科技英语阅读（李健版）

些能接触到充足阳光的植物颜色更艳丽。像欧龙牙草、许多蘑菇、一些蕨类植物也能在这种环境中大量生长。在这种环境下叶绿色粒子都按照很特殊的形式在运动。落在植物细胞上的光线聚焦在叶绿色分子上就能提供它足够的能量制造食物。

Plants also receive a minimum of light in the depths of the sea or at the bottom of lakes and pools, since sunlight is weak or absent there. The light under water diminishes in proportion to the depth. It is also greatly influenced by the amount of sediment in suspension and consequently varies before and after storms and at different distances from the mouths of rivers and streams.

即使在光线很弱或者稀薄的深海或者湖泊和水塘的底部，植物也能得到少量的光线。而光线在水下的削弱程度和水深是成正比的，它会被水下大量的悬浮颗粒所影响。在暴风雨前后这个比例关系也是不停变化，甚至离小河和溪流的入口处不同距离的比例也是不同的。

Complete darkness reigns at depths greater than 200 meters below the surface of clear sea water. At a depth of 170 meters, the illumination is about equal to that at the surface of the water during moonlight. Under such conditions, plants possessing chlorophyll cannot manufacture the sugars ordinarily formed by green plants in sunlight. This explains why plants possessing green coloring matter are rarely seen at depths of more than 60 meters. As a matter of fact, by far the greatest part of the vegetation of the sea is found within about 30 meters of the surface.

在海平面下方两百多米深度几乎是黑暗的区域。在170米处水下的光线强度和夜晚月光的强度差不多。在这样的情况下，这里的植物就不能像原始的植物通过叶绿素来制造糖类了。这也就解释了为什么在60米水深以下植物含有的叶绿色就很少了。所以，海里大部分的植物还是生活在水深三十米以上的。

In the process of photosynthesis the leaves of plants do not absorb all the colors of the spectrum to the same degree. The red, orange and yellow rays of light that reach the leaves are absorbed much more effectively than the rest. In deep marine water, vegetation receives more blue to green light than it does red to yellow. This is another reason why conditions are particularly unfavorable for plant growth at considerable depths below the surface of the sea.

在光合作用的过程当中，植物对各种颜色光谱的吸收程度是不同 的。红、橙、黄光谱比其他颜色的光谱更容易被吸收。植物在深水里吸收的蓝色光谱比绿色光谱更多，这也是深水为什么不适宜植物生长的原因了。

A striking adaptation is found in red algae. These plants contain, in addition to chlorophyll, pigments known as carotenoids and phycoerythrins. These pigments are present in considerable quantities and give the red algae their characteristic color. They also absorb blue to green colors of light more than chlorophyll does. It is suspected that after they absorb light, they transmit the energy from this light to chlorophyll, for photosynthesis.

红藻有很强的适应性，因为这类植物除了叶绿素以外还有如类胡萝卜素和藻红蛋白。这些色素大量的存在于红藻当中并使它们具有特定的颜色。它们也能比叶绿色吸收更多的蓝光和绿光。令人不可思议的是吸收阳光后它们能利用光合作用把光能存到叶绿素当中。

In tropical forests the tree growth is often so profuse that sunlight may never reach the ground. In these hot and humid climates there are a great many epiphytes—plants such as Spanish moss, orchids and staghorn fern—that grow on other plants.

热带雨林中的植物通常茂密到能遮挡住所有的光线。在这种又热又潮湿的气候条件下生长着大量的附生植物，例如寄生藤、兰花和鹿角蕨。

The epiphytes grow on upper limbs of trees and on poles. Their roots are suspended in air and they absorb moisture and gases from the humid atmosphere. The cells of epiphytes are not

directly parasitic, for they contain chlorophyll and they manufacture their own food. However, they may injury trees by their sheer weight.

那些附生植物生长在一些树木的枝干上，它们将自己的根暴露在空气中来吸收这潮湿空气中的水分和空气。这些寄生植物也并不需要直接寄生，它们含有自己的叶绿色能制造食物，但它们自身的重量可能损伤到大树。

The liana is a vine with a woody stem, which encircle the trunk of a tree as it climbs to the highest branches. In this way, though the liana is rooted in the soil, it can reach the sunlight.

那些有着木质藤条的藤本植物缠绕着树干生长，似乎想爬到最高的树枝去一样。就这样即使它扎根在土里也能照射到阳光。

Unit 4 Landscaping and Homes

Landscaped Roofs Have Chicago Mayor Seeing Green 芝加哥的屋顶绿化

When cities run out of valuable real estate, planners look up. The search for green space is no exception. Europe’s green roofs have long provided environmental, aesthetic and economic benefits. Is the idea growing in the United States?

