Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembl...Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems.Herein,the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity,namely[Co_(19)(HL1)_(8)(L1)_(12)(L′)_(2)(Ac)_(4)]·10CH_(3)CH_(2)OH·6H_(2)O(1,H_(2)L1=1H-benzo[d]imidazole-2-yl)methanol,HL'=1H-benzo[d]imidazole),was obtained with in-situ ligand transformation from H_(2)L1 to L′.It features a hierarchical trilayer and void-cage inside structure,consisting of central disc-shaped[Co_(7)L_(10)]core with two[Co_(6)]rings on both sides.ESI-MS of crystal 1 yields a series of more than sixteen fragments,all featuring an integrated[Co_(19)]core,suggesting stability of the polynuclear cluster in solution.During increased in-source energy from 0 to 100 eV,all MS peaks shifted to a lower m/z range,but the[Co_(19)]core remained intact,excepting for the stepwise elimination of up to three Ac^(−)anions or three L1 linkers.PXRD tracking of the reaction sediments showed the formation of a key precursor of[Co_(4)L_(4)]cubane at 3 h,and its content decreased at 6 h and vanished at 12 h,followed by the appearance of crystals 1 by the generation of a clear solution at 18 h,suggesting an initial cluster assembly-disassembly process.ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of[Co_(7)L_(10)]disk and its expansion of[Co_(13)L_(12)(L′)_(2)].A probable tandem assembly-disassembly-reassembly mechanism is put forward as[CoL_(2)]→[Co_(4)L_(4)]→[Co_(7)L_(10)]→[Co_(13)L_(12)(L′)_(2)]→[Co_(19)L_(2)0(L′)_(2)].Their evolution also indicated the ingenious synergy of coexisting organic,inorganic and in-situ generated ligands,along with diverse coordination geometries of metal ions,plays a directional role in forming odd-numbered and high-nuclearity coordination clusters.Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.展开更多
Herein we demonstrate the construction of three types of parallel gold nanorod(AuNR) clusters using a DNA origami rod(DOR) as the template. Based on the precise control over the position of capture strands on DOR, num...Herein we demonstrate the construction of three types of parallel gold nanorod(AuNR) clusters using a DNA origami rod(DOR) as the template. Based on the precise control over the position of capture strands on DOR, number and orientation of the AuNR clusters can be well engineered, as evidenced by biological transmission electron microscope(TEM). Importantly, the AuNR clusters exhibit chiroptical responses which are strongly affected by the number of AuNR on rod-like DNA origami.展开更多
Northern wild rice(NWR;Zizania palustris L.),an annual aquatic plant in the Poaceae family,has high economic importance due to its nutrient-rich grains.However,the existing NWR genome assembly for this species has sev...Northern wild rice(NWR;Zizania palustris L.),an annual aquatic plant in the Poaceae family,has high economic importance due to its nutrient-rich grains.However,the existing NWR genome assembly for this species has severe fragmentation and incomplete gene representation.A near-complete genome was assembled in this study to provide a high-quality genomic reference for NWR-associated research.The assembled genome exhibited a total contig length of 1.41 Gb and a contig N50 of 109.22 Mb.Overall,a 73.60%repetitive sequence content was identified and 47,804 genes predicted.Phylogenetic analysis indicated that Z.palustris was most closely related to Zizania latifolia,with an estimated divergence time of 4.57–8.15 Mya.Meanwhile,Z.palustris underwent a recent,species-specific long terminal repeat(LTR)expansion,associated with its larger genome size.We identified two genomic blocks in the Z.palustris and Z.latifolia genomes that exhibit strong synteny with the rice phytocassane biosynthetic gene cluster.The centromeric satellite repeats in Z.palustris identified in this study primarily comprised a 145 bp repetitive unit.The findings also revealed centromere homogenisation and rearrangement accompanied by LTR invasion in NWR.Among the genes missing in the previous NWR genome,we observed LTR insertion events that resulted in expanded gene lengths in our updated NWR genome.The present updated NWR genome provides a valuable resource for crop genetic improvement,functional gene discovery,and research on critical biological processes.展开更多
Self-assembly cluster compound [WS4Cu3(PPh2Py)3Br]2·CH3OH (1) was synthesized by the reaction of (NH4)2WS4, CuBr and diphenyl-2-pyridyl-phosphine (PPh2Py) in CH3OH solution under a purified nitrogen atmosphere us...Self-assembly cluster compound [WS4Cu3(PPh2Py)3Br]2·CH3OH (1) was synthesized by the reaction of (NH4)2WS4, CuBr and diphenyl-2-pyridyl-phosphine (PPh2Py) in CH3OH solution under a purified nitrogen atmosphere using standard Schlenk techniques. Its structure was determined by X-ray crystallography. It crystallizes in the triclinic crystal system P-1 space group with a=1.178 6 (1) nm, b=1.302 6 (1) nm, c=1.991 7 (2) nm, α=74.671 (7)-, β=86.188 (8)-, γ=64.141 (6)-, V=2.649 5 (5) nm3, Z=1. The W center is slightly distorted from tetrahedral coordination geometry, and the structure is built up from three [Cu(PPh2Py)]+ units bridged by WS 24- multifunctional ligand to form a tetranuclear symmetrical cube-like molecule. Measurement of the nonlinear optical (NLO) properties using the Z-scan technique with an 8 ns pulsed laser at 532 nm shows that the compound possesses NLO absorption and effective self-focusing effect at α2=6.7×10-11 m/W and n2=5.64×10-18 m2/W in a 1.5×10-4 mol/L DMF solution.展开更多
