The relationship between the silicon saturation coefficient of hydrogarnets and Bayer reaction parameters was studied. The peak position, crystal plane spacing, and cell edge length of typical hydrogarnet patterns wer...The relationship between the silicon saturation coefficient of hydrogarnets and Bayer reaction parameters was studied. The peak position, crystal plane spacing, and cell edge length of typical hydrogarnet patterns were calculated to find the key factors influencing the relationship. The results showed that the crystal face(420) is the optimal garnet growth direction during hydration and crystal growth along the faces(521) and(611) were not affected significantly by the varying experimental conditions. The reaction temperature significantly influenced the silicon saturation coefficient of hydrogarnets. The silicon saturation coefficient of hydrogarnets increased from 0.2 to about 1.0 in the temperature range of 30–270 °C and a rapid expansion process was observed in the temperature range of 120–150 °C. Moreover, the reaction time, alumina concentration, and C/S were shown to be less important factors. Averaging the results obtained by the 3 methods was shown suitable for calculating the SiO2 saturation coefficient of hydrogarnets. The calculated results of the Al2O3 and SiO2 contents matched the actual ones. However, the actual SiO2 content was about10 % less than the calculated one for SiO2 saturation coefficients higher than 1.展开更多
The magnetic properties and magnetocaloric effect in Fe4MnSi3B~ compounds with x=0, 0.05, 0.10, 0.15, 0.20, 0.25 have been investigated. X-ray diffraction study shows that all these compounds investigated crystallize ...The magnetic properties and magnetocaloric effect in Fe4MnSi3B~ compounds with x=0, 0.05, 0.10, 0.15, 0.20, 0.25 have been investigated. X-ray diffraction study shows that all these compounds investigated crystallize in the MnsSi3-type structure with space group P63/mcm. Boron insertion in the host ternary silicide Fe4MnSi3 does not change the crystal symmetry, only leads to an increase of the lattice parameters, indicating the B atoms entered the interstitial sites. With increasing B content, the Curie temperature shifts to higher temperatures. The maximal magnetic-entropy changes of the Fe4MnSi3Bx compounds with x=0, 0.10 and 0.20 are about 1.8 J/（kg.K）, 1.8 J/（kg-K） and 1.6 J/（kg.K）, respectively, for a field change from 0 to 1.5 T.展开更多
This research demonstrated the feasibility of converting source-separated human urine into a solid fertilizer by means of continuous absorption and solar thermal evaporation using dried water hyacinth as adsorbent. In...This research demonstrated the feasibility of converting source-separated human urine into a solid fertilizer by means of continuous absorption and solar thermal evaporation using dried water hyacinth as adsorbent. In a preliminary experiment, the dried petioles of water hyacinth (DWH) absorbed urine in a mean rate of 18.78 ml·g-1 within 7 d, retrieving about 3.46% urine dissolved solids (UDS). In an advanced experiment, the DWH’s capacity of urine absorption declined from an initial 2.73 L·kg-1·d-1 to 0.68 L·kg-1·d-1, with a requirement of material change in about 25 effective days and an average ratio of 25 (L) to 1 (kg). Phosphorus (P2O5) concentration in the adsorbent increased from 0.46% (material baseline) to 3.14% (end product), suggesting a satisfactory recovery of the element. In field application, the urine was discharged, not in wet weather, onto the DWH via a tube connected to a waterless urinal. There are several ways to use the UDS-DWH as P(K)-rich fertilizer, e.g., making soluble fertilizer for foliage spraying to encourage prolific flowering and fruiting. Apparently, utilization of water hyacinth waste to recover dissolved plant nutrient elements from source-separated urine will benefit the environment in a wide range of perspectives. The herein innovative use of water hyacinth is also expected to be useful in the recycling of certain dissolved hazardous materials.展开更多
