摘要：湖北省咸宁市通山县位于鄂、湘、赣三省交界,其聚落布局、结构、工艺、色彩风貌皆体现出多元融合的发展态势,并最终形成极具地域特色的聚落面貌。在当代乡村振兴的国家战略背景下,针对传统村落的色彩风貌控制策略研究,有助于凝练村落特色、提升环境和谐度,尤其在部分新建民居建筑进入到传统聚落环境中时,由于建筑材料与建造工艺的改变,在最终呈现出的色彩风貌上面临着新旧关系衔接的问题。该文以通山县13个传统村落作为主要调研样本,结合通山县传统村落文献记载和实地照片等定性分析,利用孟塞尔色彩体系的色彩表达方法进行色相、彩度、明度的定量分析,解析通山县传统民居的色彩现状。以宝石村为重点研究对象,选取村落中具有代表性的街巷与典型民居建筑,根据民居搭建年代筛选出可保留的民居色彩,提出推荐色谱,为宝石村提炼出更具地域特色的色彩组成,为其后续修复与发展提供色彩风貌控制的方向与策略。

摘要：针对防御导弹在机动能力和速度等方面不具有优势的情况,基于我方目标和防御导弹之间的协同,设计了一种用于拦截来袭寻的导弹的满足终端碰撞角约束的协同最优预测制导律。基于线性化假设,构建了线性化运动模型,并考虑终端脱靶量、终端碰撞角和能量消耗等因素构建了最优制导问题;通过定义零控脱靶量对状态方程降阶,得到了简化后的最优制导问题;基于变分法求解出了COPGL-CTIA的制导指令。通过数值仿真验证了COPGL-CTIA的制导性能。仿真结果表明,相比于其他制导律,COPGL-CTIA能够降低防御导弹所需过载、提高拦截精度和实现终端碰撞角约束。

摘要：[目的]在“双碳”目标下,定量研究园林植物的光合固碳机理,评价、筛选高固碳能力的园林绿化树种,为城市绿地中植物材料的选择与配置提供科学的理论依据,助力低碳园林建设。[方法]以北京城市绿地30种常用园林绿化树种为研究对象,实地监测树种的光合生理指标,计算不同树种在不同季节的日均光合速率。采用同化量法核算供试树种单位叶面积年固碳量、单位土地面积年固碳量和单株年固碳量。根据上述3项指标数据,通过聚类分析对树种的固碳能力进行分级。[结果]在供试树种中,常绿和落叶树种在不同季节的日均光合速率均值变化规律均表现为夏季>春季>秋季>冬季。对于同一生活型的树种,不同树种的日均光合速率均存在差异。根据单位叶面积年固碳量、单位土地面积年固碳量和单株年固碳量,可将供试树种年固碳量由高到低划分为Ⅰ、Ⅱ、Ⅲ3个等级。其中,榆(Ulmus pumila)的3项指标均为Ⅱ级及以上。综合单位土地面积年固碳量和单株年固碳量对供试树种的综合碳汇效应进行评价,乔木中旱柳(Salix matsudana)、榆、毛泡桐(Paulownia tomentosa)、杜仲(Eucommia ulmoides)、七叶树(Aesculus chinensis),灌木中毛樱桃(Prunus tomentosa)、荆条(Vitex negundo ***)、鸡树条(Viburnum opulus ***)和黄刺玫(Rosa xanthina)的综合碳汇效应较强。乔木类树种单株年固碳量显著高于灌木类树种,但在单位土地面积年固碳量、单位叶面积年固碳量方面两者无显著差异,这可能与灌木类树种的应用方式有关。[结论]基于对北京市30种常用园林绿化树种固碳能力的核算、比较,筛选出综合碳汇效应较强的树种,可为未来北京市低碳园林建设的树种选择与景观营建提供科学参考。

摘要：在乡村振兴的时代背景下,设施农业政策通过调整乡村产业发展,影响设施大棚的建设,进而引起乡村空间形态的演变。该文以齐齐哈尔市大五福玛村为研究对象,梳理设施农业相关政策,运用向量自回归模型和景观格局分析法,多尺度分析乡村空间形态的演变特征,探索乡村空间形态演变规律与政策的关联性。研究发现:在以设施农业为主要产业的乡村中,设施农业政策对乡村空间形态各个层面的演变均有一定影响,这种影响表现出时滞性;在政策实施前期,对乡村空间边界和产业空间的影响较大,后期趋向稳定;对生活空间的发展具有抑制效果。此外,该文采用计量经济模型定量分析乡村空间形态与政策的相关性,对于新时代研究政策影响下的乡村空间形态演变具有积极指引意义。

