323 research outputs found
Compound control method of neutral point voltage of three level NPC inverter based on the vector method of virtual space and hysteresis control
No full textThe hydroxyl radical scavenging activity of chitosan, hyaluronan, starch and their O-carboxymethylated derivatives
No full textIn order to study the effect of active hydroxyl and amino groups on scavenging activity against hydroxyl radicals of polysaccharides, three kinds of carboxymethylated polysaccharides (carboxymethyl chitosan (O-CM-chitosan), carboxymethyl hyaluronan (CMHA), and carboxymethyl starch (CMS)) were prepared and their antioxidant activities against hydroxyl radicals were assessed, respectively. Results showed that O-CM-chitosan had lower scavenging ability on hydroxyl radicals than chitosan. CMHA and CMS had the same tendency. For the three kinds of polysaccharides, scavenging ability on hydroxyl radicals was found to be in the order of chitosan > HA > starch. The scavenging ability of carboxymethylated polysaccharides had the same order as related to its corresponding polysaccharides at higher concentrations (>= 0.8mg/ml). There were not only hydroxyl groups but also amino or acetamino (CH3CONH-) groups in the molecules of chitosan and HA, but only hydroxyl group for starch. It was suggested that the sequence influence the scavenging activity against hydroxyl radicals might be amino group > acetamide group > hydroxyl group. (C) 2010 Elsevier Ltd. All rights reserved.In order to study the effect of active hydroxyl and amino groups on scavenging activity against hydroxyl radicals of polysaccharides, three kinds of carboxymethylated polysaccharides (carboxymethyl chitosan (O-CM-chitosan), carboxymethyl hyaluronan (CMHA), and carboxymethyl starch (CMS)) were prepared and their antioxidant activities against hydroxyl radicals were assessed, respectively. Results showed that O-CM-chitosan had lower scavenging ability on hydroxyl radicals than chitosan. CMHA and CMS had the same tendency. For the three kinds of polysaccharides, scavenging ability on hydroxyl radicals was found to be in the order of chitosan > HA > starch. The scavenging ability of carboxymethylated polysaccharides had the same order as related to its corresponding polysaccharides at higher concentrations (>= 0.8mg/ml). There were not only hydroxyl groups but also amino or acetamino (CH(3)CONH-) groups in the molecules of chitosan and HA, but only hydroxyl group for starch. It was suggested that the sequence influence the scavenging activity against hydroxyl radicals might be amino group > acetamide group > hydroxyl group. (C) 2010 Elsevier Ltd. All rights reserved
The moisture absorption and retention abilities of quaternized carboxymethyl chitosan
No full textDifferent types of quaternized carboxymethyl chitosans (QCMCs) were prepared in this study. The moisture absorption abilities of each QCMCs were measured at 81% and 43% relative humidity (RH), and the moisture retention abilities were done at 81% RH, at 43% RH and in silica gel. Hyaluronic acid (HA) was used as control in each condition. Results showed that, both at 81% and 43% RH, each QCMCs had better properties both in moisture absorption and retention than HA. And in silica gel, the moisture retention ability of each QCMCs was better than or close to that of HA. Therefore, it is hopeful that certain of the QCMCs would replace HA as the moisture absorption and retention ingredient in cosmetics in the future. ©2009 IEEE
Synthesis and moisture absorption and retention activities of a carboxymethyl and a quaternary ammonium derivative of alpha,alpha-trehalose
