JDZ-1型固态存储雨量器降水量误差成因分析

对JDZ-1型固态存储雨量器与虹吸自记雨量计平行观测资料进行了系统分析,分析了两者存在误差的影响因素。对JDZ-1型固态存储雨量器在北方地区使用过程中存在的问题提出了解决方法,以保证和提高JDZ-1型固态存储雨量器资料质量。     

Use of chemical variation and predation as plant defenses byEncelia farinosa against a specialist herbivore

Larvae of the monophagous herbivore,Trirhabda geminata, selectively eat particular plants and plant parts of its natural host,Encelia farinosa. Measurements of leaf damage and larval positions on branches through time support this observation. Time-lapse movie photography revealed that larvae are sufficiently mobile to search most of a plant in a 48-hr period and that aggregations were the result of larval activity and not directly the result of oviposition. Experiments withT. geminata larvae on artificial diets containing a range of natural concentrations of chemical extracts fromE. farinosa leaves showed that the larvae grew significantly slower and had a lower overall survivorship at the high concentration. Combining the results of all choice tests, larvae appeared unable to distinguish between high- and low-concentration agar diets. Considered individually, larval preferences for natural production concentrations changed as the season progressed. Early-season larvae preferred low-concentration leaves, while late-season larvae preferred high-concentrations. Measurements of chemical and nitrogen content of leaves selected by larvae in the field confirmed this pattern. Percent parasitism in field-collected larvae increased with season as the larval population decreased. This combination of slowed growth and increasing parasitism and predation is a putative defense strategy ofEncelia farinosa to prevent adaptation by a specialist herbivore to the total range of compounds elaborated.     

Ti_3Al PHASE PRECIPITATION DURING VIBRATION FATIGUING FOR A TITANIUM ALLOY

Ｔｉ_３ＡｌＰＨＡＳＥＰＲＥＣＩＰＩＴＡＴＩＯＮＤＵＲＩＮＧＶＩＢＲＡＴＩＯＮＦＡＴＩＧＵＩＮＧＦＯＲＡＴＩＴＡＮＩＵＭＡＬＬＯＹ￥ＴａｏＣｈｕｎｈｕ；ＺｈａｎｇＳｈａｏｑｉｎｇ；ＹａｎＭｉｎｇｇａｏ（ＩｎｓｔｉｔｕｔｅｏｆＡｅｒｏｎａｕｔｉｃａｌＭ?..     

砼回弹法测强统计分析

简述了砼回弹法测强与抗压强度对比试验的方法，得出了影响砼回弹测强的种种因素，通过统计分析给出了砼回弹测强的实用计算公式，从而就可在结构物上直接进行回弹测强，达到及时，方便，准确地了解结构物的强度．     

氨水—铜试剂分离法测定球铁中镁

本文采用了与常规（容量法）相反的方法测定球铁中的镁，并克服了其它方法的弊端，进一步找到了在工业上分析镁的适宜条件。     

Convex relaxation for a 3D spatiotemporal segmentation model using the primal-dual method

A method based on 3D videos is proposed for multi-target segmentation and tracking with a moving viewing system. A spatiotemporal energy functional is built up to perform motion segmentation and estimation simultaneously. To overcome the limitation of the local minimum problem with the level set method, a convex relaxation method is applied to the 3D spatiotemporal segmentation model. The relaxed convex model is independent of the initial condition. A primal-dual algorithm is used to improve computational efficiency. Several indoor experiments show the validity of the proposed method.     

河道生态基流生态经济价值及其时间变化研究

为了解决普遍采用单方水资源价值计算河道生态基流价值的缺陷,以及探索河道生态基流价值定量化计算新方法,采用水力学方法将河道生态基流从径流量中分离出来,并确定河道生态基流对应水面面积,进而采用当量因子法计算河道生态基流价值和并探索分析了河道生态基流价值的时间变化特征。以渭河干流宝鸡段为例进行研究,结果表明:渭河干流宝鸡段的丰水年、平水年以及枯水年的年平均河道生态基流量分别为5.82 m~3/s、3.59 m~3/s和2.76 m~3/s。近21 a来,该段河道生态基流价值在时间上总体呈下降趋势,该价值多年平均值为5.61亿元,单方河道生态基流价值为6.27元/m~3,单方价值与价值总量变化趋势相反。河道生态基流价值年内变化具有明显的周期性,总体呈倒"V"字型,汛期河道生态基流价值比非汛期大,单方河道生态基流价值与之相反。通过相同区域以及相近区域的河道生态基流价值研究成果以及价值变化特征的对比分析,证明研究成果较为合理。该方法可为河道生态基流合理保障提供定量化依据。     

变化环境下韩江生态流量演变特征分析

选取位于粤东、闽西南地区的韩江流域为研究对象,基于CA-Markov模型对2050年流域土地利用空间格局进行预测,构建SWAT分布式水文模型,以未来土地利用情景和气候变化情景为变量进行水文模拟,分析不同情景下韩江生态流量的时空演变特征。结果表明,未来城镇化扩张将使梅江支流中上游成为韩江流域内生态流量对土地利用变化最为敏感的区域;土地利用和气候变化将导致韩江流域枯水期流量整体减小,枯水期流量对环境变化更加敏感;韩江流域生态流量变化特征将呈现从西南到东北由升到降的趋势,梅江支流中上游地区的生态流量将得到改善;梅江和汀江两大支流上游区域生态流量对气候变化更为敏感;韩江流域径流总量下降,但丰枯流量分化加剧,长期来看枯季生态流量保障风险可能进一步增大。