摘要：夹板剪力墙抗侧力性能优异,其抗侧刚度和承载力是普通轻木剪力墙的2~3倍。然而,夹板剪力墙中常用的三角形抗拔锚固件(hold⁃down)会使端部墙骨柱偏心受拉,并易在顶部螺栓孔处发生断裂,严重制约墙体抗侧承载能力。采用U型锚固连接件能很好解决该不利破坏。对采用了不同紧固件形式和数量的4组U型锚固件节点进行单调和低周往复加载试验,分析其破坏模式、荷载⁃位移曲线、初始刚度、极限承载力和延性系数,并基于GB 50005—2017《木结构设计标准》对其承载力和屈服模式进行理论计算和预测。研究结果表明,采用螺钉连接的U型hold⁃down节点(6SH、10SH)均表现为螺钉弯曲和拔出破坏,而采用3根和5根螺栓连接(3BH和5BH)的U型hold⁃down节点则分别表现为螺栓弯曲和墙骨断裂破坏。采用螺栓连接的U型hold⁃down节点刚度和极限承载力分别比采用螺钉连接的节点高81.5%和62.0%以上,但延性较后者低23.2%以上。采用3根螺栓连接的U型hold⁃down节点(3BH)充分利用了螺栓的屈服强度和弹塑性变形能力,综合性能表现最佳。基于GB 50005—2017能准确预测采用螺钉连接U型hold⁃down节点的屈服模式和承载力,但会低估32%~43%的螺栓连接U型hold⁃down节点承载力。研究得到的U型hold⁃down节点荷载⁃位移关系和力学性能指标可为后续的夹板剪力墙数值模拟研究提供关键数据。

摘要：虚假广告是指经营者利用广告虚构事实,造成消费者对其商品或服务的误解,从而获取利益的行为。本文考虑了政府、消费者在企业广告决策中的作用,建立两阶段模型,研究了企业利润最大化目标下政府监管力度、消费者负面口碑效应、产品生产成本等因素对广告策略选择的影响。基于企业在四类广告策略(不进行虚假广告、仅前期进行虚假广告、仅后期进行虚假广告和一直进行虚假广告)中的选择,本文着重分析了政府相应的监管策略。通过详实的数值分析,探究了在不同的市场环境下的企业利润和具体的政府监管策略,最终提出对策和建议来限制企业的虚假广告宣传、提高消费者效益并净化市场环境。

摘要：Strong shock waves and flow separation often occur during the integration of nacelle and airframe for blended-wing-bodies with podded engines. To address this problem, this paper presents an integration method with numerical simulations. The philosophy of channeling flow and avoiding the throat effect on the nacelle and airframe is established based on the analysis of flow interference in the initial configuration. A parametric integration design method is proposed from twodimensional plane to three-dimensional space with control mechanisms and selection principles of the key parameters determined by their influences. Results show that strong shock waves and flow separation can be successfully eliminated under the influence of both the reshaped channel and decelerated inflow below the nacelle. Supersonic regions around the nacelle are effectively reduced, concentrating mainly on the lip position. Thus, a significant cruise drag reduction(8.7%) is achieved though the pressure drag of the nacelle increases.

摘要：Civil aviation faces great challenges because of its robust projected future growth and potential adverse environmental effects. The classical Tube-And-Wing(TAW) configuration following the Cayley’s design principles has been optimized to the architecture’s limit, which can hardly satisfy the further requirements on green aviation. By past decades’ investigations the BlendedWing-Body(BWB) concept has emerged as a potential solution, which can simultaneously fulfill metrics of noise, emission and fuel burn. The purpose of the present work is to analyze the developments of critical technologies for BWB conceptual design from a historical perspective of technology progress. It was found that the high aerodynamic efficiency of BWB aircraft can be well scaled by the mean aerodynamic chord and wetted aspect ratio, and should be realized with the trade-offs among stability and control and low-speed performance. The structure concepts of non-cylinder pressurized cabin are of high risks on weight prediction and weight penalty. A static stability criterion is recommended and further clear and adequate criteria are required by the evaluations of flying and handling qualities. The difficulties of propulsion and airframe integration are analyzed. The energy to revenue work ratios of well-developed BWB configurations are compared,which are 31.5% and 40% better than that of TAW, using state-of-art engine technology and future engine technology, respectively. Finally, further study aspects are advocated.

摘要：Blended-Wing-Body(BWB) configuration, as an innovative transport concept, has become a worldwide research focus in the field of civil transports development. Relative to the conventional Tube-And-Wing(TAW) configuration, the BWB shows integrated benefits and serves as a most promising candidate for future ‘‘green aviation'. The objective of the present work is to figure out the effects of the stability margin and Thrust Specific Fuel Consumption(TSFC) on the BWB design in the framework of Multi-Disciplinary Optimization(MDO). A physically-based platform was promoted to study the effect static stability margin and engine technology level. Low-order physically based models are applied to the evaluation of the weight and the aerodynamic performance. The modules and methods are illustrated in detail, and the validation of the methods shows feasibility and confidence for the conceptual design of BWB aircrafts. In order to find out the relation between planform changes and the selection of stability and engine technology level, two sets of optimizations are conducted separately. The study proves that these two factors have dominant effects towards the optimized BWB designs in both aerodynamic shapes, weight distribution, which needs to be considered during the MDO design process. A balance diagram analysis is applied to find out a reasonable static stability margin range. It can be concluded that a recommended stability margin of a practical BWB commercial aircraft can be half of that of a conventional TAW design.

摘要：首先探寻创意城市兴起的历史背景、定义与内涵,总结出创意城市的运行机理;分析国外创意城市的运行和发展,发现创意产业园区是创意城市落实必要的空间载体。其次借助上海创意产业园区的案例,总结出嫁接、提升和内生三种模式,揭示其对城市历史空间、功能空间和社会空间的影响。