Comprehensive analysis of the impact of climatic changes on Chinese terrestrial net primary productivity

Recent climatic changes have affected terrestrial net primary productivity (NPP). This paper presents an investigation of the impact of climatic changes on Chinese terrestrial vegetation NPP by analyzing 18 years’ (1982 to 1999) climatic data and satellite observations of vegetation activity. Results indicate that climatic changes in China have eased some critical climatic constraint on plant growth. (1) From 1982 to 1999, modeled NPP increased by 1.42%·a-1 in water-limited regions of Northwest China, 1.46%·a-1 in temperature-limited regions of Northeast China and Tibet Plateau, and 0.99%·a-1 in radia- tion-limited regions of South China and East China. (2) NPP increased by 24.2%, i.e. 0.76 petagram of carbon (Pg C) over 18 years in China. Changes in climate (with constant vegetation) directly contrib- uted nearly 11.5% (0.36 Pg C). Changes in vegetation (with constant climate) contributed 12.4% (0.40 Pg C), possibly as a result of climate-vegetation feedbacks, changes in land use, and growth stimula- tion from other mechanisms. (3) Globally, NPP declined during all three major El Ni-o events (1982 to 1983, 1987 to 1988, and 1997 to 1998) between 1982 and 2000, but Chinese vegetation productivity re- sponded differently to them because of the monsoon dynamics. In the first three events (1982 to 1983, 1987 to 1988, and 1992), Chinese vegetation NPP declined, while in the later two events (1993, 1997 to 1998) increasing obviously.     

Al2O3或TiO2掺杂的ScSZ固体电解质纳米晶薄膜的制备及表征

利用溶胶-凝胶旋涂法,在单晶硅基片(100)上分别制得了厚度约为0.31μm的(Al₂O₃)_0.10(Sc₂O₃)_0.08(ZrO2)_0.82和0.36μm的(Sc₂O₃)_0.125(TiO₂)_0.175(ZrO₂)_0.70固体电解质纳米晶薄膜。烧结实验结果表明,两种薄膜均在650℃以上开始晶化,温度越高,晶化越完全,在800℃可完全晶化;所得纳米晶颗粒呈纯的萤石结构立方相;铝和钛掺杂的纳米晶颗粒的平均大小分别为47和51nm。铝掺杂的薄膜非常均匀致密,然而,钛掺杂的薄膜存在少量微气孔。     

Moisture variations over the past millennium characterized by Qaidam Basin tree-ring δ 18O

High-resolution tree-ring δ ¹⁸O chronologies covering the last millennium, although scarce, are essential in understanding patterns of climatic changes in the northeastern region of the Qinghai-Tibetan Plateau. For this study, a tree-ring δ ¹⁸O chronology with a temporal resolution of 3-years was developed from the long-lived Qilian juniper (Sabina przewalskii Kom.), extending back in time to AD 991. This long δ ¹⁸O chronology was significantly correlated with the yearly δ ¹⁸O in tree rings during the common period from 1800 to 2006, and was an effective proxy for relative humidity during the growing season. A low-frequency moisture pattern signified the occurrence of a slight drought during the Medieval Climate Anomaly, a marked occurrence of a wet period during the Little Ice Age, and a trend in increasing moisture levels, although lower than average, alongside the Twentieth Century warming trend. Comparisons to other hydroclimatic reconstructions indicate that this tree-ring δ ¹⁸O chronology serves as a reliable paleo-humidity proxy for the Qaidam Basin as well as documenting details of past humidity levels in the region.     

OOP在Delphi开发中的应用

为解决Ｄｅｌｐｈｉ中文提示的两种方法－增加操作和继承，说明了在面向对象的编程环境中，应充分应用面向对象的程序设计思想。