An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion yea...An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes(i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350–450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features.Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves(e.g., grasses) comprise in total an area of around 250 million km^2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al.(Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic nonvascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology for this diversity is provided. Simplified, the fun展开更多
We describe a few mathematical tools which allow to investigate whether air-water interfaces exist(under prescribed conditions)and are mechanically stable and temporally persistent.In terms of physics,air-water interf...We describe a few mathematical tools which allow to investigate whether air-water interfaces exist(under prescribed conditions)and are mechanically stable and temporally persistent.In terms of physics,air-water interfaces are governed by the Young-Laplace equation.Mathematically they are surfaces of constant mean curvature which represent solutions of a nonlinear elliptic partial differential equation.Although explicit solutions of this equation can be obtained only in very special cases,it is -under moderately special circumstances-possible to establish the existence of a solution without actually solving the differential equation.We also derive criteria for mechanical stability and temporal persistence of an air layer.Furthermore we calculate the lifetime of a non-persistent air layer.Finally,we apply these tools to two examples which exhibit the symmetries of 2D lattices.These examples can be viewed as abstractions of the biological model represented by the aquatic fern Salvinia.展开更多
Objective:To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans andCeratophyllum demersum). <br> Methods:The aquatic plants were brought from Shatt Al-Arab Rive...Objective:To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans andCeratophyllum demersum). <br> Methods:The aquatic plants were brought from Shatt Al-Arab River in 2016. Equal weights of aquatic plants were aquacultured in aquaria, and were exposed to three different temperatures ( 12, 22 and 32°C). <br> Results: The results showed that the two plants did not show significant differences with respect to their effects on pH and electrical conductivity values. Time and temperature did not affect the values of pH and electrical conductivity. The values of dissolved oxygen was significantly influenced with variation of time and temperature, while the two plants did not have significant differences on dissolved oxygen values, nitrate ion concentration and was not significantly influenced with variation of plant species or temperature or time. Plant species and temperature significantly affected phosphate ion concentration, while the time did not significantly influence the concentration of phosphate ion. Chlorophyll a content and biomass were significantly influenced with the variation of plant species, and temperature . <br> Conclusions:Aquatic plants has a species specific respond to temperatures change in their environment. Water plant,Ceratophyllum demersum is more tolerant to temperatures change thanSalvinia natans.展开更多
A teleomorph of the fungus </span><i><span style="font-family:Verdana;">Botryosphaeria</span></i><span style="font-family:Verdana;"> <i>rhodina</i>&l...A teleomorph of the fungus </span><i><span style="font-family:Verdana;">Botryosphaeria</span></i><span style="font-family:Verdana;"> <i>rhodina</i></span><span style="font-family:""><span style="font-family:Verdana;"> (Berkeley et Curtis) von Arx, (</span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;">) </span></span><span style="font-family:""><span style="font-family:Verdana;">was evaluated as a bioherbicide for control of giant salvinia (</span><i><span style="font-family:Verdana;">Salvinia</span></i> <i><span style="font-family:Verdana;">molesta</span></i><span style="font-family:Verdana;"> D.S. Mitchell) under greenhouse conditions and in small-scale field trials. We found that fungal mycelium was highly infective and could be rapidly produced (48+</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">h) in soy</span><span style="font-family:""> </span><span style="font-family:Verdana;">flour-cornmeal liquid media contained in shake flasks or fermenters. A dew period was not required to achieve infection and mortality</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">of inoculated plants. A surfactant (Silwet L-77, a polyalkyleneoxide modified heptamethyl-trisiloxane) incorporated in the fungal formulation was required for </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> to infect and kill plants. Infection and mortality occurred rapidly (within 48 h after treatment), and re-growth of treated plants did not occur. In replicated</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">field trials, </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> controlled giant salvinia ~95%. </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> also infected other plants, such as common salvinia (</span><i><span style="展开更多
基金supported by the Deutsche Bundesstiftung Umwelt DBUthe German Research Council DFG+1 种基金the Federal Ministry for Science and Education BMBFthe Academy of Science and Literature in Mainz
文摘An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes(i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350–450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features.Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves(e.g., grasses) comprise in total an area of around 250 million km^2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al.(Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic nonvascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology for this diversity is provided. Simplified, the fun
基金funded by grants from the Deutsche Forschungsgemeinschaft,the Bundesministerium für Bildung und Forschung and the Landesgraduiertenfrderungsgesetz des Landes Baden-Württemberg
文摘We describe a few mathematical tools which allow to investigate whether air-water interfaces exist(under prescribed conditions)and are mechanically stable and temporally persistent.In terms of physics,air-water interfaces are governed by the Young-Laplace equation.Mathematically they are surfaces of constant mean curvature which represent solutions of a nonlinear elliptic partial differential equation.Although explicit solutions of this equation can be obtained only in very special cases,it is -under moderately special circumstances-possible to establish the existence of a solution without actually solving the differential equation.We also derive criteria for mechanical stability and temporal persistence of an air layer.Furthermore we calculate the lifetime of a non-persistent air layer.Finally,we apply these tools to two examples which exhibit the symmetries of 2D lattices.These examples can be viewed as abstractions of the biological model represented by the aquatic fern Salvinia.
文摘Objective:To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans andCeratophyllum demersum). <br> Methods:The aquatic plants were brought from Shatt Al-Arab River in 2016. Equal weights of aquatic plants were aquacultured in aquaria, and were exposed to three different temperatures ( 12, 22 and 32°C). <br> Results: The results showed that the two plants did not show significant differences with respect to their effects on pH and electrical conductivity values. Time and temperature did not affect the values of pH and electrical conductivity. The values of dissolved oxygen was significantly influenced with variation of time and temperature, while the two plants did not have significant differences on dissolved oxygen values, nitrate ion concentration and was not significantly influenced with variation of plant species or temperature or time. Plant species and temperature significantly affected phosphate ion concentration, while the time did not significantly influence the concentration of phosphate ion. Chlorophyll a content and biomass were significantly influenced with the variation of plant species, and temperature . <br> Conclusions:Aquatic plants has a species specific respond to temperatures change in their environment. Water plant,Ceratophyllum demersum is more tolerant to temperatures change thanSalvinia natans.
文摘A teleomorph of the fungus </span><i><span style="font-family:Verdana;">Botryosphaeria</span></i><span style="font-family:Verdana;"> <i>rhodina</i></span><span style="font-family:""><span style="font-family:Verdana;"> (Berkeley et Curtis) von Arx, (</span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;">) </span></span><span style="font-family:""><span style="font-family:Verdana;">was evaluated as a bioherbicide for control of giant salvinia (</span><i><span style="font-family:Verdana;">Salvinia</span></i> <i><span style="font-family:Verdana;">molesta</span></i><span style="font-family:Verdana;"> D.S. Mitchell) under greenhouse conditions and in small-scale field trials. We found that fungal mycelium was highly infective and could be rapidly produced (48+</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">h) in soy</span><span style="font-family:""> </span><span style="font-family:Verdana;">flour-cornmeal liquid media contained in shake flasks or fermenters. A dew period was not required to achieve infection and mortality</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">of inoculated plants. A surfactant (Silwet L-77, a polyalkyleneoxide modified heptamethyl-trisiloxane) incorporated in the fungal formulation was required for </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> to infect and kill plants. Infection and mortality occurred rapidly (within 48 h after treatment), and re-growth of treated plants did not occur. In replicated</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">field trials, </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> controlled giant salvinia ~95%. </span><i><span style="font-family:Verdana;">Br</span></i><span style="font-family:Verdana;"> also infected other plants, such as common salvinia (</span><i><span style="