With the rapid development of space technology and the increasing demand for space missions,the traditional spacecraft manufacturing,deployment and launch methods have been unable to meet existing needs.In-space assem...With the rapid development of space technology and the increasing demand for space missions,the traditional spacecraft manufacturing,deployment and launch methods have been unable to meet existing needs.In-space assembly(ISA)technologies can effectively adapt to the assembly of large space structures,improve spacecraft performance,and reduce operating costs.In this paper,the development and technologies for ISA are reviewed.ISA is classified from multiple angles,and the research status of ISA is shown clearly through the visual mapping knowledge domain.Then the development status of autonomous robot assembly in the United States,Europe,Japan,Canada and China is reviewed.Furthermore,the key technologies of ISA are analyzed from three aspects:assembly structure design,robot technologies and integrated management technologies.ISA technologies are still facing major challenges and need to be further explored to promote future development.Finally,future development trends and potential applications of ISA are given,which show that ISA will play a vital role in human space exploration in the future.展开更多
The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur...The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur-nitrogen cluster complexes has been a very active and attracting field for many years as a result of the novelty and versatility of the crystal structures and reactivities of such clusters, as well as their potential applications as the models for the active sites in non-heme proteins. At the same time, there is currently considerable interest in the formation of metal complexes with heterocyclic ligands because of the diverse characteristics of ligands and their consequential wide range of applications.展开更多
A new copper-thiolate cluster assembled framework[Cu2(μ4-SCH3)Cl]n(1),has been solvothermally synthesized through in situ reaction viz.,in situ ligand generation and metal reduction.Compound 1 represents the first 3 ...A new copper-thiolate cluster assembled framework[Cu2(μ4-SCH3)Cl]n(1),has been solvothermally synthesized through in situ reaction viz.,in situ ligand generation and metal reduction.Compound 1 represents the first 3 D framework based on Atlas-sphere functionalized by singleμ2-Cl groups.DOS calculation reveals the interaction of electronic structures.It is found that the HOMO is mainly distributed on Cl,Cu and S bonding orbitals,while the LUMO is dominated by Cu-Cl antibonding orbitals.展开更多
This is a further development work on grouping of printed circuit boards(PCBs)for Surface Mount Assembly in the electronic industry.The arrangement of PCBs among several surface mount machine lines is a typical kind o...This is a further development work on grouping of printed circuit boards(PCBs)for Surface Mount Assembly in the electronic industry.The arrangement of PCBs among several surface mount machine lines is a typical kind of group technology(GT)problem.From literatures,there are various clustering techniques developed to solve the clustering problems.In this paper,fuzzy c-means clustering(FCM)is used to solve the PCBs grouping problem.Applying them in a real problem compares the results of the two methods.The result shows that there should be a systematic method to arrange the scheduling of PCB assemblies in electronic industry to improve the operations planning process.展开更多
Cobalt doped ZnO film assembled by the nanoparticles was prepared by low energy cluster beam deposition.The microstructure,phase structure and optical properties were investigated for the nanostructured films.The resu...Cobalt doped ZnO film assembled by the nanoparticles was prepared by low energy cluster beam deposition.The microstructure,phase structure and optical properties were investigated for the nanostructured films.The results show that the nanostructured film was assembled by monodisperse spherical nanoparticles with average diameter of about 29.3 nm which are distributed uniformly and compactly.The results of X-ray diffraction(XRD)show that cobalt doped ZnO nanostructured film is indexed to a wurtzite structure of ZnO,and no Co-phase structure and other phases are observed.The UV-visible absorption spectra show that the optical band-gap of the film is broadened after doping.展开更多
We devised a new self-assembly method towards the construction of molecular materials via a“wheel mounting”mode of[Ti_(3)M](M=Co or Zn)clusters.Assembly of these clusters was designable and customizable into desirab...We devised a new self-assembly method towards the construction of molecular materials via a“wheel mounting”mode of[Ti_(3)M](M=Co or Zn)clusters.Assembly of these clusters was designable and customizable into desirable size,shape,and properties.An optical-driven molecular transition was realized with the stimulus–response of photochromism.This work not only provides an approach towards predictable and designable clusters,it also establishes a cluster-based structural model of molecular materials.展开更多