No full textCarboxymethyl alpha,alpha-trehalose (CMT) and a quaternary ammonium derivative of alpha,alpha-trehalose (QT) were successfully prepared, and their moisture absorption and retention activities were assessed. Results showed that both CMT and QT had better moisture absorption abilities at 43% and 81% relative humidity (RH) than alpha,alpha-trehalose. In addition, the two alpha,alpha-trehalose derivatives had better moisture retention abilities than alpha,alpha-trehalose under three humidity conditions: 81% RH, 43% RH, and under dry conditions. Therefore, carboxymethylation and quaternarization could improve the moisture absorption and retention abilities of alpha,alpha-trehalose. CMT and QT showed better moisture absorption ability and moisture retention ability than that of hyaluronan (HA), and could potentially find a use as moisture retention ingredient, for example, in cosmetics. (C) 2009 Elsevier Ltd. All rights reserved.Carboxymethyl alpha,alpha-trehalose (CMT) and a quaternary ammonium derivative of alpha,alpha-trehalose (QT) were successfully prepared, and their moisture absorption and retention activities were assessed. Results showed that both CMT and QT had better moisture absorption abilities at 43% and 81% relative humidity (RH) than alpha,alpha-trehalose. In addition, the two alpha,alpha-trehalose derivatives had better moisture retention abilities than alpha,alpha-trehalose under three humidity conditions: 81% RH, 43% RH, and under dry conditions. Therefore, carboxymethylation and quaternarization could improve the moisture absorption and retention abilities of alpha,alpha-trehalose. CMT and QT showed better moisture absorption ability and moisture retention ability than that of hyaluronan (HA), and could potentially find a use as moisture retention ingredient, for example, in cosmetics. (C) 2009 Elsevier Ltd. All rights reserved
Rethinking lawns as prevalent elements of urban green spaces
No full textThe lawn is one of the most visible elements of urban green spaces and Western landscape styles. China has seen a dramatic increase in planted lawn areas. However, there is an urgent need for sustainable lawn alternatives (SLTs) in China due to serious threats to the urban environment from intensive lawn maintenance and cultural inadequacy of lawns. This thesis attempts to examine the reasons behind the historical context and current situation of lawns in China and offers suggestions for SLTs via a case study of Xi’an using transdisciplinary research framework from social-cultural and ecological perspectives.
A historical study was performed on reasons of lawn development in Chinese cities and modern European and Chinese examples of lawn alternatives by reviewing literature and through field observation. Face-to-face interviews, questionnaires and observations were conducted to evaluate how stakeholders and park visitors perceive lawns and how this affects their decisions in designing, managing and using lawns and lawn alternatives. To identify how the design and management shape plant and pollinator diversity, biodiversity inventories were conducted. Finally, results from the three studies were analysed following a framework based on theories in landscape sustainability and ecosystem services.
The results suggested that the Chinese people’s paradigm of lawns is influenced by westernisation and globalisation after the 1840s. Lawns evolve from changes in the relation-ship between humans and the environment. In classical Chinese gardens, groundcover species were used according to their ecological characteristics and suitability to site conditions. Lawns in Xi’an have the same core grass species as lawns used in geographically distant regions, contributing to lawn plant species homogenisation worldwide. Intensive maintenance negatively affected plant species diversity and native plant species, while in more planned green spaces, older and larger lawns harbour diverse plant species and native plant species. The aesthetic value and regulating services of lawns are mostly recognised by park visitors and stakeholders although lawns impair the provision of some regulating services for the intensive maintenance. Lawns fail to provide some culture services because of their limited accessibility and symbolism of Western culture. Pollination services can be provided if certain spontaneous native plant species are allowed to flower. Concrete suggestions for SLTs in China were proposed, although challenges that impinge the transition to SLTs were identified. Meanwhile, current social-cultural, environmental and economic conditions in China encourage their implementation.
