Pakistan has a rich fauna of planthoppers but members of the family Meenoplidae have not been reported from this region. In this study Nisa atrovenosa of the family Meenoplidae is recorded for the first time from Khyb...Pakistan has a rich fauna of planthoppers but members of the family Meenoplidae have not been reported from this region. In this study Nisa atrovenosa of the family Meenoplidae is recorded for the first time from Khyber Pakhtunkhwa Province of Pakistan. A morphological description and illustrations are provided.展开更多
The forewing base structure of a representative species from 13 families of Fulgoroidea were examined.Results show that these families differ mainly from the characters of various sclerites,the presence or absence of ...The forewing base structure of a representative species from 13 families of Fulgoroidea were examined.Results show that these families differ mainly from the characters of various sclerites,the presence or absence of humeral plate,proximal and distal median plate,and the method of connection between each sclerite.The phylogenetic relationships based on forewing structure support the monophyly of Fulgoroidea.Ricaniidae and Flatidae were recovered as sister taxa.Kinnaridae is the most primitive family in Fulgoroidea.展开更多
Microencapsulation of phase change materials(Micro PCMs) has been paid special attention because of their extensive applications in saving and releasing energy. Micro PCMs containing paraffin with a melting point of ...Microencapsulation of phase change materials(Micro PCMs) has been paid special attention because of their extensive applications in saving and releasing energy. Micro PCMs containing paraffin with a melting point of 55 ℃ in polystyrene-divinylbenzene(P(St-DVB)) were prepared by suspension-like polymerization. The characterization of microcapsules by FTIR, DSC and TG proved that paraffin had been successfully encapsulated and the proportion of encapsulated paraffin was 49.8%—58.5%. The effects of polyvinylpyrrolidone(PVP) with different molecular weights serving as the suspension stabilizer were investigated in detail. The results illustrated that the type of PVP had a significant influence on the particle size of Micro PCMs. The average diameter of Micro PCMs decreased with an increasing molecular weight of PVP. Moreover, the crosslinker-postaddition method was adopted in this study to improve the morphology of P(St-DVB) Micro PCMs. SEM images showed that when the DVB was added at the 2nd hour of polymerization the morphology of obtained P(St-DVB) Micro PCMs exhibited good sphericity since it could avoid the influence of cross-linker agent during the nucleation period.展开更多
The production of deep well-shaped WC-Co cemented carbide blocks via industrial powder pressing remains a challenging technical problem,primarily due to the unsuitability of the forming agent.The forming agent paraffi...The production of deep well-shaped WC-Co cemented carbide blocks via industrial powder pressing remains a challenging technical problem,primarily due to the unsuitability of the forming agent.The forming agent paraffin wax was modified through four types of modifiers,including organic high-molecular-mass resins,plasticizers,surfactants and lubricants.The qualitative screening of resin types was explored and an orthogonal experiment involving the combination of these four paraffin wax modifiers was conducted to obtain an optimized quantitative ratio of modifiers.The results reveal that the insertion of the small molecule chain of resin into the interstitial spaces of paraffin wax crystals is likely a crucial factor for improving the compatibility between the resin and paraffin wax.Through orthogonal experiments,the optimized formulation for the forming agent is determined:100 parts of 58#paraffin wax,15 parts of EVA-2,4 parts of DPHP,4 parts of oleic acid amide and 2 parts of stearic acid.This optimized formulation is applied to industrial production at one Chinese company,and qualified deep well-shaped cemented carbide products are achieved,which contain 90wt%WC and 10wt%Co.展开更多
Many studies have observed that leaf wax δDn-alkane values differed significantly between woods and grasses in modern plants, with grasses D-depleted by 40 %0-70 ‰. The reasons for the differences in leaf wax δDn-a...Many studies have observed that leaf wax δDn-alkane values differed significantly between woods and grasses in modern plants, with grasses D-depleted by 40 %0-70 ‰. The reasons for the differences in leaf wax δDn-alkane values between woods and grasses, however, remain unclear. In this study, we measured the δD values of soil water （δDsw）, leaf water （δDlw）, and leaf wax n-alkane （δDn-alkane） for woods and grasses. We found no significant differences in the δD values of soil water （P = 0.82） and leaf water （P= 0.74） between the two life forms of plants. Therefore, the differences in leaf wax δDn-alkane values between woods and grasses may correlate with inherent properties of different plant life forms, such as leaf structures, biosynthetic processes, and leaf morphologies. Moreover, it is also possible that soil water with different 6Dsw at different depths utilized by woods and grasses may be responsible for some of the differences in leaf wax δDn-alkane values between the two life forms of plants, if woods mainly use soil water from the 〉100 cm depth, whereas grasses mainly use soil water from the 〈100 cm depth. The results of this work allow us to better understand the leaf wax δDn-alkane values of different plant life forms in a region.展开更多
基金supported by National Natural Science Foundation of China(31420103911)
文摘Pakistan has a rich fauna of planthoppers but members of the family Meenoplidae have not been reported from this region. In this study Nisa atrovenosa of the family Meenoplidae is recorded for the first time from Khyber Pakhtunkhwa Province of Pakistan. A morphological description and illustrations are provided.
