大亚湾开发区经济发展与土地资源的可持续利用

大亚湾开发区由于自然地理条件优越，特别是曾因美国的熊猫汽车和英荷壳牌石油等的落户而带动了区域经济的迅速发展，成为广东省沿海地区外商投资的热点，使原为滨海小镇的穷乡僻壤面临大规模高强度的开发．本文根据区域自然环境条件和经济发展势态．对土地资源的利用现状、土地利用结构的动态变化以及土地承载力状况进行分析；指出在开发过程中存在的耕地面积急剧下降．农田用多养少，土地征而未用以及在规划上对农业的重视不足等问题；最后从协调经济发展与土地利用保护的矛盾，维护区域的良好自然生态环境和土地资源的可持续利用出发，对区域的土地利用保护提出了六点对策性措施．     

水分亏缺时氮磷营养对春小麦幼苗抗逆性的影响

在盆栽条件下研究了水分亏缺时，氮、磷营养对春小麦幼苗渗透物质及相关保护酶活性的影响．结果表明：水分胁迫使春小麦幼苗叶片游离脯氨酸、可溶性糖含量增加，RWC降低，POD、CAT活性增强．随着水分亏缺加剧，氮营养相应地提高了幼苗叶片脯氨酸、可溶性糖含量以及POD、CAT活性；磷营养仅能提高叶片脯氨酸含量以及POD活性，但使其可溶性糖含量以及CAT活性维持在较低水平上．施肥使叶片RWC降低．春小麦的抗逆性指标之间存在相关性，特别是小麦幼苗叶片POD活性与游离脯氨酸累积量之间有极显著正相关关系，其决定系数r^2为0．7472．图1表2参12     

含溴自由基对臭氧光解损耗的影响

本文研究了２５３．７ｎｍ的紫外光照条件下臭氧的损耗，以及在有Ｎ２和Ｏ２的体系中臭氧损耗的状况，得到不同条件下氧损耗的量子产额。并进一步测定了近似同层条件下溴损氧的量子产额为２４±１，计算出ＢｒＯ＋ＢｒＯ反应的两个分支反应通道的速率比为５．２５±０．２６。     

德国高等职业教育的特点

基于了解德国“双元制”职业教育基础上，介绍了德国职业教育体系，研究了高等职业教育模式、入学条件、培养目标、培养模式、学制、文凭以及人才培养途径，分析了高等职业教育的师资培养措施与过程、经费保障以及法律保障，阐述了高等职业教育改革的基本目标、基本原则、改革重点、发展趋势以及基本理念．     

博罗县下村农场土壤养分概况

本文探讨了博罗县下村农场土壤养分含量概况，为今后长期试验研究提供基本理论依据。分析结果表明：下村场土镶有机质含量低，土壤酸性强，不利于土壤肥力的发挥，土壤全量养分Ｎ、Ｐ、Ｋ含量不平衡，速效养分虽然有些较高以至很丰富，但其含量范围大，有相当部分土壤仍很低，所以其供应水平亦很不平衡。而坡地赤红壤则全氮低，全磷不高，全钾则高低差异很大．至于果园土壤（即耕地），养分含量亦很不一致，相差极为悬殊，没有一定的规律性．土壤养分的高低水平，对作物的养分供应起很大的作用。由于下村场土壤养分的不均衡性，在生产管理上，应因地制宜，协调养分含量，以提高施肥效果。根据下村场土壤养分含量的特点，应增施有机肥，改良土壤，并适施石灰以改善土壤酸性，以利于作物的正常生长．     

溴氟菊酯的光解、水解与土壤降解

在实验室测定了溴氟菊酯的光解、不同ｐＨ条件下的水解以及在太湖水稻土、江西红壤与东北黑土等３种不同土壤中的降解。试验结果表明：在３００Ｗ低压汞灯下，溴氟菊酯的水相溶液与其石油醚相济液中的光解均呈二级反应动力学方程，光解半衰期分别为１３．７与９．４ｍｉｎ；在ｐＨ为５，７，９的缓冲溶液中其水解半衰期分别为１５．６，８．３与４．２ｄ；在３种不同土壤中的降解半衰期为４．８～８．８ｄ。     

聚丙烯酰胺生物降解研究进展

聚丙烯酰胺（PAM）是丙烯酰胺均聚物和各种共聚物的统称，作为一种高技术含量、高附加值的重要化工产品，已广泛应用到工农业生产的各个领域并渗透到人们的日常生活中．过去通常认为聚丙烯酰胺是非常稳定的高分子聚合物，事实上，在自然条件下，聚丙烯酰胺会发生缓慢的物理降解（热、剪切）、化学降解（水解、氧化以及催化氧化）和生物降解，最终生成各种低聚物以及具有神经毒性的剧毒丙烯酰胺单体，对人体造成了极大的间接或直接危害．因此，进行聚丙烯酰胺的降解研究很有意义，而聚丙烯酰胺的生物降解研究领域几乎为空白．参33     

