Advances in estimation methods of vegetation water content based on optical remote sensing techniques

Quantitative estimation of vegetation water content(VWC) using optical remote sensing techniques is helpful in forest fire as-sessment,agricultural drought monitoring and crop yield estimation.This paper reviews the research advances of VWC retrieval using spectral reflectance,spectral water index and radiative transfer model(RTM) methods.It also evaluates the reli-ability of VWC estimation using spectral water index from the observation data and the RTM.Focusing on two main definitions of VWC—the fuel mois...     

Creep and tensile properties of press molding joined GMT-sheets

GMT-sheet is used in automobile bumper with high rigidity and strength, and its joining strength is influenced by lap length, one of the joined molding conditions. Fracture strength was calculated by dividing fracture load with cross-sectional area. Total five repeated measurements were made to obtain the average value. Tensile test was conducted at room temperature for 10 specimens. In addition, the effect of compression ratio on creep and tensile performance during lap joined molding was discussed. With increasing lap length, the lap joining efficiency of GMT-sheet was increased. However, higher compression ratio reduced the joining efficiency. Creep test on GMT-sheet showed abrupt fracture without tertiary creep. This can be explained by the weak thermal resistance of the resin. If GMT-sheet was exposed to high temperature for a long time, it was easily failed by external force.     

电厂蒸汽回路系统中腐蚀损伤的决定论预测

局部腐蚀,包括点腐蚀、应力腐蚀开裂和腐蚀疲劳是导致电厂发电装置损伤的重要原因,它们诱发50%以上的意外停机事故。迄今,腐蚀破坏的预测一直沿用经验和统计的方法,但是,由于已证实该方法的适用性和其结果的准确性欠佳,故不宜作为例行检修规程的基础。本文提出了预测局部腐蚀损伤的决定论方法,并使用这个方法说明点腐蚀如何引发低压蒸汽轮机涡轮盘Wilson线下游部位的应力腐蚀开裂(SCC),我们的计算表明SCC的萌发与扩展对蒸汽小氧含量、冷凝液膜的环境和涡轮盘所承受的应力这三个因素敏感。     

Studies and advances on joint source-channel encoding/decoding techniques in flow media communications

Joint source-channel coding/decoding (JSCC/JSCD) techniques in flow media communications have become a state-of-the-art and one of the challenging research subjects in the spatial communication area. They have great application prospective and deep impact in various manned space flights, satellite missions, mobile radio communications and deep-space explorations. In the last few years, there have been influential achievements in JSCC/JSCD studies. This paper aims at an introduction to the basic principles o...     

虚拟现实技术在绿色基础设施健康效益评估中的应用

快速的城市化进程在不经意间将人类与自然环境割裂开来。因此所带来的日益严重的城市污染和人们进行户外活动的局限性,对人的身心健康和认知都产生了影响。城市规划师可以通过绿色基础设施营建来降低城市化带来的负面影响,如自然式公园、生态滤沟、植物墙和行道树等。然而,哪些绿色基础设施要素能否用于改善人们的健康福祉仍不十分明确。研究人员在绿色基础设施健康效益研究中引入虚拟现实技术（VR）,为循证设计提供科学可靠的依据。VR技术仅需要较低的成本和专业技术。受试者佩戴仪器进入沉浸式虚拟世界,过程中同步采集心理和生理指标,用于预测不同自然场景对健康和认知功能的长期影响。通过对VR系统、内容创作、实验设计、健康指标测量和安全注意事项的方法论进行概述,使读者了解VR技术如何用于研究,并作为一种替代治疗的手段,用于改善绿色基础设施的健康福祉,为VR技术的研究应用提供理论与实践基础。     

Unusual W-shaped Galvanic Cell Model of ISCC of α-brass in Neutral Mattsson''''s Solution

Intergranular stress corrosion cracking(ISCC) of α-brass in neutral Mattsson's solutionwas found to be controlled by an unusual"W"-shaped galvanic cell whose cathode is thegrain boundary oxide film (G.B.0. film) andsurface film and the anode is fresh metal atthe cracked tip on both sides of the G.B.0.film. Redox reactions involved in the cellhave been proposed here. According to thismdel, initidtion of ISCC is caused by therupturing of surface film along grain boundaries,thus forming a galvanic cell. Propagation ofISCC resulted from alternate advances of G.B.0.film and dissolution on both sides of G.B.0.film caused by the effect of electrochemicalreaction. This work developed an effective approachto investigate the embrittlement process atthe tip of the crack, by increasing the lengthof the embrittlement region through constantstrain test and distinguishing the morphologyand the nature of the corrosion products byoptical microscopy and scanning electronmicroscopy (SEH).     

抗人A血型杂交瘤细胞高密度培养条件的研究

抗人 A 血型杂交瘤15B_4细胞在 CelliGen 细胞培养罐中进行连续灌注培养,细胞密度达1.6×10~7/ml。每天灌注新培养液量由1000ml 增到2300ml,第14天后又逐日减少至1000ml,死细胞数随着转速的增加和灌注量的减少而增多。血凝效价呈梯度上升,滴度达到2~(14),相当于腹水效价。培养6天 IgM 产量为0.2克/升/天,10～18天波动在1.45～1.8克/升/天。15B_4细胞代谢与葡萄糖、乳酸有关,与氨无关。CelliGen 自控效果较好,适用于杂交瘤细胞的高密度培养。搅拌速度在120～150r/min 对细胞产生的剪切力有明显地破坏作用。溶氧控制系统有待改进。     

Idiom literality judgments in younger and older adults: Age-related effects in resolving semantic interference.

To study age effects in the resolution of idiomatic semantic ambiguity, we focus on decomposability, the extent to which a literal reading of an idiom's words shares meaning with its figurative interpretation. Younger and older adults judged whether decomposable and nondecomposable idioms and nonidioms had a literal interpretation. Older adults were slower at making literality judgments and more sensitive to conflicts between literal and figurative meanings. The results support claims of decompositional analysis of idioms during later processing stages and of obligatory activation of figurative meanings. They also lend support to research that has shown age-related effects in ambiguity resolution. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Numerical simulation of magnetospheric ULF waves excited by positive and negative impulses of solar wind dynamic pressure

The sources of ultra low frequency (ULF) waves in the magnetosphere are generally believed to be either the external solar wind perturbations or the internal plasma instabilities. When a sudden impulse of the solar wind dynamic pressure impinges on the magnetopause, ULF waves might be excited and thus the solar wind energy is transported into the earth’s magnetosphere. In this paper, we study the ULF waves excited by different kinds of sudden solar wind pressure impulses through an MHD simulation. We primar...