基金supported by the National Natural Science Foundation of China(32170475,31750002)。
文摘The forewing base structure of a representative species from 13 families of Fulgoroidea were examined.Results show that these families differ mainly from the characters of various sclerites,the presence or absence of humeral plate,proximal and distal median plate,and the method of connection between each sclerite.The phylogenetic relationships based on forewing structure support the monophyly of Fulgoroidea.Ricaniidae and Flatidae were recovered as sister taxa.Kinnaridae is the most primitive family in Fulgoroidea.
基金financially supported by the National Natural Science Foundation of China (No. 20973022 and 11472048)the State Key Laboratory of Catalytic Materials and Reaction Engineering (RIPP, SINOPEC)
文摘Microencapsulation of phase change materials(Micro PCMs) has been paid special attention because of their extensive applications in saving and releasing energy. Micro PCMs containing paraffin with a melting point of 55 ℃ in polystyrene-divinylbenzene(P(St-DVB)) were prepared by suspension-like polymerization. The characterization of microcapsules by FTIR, DSC and TG proved that paraffin had been successfully encapsulated and the proportion of encapsulated paraffin was 49.8%—58.5%. The effects of polyvinylpyrrolidone(PVP) with different molecular weights serving as the suspension stabilizer were investigated in detail. The results illustrated that the type of PVP had a significant influence on the particle size of Micro PCMs. The average diameter of Micro PCMs decreased with an increasing molecular weight of PVP. Moreover, the crosslinker-postaddition method was adopted in this study to improve the morphology of P(St-DVB) Micro PCMs. SEM images showed that when the DVB was added at the 2nd hour of polymerization the morphology of obtained P(St-DVB) Micro PCMs exhibited good sphericity since it could avoid the influence of cross-linker agent during the nucleation period.
文摘The production of deep well-shaped WC-Co cemented carbide blocks via industrial powder pressing remains a challenging technical problem,primarily due to the unsuitability of the forming agent.The forming agent paraffin wax was modified through four types of modifiers,including organic high-molecular-mass resins,plasticizers,surfactants and lubricants.The qualitative screening of resin types was explored and an orthogonal experiment involving the combination of these four paraffin wax modifiers was conducted to obtain an optimized quantitative ratio of modifiers.The results reveal that the insertion of the small molecule chain of resin into the interstitial spaces of paraffin wax crystals is likely a crucial factor for improving the compatibility between the resin and paraffin wax.Through orthogonal experiments,the optimized formulation for the forming agent is determined:100 parts of 58#paraffin wax,15 parts of EVA-2,4 parts of DPHP,4 parts of oleic acid amide and 2 parts of stearic acid.This optimized formulation is applied to industrial production at one Chinese company,and qualified deep well-shaped cemented carbide products are achieved,which contain 90wt%WC and 10wt%Co.
文摘Many studies have observed that leaf wax δDn-alkane values differed significantly between woods and grasses in modern plants, with grasses D-depleted by 40 %0-70 ‰. The reasons for the differences in leaf wax δDn-alkane values between woods and grasses, however, remain unclear. In this study, we measured the δD values of soil water （δDsw）, leaf water （δDlw）, and leaf wax n-alkane （δDn-alkane） for woods and grasses. We found no significant differences in the δD values of soil water （P = 0.82） and leaf water （P= 0.74） between the two life forms of plants. Therefore, the differences in leaf wax δDn-alkane values between woods and grasses may correlate with inherent properties of different plant life forms, such as leaf structures, biosynthetic processes, and leaf morphologies. Moreover, it is also possible that soil water with different 6Dsw at different depths utilized by woods and grasses may be responsible for some of the differences in leaf wax δDn-alkane values between the two life forms of plants, if woods mainly use soil water from the 〉100 cm depth, whereas grasses mainly use soil water from the 〈100 cm depth. The results of this work allow us to better understand the leaf wax δDn-alkane values of different plant life forms in a region.