The directed and controllable synthesis of lanthanide clusters with precise structures has received considerable research attention,however,progress in such remains sluggish.The steps performed in a reaction system un...The directed and controllable synthesis of lanthanide clusters with precise structures has received considerable research attention,however,progress in such remains sluggish.The steps performed in a reaction system under“black-box”conditions are unpredictable and have very low controllability.The precise customization of lanthanide clusters with the same number of cores but different arrangements is particularly difficult.Using bis-acylhydrazone-derived multidentate chelating ligands with different substituents,differentially arranged hexanuclear lanthanide clusters(Dy_(6)and HNP-Dy_(6))with identical core connections but different template-motif arrangements were constructed herein for the first time using a multidentate chelating coordination method.Specifically,Dy_(6)with face-to-face and dislocation-arrangement template motifs was obtained using-N(Et)_(2)-substituted bis-acylhydrazone ligands with a strong steric hindrance effect.Changing-N(Et)_(2)to a benzene ring with a strong π-π interaction yielded HNP-Dy_(6)with inverted and coplanar arrangements of template motifs.The controllable construction of these two hexanuclear dysprosium clusters represented great progress in the precise synthesis of lanthanide clusters.High-resolution electrospray ionization-mass spectrometry(HRESI-MS)with different ionsource energies demonstrated the high stabilities of Dy_(6)and HNP-Dy_(6)in solutions.Time-dependent HRESI-MS tracked the formation processes of Dy_(6)and HNP-Dy_(6)and led to the following possible selfassembly mechanisms:L^(1)+2Dy→Dy_(2)L^(1)→Dy_(3)L^(1)→Dy_(6)(L^(1))_(2) and L^(2)+2Dy→Dy_(2)L^(2)→Dy_(3)L^(2)→Dy5(L^(2))_(2)/Dy_(6)(L^(2))_(2)→Dy_(6)(L^(2))_(2).At 1-T magnetic field,the longitudinal and transverse relaxation rates of Gd6 were 12.06 and 24.10 mM^(−1)s^(−1),respectively.Gd6 with highly aggregated Gd(Ⅲ)exhibited high relaxation rates,indicating its great potential as a T1-weighted magnetic resonance imaging contrast agent.This work provides an example of the design and synthesis of lanthanide clusters with high stabilities and relaxation rates,taking a big step toward the precise and controllable synthesis of lanthanide clusters.展开更多
Great progress has been made in the design and synthesis of high-nuclear lanthanide clusters with impressive structural connections,high stability,and special topologies,but still lack reliable regularity.Herein,a dro...Great progress has been made in the design and synthesis of high-nuclear lanthanide clusters with impressive structural connections,high stability,and special topologies,but still lack reliable regularity.Herein,a drone-shaped lanthanide cluster(1)was obtained by mixing stoichiometric ratios of 2-pyridinecarbohydrazide,2,3,4-trihydroxybenzaldehyde.展开更多
Supracluster assembly offers a unique opportunity for the isolation of customized materials using functional cluster precursors.Herein,for the first time,we demonstrate supracluster assembly based on an Al_(4)^(4−)pre...Supracluster assembly offers a unique opportunity for the isolation of customized materials using functional cluster precursors.Herein,for the first time,we demonstrate supracluster assembly based on an Al_(4)^(4−)precursor through both non-covalent interactions and coordination bonds.By reacting readily available,ultrastable,and soluble Al_(4)^(4−)as an anionic precursor with a metal center and neutral chelated chromophores,we successfully synthesized an extensive library of supracluster assembled crystalline solids,ranging from ion-pair structures,surface-modified clusters,and chains,to layered compounds.The advantage of this method is that it achieves stepwise performance regulation and enhancement using given functional precursors.These materials from supracluster assembly possess a broad range of tunable photophysical properties,including photoluminescence and third-order nonlinear optical(NLO)properties.Such extraordinary supracluster assembly will be widely applicable for creating a new generation of rationally organized solid materials with tailorable and customized properties.展开更多
