The dislocation evolution wassimulated by using positiveand negative parallelstraightedgedislocationsrandomly distributing on the primary slip planes astheinitialconditions. Thevein and wallstructuresof dynamicequilib...The dislocation evolution wassimulated by using positiveand negative parallelstraightedgedislocationsrandomly distributing on the primary slip planes astheinitialconditions. Thevein and wallstructuresof dynamicequilibrium have been obtained. Abig dipolestructure wasfound inthesimulation.展开更多
Phosphorene,which is designated as a monolayer or a few-layer of orthorhombic black phosphorus(BP),has emerged as a new promising member of the two-dimensional material family.A plethora of exciting applications of ph...Phosphorene,which is designated as a monolayer or a few-layer of orthorhombic black phosphorus(BP),has emerged as a new promising member of the two-dimensional material family.A plethora of exciting applications of phosphorene have been reported based on its intriguing properties.Unfortunately,due to the lack of reliable methods for the direct synthesis of highly crystalline phosphorene,bulk BP single crys tals have been the sole precursor to achieve high-quality phosphorene.A chemical vapor transport(CVT)reaction method has been deemed the most successful method for the growth of bulk BP single crystals.Herein,recent progress in the controlled growth of bulk BP single crystals by the CVT reaction is briefly reviewed.The emphasis is focused on the reaction system,nucleation and growth mechanism of the CVT synthesis of bulk BP crystals as well as the recent development in the growth of doped and substituted BP single crystals by the CVT reaction method.The challenges and perspectives ahead of the CVT growth of BP crystals are also pointed out.展开更多
YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tic...YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tical (N LO) properties and a great promise as a laser host material.Unfortunately,liking most of nonlinear optical crystals,the laser induced damages were also created in the new crystal family when irradiated by ultraviolet laser.In this report we present our preliminary results of the investigation on the radiation induced damage in YCOB crystals.展开更多
The first part of this report describes the data reduction of non-merohedrally twinned crystals measured on Bruker and Agilent area-detector diffractometers. The image frames of methyl-2-aminopyrazine-3-carboxylate we...The first part of this report describes the data reduction of non-merohedrally twinned crystals measured on Bruker and Agilent area-detector diffractometers. The image frames of methyl-2-aminopyrazine-3-carboxylate were processed with APEX2 to furnish a set of overlapping diffraction indices that were used for solution and refinement. CrysAlisPRO was used for processing the frames of bis（diethyldicarbamato）nickel, which exists in monoclinic and tetragonal polymorphs, and in untwinned and twinned forms. In the second part, the crystal structure of [（3-formyl-4- hydroxyphenyl）methyl]triphenylphosphanium chloride was refined through the ‘HKLF 5＇（based on a combined set of diffraction indices） and PLATON（based on one set of diffraction indices） routes to give identical outcomes because the amount of overlap of the twin domains is small. For the third part, in a proof-of-concept investigation, the diffraction pattern of untwinned and twinned 4-{（E）-（4-aminophenyl）diazenyl]phenylamine was recorded simultaneously in one run; the three domains could be indexed and the crystal structure satisfactorily refined. The refinement was identical to those derived from independent measurements; the crystal structure features two independent centrosymmetric molecules, one of which is ordered and the other whole-molecule-disordered. This two-in-one run opens up the possibility that two or more crystals having different atomic compositions can be measured simultaneously if their reciprocal lattices do not overlap significantly.展开更多
A new birefringent crystal [C(NH_(2))_(3)]_(2)S_(2)O_(8) was obtained by combining the π-conjugated [C(NH_(2))_(3)] cation and the [S_(2)O_(8)] groups with localized O-O π-bonds.Optical measurements show that the UV...A new birefringent crystal [C(NH_(2))_(3)]_(2)S_(2)O_(8) was obtained by combining the π-conjugated [C(NH_(2))_(3)] cation and the [S_(2)O_(8)] groups with localized O-O π-bonds.Optical measurements show that the UV cutoff wavelength of [C(NH_(2))_(3)]_(2)S_(2)O_(8) is 222 nm,and its birefringence is 0.102 at 546 nm.The calculated results show that its large birefringence is attributed to the synergistic effect of the [C(NH_(2))_(3)] and [S_(2)O_(8)] units,which is the first case among known birefringent crystals.These results provide new insights into the design of superior birefringent materials.展开更多
ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be invo...ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be involved in regulating seedling photomorphogenesis;however,the underlying mechanism remains elusive.Here,we show that the role of ABI4 in regulating photomorphogenesis is generally regulated by sucrose,but ABI4 promotes hypocotyl elongation of Arabidopsis seedlings under blue(B) light under all tested sucrose concentrations.We further show that ABI4 physically interacts with PHYTOCHROME INTERACTING FACTOR 4(PIF4),a well-characterized growth-promoting transcription factor,and post-translationally promotes PIF4 protein accumulation under B light.Further analyses indicate that ABI4 directly interacts with the B light photoreceptors cryptochromes(CRYs) and inhibits the interactions between CRYs and PIF4,thus relieving CRY-mediated repression of PIF4 protein accumulation.In addition,while ABI4 could directly activate its own expression,CRYs enhance,whereas PIF4 inhibits,ABI4-mediated activation of the ABI4 promoter.Together,our study demonstrates that the ABI4–PIF4 module plays an important role in mediating CRY-induced B light signaling in Arabidopsis.展开更多
文摘The dislocation evolution wassimulated by using positiveand negative parallelstraightedgedislocationsrandomly distributing on the primary slip planes astheinitialconditions. Thevein and wallstructuresof dynamicequilibrium have been obtained. Abig dipolestructure wasfound inthesimulation.
