Modeling and Its Application of Reinforced Concrete Columns Considering Nonlinear Shear Effects

A fiber beam-column element in conjunction with zero-length elements attached to its ends was proposed to simulate the flexural and shear mechanism respectively. Based on the Limit State Material model and the Shear Limit Curve model provided by OpenSees, the nonlinear shear effect of reinforced concrete column and its coupling with the flexural effect were defined. The reliability of the proposed model was validated by means of comparisons with existing test results. Finally, a plane frame from in-situ pushover test was simulated. It is shown that the proposed method, by taking the nonlinear shear effect into account, produces satisfactory results for frame columns with shear strength and stiffness degradation, while the conventional fiber beam-column element can hardly simulate actual flexure-shear failure mechanism for columns characterized by insufficient transverse reinforcement. The proposed method is applicable for nonlinear analysis of reinforced concrete frame structures with shear deficiencies.     

Deterioration Model and Reliability Analysis on Concrete Material at Stress States

According to the analysis of existing test data, the stress influence coefficient and water-cement ratio influence coefficient in the existing concrete carbonation depth forecasting models are modified and improved. Based on the reliability analysis, the rule of deterioration life is presented. The analysis shows that the rate of carbonation of concrete is accelerated or restricted at the status of tensile or compressive stress, respectively. Especially with the increase of the level of tensile stress, the carbonation rate of concrete will become faster and faster. According to the results of reliability analysis, the relation between probability and reliability of the concrete deterioration is one-to-one corresponsive, meanwhile, the concrete cover thicknesses and stress levels have great influences on the durability life of concrete structures. And with the same reliability, the time of deterioration of concrete decreases with a higher stress levels and a less cover thickness.     

A Study of Residential Grey Water Treated by Subsurface Horizontal Constructed Wetland

Ceramsite and natural zeolite were used as mixed substrates in subsurface horizontal constructed wetland which is planted with Yellow flag to investigate the treatment efficiency of real residential grey water, Inflow rate was 50l/d, HRT was 2d. The wetland reduced COD, NH3-N, TN, TP and turbidity from 164mg/l,4.3mg/l,5.2mg/l,0.44mg/l,82.4NTU to 70 mg/l, 1.07 mg/l, 2.07 mg/l, 0.33 mg/l, 7.27NTU, removal efficiency was respectively 57.32%,75.19%,60.26%,24.24%,91.18%,and have a good performance in COD,NH3-N,TN, turbidity treatment. Used synthetic grey water to study different HRT effect of wetland. Increasing HRT could be increase the wetland ability of COD, NH3-N removal. When the HRT was 3d, the wetland had the best decontamination effect. The removal efficiency of COD,NH3-N,TN,TP,turbidity was respectively 68.46%,81.75%,66.67%,34%,86.91%.     

阿木尔林业局营林建设的可持续发展

森林是一个国家经济可持续发展的基础,对于国家经济建设与持续发展具有不可替代的作用和地位。来自生态保护和木材需求的两大压力形成了对我国林业的巨大挑战,我国林业建设任务艰巨。阐述了阿木尔林业局改进营林措施,包括病虫害防护和造林技术。期望能为国有林区可持续发展能力建设尽一点微薄之力。     

马尾松自由授粉家系产脂力的年度变化及遗传分析

以来自马尾松天然群体的49个高产脂优树半同胞家系子代为对象,测定6个年度产脂力.结果表明:马尾松在早期的产脂力随树龄的增长而迅速增大,13年后进入稳定期.不同家系的产脂力差异显著,但产脂力变异幅度随树龄的增长而降低.产脂力变异受中等遗传控制,其中早期遗传力较高,后期遗传力较低且稳定,家系遗传力明显高于单株遗传力.早期与成熟期的产脂力具有紧密的遗传正相关,且相关性随树龄的增长而增加.产脂力的早期选择效率随树龄的增大而提高,11年时达到0.813,是理想的早期选择时间节点.利用综合育种值法筛选到13个优良产脂家系,入选家系的年度育种值均显著高于对照,且随树龄的增大而增加.     