The formation of heterometallic clusters usually involves a much more complex self-assembly process than that of homometallic clusters.Thus the tracking of their assembly mechanism is challenging.To achieve this task,...The formation of heterometallic clusters usually involves a much more complex self-assembly process than that of homometallic clusters.Thus the tracking of their assembly mechanism is challenging.To achieve this task,we designed one OH-containing Schiff base ligand of 1-[[(2-hydroxyethyl)imino]methyl]-2-naphthalenol(H_(2)L)with coordination pockets facile for selective coordination with CoII/NiII and 4f metal ions.Its reactions with the corresponding metal ions gave two new isostructural dodecanuclear complexes[Dy_(4)Co_(8)(μ_(3)-OH)_(8)(L)_(8)(OAc)_(4)(H_(2)O)_(4)]·3EtOH·3CH_(3)CN·H_(2)O(1)and[Dy_(4)Ni_(8)(μ_(3)-OH)_(8)(L)_(8)(OAc)_(4)(H_(2)O)_(4)]·3.5EtOH·0.5CH_(3)CN·5H_(2)O(2),which feature a vertex-sharing tetracubane cyclic skeleton with the four DyIII ions wrapped by the eight 3d metal ions.High-resolution electrospray mass spectrometry(HRESI-MS)tests showed that the skeletons of clusters 1 and 2 have high stability even under gradually increasing energy of the ion source.Most notably,the intermediates formed in the reaction courses for clusters 1 and 2 were tracked using time-dependent HRESI-MS,which gave different proposed assembly mechanisms for 1(H_(2)L→DyL→DyCoL→Dy_(2)CoL→Dy_(3)CoL→Dy_(4)CoL_(2)→Dy_(4)Co_(2)L_(3)→Dy_(4)Co_(4)L_(4)→Dy_(4)Co_(8)L_(8))and 2(H_(2)L→NiL→Dy_(2)NiL_(2)→Dy_(3)NiL_(2)→Dy_(4)NiL_(2)→Dy_(4)Ni_(2)L_(3)→Dy_(4)Ni_(4)L_(3)→Dy_(4)Ni_(6)L_(4)→Dy_(4)Ni_(8)L_(8)),respectively.This is the first time that different assembly mechanisms for isostructural heterometallic complexes are shown.Detailed magnetic studies revealed the absence of slow magnetic relaxation for 1 and the presence of slow magnetic relaxation for 2 with an energy barrier of 7.66 K and a pre-exponential factor of 1.45×10^(-6) s.The different magnetic performances of the two title complexes might be caused by the different metal ions of Co_((II))and Ni_((II)).展开更多
Developing a new strategy for the synthesis of high-nuclear transition metal(TM)cluster substituted polyoxometalates(POMs)provides an avenue for new materials with unique functions.Herein,the synergetic coordination s...Developing a new strategy for the synthesis of high-nuclear transition metal(TM)cluster substituted polyoxometalates(POMs)provides an avenue for new materials with unique functions.Herein,the synergetic coordination strategy of 1,2,4-1H-triazole(Htrz),ethylenediamine(en),and a lacunary POM was applied to construct a highnuclear Ni cluster substituted POM.As a result,a{Ni_(30)}cluster substituted POM,[Ni(trz)3]2@[Ni_(30)(H2O)16]POM.展开更多
A series of polynuclear lanthanide(Ln)complexes were prepared by the hydrolysis of lanthanide ions using L-histidine as a supporting ligand.Halide ions(X^(−)=Cl^(−),Br^(−),and I^(−))have been found to play a major rol...A series of polynuclear lanthanide(Ln)complexes were prepared by the hydrolysis of lanthanide ions using L-histidine as a supporting ligand.Halide ions(X^(−)=Cl^(−),Br^(−),and I^(−))have been found to play a major role in templating the assembly of pentadecanuclear complexes for Nd(III)and Gd(III)with the definitive evidence ofμ5-X^(−)in the cluster core formed by five corner-shared cubane units of[Ln_(4)(μ_(3)-OH)_(4)]^(8+).展开更多
The development of crystalline titanium-oxo clusters has made great progress in recent years.However,the geometric assembly of titanium-oxo clusters is still very challenging.Herein,we report the assembly of two cycli...The development of crystalline titanium-oxo clusters has made great progress in recent years.However,the geometric assembly of titanium-oxo clusters is still very challenging.Herein,we report the assembly of two cyclic titanium-oxo clusters with ferrocene connectors,formulated as Ti_(12)(μ_(3)-O)_(4)(Fcdc)_(4)(O^(i)Pr)_(32)·0.5CH_(2)Cl_(2)(Fcdc=1,1’-ferrocenedicarboxylic acid;Ti_(12)Fcdc_(4))and Ti_(18)(μ_(2)-O)_(6)(μ_(3)-O)_(6)(Fcdc)_(2)(L1)2(L2)_(4)(O^(i)Pr)_(34)·2HO^(i)Pr(L1=isonicotinic acid;L2=salicylhydroxamic acid;Ti_(18)Fcdc_(2)).Singlecrystal X-ray diffraction studies demonstrate that ferrocene with two carboxylic arms can adhere to the surface of{Ti_(6)}and/or{Ti_(3)}units,resulting in fascinating cyclic structures of Ti_(12)Fcdc_(4) and Ti_(18)Fcdc_(2).Notably,ferrocene ligands can not only serve as connectors to induce the geometric assembly of Ti-oxo clusters,but can also act as photosensitizers to greatly improve the light absorption behavior of the resulting compounds.Furthermore,the DFT calculation results suggest that the HOMO→LUMO transition mainly involves ferrocenyl group→Ti-oxo core charge transfer.Using the two ferrocene-containing clusters as electrode precursors,both electrodes exhibited excellent photocurrent responses.Our work opens a new way for the geometric assembly of titanium-oxo clusters and also contributes to the deep understanding of the structure–property relationships of sensitized Ti-based materials.展开更多
Two systems of carbonate complexes were constructed by employing a newly prepared Schiff based ligand(H_(2)L;H_(2)L=2-(hydroxyimino)-2-[(3-methoxyl-2-hydroxyphenyl)methylene]hydrazide)and Ln(acac)_(3)·H_(2)O(Haca...Two systems of carbonate complexes were constructed by employing a newly prepared Schiff based ligand(H_(2)L;H_(2)L=2-(hydroxyimino)-2-[(3-methoxyl-2-hydroxyphenyl)methylene]hydrazide)and Ln(acac)_(3)·H_(2)O(Hacac=acetylacetone)in different reaction solutions.展开更多
基金supported by the BAGUI Talent Program in Guangxi Province(No.2019AC26001)the National Natural Science Foundation of China(Nos.22171075,U23A2080,22371173).