基金supported by the National Natural Science Foundation of China(No.21671115)the Science Challenge Project(TZ2018004)+1 种基金the Innovation Center of Radiation Application(KFZC2018040204)the Tsinghua University Initiative Scientific Research Program(2018Z05JZY022).
文摘Phosphorene,which is designated as a monolayer or a few-layer of orthorhombic black phosphorus(BP),has emerged as a new promising member of the two-dimensional material family.A plethora of exciting applications of phosphorene have been reported based on its intriguing properties.Unfortunately,due to the lack of reliable methods for the direct synthesis of highly crystalline phosphorene,bulk BP single crys tals have been the sole precursor to achieve high-quality phosphorene.A chemical vapor transport(CVT)reaction method has been deemed the most successful method for the growth of bulk BP single crystals.Herein,recent progress in the controlled growth of bulk BP single crystals by the CVT reaction is briefly reviewed.The emphasis is focused on the reaction system,nucleation and growth mechanism of the CVT synthesis of bulk BP crystals as well as the recent development in the growth of doped and substituted BP single crystals by the CVT reaction method.The challenges and perspectives ahead of the CVT growth of BP crystals are also pointed out.
文摘YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tical (N LO) properties and a great promise as a laser host material.Unfortunately,liking most of nonlinear optical crystals,the laser induced damages were also created in the new crystal family when irradiated by ultraviolet laser.In this report we present our preliminary results of the investigation on the radiation induced damage in YCOB crystals.
文摘The first part of this report describes the data reduction of non-merohedrally twinned crystals measured on Bruker and Agilent area-detector diffractometers. The image frames of methyl-2-aminopyrazine-3-carboxylate were processed with APEX2 to furnish a set of overlapping diffraction indices that were used for solution and refinement. CrysAlisPRO was used for processing the frames of bis（diethyldicarbamato）nickel, which exists in monoclinic and tetragonal polymorphs, and in untwinned and twinned forms. In the second part, the crystal structure of [（3-formyl-4- hydroxyphenyl）methyl]triphenylphosphanium chloride was refined through the ‘HKLF 5＇（based on a combined set of diffraction indices） and PLATON（based on one set of diffraction indices） routes to give identical outcomes because the amount of overlap of the twin domains is small. For the third part, in a proof-of-concept investigation, the diffraction pattern of untwinned and twinned 4-{（E）-（4-aminophenyl）diazenyl]phenylamine was recorded simultaneously in one run; the three domains could be indexed and the crystal structure satisfactorily refined. The refinement was identical to those derived from independent measurements; the crystal structure features two independent centrosymmetric molecules, one of which is ordered and the other whole-molecule-disordered. This two-in-one run opens up the possibility that two or more crystals having different atomic compositions can be measured simultaneously if their reciprocal lattices do not overlap significantly.
基金supported by the National Natural Science Foundation of China (Grant No.21975062,52072109,22101069)the Hebei Province Outstanding Youth Fund (Grant No.E2020201003)+2 种基金the Science and Technology Project of Hebei Education Department (Grant No.BJ2020020)the Natural Science Foundation of Hebei Province (Grant No.B2020201029)the Advanced Talents Incubation Program of the Hebei University (Grant No.521000981271).
文摘A new birefringent crystal [C(NH_(2))_(3)]_(2)S_(2)O_(8) was obtained by combining the π-conjugated [C(NH_(2))_(3)] cation and the [S_(2)O_(8)] groups with localized O-O π-bonds.Optical measurements show that the UV cutoff wavelength of [C(NH_(2))_(3)]_(2)S_(2)O_(8) is 222 nm,and its birefringence is 0.102 at 546 nm.The calculated results show that its large birefringence is attributed to the synergistic effect of the [C(NH_(2))_(3)] and [S_(2)O_(8)] units,which is the first case among known birefringent crystals.These results provide new insights into the design of superior birefringent materials.
基金supported by grants from the National Natural Science Foundation of China(32225006)the Beijing Natural Science Foundation(5232011)+1 种基金the Chinese Universities Scientific Fund(2024TC166)by the Postdoctoral Fel owship Program of CPSF under Grant Number GZC20230717。
文摘ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be involved in regulating seedling photomorphogenesis;however,the underlying mechanism remains elusive.Here,we show that the role of ABI4 in regulating photomorphogenesis is generally regulated by sucrose,but ABI4 promotes hypocotyl elongation of Arabidopsis seedlings under blue(B) light under all tested sucrose concentrations.We further show that ABI4 physically interacts with PHYTOCHROME INTERACTING FACTOR 4(PIF4),a well-characterized growth-promoting transcription factor,and post-translationally promotes PIF4 protein accumulation under B light.Further analyses indicate that ABI4 directly interacts with the B light photoreceptors cryptochromes(CRYs) and inhibits the interactions between CRYs and PIF4,thus relieving CRY-mediated repression of PIF4 protein accumulation.In addition,while ABI4 could directly activate its own expression,CRYs enhance,whereas PIF4 inhibits,ABI4-mediated activation of the ABI4 promoter.Together,our study demonstrates that the ABI4–PIF4 module plays an important role in mediating CRY-induced B light signaling in Arabidopsis.