秆粪肥在赤红壤中的矿化研究

采用十一种有机物肥进行矿化研究，肥效试验设高、中、低化肥水平比较．结果表明：（１）不同肥料对玉米苗期干物重的影响是：粪肥＞化肥＞秆肥．施入６２ｄ，土场总碳量是，施粪肥的比对照高１．３７倍，施秆肥的高１．２４倍，单施化肥的反比对照下降１４．３％。当然，不同秆粪肥的肥效也不完全一样．（２）在南方高温多雨的条件下，秆粪肥施入土壤后的分解是很快的，尤其是施后的第一个月，其分解速率杠肥平均为４３．４％；粪肥为３５．４％．秆肥中分解最快的是玉米秆，最慢的是甘蔗渣，分解速率分别为５０．１％和２３．４％；粪肥中分解最快的是鸡粪，最慢的是鸭粪，分解速率分别为５５．７％和２１．５％．一个月后分解速率则明显下降．秆粪肥在土壤中的分解一直延缓到三年以后。（３）施后第一年的腐殖化系数，秆肥为２．５４３×１０（－３）－４．３１９×１０（－３），其中番薯藤的最大，黄豆秆的最小；粪肥的除鸡粪和猪粪较小外，牛、鸭粪的达４×１０（－３）以上。一年以后便逐年明显减小．     

市售绿茶自混合水溶液中吸附除去铬（Ⅵ）的研究

本文探讨了国产茶叶（市售云南产绿茶）的结构、成份和溶解，以及在不同浓度、时间、ｐＨ、温度的条件下，自混合溶液中大量吸附铬（Ⅵ）的特性。结果表明，浸泡过的茶叶对Ｃｒ（Ⅵ）的吸附率略低于未泡茶样，在一定条件下，Ｃｒ（Ⅵ）的吸附量可达到４．９６ｍｇ／ｇ。我们建议在这复杂体系中，用离子交换吸附过程形成表面配合物，以及发生化学作用的综合吸附机理来解释。     

甲氰菊酯对罗氏沼虾幼体急性致毒的研究

用甲氰菊酯对罗氏沼虾幼体进行急性毒性试验，在30℃水温条件下，甲氰菊酯对罗氏沼虾Z1、Z2、Z4、Z6、Z8幼体的24hEC50分别为0．050、0．040、0．035、0．030、0．028μg／L；在26℃条件下，分别为0．080、0．069、0．060、0．050、0．035μg／L，随着发育期的递进，幼体对甲氰菊酯变得更加敏感；对于同一期的幼体来说，甲氰菊酯的毒性随水温的升高增强．     

Experimental Demonstration of an Allee Effect in American Ginseng

Abstract: Harvesting of wild American ginseng (   Panax quinquefolius ) for the herbal trade has lowered natural population sizes. We tested for reproductive limitation due to small population size (a form of the Allee effect) by experimentally planting "natural" populations numbering 4, 16, and 64 using 4-year-old cultivated plants. Plant size traits and reproductive traits ( bud, flower, green fruit, and mature fruit) were recorded through the ensuing summer. Fruit production per flower and per plant increased in proportion to flowering population size (  p = 0.0063 and p = 0.0017, respectively), strongly suggesting that an Allee effect occurs in very small populations. The increase in fruit production was not explained by either plant or inflorescence size differences. Although population size-dependent pollination, through insufficient pollinator visitation rate or pollen transfer rate, seems the most likely cause of the observed effects, our limited observations of pollinators were not sufficient to demonstrate a change in pollination rates as a function of population size. Knowledge of the presence as well as the mechanism underlying this Allee effect may be especially useful for management and determination of minimum viable population size of the species in the wild.     

三七及其中药制剂中砷和重金属含量及健康风险评估

我国传统珍贵草本药用植物三七Panax notoginseng(Burk.)F.H.Chen的重金属污染问题已引起关注。详细调查了某市以三七为原料的药品中As和重金属的含量。结果表明,三七药品中主要以As和Pb污染为主,超标率分别为56%和97%,而Cu、Cr、Ni和Zn则均远低于限量标准;三七药品中As和Pb污染可能同时来源于原料和加工炮制过程;三七中As和Pb摄入的人体健康风险(以CDI与PDE的百分比计)最高分别为780%和3294%;Cr和Ni含量虽然远低于限量标准,但其健康风险最高也已达45%和30%。本研究可为三七乃至其他中药制剂的As和重金属污染控制提供科学依据。     

Interactive Effects of Harvest and Deer Herbivory on the Population Dynamics of American Ginseng