文摘Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems.Herein,the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity,namely[Co_(19)(HL1)_(8)(L1)_(12)(L′)_(2)(Ac)_(4)]·10CH_(3)CH_(2)OH·6H_(2)O(1,H_(2)L1=1H-benzo[d]imidazole-2-yl)methanol,HL'=1H-benzo[d]imidazole),was obtained with in-situ ligand transformation from H_(2)L1 to L′.It features a hierarchical trilayer and void-cage inside structure,consisting of central disc-shaped[Co_(7)L_(10)]core with two[Co_(6)]rings on both sides.ESI-MS of crystal 1 yields a series of more than sixteen fragments,all featuring an integrated[Co_(19)]core,suggesting stability of the polynuclear cluster in solution.During increased in-source energy from 0 to 100 eV,all MS peaks shifted to a lower m/z range,but the[Co_(19)]core remained intact,excepting for the stepwise elimination of up to three Ac^(−)anions or three L1 linkers.PXRD tracking of the reaction sediments showed the formation of a key precursor of[Co_(4)L_(4)]cubane at 3 h,and its content decreased at 6 h and vanished at 12 h,followed by the appearance of crystals 1 by the generation of a clear solution at 18 h,suggesting an initial cluster assembly-disassembly process.ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of[Co_(7)L_(10)]disk and its expansion of[Co_(13)L_(12)(L′)_(2)].A probable tandem assembly-disassembly-reassembly mechanism is put forward as[CoL_(2)]→[Co_(4)L_(4)]→[Co_(7)L_(10)]→[Co_(13)L_(12)(L′)_(2)]→[Co_(19)L_(2)0(L′)_(2)].Their evolution also indicated the ingenious synergy of coexisting organic,inorganic and in-situ generated ligands,along with diverse coordination geometries of metal ions,plays a directional role in forming odd-numbered and high-nuclearity coordination clusters.Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.
基金supported by the National Natural Science Foundation of China (Nos. 21504053, 21661162001, 21673139, 91527304, 21722502)Shanghai Pujiang Talent Project (No. 16PJ1402700)+1 种基金the Innovation Fund from Joint Research Center for Precision Medicine set up by Shanghai Jiao Tong University & Affiliated Sixth People's Hospital South Campus (No. IFPM 2016B001)the special program for collaborative innovation in Shanghai University of Medicine & Health Sciences (SPCI-17-15-001)
文摘Herein we demonstrate the construction of three types of parallel gold nanorod(AuNR) clusters using a DNA origami rod(DOR) as the template. Based on the precise control over the position of capture strands on DOR, number and orientation of the AuNR clusters can be well engineered, as evidenced by biological transmission electron microscope(TEM). Importantly, the AuNR clusters exhibit chiroptical responses which are strongly affected by the number of AuNR on rod-like DNA origami.
基金supported by the Youth Innovation Program of the Chinese Academy of Agricultural Sciences(Y2023QC34)the Natural Science Foundation of Shandong province(ZR2023MC034)+2 种基金the Technological Innovation Project of ECS-CAAS(ECS-KY-N-2024008)the Agricultural Science and Technology Innovation Program(ASTIP-TRIC05-2025)the Central Public-interest Scientific Institution Basal Research Fund(1610232024005,1610232023003).
文摘Northern wild rice(NWR;Zizania palustris L.),an annual aquatic plant in the Poaceae family,has high economic importance due to its nutrient-rich grains.However,the existing NWR genome assembly for this species has severe fragmentation and incomplete gene representation.A near-complete genome was assembled in this study to provide a high-quality genomic reference for NWR-associated research.The assembled genome exhibited a total contig length of 1.41 Gb and a contig N50 of 109.22 Mb.Overall,a 73.60%repetitive sequence content was identified and 47,804 genes predicted.Phylogenetic analysis indicated that Z.palustris was most closely related to Zizania latifolia,with an estimated divergence time of 4.57–8.15 Mya.Meanwhile,Z.palustris underwent a recent,species-specific long terminal repeat(LTR)expansion,associated with its larger genome size.We identified two genomic blocks in the Z.palustris and Z.latifolia genomes that exhibit strong synteny with the rice phytocassane biosynthetic gene cluster.The centromeric satellite repeats in Z.palustris identified in this study primarily comprised a 145 bp repetitive unit.The findings also revealed centromere homogenisation and rearrangement accompanied by LTR invasion in NWR.Among the genes missing in the previous NWR genome,we observed LTR insertion events that resulted in expanded gene lengths in our updated NWR genome.The present updated NWR genome provides a valuable resource for crop genetic improvement,functional gene discovery,and research on critical biological processes.
