Interactive effects of natural and human disturbances on vegetation dynamics across landscapes.

Accurate measures of human effects on landscape processes require consideration of both the direct impacts from human activities and the indirect consequences of the interactions between humans and the landscape. This is particularly evident in systems experiencing regular natural disturbances such as in the mountainous areas of southwestern China, where the remaining population of giant pandas (Ailuropoda melanoleuca) is supported. Here the spatiotemporal patterns of human impacts, forests, and bamboo episodic die-offs combine to determine the distribution of panda habitat. To study the complex interactions of humans and landscapes, we developed an integrated spatiotemporally explicit model of household activities, natural vegetation dynamics, and their impacts on panda habitat. Using this model we examined the direct consequences of local fuelwood collection and household creation on areas of critical giant panda habitat and the indirect impacts when coupled with vegetation dynamics. Through simulations, we found that over the next 30 years household impacts would result in the loss of up to 30% of the habitat relied on by pandas during past bamboo die-offs. The accumulation and spatial distribution of household impacts would also have a considerable indirect influence on the spatial distribution of understory bamboo. While human impacts influence both bamboo die-off and regeneration, over 19% of pre-existing low-elevation bamboo habitat may be lost following an episodic die-off depending on the severity of the impacts and timing of the die-offs. Our study showed not only the importance of the spatial distribution of direct household impacts on habitat, but also the far-reaching effects of the indirect interactions between humans and the landscapes they are modifying.     

试论责任会计在高校财务管理中的应用

论述了高校运用责任会计进行财务管理工作的必要性及其可能性,提出了高校财务管理应用责任会计的某些构想,最后指出了高校全面推行责任会计存在的几个问题。     

X－射线荧光光谱法测定道路扬尘中21种元素

本文用Ｘ－射线荧光光谱法，一次测定道路扬尘中Ｎａ等２１种元素。人工配制标样，回归法求取校准曲线常数，用散射线内标法和经验系数法校正基体效应。方法的准确度、精密度较好，分析结果令人满意。     

带希夫碱和酰肼基团的壳聚糖螯合树脂的合成及其吸附性能

本文利用壳聚糖Ｃ２位上活泼氨基与水杨醛进行大分子反应，再以环硫氯丙烷作交联剂，合成了带有邻羟基希夫碱基团的交联型壳聚糖螯合树脂；利用带有游离氨基的交联壳聚糖与丙烯腈进行大分子反应，合成了带有氰基的功能聚合物，再由ＣＴ－ＣＮ与水合肼进一步反应，制得了带有酰肼基轩物壳聚糖螯合树脂。     

铁催化聚丙烯腈脱氮的研究

应用热天平研究了载铁聚丙烯腈的脱氮碳化行为，负载铁对ＰＡＮ的稳定化和脱氮碳化均具有显著的催化作用，并在５８０－７６０℃范围内明显增加了Ｎ２形成速率。ＸＰＳ和ＸＲＤ对碳化过程中铁和氮化学形态变化的研究结果表明，铁催化反应机理可能是负载铁与吡啶氮作用形成中间体铁氮化物，后者进而分解释放出Ｎ２。     

燃煤电厂排放颗粒物中重金属形态的研究

本文分析用模拟酸雨浸提和Ｔｅｓｓｉｅｒ形态分离法，对燃煤电厂排放颗粒物中重金属形态进行了研究。结果表明，痕量金属绝大部分以稳定态存在，微米级飞灰中有较大活性的形态高于灰渣，煤燃烧高温条件使颗粒物中活性较大的形态含量减小。     

味精废水中重金属及金属污染对处理利用的影响

本文应用等离子光谱（ＩＣＰ）测试三个厂家味精生产废水中２１种金属元素的水平，其中金属元素的总水平分别达１９１９２ｍｇ．ｌ＾－１，３１９０ｍｇ．ｌ＾－１和３１６１ｍｇ．ｌ＾－１，对照国内外有关的四项水质标准，三厂家味精生产废水中存在着Ｆｅ，Ｚｎ等多种重金属或其他金属元素严重超标现象，味精生产废水对青芋存在急性毒性，２４，４８，７２和９６ｈ的半致死味精废水浓度ＬＣ５０分别为６．９％，３．２％，２．５％     

知识经济时代的企业经营与管理

21世纪经济正向着知识经济时代迈进.知识经济不仅对人类的生产方式和生活方式产生着深远影响,而且对企业的经营方式和管理模式也将产生深远的影响.我国企业在知识经济时代下,如何转变和调整经营与管理方式己成为新世纪的重大课题.     

城市生活垃圾的DSC和TGA分析与热值估算

利用微分扫描量热仪（ＤＳＣ）准确地测定了城市生活垃圾的含水率；热重分析仪（ＴＧＡ）测定了垃圾的水和低温下有机物总含量、难挥发性有机物和灼烧残渣的含量。根据量热和热量分析结果，可方便地计算垃圾的水和低温条件下易挥发性有机物含量，结合６０９种有机物的燃烧热，估算了垃圾的热值。     

Scenarios of major terrestrial ecosystems in China

The spatial pattern and mean-center shift of major terrestrial ecosystems, termed Holdridge Life Zones (HLZ), during the periods from 1961 to 1990 (T1), from 2010 to 2039 (T2), from 2040 to 2069 (T3) and from 2070 to 2099 (T4) were analyzed by combining the zonal patterns of climatic change in China and the climatic change scenarios of HadCM2 and HadCM3. The results showed that nival area would decrease rapidly with temperature increase in the future. HadCM2 and HadCM3 predicted that the nival areas might disappear in 552 years and 204 years, respectively. Using both HadCM2 and HadCM3, the five HLZ types with the largest areal extent are nival zone, cool temperate moist forest, warm temperate moist forest, subtropical moist forest and boreal wet forest, which collectively account for more than 50% of China's land mass. Among these five HLZ types, nival zone, warm temperate moist forest and boreal wet forest would decrease continuously, whereas subtropical moist forest and cool temperate forest would increase continuously during the four periods. HLZ diversity and patch connectivity would increase continuously in the 21st century. The shift distances of mean centers of HLZ types simulated using HadCM3 were markedly greater than those simulated using HadCM2, in general. The results from both HadCM2 and HadCM3 showed that boreal wet forest, subtropical moist forest, tropical dry forest, warm temperate moist forest and subtropical wet forest had bigger shift ranges, indicating that these HLZ types are more sensitive to the climatic change scenarios of HadCM2 and HadCM3.