试论西藏一江两河地区综合防护林体系建设

本文通过林业建设环境分析、论证,提出一江两河地区综合防护林体系建设的战略构想:在认真保护、科学经营现有森林资源的基础上,以拉萨河、雅鲁藏布江中段、年楚河谷地为主线,重点建设沿江防护林带,构成防护林体系的主要骨架;在河谷农田草场加速防护林网建设,完成防护林体系的网络结构;依土地条件积极营造薪炭林,适当发展用材林和四旁植树(含林卡和经济果树等),完善防护林体系的带网片结,建立起我国高原最大的综合防护林体系,保护好地理环境独特的高寒农业区和“世界第三极”。     

盘锦市危险废物现状及管理对策的初探

以盘锦市2002年危险废物申报登记的结果为依据，进行了危险废物统计分析，找出盘锦市重点危险废物是含铅废物，其主要集中在八家石油、天然气开采企业、占产生危险废物总量的70％以上。并提出了危险废物的管理对策和建议。     

参加交通部溢油应急技术代表团赴美培训的启示和思考

交通部于2002年5月31日—6月20日组织各直属海事局从事船舶防污染管理的17名专业人员赴美国考察、培训海上溢油应急技术。代表团参观了美国海岸警卫队、环保局、溢油应急办公室和防污基金等单位。文中总结了美国现行的海上溢油应急反应体系和防污基金的建立和管理，提出了建立中国在防治海上溢油和防污基金的设想。     

用实测冲击环境数据确定冲击试验条件

冲击响应谱作为试验规范已被用于冲击环境试验.制订一个能真实模拟实际冲击环境的冲击响应谱是冲击环境试验的前提,文中对冲击实测时域数据的预处理,冲击持续时间的确定,冲击响应谱的计算,冲击响应谱的归纳方法进行了研究,并用实测的冲击数据,归纳出某型号冲击试验的冲击响应谱.     

Photochemical production of ozone and control strategy for Southern Taiwan

An observation-based method (OBM) is developed to evaluate the ozone (O₃) production efficiency (O₃ molecules produced per NO_x molecule consumed) and O₃ production rate (P(O₃)) during a field campaign in southern Taiwan. The method can also provide an estimate of the concentration of OH. A key step in the method is to use observed concentrations of two aromatic hydrocarbons, namely ethylbenzene and m,p-xylene, to estimate the degree of photochemical processing and amounts of photochemically consumed NO_x and NMHCs by OH. In addition, total oxidant (O₃+NO₂) instead of O₃ itself turns out to be very useful for representing ozone production in the OBM approach. The average O₃ production efficiency during the field campaign in Fall (2003) is found to be about 10.2±3.9. The relationship of P(O₃) with NO_x is examined and compared with a one-dimensional (1D) photochemical model. Values of P(O₃) derived from the OBM are slightly lower than those calculated in the 1D model. However, OH concentrations estimated by the OBM are about a factor of 2 lower than the 1D model. Fresh emissions, which affect the degree of photochemical processing appear to be a major cause of the underestimate. We have developed a three-dimensional (3D) OBM O₃ production diagram that resembles the EKMA ozone isopleth diagram to study the relationship of the total oxidant versus O₃ precursors. The 3D OBM O₃ production diagram suggests that reducing emissions of NMHCs are more effective in controlling O₃ than reducing NO_x. However, significant uncertainties remain in the OBM, and considerable more work is required to minimize these uncertainties before a definitive control strategy can be reached. The observation-based approach provides a good alternative to measuring peroxy radicals for evaluating the production of O₃ and formulating O₃ control strategy in urban and suburban environments.     

湖南省几种主要菜园土铅的化学行为及其作物效应的初步研究

温度、ｐＨ、有机质及不同价态阳离子对铅吸持－解吸量有明显的影响．土壤中的铅在低浓度范围内（红茶园土为１００μｇ／ｇ，石灰性菜园土为５００μｇ／ｇ）对小白菜生长有刺激作用，超过一定浓度（红菜园土为≥５００μｇ／ｇ，石灰性莱园土为≥１００μｇ／ｇ）则有抑制作用．小白莱的含铅量随土壤铅浓度的增加而增加，两者呈极显著正相关．三种改良剂对铅污染土壤有明显的改良效果，其中以猪粪、石灰两种改良剂的效果为好，钙镁磷肥次之．     

基于张家界市环境质量变化的生态环境建设对策

本文通过对“九五”期间张家界市的生态环境质量进行回顾性分析评价,在掌握其区域自然特征和生态环境现状的基础上,运用环境科学的基本理论分析了张家界市环境质量变化原因和趋势,指出了张家界市存在的主要生态环境问题,并提出了若干对策来引导张家界市的生态环境建设,以实现其建设生态城市的宏伟目标.     