基金Project(2006FJ4235) supported by the Post-Doctoral Foundation of Hunan Province, China
文摘Self-assembly cluster compound [WS4Cu3(PPh2Py)3Br]2·CH3OH (1) was synthesized by the reaction of (NH4)2WS4, CuBr and diphenyl-2-pyridyl-phosphine (PPh2Py) in CH3OH solution under a purified nitrogen atmosphere using standard Schlenk techniques. Its structure was determined by X-ray crystallography. It crystallizes in the triclinic crystal system P-1 space group with a=1.178 6 (1) nm, b=1.302 6 (1) nm, c=1.991 7 (2) nm, α=74.671 (7)-, β=86.188 (8)-, γ=64.141 (6)-, V=2.649 5 (5) nm3, Z=1. The W center is slightly distorted from tetrahedral coordination geometry, and the structure is built up from three [Cu(PPh2Py)]+ units bridged by WS 24- multifunctional ligand to form a tetranuclear symmetrical cube-like molecule. Measurement of the nonlinear optical (NLO) properties using the Z-scan technique with an 8 ns pulsed laser at 532 nm shows that the compound possesses NLO absorption and effective self-focusing effect at α2=6.7×10-11 m/W and n2=5.64×10-18 m2/W in a 1.5×10-4 mol/L DMF solution.
基金supported in part by National Key R&D Program of China(No.2018YFB1304600)the Natural Science Foundation of China(No.51775541)CAS Interdisciplinary Innovation Team(No.JCTD-2018-11)。
文摘With the rapid development of space technology and the increasing demand for space missions,the traditional spacecraft manufacturing,deployment and launch methods have been unable to meet existing needs.In-space assembly(ISA)technologies can effectively adapt to the assembly of large space structures,improve spacecraft performance,and reduce operating costs.In this paper,the development and technologies for ISA are reviewed.ISA is classified from multiple angles,and the research status of ISA is shown clearly through the visual mapping knowledge domain.Then the development status of autonomous robot assembly in the United States,Europe,Japan,Canada and China is reviewed.Furthermore,the key technologies of ISA are analyzed from three aspects:assembly structure design,robot technologies and integrated management technologies.ISA technologies are still facing major challenges and need to be further explored to promote future development.Finally,future development trends and potential applications of ISA are given,which show that ISA will play a vital role in human space exploration in the future.
基金Supported by the National Natural Science Foundation of China(Nos. 20476011 and 20371007).
文摘The self-assembly of clusters in inorganic systems is an interesting subject. The self-assembly of big molecules has been well established in biological systems. In addition, the coordination chemistry of metal-sulfur-nitrogen cluster complexes has been a very active and attracting field for many years as a result of the novelty and versatility of the crystal structures and reactivities of such clusters, as well as their potential applications as the models for the active sites in non-heme proteins. At the same time, there is currently considerable interest in the formation of metal complexes with heterocyclic ligands because of the diverse characteristics of ligands and their consequential wide range of applications.
基金the National Natural Science Foundation of China(Nos.21861012 and 21603109)the Henan Joint Fund of the National Natural Science Foundation of China(No.U1404216)+6 种基金the Natural Science Foundation of Guizhou Education Commission(Nos.2018148 and 2018016)Guizhou Science&Technology Commission(Nos.20201Z005,20191157 and 20191156)the Natural Science Foundation of Shandong Provinceof China(No.ZR2016BM14)Tai’an Science&Technology Project(No.2016GX1046)the Postgraduate Foundation of Taishan University(No.Y2015-1-011)the Natural Science Foundation of Guizhou Minzu University(No.GZMU2019YB06)the Natural Science Foundation of Liaoning Shihua University(No.2019XJJL019)。
文摘A new copper-thiolate cluster assembled framework[Cu2(μ4-SCH3)Cl]n(1),has been solvothermally synthesized through in situ reaction viz.,in situ ligand generation and metal reduction.Compound 1 represents the first 3 D framework based on Atlas-sphere functionalized by singleμ2-Cl groups.DOS calculation reveals the interaction of electronic structures.It is found that the HOMO is mainly distributed on Cl,Cu and S bonding orbitals,while the LUMO is dominated by Cu-Cl antibonding orbitals.
文摘This is a further development work on grouping of printed circuit boards(PCBs)for Surface Mount Assembly in the electronic industry.The arrangement of PCBs among several surface mount machine lines is a typical kind of group technology(GT)problem.From literatures,there are various clustering techniques developed to solve the clustering problems.In this paper,fuzzy c-means clustering(FCM)is used to solve the PCBs grouping problem.Applying them in a real problem compares the results of the two methods.The result shows that there should be a systematic method to arrange the scheduling of PCB assemblies in electronic industry to improve the operations planning process.
基金Projects(1090406510674056+5 种基金1077407090606002)supported by the National Natural Science Foundation of ChinaProject(20080441042)supported by China Postdoctoral Science FoundationProject(200926)supported by Tonghua Normal University FoundationProject(2010CB923401)supported by the National Basic Research Program of ChinaProject(BK2008024)supported by the Natural Science Foundation of Jiangsu of Province,China
文摘Cobalt doped ZnO film assembled by the nanoparticles was prepared by low energy cluster beam deposition.The microstructure,phase structure and optical properties were investigated for the nanostructured films.The results show that the nanostructured film was assembled by monodisperse spherical nanoparticles with average diameter of about 29.3 nm which are distributed uniformly and compactly.The results of X-ray diffraction(XRD)show that cobalt doped ZnO nanostructured film is indexed to a wurtzite structure of ZnO,and no Co-phase structure and other phases are observed.The UV-visible absorption spectra show that the optical band-gap of the film is broadened after doping.