由于当城市中宝贵的房屋建筑用地已所剩无几，城市规划者开始将目光转向空中。寻找绿色空间也不例外。欧洲的绿色屋顶长期以来为人们提供了环境、审美和经济方面的利益。这种想法是否也会根植在美国呢？

Mayor Richard Daley began a green roof initiative in Chicago, Illinois, after he saw the gardenlike roofs in Europe.

在伊利诺伊州芝加哥市，当市长理查德?戴利看到了欧洲花园般的屋顶之后，便开始了绿色屋顶的创意。

“I thought, with all the flat roofs in Chicago, you could reclaim thousands of acres for the environment and also help buildings with heating and cooling and controlling rainwater going into the sewer system,” he said during a recent telephone interview.

在最近的一次电话采访时他说：“我认为，如果把芝加哥所有平坦的屋顶都利用起来，可以开辟数千英亩的土地用于美化环境，还有利于建筑物供暖、降温，以及进入排污系统的雨水控制。”

“When you look out over the city, instead of steel and concrete, you see something for the environment,” he continued. “So I just thought that was the way for us to go”

他继续说：“当你透过窗户眺望看这个城市时，你看到的不是钢筋混凝土，而是一些美化的环境。所以我想，这就是我们应该做的到事情。”

绿色屋顶通常是由无需经常维护的抗旱植物组成（如景天属暑天景植物）。这些屋顶的厚度均小于4英寸（10厘米），可直接在上面种植或制作成已有植物预先栽种在上面的种植垫。即使斜屋顶也可以进行绿色屋顶处理。

利用率较高的绿色屋顶系统可以包括多种植物和园林要素，如树木，但只有在平坦的屋顶上才行。这种绿色屋顶需要更深的种植材料或土壤替代物，它们更重，更昂贵，并且需要更多的维护。

绿化屋顶的最大好处之一是水资源管理。它们能吸收落在屋顶上的大约50%-60%的雨水，这些雨水一部分通过植物蒸发（或“呼气”）回到大气中而消耗掉了，另一部分水保留在土壤中或其他培养媒介中，。其余的则缓慢地、在人们的控制下缓慢地流入城市雨水排水系统，这个过程有助于抑制城市供水系统中大量雨水激增的现象，而要扩充该系统的费用是很昂贵的。

位于东兰辛伊斯兰莘市的密歇根州立大学植物和土壤学家布拉德?罗说：“在许多城市，甚至一场雷雨就可能造成（雨水的排水系统）溢流，并与污水混在一起。谁知道它们会流到哪儿去呢？”

绿色屋顶的支持者还列举出其他好处，如节省能源。一个绿色屋顶可以降低多少能源成本，这取决于屋顶类型和使用该屋顶当地的气候。比较温暖的气候是节省能源的最佳条件，因为与降低取暖费相比，使用绿色屋顶能够更有效地减少空调费用。

绿色屋顶的另一个好处是它的寿命长于常规屋顶，典型的屋顶可能使用20年，而绿色屋顶将持续40-50年。他们可以保护屋顶防水层免受紫外线和昼夜极端温度波动的损坏，这些问题有可能导致屋顶裂缝。

虽然绿色屋顶的成本是传统常规屋顶成本的1.5-2倍，但支持者认为，即使不考虑节能因素，从长远经济利益看，屋顶绿化仍很划算。

屋顶绿化也有助于减轻被称为“城市热岛效应”的现象，当高密度人造建筑材料吸收阳光的热能时，就会发生这种小气候现象。

罗说：“在亚特兰大炎热的夏季，亚特兰大城市的温度可能比农村的温度高10华氏度（5.6摄氏度）。绿色屋顶有助于温度的这种非自然上升。” Green-Roof Zoning 绿色屋顶区

In Germany, where green roof are most common, the city of Stuttgart has promoted green roof and fa?ade planting through subsidies for nearly 20 years.

在德国，绿色屋顶是最常见的。，在财政补贴的支持下，斯图加特市在财政补贴的支持下促进屋顶和建筑物正面外墙的绿化已将近20年了。

Martina Laun and Klaus-Juergen Evert serve in the city’s park and cemetery department. They noted that the number of green roofs in the city is permanently increasing, thanks to a combination of subsidies and zoning laws, which require green roofs in certain areas.

