A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends mo...A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.展开更多
S concentrations in samples of mulberry leaves and silkworm (Bombyx mori L.) cocoon shells and quality of cocoon taken from typical mulberry gardens of six provinces located in the lower to middle reaches of the Yangt...S concentrations in samples of mulberry leaves and silkworm (Bombyx mori L.) cocoon shells and quality of cocoon taken from typical mulberry gardens of six provinces located in the lower to middle reaches of the Yangtze River were analyzed by the method of applied biostatistics on sericulture to study the relationships between cocoon quality and S concentrations in mulberry leaves and cocoon shells. The results showed that two-power function relationships between concentration of sulfur in mulberry leaves and characters of cocoon quality were significant (R2 = 0.139*-0.329**, n = 24-29, a < 0). The range of optimum S concentrations in mulberry leaves was 1.90-2.49 g kg-1 (mean±SE = 2.10±0.15 g kg-1) for high quality of cocoon. There existed significant two-power function or positive linear relationships between S concentration in cocoon shell and characters of cocoon quality (R2 = 0.153*-0.458**, n = 24-29). The range of optimum concentrations of sulfur in cocoon shell was 1.51-1.61 g kg-1 for high quality of cocoon.展开更多
Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is...Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields.Herein,we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck.Localized processing of silk fiber,including nano-holing,nano-grooving,and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber.An extremely narrow nanohole with a width of^64 nm was successfully achieved.The processed silk fiber can be used to transfer micro/nanoparticles and drugs,showing potential for biomedical engineering.The processing strategy developed in this study can also be extended to other materials,paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.展开更多
The silkworm,Bombyx mori,played an important role in the old Silk Road that connected ancient Asia and Europe.However,to date,there have been few studies of the origins and domestication of this species using molecula...The silkworm,Bombyx mori,played an important role in the old Silk Road that connected ancient Asia and Europe.However,to date,there have been few studies of the origins and domestication of this species using molecular methods.In this study,DNA sequences of mitochondrial and nuclear loci were used to infer the phylogeny and evolutionary history of the domesticated silkworm and its relatives.All of the phylogenetic analyses indicated a close relationship between the domesticated silkworm and the Chinese wild silkworm.Domestication was estimated to have occurred about 4100 years ago(ya),and the radiation of the different geographic strains of B.mori about 2000 ya.The Chinese wild silkworm and the Japanese wild silkworm split about 23600 ya.These estimates are in good agreement with the fossil evidence and historical records.In addition,we show that the domesticated silkworm experienced a population expansion around 1000 ya.The divergence times and the population dynamics of silkworms presented in this study will be useful for studies of lepidopteran phylogenetics,in the genetic analysis of domestic animals,and for understanding the spread of human civilizations.展开更多
文摘A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.
基金supported by the National Natural Science Foundation of China(No. 49771051), the Postdoctoral Fund of People's Government of Ji
文摘S concentrations in samples of mulberry leaves and silkworm (Bombyx mori L.) cocoon shells and quality of cocoon taken from typical mulberry gardens of six provinces located in the lower to middle reaches of the Yangtze River were analyzed by the method of applied biostatistics on sericulture to study the relationships between cocoon quality and S concentrations in mulberry leaves and cocoon shells. The results showed that two-power function relationships between concentration of sulfur in mulberry leaves and characters of cocoon quality were significant (R2 = 0.139*-0.329**, n = 24-29, a < 0). The range of optimum S concentrations in mulberry leaves was 1.90-2.49 g kg-1 (mean±SE = 2.10±0.15 g kg-1) for high quality of cocoon. There existed significant two-power function or positive linear relationships between S concentration in cocoon shell and characters of cocoon quality (R2 = 0.153*-0.458**, n = 24-29). The range of optimum concentrations of sulfur in cocoon shell was 1.51-1.61 g kg-1 for high quality of cocoon.
基金the support from the National Key R&D Program of China(2017YFB1104300,2016YFA0200103 and 2018YFB1107200)the National Program for the Support of Top-notch Young Professionalsthe National Natural Science Foundation of China(51775303)。
文摘Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields.Herein,we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck.Localized processing of silk fiber,including nano-holing,nano-grooving,and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber.An extremely narrow nanohole with a width of^64 nm was successfully achieved.The processed silk fiber can be used to transfer micro/nanoparticles and drugs,showing potential for biomedical engineering.The processing strategy developed in this study can also be extended to other materials,paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.
基金supported by the National Natural Science Foundation of China(Grant No. 30671587)the Programme for Introducing Talents of Discipline to Universities(Grant No.B07045)+1 种基金the Doctorial Innovation Fund of Southwest University(Grant No.Kb2009019)supported by grants from the U.S.National Science Foundation(Grant Nos.0531769, 0531626,and DEB-0212910)
文摘The silkworm,Bombyx mori,played an important role in the old Silk Road that connected ancient Asia and Europe.However,to date,there have been few studies of the origins and domestication of this species using molecular methods.In this study,DNA sequences of mitochondrial and nuclear loci were used to infer the phylogeny and evolutionary history of the domesticated silkworm and its relatives.All of the phylogenetic analyses indicated a close relationship between the domesticated silkworm and the Chinese wild silkworm.Domestication was estimated to have occurred about 4100 years ago(ya),and the radiation of the different geographic strains of B.mori about 2000 ya.The Chinese wild silkworm and the Japanese wild silkworm split about 23600 ya.These estimates are in good agreement with the fossil evidence and historical records.In addition,we show that the domesticated silkworm experienced a population expansion around 1000 ya.The divergence times and the population dynamics of silkworms presented in this study will be useful for studies of lepidopteran phylogenetics,in the genetic analysis of domestic animals,and for understanding the spread of human civilizations.