Circular RNAs(circRNAs)are involved in various biological processes and disease pathogenesis.However,only a small number of functional circRNAs have been identified among hundreds of thousands of circRNA species,partl...Circular RNAs(circRNAs)are involved in various biological processes and disease pathogenesis.However,only a small number of functional circRNAs have been identified among hundreds of thousands of circRNA species,partly because most current methods are based on circular junction counts and overlook the fact that a circRNA is formed from the host gene by backsplicing(BS).To distinguish the expression difference originating from BS or the host gene,we present differentially expressed back-splicing(DEBKS),a software program to streamline the discovery of differential BS events between two rRNA-depleted RNA sequencing(RNA-seq)sample groups.By applying to real and simulated data and employing RT-qPCR for validation,we demonstrate that DEBKS is efficient and accurate in detecting circRNAs with differential BS events between paired and unpaired sample groups.DEBKS is available at https://github.com/yangence/DEBKS as open-source software.展开更多
The designed synthesis of chiral covalent organic frameworks(COFs) featuring intriguing properties is fairly scant and remains a daunting synthetic challenge.Here we develop a de novo synthesis of an enantiomeric pair...The designed synthesis of chiral covalent organic frameworks(COFs) featuring intriguing properties is fairly scant and remains a daunting synthetic challenge.Here we develop a de novo synthesis of an enantiomeric pair of 2 D hydroxyl-functionalized hydrazone-linked chiral COFs,(S)-and(R)-HthBta-OH COFs,using enantiopure 2,5-bis(2-hydroxypropoxy)terephthalohydrazide(Hth) as monomers.The fo rmation process of hydroxyl-functionalized chiral COFs was monitored using rigorous time-dependent PXRD,vibrational circular dichroism(VCD),and electronic circular dichroism(ECD) studies.Remarkably,VCD spectra indicated a unique chiral signal inversion from the positive Cotton effect of(S)-Hth monomer to the negative Cotton effect of(S)-HthBta-OH COF,which has never been reported in chiral COFs.Moreover,two unprecedented carboxyl-functionalized chiral COFs,(S)-and(R)-HthBta-COOH,were constructed by a post-synthetic modification of the corresponding hydroxyl chiral COFs with succinic anhydride.Notably,carboxyl-functionalized COFs retained homochirality and crystallinity without linker racemization and structural collapse after the chemical modification due to the chemically robust nature of pristine hydrazone-linked chiral COFs.展开更多
Aiming at the typical engineering problem of black cotton soil(BCS)subgrade under the alternation of dry and wet climate in the region of Nairobi,Kenya,this paper takes the pavement structure as the research object,an...Aiming at the typical engineering problem of black cotton soil(BCS)subgrade under the alternation of dry and wet climate in the region of Nairobi,Kenya,this paper takes the pavement structure as the research object,and the numerical calculation model of BCS subgrade is established based on the consolidation coupling theory of unsaturated soil.Taking the modulus and thickness of the subbase as variables,the deformation characteristics and additional stresses of different pavement structures are analysed.Then the adaptability of different pavement structures to replacement treatment subgrade of BCS is evaluated by gray incidence decision analysis method.The results show that whatever the pavement structure is,neither subgrade modulus nor thickness is sensitive to the pavement surface deformation,and the deformation differences between each pavement structure are more obvious in wet season;the additional stress at control layer bottom and pavement surface decreases with the increase of subbase modulus,whereas the stress may increase at subbase bottom;the additional stress at subbase bottom,control layer bottom and pavement surface all decreases with the increase of subbase thickness for pavement Structure I and II.For pavement Structure III,the change of subbase thickness is not sensitive to the additional stress at the control layer bottom and pavement surface,whereas the stress at subbase bottom increases with the increase of subbase thickness.It is concluded that the most adaptable structure is pavement Structure I,which can minimize the comprehensive level of pavement settlement and additional stress.展开更多
