对玫瑰精油制备方法进行了综述。按照化学物种类归纳了国产玫瑰精油的化学成分并对其香气特征进行了分析。
Then, according to chemical kinds, components and their aromatic characteristics of rose essential oil produced in China were summed up.
甲烷在大气中的浓度以每年1%的速度增长，其不仅影响气候的变化，而且引起大气中OH，O_3等浓度的变化，是非常重要的化学物种。
The methane concentration is increasing at 1% per year, which affects not only climate change but OH, O_3 concentration change in atmosphere.
对无脊椎动物猎物的化学分析显示，不同物种之间的营养成分存在显著差异；即使在种内，营养成分也可能有很大的差异。
Chemical analysis of invertebrate prey reveals remarkable variation in nutrient composition among species; even within species, nutrient composition may vary considerably.
然而，就生物化学的最基本层面来看，物种之间并不存在太多的差异。
And yet, at the most basic level of biochemistry, it has just been more of the same.
“不同隐性物种对这些化学药品有不同的耐药性是可能的，”金说。
"It is possible that the different cryptic species will have different tolerances to these chemicals," says King.
生物化学家詹姆斯·洛夫·洛克就这种相拥状况写道：“物种的进化与其所处环境的演变密不可分。”
Biochemist James Lovelock writes of this embrace, "the evolution of a species is inseparable from the evolution of its environment."
例如有些物种，当它们的叶子被破坏时会散发出一种化学物来保护自己。
Some plant species, for instance, protect themselves from predators by emitting volatile compounds when their leaves get damaged.
该物种在巴塔哥尼亚的雨林里被发现，它能分泌一种天然的化学物质，性状类似柴油。
The organism, found in the Patagonian rainforest, naturally produces a mixture of chemicals that is remarkably similar to diesel.
这意味着两种物种有着不同的生物化学性。
他们推测入侵性强的物种拥有本土植物所不具备的化学武器，因此，本土的害虫、寄生虫和其它植物群对此化学武器都没有任何还击之力。
Their hypothesis was that highly invasive species would have chemical weapons not found in native plants and which pests parasites and other plants would therefore not have evolved any resistance to.
国家化学残留监控计划是加拿大食品检验署监控各种物种的主要计划，以确定所担心的各种化合物残留的情况。
The National Chemical residue monitoring program is CFIA's main program for monitoring various species to determine the prevalence of residues of various compounds of concern.
这都是源于信息素，这种化学信号能够帮助同一物种的植物或动物成员进行信息沟通。
It's all down to pheromones the chemical signals that allow members of the same species of plant or animal to communicate.
只有热衷有机化学的人才会认为新物种一定是血肉之躯的人类后代。
Only an organic chemistry enthusiast would assume that the new species must be man's flesh-and-blood descendants.
昆虫在它们进化的过程中很早就已楔入在相近植物物种间的化学关系的系统之中。
Insects keyed into this system of chemical relationships between related plant species very early in their evolution.
总有一些物种的基本热化学数据的一些错误。
There are always some errors in the basic thermochemical data of the species.
表面金属有机化学是设计制备组成和结构明确的表面金属物种的一条有效途径。
Surface organometallic chemistry (SOMC) is an effective route to design and prepare surface metal species with well-defined composition and molecular structure.
古生物学专业研究化石和学习已灭绝的生物物种。课程包括化石的形成和化学，植物化石，实地和实验室的研究方法等。
Paleontology majors study fossils and learn about extinct life forms. Topics of study include fossil formation and chemistry, fossil plants, methods of research in the field and lab, and more.
介绍植物种籽胶化学改性的工艺过程和反应原理，并就糊料研制中的重要环节、影响因素和应用性能进行了分析讨论。
The chemical modification process and reaction mechanism of the vegetable seed gum are described, with discussions on the development process, adverse factors and performances of the thickener.
有机化合物种类繁多，有机反应复杂，有机化学的教学方法与其他专业基础课程有着较大差异。
Due to the variety of organic compounds and the complex of chemical reaction, the method of teaching organic chemistry is different from other fundamental courses.
因此，损失的物种将会损害生态系统的生物地球化学功能的发挥。
Thus, the loss of species will impair the biogeochemical functioning of an ecosystem.
作为一种复杂的包含化学反应的有旋流动，火旋风在不同的可燃物种类和物理条件，以及不同的环境流场条件下，会表现出复杂的动力学特征。
As a kind of complicated rotational flow with chemical reaction, fire whirl has complex dynamical behaviors under different conditions of fuel species, physical parameters, and environmental flow.
对造纸沉积物的目视观察、化学分析和仪器分析手段进行了介绍，并根据实验室多年的分析结果，统计指出了造纸工业常见的沉积物种类。
This paper introduces visual observation, chemical test and instrumental analysis commonly used for deposit analysis. Lab statistics of deposit analysis results is also presented.
无法培养的大部分微生物可商榷地代表我们地球上最大的一群尚未探索的生物与化学新物种。
The "uncultivable" microbial majority arguably represents our planet's largest unexplored pool of biological and chemical novelty.
摘要：植物缩合单宁广泛存在于众多植物种群，具有抵御动物摄食的化学防卫功能。
Abstract: plant condensed tannins are widely distributed in the plant kingdom, and have capabilities of chemical defense for ingestion of herbivores.
摘要植物缩合单宁广泛存在于众多植物种群，具有抵御动物摄食的化学防卫功能。
Abstract: plant condensed tannins are widely distributed in the plant kingdom, and have capabilities of chemical defense for ingestion of herbivores.
摘要植物缩合单宁广泛存在于众多植物种群，具有抵御动物摄食的化学防卫功能。
Abstract: plant condensed tannins are widely distributed in the plant kingdom, and have capabilities of chemical defense for ingestion of herbivores.
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