Monthly changes in sedimentation and sediment properties were studied for three different culture treatments： sea cucumber monoculture （Mc）, sea cucumber and scallop polyculture （Ps-c） and scallop monoculture （M...Monthly changes in sedimentation and sediment properties were studied for three different culture treatments： sea cucumber monoculture （Mc）, sea cucumber and scallop polyculture （Ps-c） and scallop monoculture （Ms）. Results indicated that the survival rate of sea cucumber was significantly higher in Ps-c cultures than in Mc cultures. Sea cucumber yield was 69.6% higher in Ps-c culture than in Mc culture. No significant differences in body weight and scallop shell length were found between Ps-c and Ms cultures. The mean sedimentation rate of total particulate matter （TPM） was 72.2 g/（m^2.d） in Ps-c cultures, with a maximum of 119.7 g/（mE.d）, which was markedly higher than that of Mc （mean value）. Sedimentation rates of organic matter （OM）, total organic carbon （TOC）, total nitrogen （TN） and total phosphorus （TP） in Ps-c cultures were also significantly higher than those in Mc cultures. TOC and TN contents of sediment increased rapidly in the first 5 months in Ms cultures and remained at a high level. TOC and TN contents in Mc and Ps-c cultures decreased during sea cucumber feeding seasons and increased during sea cucumber dormancy periods （summer and winter）. The study demonstrates that co-culture of sea cucumber and scallop in earthen ponds is an alternative way to alleviate nutrient loads and improve water quality in coastal aquaculture systems. Moreover, it provides the additional benefit of an increased sea cucumber yield.展开更多
Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their ph...Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their photoluminescence(PL) mechanisms, which have been widely studied, is of significance in guiding the synthesis and promoting applications of CDs with tunable PL emissions. However,the intrinsic mechanism of PL emission remains unclear, and a unified mechanism has not been found because of differences in particle structures. This review generalizes the categories of CDs, noting their structural diversity. Three types of PL mechanism pertaining to structural differences are outlined: internal factors dominated emission(including the conjugation effect, the surface state, and the synergistic effect), external factors dominated emission(including the molecular state and the environment effect),and crosslink-enhanced emission. Optical applications of CDs are also briefly mentioned. Finally, the prospects for research into PL mechanisms are discussed, noting the remaining challenges and directions for future work.展开更多
Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dis...Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dispersers.However,studies with empirical data interrogating this hypothesis are lacking.Weekly monitoring of flowering and fruiting patterns on a generalist mistletoe Dendrophthoe pentandra(Loranthaceae)was conducted for two consecutive years in tropical Xishuangbanna,Southwest China.We examined whether flowering and fruiting patterns were seasonal,quantified the degree of stagger within D.pentandra populations and determined the factors influencing the first flowering date(FFD)of D.pentandra.Furthermore,the effect of change in the number of host species on reproductive phenological asynchrony of mistletoe was examined.We found that(i)both flowering and fruiting exhibited unimodal peaks in the two consecutive years of the study;(ii)the FFD was significantly influenced by crown area of mistletoe and light,such that clump with larger crown and more light exposure had an earlier FFD and longer flowering and fruiting durations;(iii)different host species had a significant impact on the phenology of mistletoes.However,contrary to our hypothesis,the number of host species did not significantly change the asynchrony of reproductive phenology of mistletoe.Therefore,these results suggest that alternative hypotheses are needed to interpret the ecological significance of the number of host species and phenological asynchrony of generalist mistletoes.展开更多
基金Supported by the National Key Technology Research and Development Program of China (Nos. 2006BAD09A01, 200905020)the National Natural Science Foundation of China (No. 30871931)the Program for New Century Excellent Talents in University (No. NCET-08-0503)
文摘Monthly changes in sedimentation and sediment properties were studied for three different culture treatments： sea cucumber monoculture （Mc）, sea cucumber and scallop polyculture （Ps-c） and scallop monoculture （Ms）. Results indicated that the survival rate of sea cucumber was significantly higher in Ps-c cultures than in Mc cultures. Sea cucumber yield was 69.6% higher in Ps-c culture than in Mc culture. No significant differences in body weight and scallop shell length were found between Ps-c and Ms cultures. The mean sedimentation rate of total particulate matter （TPM） was 72.2 g/（m^2.d） in Ps-c cultures, with a maximum of 119.7 g/（mE.d）, which was markedly higher than that of Mc （mean value）. Sedimentation rates of organic matter （OM）, total organic carbon （TOC）, total nitrogen （TN） and total phosphorus （TP） in Ps-c cultures were also significantly higher than those in Mc cultures. TOC and TN contents of sediment increased rapidly in the first 5 months in Ms cultures and remained at a high level. TOC and TN contents in Mc and Ps-c cultures decreased during sea cucumber feeding seasons and increased during sea cucumber dormancy periods （summer and winter）. The study demonstrates that co-culture of sea cucumber and scallop in earthen ponds is an alternative way to alleviate nutrient loads and improve water quality in coastal aquaculture systems. Moreover, it provides the additional benefit of an increased sea cucumber yield.
基金financially supported by the National Natural Science Foundation of China(21905253,51973200)the China Postdoctoral Science Foundation(2018M640681,2019T120632)。
文摘Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their photoluminescence(PL) mechanisms, which have been widely studied, is of significance in guiding the synthesis and promoting applications of CDs with tunable PL emissions. However,the intrinsic mechanism of PL emission remains unclear, and a unified mechanism has not been found because of differences in particle structures. This review generalizes the categories of CDs, noting their structural diversity. Three types of PL mechanism pertaining to structural differences are outlined: internal factors dominated emission(including the conjugation effect, the surface state, and the synergistic effect), external factors dominated emission(including the molecular state and the environment effect),and crosslink-enhanced emission. Optical applications of CDs are also briefly mentioned. Finally, the prospects for research into PL mechanisms are discussed, noting the remaining challenges and directions for future work.
基金supported by the National Natural Science Foundation of China(31670393)to L.Z.
文摘Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dispersers.However,studies with empirical data interrogating this hypothesis are lacking.Weekly monitoring of flowering and fruiting patterns on a generalist mistletoe Dendrophthoe pentandra(Loranthaceae)was conducted for two consecutive years in tropical Xishuangbanna,Southwest China.We examined whether flowering and fruiting patterns were seasonal,quantified the degree of stagger within D.pentandra populations and determined the factors influencing the first flowering date(FFD)of D.pentandra.Furthermore,the effect of change in the number of host species on reproductive phenological asynchrony of mistletoe was examined.We found that(i)both flowering and fruiting exhibited unimodal peaks in the two consecutive years of the study;(ii)the FFD was significantly influenced by crown area of mistletoe and light,such that clump with larger crown and more light exposure had an earlier FFD and longer flowering and fruiting durations;(iii)different host species had a significant impact on the phenology of mistletoes.However,contrary to our hypothesis,the number of host species did not significantly change the asynchrony of reproductive phenology of mistletoe.Therefore,these results suggest that alternative hypotheses are needed to interpret the ecological significance of the number of host species and phenological asynchrony of generalist mistletoes.