The thesis contributes to knowledge that addresses the mismatch between perceived and actual ecosystem services provided by lawns. The results can be used as references for design and management of SLTs in practice
Historical development and practices of lawns in China
No full textLawn, the most common human-created and culture-shaped habitat in urban green areas, has recently been questioned because of the negative environmental impacts from intensive lawn management. China, a late adopter of lawns, has a great potential to implement sustainable lawns. Based on a literature review and field observations in Chinese cities, this study sought inspiration for sustainable lawns within classical Chinese gardening and European and Chinese examples and identified the drivers of lawn development in China. The definition of lawns has varied over time, which evolves with people’s changing perception on nature. Chinese people’s paradigm on lawns is influenced by the trend of westernization and globalization after 1840s. Shifting the existing paradigm to environmentally friendly lawn aesthetics was identified as the most difficult step in achieving sustainable lawns in China. This paper creates a better understanding of the lawn phenomenon in China and is of great importance in shifting people’s paradigm of lawns in order to revolutionize urban landscapes especially in countries which are later adopters of lawns
A gadolinium (III)–containing complex based on nitronyl nitroxide ligand: Structure and magnetic property study
No full textThe moisture absorption and retention abilities of hyaluronan, chitosan, starch and their quaternary derivatives
No full textQuaternary ammonium salt of hyaluronan (QHA), quaternary ammonium salt of starch (QS), and quaternary ammonium salt of chitosan (QCTS) were successfully prepared. Infrared spectroscopy (IR), 1H NMR and 13C NMR techniques were used to characterize the molecular structure of QHA. Results showed that QHA had better moisture absorption abilities than HA both at 43% and 81% RH. QS and QCTS had the same tendency. In addition, the three quaternized polysaccharides had better moisture retention abilities than their corresponding polysaccharides under three humidity conditions: 81% RH, 43% RH and dry condition. The -N+ (CH3)3 group played a very important role in moisture-absorption and retention ability of the quaternized polysaccharides. QCTS and QHA showed parallel or better Ra and R h than that of HA, and had potential to use as moisture-retention ingredient, e. g., in cosmetics
Amphinemura simifleurdelia Mo & Wang & Yang & Li & Murányi 2020, sp. n.
No full textAmphinemura simifleurdelia sp. n. (Figs. 5–8) Diagnosis. Male: terga IX–X with short spines, epiproct with apically outcurved and downcurved lateral processes and slightly longer, apically upcurved median process, paraproctal median lobe long and apically with a black spine, outer lobe heavily sclerotized and with double apical spines. Female: pregenital plate pale, subgenital plate subquadrate and bicolored with small posteromedial indentation, inner genitalia with a short and stripe-like medial sclerite. Male habitus (Figs. 5 a–5b). Body color brown to dark brown. Head and mouthparts dark brown; antennae brown, and palpi paler; compound eyes black; head wider than pronotum; pronotum brown with paler lateral edges, rectangular with obscure rugosities but older or well sclerotized specimens with distinct dark brown markings; legs brown, femora paler. Wing membranes subhyaline, veins brown. Abdominal segments light brown with darker terminalia. Male (Figs. 5–7). Forewing length 5.3–5.5 mm, hind wing length 4.3–4.5 mm. Tergum IX heavily sclerotized, but lateral area lighter, with subtriangular anterior and posterior indentations, and with two groups of tiny black spines and several long bristles present along mid-posterior margin. (Figs. 6a, 6c, 7a, 7c). Slender vesicle of sternum IX claviform, length 3.0X maximum width, basally and medially constricted. Hypoproct rectangular basally, gradually narrowing toward nipple-like tip (Figs. 6 b–6c, 7b–7c). Tergum X darkly sclerotized, a membranous concavity present below the epiproct, and with two groups of short, black spines on either sides of the epiproct. Cercus slightly sclerotized, short, cylindrical, weakly curved inward, about as long as 2.5X width. Epiproct (Figs. 6a, 6 c–6d, 7a, 7c–7d) subrectangular, trifurcate with a median process and a pair of horn-like lateral processes, the median process slightly longer than lateral processes. Dorsal sclerite with a rectangular membranous basal half; horn-like lateral processes strongly sclerotized, apically outcurved and downcurved with several denticles on both sides of the blunt tip. Ventral sclerite dark and strongly sclerotized, subtriangular in dorsal view, broad at base, tapering toward tip, slightly up-curved apically in lateral view, expanded ventrally into a small ridge with rows of tiny black spines. Paraproct trilobed (Figs. 5 c–5e, 6a–6c, 7a–7c): inner lobe sclerotized, triangular and moderately long; median lobe long and narrow, distinctly sclerotized, strongly