Due to fiber swelling,textile fabrics containing hygroscopic fibers tend to decrease pore size under wet or increasing humid-ity and moisture conditions,the reverse being true.Nevertheless,for personal thermal regulat...Due to fiber swelling,textile fabrics containing hygroscopic fibers tend to decrease pore size under wet or increasing humid-ity and moisture conditions,the reverse being true.Nevertheless,for personal thermal regulation and comfort,the opposite is desirable,namely,increasing the fabric pore size under increasing humid and sweating conditions for enhanced ventila-tion and cooling,and a decreased pore size under cold and dry conditions for heat retention.This paper describes a novel approach to create such an unconventional fabric by emulating the structure of the plant leaf stomata by designing a water responsive polymer system in which the fabric pores increase in size when wet and decrease in size when dry.The new fabric increases its moisture permeability over 50%under wet conditions.Such a water responsive fabric can find various applications including smart functional clothing and sportswear.展开更多
We investigated the altitudinal variation of Carpinus betulus L. in the Hyrcanian forest using leaf macro-morphological and micro-morphological traits. We collected a total of 1600 leaves from two locations. In each l...We investigated the altitudinal variation of Carpinus betulus L. in the Hyrcanian forest using leaf macro-morphological and micro-morphological traits. We collected a total of 1600 leaves from two locations. In each location, we sampled six populations along an altitudinal gradient ranging from 100 m to 1,150 m. We found that trees in the higher elevations have smaller leaf lamina than those in the lower elevations. In contrast, leaf mass per area was high at low altitudes and increased newly at the higher ones. Stomatal dimension was negatively correlated with elevation, while stomatal density was positively correlated with elevation. We also found that two transects showed the same plasticity trend. Leaf area showed the highest plasticity, while the number of veins showed the lowest plasticity. This study shows that altitude, and related temperature and rainfall, represents an important driving force in Carpinus betulus leaf morphological variation. Moreover, our results suggest that leaf area, leaf mass per area and stomatal density could influence the species responses to different ecological conditions.展开更多
Buddleja macrostachya （Buddlejaceae） is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n= 12x=228. To de...Buddleja macrostachya （Buddlejaceae） is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n= 12x=228. To determine if morphological characters might be used as indicators of ploidy levels, we measured floral and fruit length, relative and absolute leaf size, trichome density on both leaf surfaces, and stomatal density and length in different populations orB. macrostachya. In general, flower and fruit length, absolute leaf size, and stomatal length in,eased with an increase at ploidy level （P〈0.01）, whereas adaxial cell and stomatal density decreased with an increase at ploidy level （P〈0.01）. We found no conspicuous differences in relative leaf size （P〉0.05） in different populations. Other characters studied such as trichome type, cuticular membrane and ornamentation of stomata, cell and stomatal shape, and anticlinal wall pattern were quite constant in this species. Thus it appears that flower and fruit length, absolute leaf size, and stomatal frequency and length can be used to distinguish hexaptoid from dodecaploid cytotypes either in the field or in herbarium specimens.展开更多
Objective:To study detail microscopic evaluation and physiochemical analysis of Dillenia indica(D.indica)leaf.Methods:Fresh leaf sample and dried power of the leaf were studied macroscopically and microscopically.Prel...Objective:To study detail microscopic evaluation and physiochemical analysis of Dillenia indica(D.indica)leaf.Methods:Fresh leaf sample and dried power of the leaf were studied macroscopically and microscopically.Preliminary phytochemical investigation of plant material was done.Other WHO recommended parameters for standardizations were also performed.Results:The detail microscopy revealed the presence of anomocytic stomata,unicellular trichome,xylem fibres,calcium oxalate crystals,vascular bundles,etc.Leaf constants such as stomatal number,stomatal index,vein-islet number and veinlet termination numbers were also measured.Physiochemical parameters such as ash values,loss on drying,extractive values,percentage of foreign matters,swelling index,etc.were also determined.Preliminary phytochemical screening showed the presence of steroids,terpenoids,glycosides,fatty acids,flavonoids,phenolic compounds and carbohydrates.Conclusions:The microscopic and physiochemical analysis of the D.indica leaf is useful in standardization for quality,purity and sample identification.展开更多
基金supported by Prof.Fan’s Faculty Startup Fund of the College of Human Ecology,Cornell Universitysupported by the National Science Foundation under Award Number DMR-1719875acknowledge Dr.Xia Zeng for equipment guidance and support,Charles V.Beach and Vincent Chicone for their assistance with the mask fabrication.Finally,the PI,Prof.Fan would like to acknowledge the funding support of RGC GRF project#15213920 and Hong Kong Polytechnic University Project of Strategic Importance#ZE1H for further analysis of the experimental data and improvement of the manuscript.