Abstract:  Few demographic models for any species consider the role of multiple, interacting ecological threats. Many forest herbs are heavily browsed by white-tailed deer ( Odocoileus virginianus ) and a number of these are also harvested for the medicinal, floral, or horticultural trades. Previous studies of the viability of American ginseng ( Panax quinquefolius ) have separately examined the effects of harvesting and deer herbivory. We followed individually marked ginseng plants in 6 populations for 8 years and documented deer browse levels, conducted helicopter surveys to estimate the deer herd size, and documented 2 ginseng harvests. We used this long-term data set to develop a stochastic demographic model that quantified the separate and interactive role of these threats to ginseng viability. Although harvesting and deer herbivory negatively affected ginseng population growth, their effects were not additive. Deer herbivory negatively affected population growth in the absence but not in the presence of harvesting. Life table response experiments revealed that in the presence of harvesting, deer herbivory had some positive effects on vital rates because browsed plants were less apparent to harvesters. Ginseng populations that were harvested responsibly (i.e., planting seeds from harvested individuals) had higher growth rates than those that were harvested irresponsibly. We concluded that both deer populations and harvesting must be managed to ensure sustainable populations of American ginseng. Our findings underscore the importance of long-term monitoring to assess threats to viability and the need for a broad ecological understanding of the complexity of ecosystem management.     

Iron (Fe2+)-induced toxicity produces morphological and physiological changes in roots in Panax ginseng grown in hydroponics

ABSTRACT

Rusty roots markedly influence on ginseng cultivation, and this phenomenon often attributed to iron (Fe) induced toxicity. To examine the physiological mechanisms underlying Fe-initiated toxicity as evidenced by rusty roots in Panax ginseng, morphological and physiological changes in roots were investigated in hydroponics using Fe²⁺ concentrations of 50 (control), 100, 200, 400 or 600 µM. Compared with control, reddish-brown deposition at the root surface increasingly appeared as Fe²⁺ concentration increased (≥200 µM). The pH also rose as Fe levels were elevated. Higher external Fe²⁺ concentrations produced changes in root organelles and cell structures. Structural alterations in mitochondria due to excess Fe storage, protoplast shrinkage and cell vacuolation as well as formation of central vacuole with deposits in roots were observed. In addition, apparent cell wall thickening, cell wall folding and shrinkage, damage of cell membranes and a large amount of cell debris occurred at higher external Fe²⁺ concentrations (≥400 µM). The Fe²⁺ mediated damage resulting in morphological and physiological changes in ginseng roots was concentration and pH dependent.     

Comparative Analysis of Management Regimes and Medicinal Plant Trade Monitoring Mechanisms for American Ginseng and Goldenseal

Abstract: Two popular and profitable native North American medicinal plants, American ginseng (    Panax quinquefolius ) and goldenseal (   Hydrastis canadensis ), both of which are listed in Appendix 2 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), are monitored under disparate domestic strategies that are designed to satisfy CITES requirements. The P. quinquefolius program has benefited the species by encouraging U.S. states to enact laws to protect wild populations and regulate collection, and by establishing a transparent system under which harvest, commerce, and export can be monitored, evaluated, and controlled routinely. But certain programmatic constraints, such as insufficient funding and gaps in biological monitoring, undermine its effectiveness as a management strategy for the species. The joint industry and government H. canadensis initiative is intended to give commercial traders more responsibility in monitoring plant trade and the federal government access to information that may otherwise be difficult to obtain without the help of traders. I examined the structure, successes, and deficiencies of the P. quinquefolius program, promising features of the evolving H. canadensis program, Turkey's management of geophytes, and other sources of information from federal agencies that might contribute to more effective management of medicinal plants in the United States. Although the main goal of domestic monitoring programs for P. quinquefolius and H. canadensis is to implement their CITES listings, it is conceivable that similar programs could be established for non–CITES medicinal plants, thereby minimizing or replacing the need for CITES protection.     

Cadmium accumulation in <Emphasis Type="Italic">Panax notoginseng</Emphasis>: levels,affecting factors and the non-carcinogenic health risk

Cadmium (Cd) contamination has been reported to be a problem for the safe usage of Panax notoginseng (Sanchi); thus, it is necessary to elucidate the Cd accumulation in Sanchi and to assess its associated health risk. Samples were collected from major producing areas in Yunnan, China. The average concentration of Cd in Sanchi was 0.43 mg/kg, which exceeds the standard level for herbal medicine in China (0.3 mg/kg). A stepwise regression analysis showed that zinc and the pH were the related factors that most significantly impacted Cd in Sanchi roots. The hazard quotient values were estimated as 0.0010 (men) and 0.0012 (women) for consumers taking preparations and were 0.011 (men) and 0.013 (women) for consumers taking health products, implying that there is no non-carcinogenic hazard associated with Sanchi consumption. However, a Monte Carlo simulation showed that approximately 0.80 % of male and 1.02 % of female consumers via drug consumption and 36.28 % of male and 41.87 % of female consumers via health product consumption had an exposure exceeding the acceptable daily intake (ADI) of Cd from drugs (1 % of the total oral ADI as suggested by the World Health Organization). These people should control their oral Cd intake from both Sanchi consumption and diet as a whole.     