玛蒂娜?劳恩和克劳斯?于尔根?埃弗特在城市公园和墓地部门工作。他们指出，该城市的绿色屋顶一直在增加，这归功于补贴和分区法这两种措施的结合，在某些地区分区法要求建设绿色屋顶。

Under a grant-aid program established by the Stuttgart City Council, private citizens are awarded grants to help cover construction costs.

根据斯图加特市议会的补助款项目的规定，公民个人可以得到补助款以支付建设绿色屋 顶的费用。

Between 1986 and 2003, the plan subsidized some 50,018 square meters (540,000 square feet) of private green roofs at a total cost of U.S.＄1,076,000. During the same period, the city also invested U.S.＄2,523,000 for roof paintings on public buildings. The total area covered was ＄102,423 square meters (1.1 million square feet).

1986年至2003年，该项目资助了50,018平方米（ 54万平方英尺）的私人绿色屋顶，总费用为107.6万美元。在同一期间，该市还投资252.3万美元进行公共建筑的屋顶绿化。总面积达到102,423平方米（ 110万平方英尺）。

Laun and Evert noted that the program has fostered aesthetic benefits as well as environmental ones. “Nature’s rhythm is made visible by seasonal changes in the vegetation, even in an urban roof environment,” the pair wrote in an e-mail to National Geographic News. “In terms of design, roof planting represents a considerable aesthetic improvement and altogether a significant ecological benefit.”

劳恩和埃弗特指出，该计划培育了人们的审美观以及环保理念。两人在一封给《国家地

理新闻》的电子邮件中说：“自然的节律是通过植被的季节性变化展现出来的，即使在城市屋顶这样的环境也是如此。”从设计上看，屋顶绿化代表了人们审美观的巨大改变并产生了显著的生态效益。 Cultivating Converts 赢得更多的支持者

The green roof concept is winning more converts in the United States. Ford Motor Company created a 10.4-acre (4.2-hectare) living roof, the world’s largest, atop its Dearborn, Michigan, truck plant final-assembly building.

在美国,绿色屋顶正在赢得越来越多的支持者。福特汽车公司在密歇根州迪尔伯恩卡车总装配厂的屋顶上建造了一个全世界最大10.4英亩（ 4.2公顷）的“活的屋顶”，面积为10.4英亩（ 4.2公顷）是世界上最大的。

In Chicago, Mayor Daley is leading by example. City Hall sports a green roof that was the city’s first. Over a hundred building projects, incorporating a million square feet (93,000 square meters) of green roof, are now underway. Official are even experimenting with green roofs at O’Hare International Airport as a means to reduce noise.

在芝加哥市，市长戴利以身作则，市政大厅第一个修建了绿色屋顶。正在施工的建设项目超过100个，其中包括100万平方英尺（93,000平方米）的绿色屋顶。官员们甚至尝试在奥黑尔国际机场建设绿色屋顶，作为一种减少噪音的手段。

At the Chicago Center for Green Technology, demos showcase green-roof technology to everyone from developers and builders to schoolchildren. The center also serves as a research center, where leading suppliers are invited to install different green-roof plots that are monitored and compared.

在芝加哥绿色科技中心，展品向包括开发商、建设者和到中小学生在内的每一个人展示绿色屋顶技术，该中心也还是一个研究中心，邀请大供应商来安装各种各样的绿色屋顶板块，并对其进行监测和比较。

And the city government is providing at least a nudge to those involved in new building ventures. Projects that receive tax-increment financing support from the city are required to include some level of green roof.

市政府至少为对那些从事新的建筑工程的人们至少提供了一些动力，凡享受城市税收增值和财政支持的项目都必须包括一定程度的绿色屋顶。

“I hate to say that we are mandating, but we’re really talking to big box stores, architects, contractors, developers and others about how important green roofs are to the environment and to business,” Delay said.

戴利说：“我不想说这是强制规定，但我们的确在向那些巨型零售商店、建筑师、承包商、开发商，以及其他人宣传绿色屋顶对环境和商业是多么的重要。”

The mayor believes that the city’s cleaner, greener roofs are an important part of long-term environmental planning close to home.

市长认为，更加清洁、更加绿色环保的屋顶是与我们家园关系密切的长期环境规划的一个重要组成部分。

“The environmental movement often seems like it’s happening somewhere else and people forget about our own community,” he said. “We need to be sure that we’re planning well.”

他说：“环境改善运动似乎总是发生在其他的地方，但人们却忘记了自己的社区。我们必须确保我们规划的很好。”