基金supported by the National Natural Science Foundation of China(21971241,21771181,21935010 and 21973096).
文摘We devised a new self-assembly method towards the construction of molecular materials via a“wheel mounting”mode of[Ti_(3)M](M=Co or Zn)clusters.Assembly of these clusters was designable and customizable into desirable size,shape,and properties.An optical-driven molecular transition was realized with the stimulus–response of photochromism.This work not only provides an approach towards predictable and designable clusters,it also establishes a cluster-based structural model of molecular materials.
基金supported by the National Natural Science Foundation of China(22061005,22271068,and 22075058)the Basic Ability Improvement Project of Young and Middle-Aged Teachers in Guangxi Colleges(2022KY0573)PhD Start-up Fund of Yulin Normal University(G2022ZK08).
文摘The directed and controllable synthesis of lanthanide clusters with precise structures has received considerable research attention,however,progress in such remains sluggish.The steps performed in a reaction system under“black-box”conditions are unpredictable and have very low controllability.The precise customization of lanthanide clusters with the same number of cores but different arrangements is particularly difficult.Using bis-acylhydrazone-derived multidentate chelating ligands with different substituents,differentially arranged hexanuclear lanthanide clusters(Dy_(6)and HNP-Dy_(6))with identical core connections but different template-motif arrangements were constructed herein for the first time using a multidentate chelating coordination method.Specifically,Dy_(6)with face-to-face and dislocation-arrangement template motifs was obtained using-N(Et)_(2)-substituted bis-acylhydrazone ligands with a strong steric hindrance effect.Changing-N(Et)_(2)to a benzene ring with a strong π-π interaction yielded HNP-Dy_(6)with inverted and coplanar arrangements of template motifs.The controllable construction of these two hexanuclear dysprosium clusters represented great progress in the precise synthesis of lanthanide clusters.High-resolution electrospray ionization-mass spectrometry(HRESI-MS)with different ionsource energies demonstrated the high stabilities of Dy_(6)and HNP-Dy_(6)in solutions.Time-dependent HRESI-MS tracked the formation processes of Dy_(6)and HNP-Dy_(6)and led to the following possible selfassembly mechanisms:L^(1)+2Dy→Dy_(2)L^(1)→Dy_(3)L^(1)→Dy_(6)(L^(1))_(2) and L^(2)+2Dy→Dy_(2)L^(2)→Dy_(3)L^(2)→Dy5(L^(2))_(2)/Dy_(6)(L^(2))_(2)→Dy_(6)(L^(2))_(2).At 1-T magnetic field,the longitudinal and transverse relaxation rates of Gd6 were 12.06 and 24.10 mM^(−1)s^(−1),respectively.Gd6 with highly aggregated Gd(Ⅲ)exhibited high relaxation rates,indicating its great potential as a T1-weighted magnetic resonance imaging contrast agent.This work provides an example of the design and synthesis of lanthanide clusters with high stabilities and relaxation rates,taking a big step toward the precise and controllable synthesis of lanthanide clusters.
基金supported by the National Natural Science Foundation of China(22271068,22061005,and 22075058)Innovation Project of Guangxi Graduate Education(YCBZ2023059).
文摘Great progress has been made in the design and synthesis of high-nuclear lanthanide clusters with impressive structural connections,high stability,and special topologies,but still lack reliable regularity.Herein,a drone-shaped lanthanide cluster(1)was obtained by mixing stoichiometric ratios of 2-pyridinecarbohydrazide,2,3,4-trihydroxybenzaldehyde.
基金supported by the National Natural Science Foundation of China(U23A20950,22371278,and 92261108)the Science Fund for Distinguished Young Scholars of Fujian Province(2021J06035)+1 种基金the Funding of the Fujian Provincial Chemistry Discipline Alliance(50025401)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2021081).
文摘Supracluster assembly offers a unique opportunity for the isolation of customized materials using functional cluster precursors.Herein,for the first time,we demonstrate supracluster assembly based on an Al_(4)^(4−)precursor through both non-covalent interactions and coordination bonds.By reacting readily available,ultrastable,and soluble Al_(4)^(4−)as an anionic precursor with a metal center and neutral chelated chromophores,we successfully synthesized an extensive library of supracluster assembled crystalline solids,ranging from ion-pair structures,surface-modified clusters,and chains,to layered compounds.The advantage of this method is that it achieves stepwise performance regulation and enhancement using given functional precursors.These materials from supracluster assembly possess a broad range of tunable photophysical properties,including photoluminescence and third-order nonlinear optical(NLO)properties.Such extraordinary supracluster assembly will be widely applicable for creating a new generation of rationally organized solid materials with tailorable and customized properties.
基金supported by the National Natural Science Foundation of China(grant no.12064002,22061004 and 21901050)the Guangxi Natural Science Foundation of China(grant no.2018GXNSFBA050031 and 2020GXNSFAA159132)+1 种基金the Guangxi Technology Base and Talent Subject(grant no.GUIKE AD19245002)the Key Project of Guangxi Normal University(grant no.2018ZD003).