基金Supported by the National Natural Science Foundation of China(51874078,U1710257,U1202274)Fundamental Research Funds for the Central Universities of China(N140203005,N140204015)+1 种基金the Science and Technology Research Projects of Liaoning Education Department(L2014096)the State Key Laboratory of Pressure Hydrometallurgical Technology of Associated Nonferrous Metal Resources(YY2016006)
文摘The relationship between the silicon saturation coefficient of hydrogarnets and Bayer reaction parameters was studied. The peak position, crystal plane spacing, and cell edge length of typical hydrogarnet patterns were calculated to find the key factors influencing the relationship. The results showed that the crystal face(420) is the optimal garnet growth direction during hydration and crystal growth along the faces(521) and(611) were not affected significantly by the varying experimental conditions. The reaction temperature significantly influenced the silicon saturation coefficient of hydrogarnets. The silicon saturation coefficient of hydrogarnets increased from 0.2 to about 1.0 in the temperature range of 30–270 °C and a rapid expansion process was observed in the temperature range of 120–150 °C. Moreover, the reaction time, alumina concentration, and C/S were shown to be less important factors. Averaging the results obtained by the 3 methods was shown suitable for calculating the SiO2 saturation coefficient of hydrogarnets. The calculated results of the Al2O3 and SiO2 contents matched the actual ones. However, the actual SiO2 content was about10 % less than the calculated one for SiO2 saturation coefficients higher than 1.
基金supported by the National Natural Science Foundation of China (GrantNo.50661004)the Graduate Student Foundation of Inner Mongolia Normal University (No.YJSZD07002)partially supported by the scientific exchange program between the Netherlands and China
文摘The magnetic properties and magnetocaloric effect in Fe4MnSi3B~ compounds with x=0, 0.05, 0.10, 0.15, 0.20, 0.25 have been investigated. X-ray diffraction study shows that all these compounds investigated crystallize in the MnsSi3-type structure with space group P63/mcm. Boron insertion in the host ternary silicide Fe4MnSi3 does not change the crystal symmetry, only leads to an increase of the lattice parameters, indicating the B atoms entered the interstitial sites. With increasing B content, the Curie temperature shifts to higher temperatures. The maximal magnetic-entropy changes of the Fe4MnSi3Bx compounds with x=0, 0.10 and 0.20 are about 1.8 J/（kg.K）, 1.8 J/（kg-K） and 1.6 J/（kg.K）, respectively, for a field change from 0 to 1.5 T.
文摘This research demonstrated the feasibility of converting source-separated human urine into a solid fertilizer by means of continuous absorption and solar thermal evaporation using dried water hyacinth as adsorbent. In a preliminary experiment, the dried petioles of water hyacinth (DWH) absorbed urine in a mean rate of 18.78 ml·g-1 within 7 d, retrieving about 3.46% urine dissolved solids (UDS). In an advanced experiment, the DWH’s capacity of urine absorption declined from an initial 2.73 L·kg-1·d-1 to 0.68 L·kg-1·d-1, with a requirement of material change in about 25 effective days and an average ratio of 25 (L) to 1 (kg). Phosphorus (P2O5) concentration in the adsorbent increased from 0.46% (material baseline) to 3.14% (end product), suggesting a satisfactory recovery of the element. In field application, the urine was discharged, not in wet weather, onto the DWH via a tube connected to a waterless urinal. There are several ways to use the UDS-DWH as P(K)-rich fertilizer, e.g., making soluble fertilizer for foliage spraying to encourage prolific flowering and fruiting. Apparently, utilization of water hyacinth waste to recover dissolved plant nutrient elements from source-separated urine will benefit the environment in a wide range of perspectives. The herein innovative use of water hyacinth is also expected to be useful in the recycling of certain dissolved hazardous materials.