curved upward and outward, apically with a black spine in membranous, slightly swollen tip; outer lobe slender and heavily sclerotized, distinctly curved outward apically, and with two short black apical spines. Female (Fig. 8). Forewing length 6.5–6.7 mm, hind wing length 5.5–5.8 mm. Sternum VII produced in a weakly sclerotized semicircular pregenital plate slightly covering anterior half of subgenital plate. Sternum VIII forms sclerotized subquadrate subgenital plate with a triangular anterior notch, posteriorly directed triangular medial area pale and lightly sclerotized, contrasting the mostly dark brown plate. Paragenital plate paired, forming subquadrate brown lobes connected with posterolateral corner of subgenital plate. Sternum IX weakly sclerotized, trapezoidal. Paraprocts short and wide triangular, with blunt tip; cerci short and pale. Inner genitalia (Fig. 8d) membranous, opening under the posteromedial notch of the subgenital plate, having a basal pouch, a pair of leaf-shaped lateromedial sclerites attached above the pouch, and an apical cone; The pouch is armed with a short, longitudinal sclerite well seen by transparency through the subgenital plate; apical cone membranous with an apical circular sclerite ring. Type Material. Holotype: male (HIST), China: Guangdong Province, Maoming City, Xinyi City, Dacheng Town, Yunkaishan National Natural Reserve, the bridge next to the security office at the entrance to the reserve, 966 m, 22º16'34" N, 111º11'43" E, 2018.X.4, light trap, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang. Paratypes: 5 males, 4 females (HIST), same locality and date as holotype; 3 males, 1 female (HIST), Yunkaishan National Natural Reserve, the river at the gate of the reserve, 987 m, 22º16’34”N, 111º11’43”E, 2018.X.5, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang; 5 males, 5 females (GXU), 2 males, 2 females (HNHM), same locality, 2018.X.4, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang. Etymology. The specific epithet refers to the similarity to the closely related A. fleurdelia (Wu, 1949). Distribution and ecology. The new species is known from southern China, the type series was collected from a stream at medium elevations of the isolated mountain systems of the Yunkaishan National Natural Reserve, Guangdong Province. Amphinemura simifleurdelia was collected together with A. retusilobata from the same habitat (Figs. 9 a–c), but not in Neichao, the other known locality of that species, suggesting perhaps a more restricted distribution of A. simifleurdelia. Remarks. The new species belongs to the A. sinensis group and closely resembles A. fleurdelia (Wu, 1949). The two species share the following characteristics: tergum X has a pair of paramedial groups of short spines, inner paraproct lobes triangular and outer lobe of paraproct strongly curved outward apically, with two black, short spines. However, ventral sclerite of epiproct is nearly straight in lateral view with slightly upcurved tip, and median paraproct lobes only slightly swollen with a distinct black apical spine in A. simifleurdelia. In A. fleurdelia, apical ventral sclerite of epiproct distinctly curved downward in lateral view and apical median paraproct lobes global with several tiny spines. At a lesser extent, the new species is also resembles A. elongata Li, Yang & Sivec, 2005b from Zhejiang Province in the tergum X, inner and outer paraproct lobes, and ventral sclerite of epiproct in lateral view, but the new species can be separated from A. elongata by the approximately equal length of median and lateral processes of epiproct and slender median paraproct lobes. In A. elongata, the median process is distinctly longer than lateral processes of epiproct, and median paraproct lobes are medially twisted. Amphinemura fleurdelia, A. elongata and A. simifleurdelia may be a species complex within the A. sinensis species group. Amphinemura fleurdelia is also present in Guangdong, specimens were described and illustrated by Li et al. (2005b: Figs. 6 –11). Discovery of further populations are needed to evaluate morphological and genetic variability within the complex, but distinction at species level seems reasonable, since several specimens in the known populations explain stable morphological characters. A single male, deposited in the National Museum Prague (Guangdong, Nanling National Nature Reserve, Dadongshan, border of mixed forest, 690 m, 24°56.0’ N, 112°42.9’ E, 2013.IV.18–21, collected at light, J. Hájek, J. Růžička), may represents a further species, distinguished by several spines on the outer lobe of the paraproct and shorter median process of the epiproct. However, this taxon will not be described until additional specimens become available for study.Published as part of Mo, Raorao, Wang, Guoquan, Yang, Ding, Li, Weihai & Murányi, Dávid, 2020, Two new species of the Amphinemura sinensis group (Plecoptera: Nemouridae) from southern China, pp. 337-350 in Zootaxa 4820 (2) on pages 343-346, DOI: 10.11646/zootaxa.4820.2.7, http://zenodo.org/record/439776
Amphinemura retusilobata Mo & Wang & Yang & Li & Murányi 2020, sp. n.