Evidence of Local Adaptation in the Demographic Response of American Ginseng to Interannual Temperature Variation

Abstract: Bioclimatic envelope models of species’ responses to climate change are used to predict how species will respond to increasing temperatures. These models are frequently based on the assumption that the northern and southern boundaries of a species’ range define its thermal niche. However, this assumption may be violated if populations are adapted to local temperature regimes and have evolved population‐specific thermal optima. Considering the prevalence of local adaptation, the assumption of a species‐wide thermal optimum may be violated for many species. We used spatially and temporally extensive demographic data for American ginseng (Panax quinquefolius L.) to examine range‐wide variation in response of population growth rate (λ) to climatic factors. Our results suggest adaptation to local temperature, but not precipitation. For each population, λ was maximized when annual temperatures were similar to site‐specific, long‐term mean temperatures. Populations from disparate climatic zones responded differently to temperature variation, and there was a linear relation between population‐level thermal optima and the 30‐year mean temperature at each site. For species that are locally adapted to temperature, bioclimatic envelope models may underestimate the extent to which increasing temperatures will decrease population growth rate. Because any directional change from long‐term mean temperatures will decrease population growth rates, all populations throughout a species’ range will be adversely affected by temperature increase, not just populations at southern and low‐elevation boundaries. Additionally, when a species’ local thermal niche is narrower than its range‐wide thermal niche, a smaller temperature increase than would be predicted by bioclimatic envelope approaches may be sufficient to decrease population growth.     

Identification and assessment of environmental burdens of Chinese copper production from a life cycle perspective

The environmental burdens of Chinese copper production have been identified and quantified in the context of typical technologies, materials supplies and environmental emissions by a life cycle approach. Primary and secondary copper production using copper ores and scraps, respectively, were analyzed in detail. The flash and bath smelting approaches and the recycling of copper scraps were selected as representative copper production processes. A quantitative analysis was also conducted to assess the influence of material transport distance in copper production. Life cycle assessment （LCA） results showed that resources depletion and human health contribute significantly to environmental burdens in Chinese copper production. In addition, the secondary copper production has dramatically lower environmental burdens than the primary production. There is no obvious distinction in overall environmental burdens in primary copper production by flash or bath smelting approach. However, resources depletion is lower and the damage to human health is higher for flash smelting approach. Ecosystem quality damage is slight for both approaches. Environ- mental burdens from the mining stage contribute most in all life cycle stages in primary copper production. In secondary copper production, the electrolytic refining stage dominates. Based on the life cycle assessment results, some suggestions for improving environmental performance were proposed to meet the sustainable development of Chinese copper industry.     

Reproductive decision-making in semelparous colonies of the bumblebee bombus terrestris

Queen and worker Bombus terrestris have different optima for the timing of gyne production. Workers, being more related to their gyne-sisters than to their sons, should ascertain that gyne production has started before attempting to reproduce. Their optimal timing for gyne production will be as early as possible, while allowing sufficient ergonomic colony growth to support gyne rearing. Queen optimum, on the other hand, should be to postpone gyne production toward the end of colony life cycle, in order to minimize the time-window available for worker reproduction. Thus, the timing of gyne production may profoundly affect the outcome of queen–worker competition over male production. In this study we investigated some of the social correlates possibly affecting this timing. It was found that neither keeping colony size constant and as low as 20 workers, nor decreasing worker average age, influenced the onset of gyne production. To test the effect of queen age we created young colonies with old queens and vice versa. When colony social composition remained unchanged, in young colonies headed by old queens gynes were produced earlier than predicted, but in the inverse situation gyne production was not delayed. When colony social composition was completely standardized queen age had a decisive effect, indicating that the timing of gyne production is both under queen influence and affected by queen age. Furthermore, queens assess colony age from the time of first worker emergence rather than from their own first oviposition. In these experiments the factors affecting gyne production also affected the onset of queen–worker conflict for male production, suggesting that both are regulated by the same causal effect. Postponing gyne production as much as possible provides another mechanism, in addition to extensive oophagy, for the queen to outcompete her workers in male production.     

广东省生物肥料的现状与发展前景

广东省生物肥料的生产和应用从20世纪50年代开始，至今已经历了三大阶段。目前其产量呈现上升的趋势。文章在阐述目前广东省6种生物肥料的主要特性，生产情况及施用效果的基础上，指出广东省生物肥料生产存在的主要问题，并预测了生物肥料生产的发展前景。