两种肥料与采穗母株剪顶高度对尾巨桉穗条的影响

为提高尾巨桉(Eucalyptus urophylla×E.grandis)无性系的穗条产量和质量,开展2种不同类型的肥料以及8种不同采穗母株剪顶高度对穗条产量和质量影响的试验,结果表明:在生产中高架沙床采穗圃施用全水溶性肥B效果更好;高架沙床采穗圃尾巨桉无性系采穗母株剪顶的最佳高度8～9 cm,不仅产穗数量多,质量好,扦插成活率也最高。     

外植体采集时期与冷藏处理对马尾松愈伤组织诱导的影响

马尾松(Pinus massoniana)无性繁殖困难,研究常采用体细胞胚胎发生和器官发生的方式繁殖,外植体采集时期是实验成功的关键.本实验采用2011年10月至2012年10月期间(每周或每两周采集1次)采集的马尾松枝梢顶端分生组织为外植体,并将外植体置于4cC冰箱冷藏做不同冷藏时间处理(4 ～ 114天).处理后的外植体接种在添加不同激素浓度的改良GD培养基中,24 ～ 25℃条件下暗培养.实验结果表明:冷藏时间对马尾松愈伤组织诱导没有显著影响;2012年3月中旬至4月底采集的马尾松外植体,愈伤组织诱导率最高达89.8％,其平均诱导率达到80％以上;外植体经流水冲洗2～3h、75％的酒精处理20 ～30 s、0.1％的升汞处理9～ 10 min并去除鳞片和针叶,能有效降低外植体污染率;外植体经流水冲洗2～3h、去除鳞片和针叶后切成长约0.2 ～0.5 cm的薄片后接种,能大大降低培养过程中外植体的褐化率.     

玉米磷酸烯醇式丙酮酸羧化酶基因的研究进展

高等植物按照CO₂不同的同化途径,分为C₃、C₄和CAM植物。由于C₄植物具有高光效基因,使其在高温、高光照、高氧分压条件下具有比C₃植物更高的光合作用效率。目前,很多学者致力于研究玉米中的高光效基因-磷酸烯醇式丙酮酸羧化酶基因（PEPC）,并试图将此基因转入到C₃植物中,使C₃植物的光合特性得到一定改善,进而使其产量提高。本文综述将C₄高光效基因转入到C₃植物后,C₃植物的生理生化变化和对其光合作用的影响,对向C₃植物中导入pepc基因能否提高其光合作用效率和产量的潜在可能性进行探讨。     

野大麦耐盐性研究进展

野大麦是禾本科小麦族耐盐性最强的盐生植物之一,其耐盐机制的研究对提高作物的耐盐性具有重要意义。野大麦耐盐性的研究起步较晚,文章分别从耐盐生物学特性描述、耐盐性新品种选育、耐盐生理响应机制、筛选盐诱导差异表达的基因、克隆耐盐相关基因和编码蛋白、种属间遗传性几个方面对其耐盐性研究进行了综述,相关研究获得了很多有价值的结果,但其根本的耐盐生理机制和基因尚不清楚,仍待进一步研究。     

紫苏油微胶囊对夸克质构的影响

将紫苏油微胶囊产品加入夸克中,考察其对夸克质构的影响.结果表明：紫苏油微胶囊的添加对夸克质构的各项指标均有不同程度的影响.硬度随着紫苏油微胶囊添加量的增大而先上升后降低,紫苏油微胶囊后添加组在2％的添加量时,弹性出现大幅回升,达到显著水平（P＜0.05）.紫苏油微胶囊无论以何种方式加入夸克,对夸克凝聚性均没有显著影响.添加紫苏油微胶囊以后,夸克的回复性显著变差（P＜0.05）.紫苏油微胶囊的两种添加方式对夸克黏着性具有相似影响.