No full textAmphinemura retusilobata sp. n. (Figs. 1–4) Diagnosis. Male: tergum IX with short spines, tergum X with long spines, epiproct with apically notched lateral processes that are shorter than median process, paraproctal outer lobe slender, median lobe flat in lateral view and the tip strongly outcurved in dorsal view. Female: pregenital plate large and dark, subgenital plate bicolored and posteriorly bilobed with deep and wide medial indentation, inner genitalia with a pair of stripe-like medial sclerites. Male habitus (Figs. 1 a–1b). Body color brown to dark brown. Head and mouthparts dark brown; antennae brown, and palpi paler; compound eyes black; head wider than pronotum; pronotum brown, rectangular with obscure rugosities, but pronotum of older or well-sclerotized specimens, trapezoidal with distinct dark brown markings; legs brown. Wing membranes subhyaline, veins brown. Abdominal segments light brown with darker terminalia. Male (Figs. 1–3). Forewing length 5.2–5.4 mm, hind wing length 4.3–4.4 mm. Tergum IX sclerotized, rather constricted medially, with triangular anterior and posterior indentations, and with two groups of tiny black spines and several long bristles present along posterior margin (Figs. 2a, 2c, 3a, 3c). Slender vesicle of sternum IX claviform, length 4.2X maximum width, constricted basally and slightly constricted medially. Hypoproct rectangular basally, gradually narrowing toward nipple-like tip (Figs. 2 b–2c, 3b–3c). Tergum X sclerotized, a membranous concavity present below the epiproct, bearing two groups of strong black spines on either sides of the epiproct. Cercus slightly sclerotized, cylindrical and weakly curved inward, as long as 2.5X width. Epiproct (Figs. 2a, 2 c–2d, 3a, 3c–3d,) subrectangular, trifurcate with a slender median process and a pair of lateral processes, the median process much longer than bifid lateral processes. Dorsal sclerite with a broadly oval, membranous basal half; lateral processes strongly sclerotized, straight but apically slightly outcurved and downcurved, apex with several small denticles and an outer semicircular lobe, tip blunt. Ventral sclerite light colored but sclerotized, triangular, tapering toward tip; apical half up-curved but bent downward apically in lateral view; ventrally expanding into a triangular ridge with a row of small black spines. Paraproct trilobed (Figs. 1 c–1d, 2, 3a–3c): inner lobe triangular, moderately long; median lobe long, the apical half strongly sclerotized in a triangular stripe ending in acute spine, apex strongly curved upwards, bear 0–2 black, long spines medially and numerous long spines along its membranous tip, seems rotated in dorsal view; outer lobe slender, sclerotized and slightly curved outward with a black, long spine at tip but the spine may lacking. Female (Fig. 4). Forewing length 6.0– 6.7 mm, hind wing length 5.1–5.8 mm. Sternum VII produced in a large, darkly sclerotized semicircular pregenital plate, covering anterior portion of subgenital plate. Sternum VIII forms bilobed subgenital plate with a deep medial indentation; the plate is lightly sclerotized medially, while lateral parts and the posterior lobes are dark. Paragenital plate paired, forming banded brownish lobe connected with posterolateral corner of subgenital plate. Sternum IX trapezoidal, full sclerotized. Paraprocts brown, wide triangular with blunt, rounded tip; cerci brownish, short. Inner genitalia (Fig. 4d) mostly membranous, inverted triangular, opening under the forked medial indention of the subgenital plate; a pair of stripe-like medial sclerites present beneath the apical tube that leads into oviductus; medial sclerites linked to medial portion of subgenital plate; apical tube distinctly sclerotized at base. Type Material. Holotype: male (HIST), China: Guangdong Province, Maoming City, Xinyi City, Dacheng