Androgen-dependent maternal effects on offspring fitness in zebra finches

There is accumulating evidence that maternal hormones may play a role in offspring sex adjustment, but little is known about the costs of such hormone-mediated mechanisms. Recent studies have reported sex-specific effects of hormones on offspring viability. Specifically, we previously found that elevating the plasma androgen level in mothers results in a male-biased offspring primary sex ratio, but it affects the viability of sons negatively and daughters positively in zebra finches (Taeniopygia guttata; Rutkowska and Cichoń, Anim Behav, 71:1283–1288, 2006). In this study, we studied further fitness consequences of exposure to elevated yolk androgen levels in zebra finches. We measured growth rate and cellular immune response of nestlings that hatched from eggs laid by females injected with testosterone during egg laying and nestlings of unaffected control females. We found that sons of testosterone-treated females grew slower in comparison to sons of control females. The significant interaction between experimental group and offspring sex indicates that sons of testosterone-treated mothers suffered impaired immune responsiveness while daughters seemed to benefit from elevated androgen level in terms of enhanced immune responsiveness. We found no effects of androgens on offspring performance at adulthood—neither fecundity of females nor attractiveness of males was affected. We conclude that the benefits of biasing sex ratio towards males by increasing androgen level in the yolk may be limited due to negative effects on male offspring performance early in life.     

Carotenoids in the egg yolks of collared flycatchers (<Emphasis Type="Italic">Ficedula albicollis</Emphasis>) in relation to parental quality,environmental factors and laying order

Birds may influence the fitness of their offspring by transmission of different amounts of carotenoids to their eggs. Carotenoids play crucial roles in antioxidant protection and immune defence mechanisms, but they may be available to females in limiting amounts. Therefore, their allocation to the eggs may be influenced by the female’s condition, age and environmental circumstances. Furthermore, the quality of the male parent, which affects the reproductive value of the offspring, may also influence this investment. In this correlational study, we investigated proximate and ultimate factors that may lead to variation in yolk lutein, zeaxanthin and β-carotene concentrations among and within clutches of a wild passerine, the collared flycatcher (Ficedula albicollis). We found that carotenoid concentration was positively associated with caterpillar supply at the time of egg formation, which suggests a proximate constraint of carotenoid availability on yolk composition. Neither female condition, body size, age, nor male plumage ornamentation, age and body size correlated with carotenoid deposition. Yolk β-carotene concentration was found to be positively linked to yolk testosterone concentration. We suggest that females allocated more β-carotene to their eggs to mitigate the potentially detrimental effects of elevated steroid concentration. We found that concentration of β-carotene increased with laying order. The possible function of this pattern may be to enhance the resistance to oxidative stress and pathogens of the disadvantaged last-hatching nestling, suggesting that collared flycatchers pursue a compensatory, “brood survival” strategy.     

Sexual selection and mating system in Zorotypus gurneyi Choe (Insecta: Zoraptera)

Body size is clearly an important factor influencing the outcome of agonistic contests, but is often weakly correlated with dominance ranks in Zorotypus gurneyi Choe (Insecta: Zoraptera). The study of the development and dynamics of dominance relations using artificially constructed colonies show that age, or tenure within the colony, is the prime determinant of dominance among males. Dominance hierarchies become relatively stable within 2 or 3 days and males that emerge later normally begin at the bottom of the hierarchy regardless of size. Males interact much more frequently when they are simultaneously introduced to each other than when they are allowed to emerge at different times. In the latter case, males that emerge late appear to recognize relative dominance of older males and avoid direct contests. Considering the high correlation between dominance rank and mating success, there is a strong selective advantage to males that emerge earlier and such pressure of sexual selection may be responsible for the difference in life history strategies between Z. gurneyi and its sympatric congener, Z. barberi Gurney, in central Panama.