文摘Due to fiber swelling,textile fabrics containing hygroscopic fibers tend to decrease pore size under wet or increasing humid-ity and moisture conditions,the reverse being true.Nevertheless,for personal thermal regulation and comfort,the opposite is desirable,namely,increasing the fabric pore size under increasing humid and sweating conditions for enhanced ventila-tion and cooling,and a decreased pore size under cold and dry conditions for heat retention.This paper describes a novel approach to create such an unconventional fabric by emulating the structure of the plant leaf stomata by designing a water responsive polymer system in which the fabric pores increase in size when wet and decrease in size when dry.The new fabric increases its moisture permeability over 50%under wet conditions.Such a water responsive fabric can find various applications including smart functional clothing and sportswear.
文摘We investigated the altitudinal variation of Carpinus betulus L. in the Hyrcanian forest using leaf macro-morphological and micro-morphological traits. We collected a total of 1600 leaves from two locations. In each location, we sampled six populations along an altitudinal gradient ranging from 100 m to 1,150 m. We found that trees in the higher elevations have smaller leaf lamina than those in the lower elevations. In contrast, leaf mass per area was high at low altitudes and increased newly at the higher ones. Stomatal dimension was negatively correlated with elevation, while stomatal density was positively correlated with elevation. We also found that two transects showed the same plasticity trend. Leaf area showed the highest plasticity, while the number of veins showed the lowest plasticity. This study shows that altitude, and related temperature and rainfall, represents an important driving force in Carpinus betulus leaf morphological variation. Moreover, our results suggest that leaf area, leaf mass per area and stomatal density could influence the species responses to different ecological conditions.
基金supported by grants-in-aid from the National Natural Science Foundation of China (NSFC 30625004,40771073)the Yunnan Natural Science Foundation(2008CC013)
文摘Buddleja macrostachya （Buddlejaceae） is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n= 12x=228. To determine if morphological characters might be used as indicators of ploidy levels, we measured floral and fruit length, relative and absolute leaf size, trichome density on both leaf surfaces, and stomatal density and length in different populations orB. macrostachya. In general, flower and fruit length, absolute leaf size, and stomatal length in,eased with an increase at ploidy level （P〈0.01）, whereas adaxial cell and stomatal density decreased with an increase at ploidy level （P〈0.01）. We found no conspicuous differences in relative leaf size （P〉0.05） in different populations. Other characters studied such as trichome type, cuticular membrane and ornamentation of stomata, cell and stomatal shape, and anticlinal wall pattern were quite constant in this species. Thus it appears that flower and fruit length, absolute leaf size, and stomatal frequency and length can be used to distinguish hexaptoid from dodecaploid cytotypes either in the field or in herbarium specimens.
基金Supported by Career Award for Young Teachers.AICTE.New Delhi.(No.1-51/RID/CA/4/2009-10)
文摘Objective:To study detail microscopic evaluation and physiochemical analysis of Dillenia indica(D.indica)leaf.Methods:Fresh leaf sample and dried power of the leaf were studied macroscopically and microscopically.Preliminary phytochemical investigation of plant material was done.Other WHO recommended parameters for standardizations were also performed.Results:The detail microscopy revealed the presence of anomocytic stomata,unicellular trichome,xylem fibres,calcium oxalate crystals,vascular bundles,etc.Leaf constants such as stomatal number,stomatal index,vein-islet number and veinlet termination numbers were also measured.Physiochemical parameters such as ash values,loss on drying,extractive values,percentage of foreign matters,swelling index,etc.were also determined.Preliminary phytochemical screening showed the presence of steroids,terpenoids,glycosides,fatty acids,flavonoids,phenolic compounds and carbohydrates.Conclusions:The microscopic and physiochemical analysis of the D.indica leaf is useful in standardization for quality,purity and sample identification.