Town, Yunkaishan National Natural Reserve, the bridge next to the security office at the entrance to the reserve, 966 m, 22º16'34" N, 111º11'43" E, 2018.X.4, light trap, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang. Paratypes: 2 males, 2 females (HIST), same locality and date as holotype; 10 males, 2 females (HIST), Yunkaishan National Natural Reserve, the river at the gate of the reserve, 987 m, 22º16’34”N, 111º11’43”E, 2018.X.5, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang; 4 males (GXU), 2 males (HNHM), 8 females (HIST), same locality, 2018. X.4, Raorao Mo, Fengping Qin, Wei Liu, Shuai Tang; 1 teneral male with weakly developed paraproct, Guangxi Zhuang Autonomous Region, Nanning City, Wuming County, Liangjiang Town, Neichao, Longmugou River, 220 m, 23°29′40”N, 108°21′37”E, 2015.III.24, Junyi Li, Shan Li, Weihai Li, Dávid Murányi; same section of Long-mugou River, 198 m, 23°29′39”N, 108°21′36”E, 2020.V.18, Raorao Mo, Yan Lai, Yingying Mo; 1 female, lower section of Longmugou River, 194 m, 23°29′33”N, 108°21′29”E, 2020.V.19, Raorao Mo, Yan Lai, Yingying Mo; 1 female, lower section of Longmugou River, 186 m, 23°29′57”N, 108°21′21”E, 2020.V.21, Raorao Mo, Yan Lai, Yingying Mo. Etymology. The name refers to the lateral processes of the male epiproct with an apical notch. Latin “retusus” means notch, and “lobus” means projection. Distribution and ecology. The new species is known from southern China, the type series was collected from low and medium elevations of two isolated mountain systems of Guangdong and Guangxi Provinces. The two mountain ranges are separated nearly by 300 km. Collected in foothill and medium elevation habitats, A. retusilobata is expected occur more widely in southern China. The type locality in Guangdong is a variable stony stream with dense riparian vegetation (Figs. 9 a–c). In Guangxi, the specimens were collected from the Longmugou River, a small foothill stream (Fig. 9d). Its upper section habitat was described and illustrated in Mo et al. (2019b: Fig. 10d), under the name Neichao River. Remarks. The new species is a distinctive member of the A. sinensis group, only resembling A. viet Stark & Sivec, 2010, a species described from northern Vietnam. The two species share a similar tergum X, inner paraproct lobe, ventral sclerite of epiproct, and dorsal sclerite of epiproct that is armed with an outer apical notch on the lateral processes. However, A. retusilobata can be easily separated from A. viet by the median lobe of paraproct which is flat in lateral view and the tip strongly outcurved in dorsal view, the median process of epiproct is much longer than lateral processes and the bifid lateral processes are having blunt apex (Figs. 1 c–1d, 2–3). In A. viet, the median lobe of paraproct is slightly club-shaped in lateral view, and swollen outside of the tip in dorsal view; median process and lateral processes subequal in length, and the lateral processes with an acute apex (figs. 24–26, Stark & Sivec 2010). In addition, outer paraproctal lobes of A. viet may be obscure, not mentioned or figured in the original description by Stark & Sivec (2010). The outer paraproct lobes of A. retusilobata are slender, distinctly sclerotized, usually with a black apical spine. The female is less distinctive, but can be identified by the combination of presence of large and dark pregenital plate, bicolored and posteriorly widely bilobed subgenital plate, and a pair of stripe–like medial sclerites of the inner genitalia.Published as part of Mo, Raorao, Wang, Guoquan, Yang, Ding, Li, Weihai & Murányi, Dávid, 2020, Two new species of the Amphinemura sinensis group (Plecoptera: Nemouridae) from southern China, pp. 337-350 in Zootaxa 4820 (2) on pages 338-342, DOI: 10.11646/zootaxa.4820.2.7, http://zenodo.org/record/439776
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