基金supported by the Beijing Municipal Science and Technology Commission,China(Grant No.Z181100001518005)the Chinese Institute for Brain Research,Beijing,China to EY,the National Natural Science Foundation of China(Grant No.81873769)to CCthe Innovation Fund for Outstanding Doctoral Candidates of Peking University Health Science Center,China(Grant No.BMU2020BSS001)to ZL.
文摘Circular RNAs(circRNAs)are involved in various biological processes and disease pathogenesis.However,only a small number of functional circRNAs have been identified among hundreds of thousands of circRNA species,partly because most current methods are based on circular junction counts and overlook the fact that a circRNA is formed from the host gene by backsplicing(BS).To distinguish the expression difference originating from BS or the host gene,we present differentially expressed back-splicing(DEBKS),a software program to streamline the discovery of differential BS events between two rRNA-depleted RNA sequencing(RNA-seq)sample groups.By applying to real and simulated data and employing RT-qPCR for validation,we demonstrate that DEBKS is efficient and accurate in detecting circRNAs with differential BS events between paired and unpaired sample groups.DEBKS is available at https://github.com/yangence/DEBKS as open-source software.
基金We are grateful for the financial support from the National Natural Science Foundation of China(Nos.21603076 and 21571070)the Natural Science Foundation of Guangdong Province(No.2018A030313193).
文摘The designed synthesis of chiral covalent organic frameworks(COFs) featuring intriguing properties is fairly scant and remains a daunting synthetic challenge.Here we develop a de novo synthesis of an enantiomeric pair of 2 D hydroxyl-functionalized hydrazone-linked chiral COFs,(S)-and(R)-HthBta-OH COFs,using enantiopure 2,5-bis(2-hydroxypropoxy)terephthalohydrazide(Hth) as monomers.The fo rmation process of hydroxyl-functionalized chiral COFs was monitored using rigorous time-dependent PXRD,vibrational circular dichroism(VCD),and electronic circular dichroism(ECD) studies.Remarkably,VCD spectra indicated a unique chiral signal inversion from the positive Cotton effect of(S)-Hth monomer to the negative Cotton effect of(S)-HthBta-OH COF,which has never been reported in chiral COFs.Moreover,two unprecedented carboxyl-functionalized chiral COFs,(S)-and(R)-HthBta-COOH,were constructed by a post-synthetic modification of the corresponding hydroxyl chiral COFs with succinic anhydride.Notably,carboxyl-functionalized COFs retained homochirality and crystallinity without linker racemization and structural collapse after the chemical modification due to the chemically robust nature of pristine hydrazone-linked chiral COFs.
基金funded by the National Natural Science Foundation of China,grant number 51878164 and 51922030Southeast University“Zhongying Young Scholars”Project,and Department of Transportation of Shandong Province,grant number 2018B51.
文摘Aiming at the typical engineering problem of black cotton soil(BCS)subgrade under the alternation of dry and wet climate in the region of Nairobi,Kenya,this paper takes the pavement structure as the research object,and the numerical calculation model of BCS subgrade is established based on the consolidation coupling theory of unsaturated soil.Taking the modulus and thickness of the subbase as variables,the deformation characteristics and additional stresses of different pavement structures are analysed.Then the adaptability of different pavement structures to replacement treatment subgrade of BCS is evaluated by gray incidence decision analysis method.The results show that whatever the pavement structure is,neither subgrade modulus nor thickness is sensitive to the pavement surface deformation,and the deformation differences between each pavement structure are more obvious in wet season;the additional stress at control layer bottom and pavement surface decreases with the increase of subbase modulus,whereas the stress may increase at subbase bottom;the additional stress at subbase bottom,control layer bottom and pavement surface all decreases with the increase of subbase thickness for pavement Structure I and II.For pavement Structure III,the change of subbase thickness is not sensitive to the additional stress at the control layer bottom and pavement surface,whereas the stress at subbase bottom increases with the increase of subbase thickness.It is concluded that the most adaptable structure is pavement Structure I,which can minimize the comprehensive level of pavement settlement and additional stress.
