.试验结果表明：截面高宽比、长细比以及偏心是影响板组效应与承载力的重要因素，能很大程度上影响试件的屈曲形式；组合作用能大大改善试件承载力，不同的组合形式还影响试件的屈曲形式.同时，建立了有限元数值模型，考虑几何和材料非线性，并考虑初始缺陷，将计算结果与试验进行了对比分析，分析结果显示试验与数值模拟吻合良好.