文摘The formation of heterometallic clusters usually involves a much more complex self-assembly process than that of homometallic clusters.Thus the tracking of their assembly mechanism is challenging.To achieve this task,we designed one OH-containing Schiff base ligand of 1-[[(2-hydroxyethyl)imino]methyl]-2-naphthalenol(H_(2)L)with coordination pockets facile for selective coordination with CoII/NiII and 4f metal ions.Its reactions with the corresponding metal ions gave two new isostructural dodecanuclear complexes[Dy_(4)Co_(8)(μ_(3)-OH)_(8)(L)_(8)(OAc)_(4)(H_(2)O)_(4)]·3EtOH·3CH_(3)CN·H_(2)O(1)and[Dy_(4)Ni_(8)(μ_(3)-OH)_(8)(L)_(8)(OAc)_(4)(H_(2)O)_(4)]·3.5EtOH·0.5CH_(3)CN·5H_(2)O(2),which feature a vertex-sharing tetracubane cyclic skeleton with the four DyIII ions wrapped by the eight 3d metal ions.High-resolution electrospray mass spectrometry(HRESI-MS)tests showed that the skeletons of clusters 1 and 2 have high stability even under gradually increasing energy of the ion source.Most notably,the intermediates formed in the reaction courses for clusters 1 and 2 were tracked using time-dependent HRESI-MS,which gave different proposed assembly mechanisms for 1(H_(2)L→DyL→DyCoL→Dy_(2)CoL→Dy_(3)CoL→Dy_(4)CoL_(2)→Dy_(4)Co_(2)L_(3)→Dy_(4)Co_(4)L_(4)→Dy_(4)Co_(8)L_(8))and 2(H_(2)L→NiL→Dy_(2)NiL_(2)→Dy_(3)NiL_(2)→Dy_(4)NiL_(2)→Dy_(4)Ni_(2)L_(3)→Dy_(4)Ni_(4)L_(3)→Dy_(4)Ni_(6)L_(4)→Dy_(4)Ni_(8)L_(8)),respectively.This is the first time that different assembly mechanisms for isostructural heterometallic complexes are shown.Detailed magnetic studies revealed the absence of slow magnetic relaxation for 1 and the presence of slow magnetic relaxation for 2 with an energy barrier of 7.66 K and a pre-exponential factor of 1.45×10^(-6) s.The different magnetic performances of the two title complexes might be caused by the different metal ions of Co_((II))and Ni_((II)).
基金financially supported by the National Natural Science Foundation of China(21773247,21521061,21875252)the Natural Science Foundation of Fujian Province(2006L2005).
文摘Developing a new strategy for the synthesis of high-nuclear transition metal(TM)cluster substituted polyoxometalates(POMs)provides an avenue for new materials with unique functions.Herein,the synergetic coordination strategy of 1,2,4-1H-triazole(Htrz),ethylenediamine(en),and a lacunary POM was applied to construct a highnuclear Ni cluster substituted POM.As a result,a{Ni_(30)}cluster substituted POM,[Ni(trz)3]2@[Ni_(30)(H2O)16]POM.
基金supported by the National Natural Science Foundation of China(no.21971106)the Shenzhen Nobel Prize Scientists Laboratory Project(C17783101),the Stable Support Project of Key Research Plan of Shenzhen,and startup fund from SUSTech.The crystallographic assistance on the first batch of crystals by Dr.S.Roberts,G.Hall,G.S.Nichol,and P.Wei is gratefully acknowledged.
文摘A series of polynuclear lanthanide(Ln)complexes were prepared by the hydrolysis of lanthanide ions using L-histidine as a supporting ligand.Halide ions(X^(−)=Cl^(−),Br^(−),and I^(−))have been found to play a major role in templating the assembly of pentadecanuclear complexes for Nd(III)and Gd(III)with the definitive evidence ofμ5-X^(−)in the cluster core formed by five corner-shared cubane units of[Ln_(4)(μ_(3)-OH)_(4)]^(8+).
基金the Qilu University of Technology Science Research Initial Fund.
文摘The development of crystalline titanium-oxo clusters has made great progress in recent years.However,the geometric assembly of titanium-oxo clusters is still very challenging.Herein,we report the assembly of two cyclic titanium-oxo clusters with ferrocene connectors,formulated as Ti_(12)(μ_(3)-O)_(4)(Fcdc)_(4)(O^(i)Pr)_(32)·0.5CH_(2)Cl_(2)(Fcdc=1,1’-ferrocenedicarboxylic acid;Ti_(12)Fcdc_(4))and Ti_(18)(μ_(2)-O)_(6)(μ_(3)-O)_(6)(Fcdc)_(2)(L1)2(L2)_(4)(O^(i)Pr)_(34)·2HO^(i)Pr(L1=isonicotinic acid;L2=salicylhydroxamic acid;Ti_(18)Fcdc_(2)).Singlecrystal X-ray diffraction studies demonstrate that ferrocene with two carboxylic arms can adhere to the surface of{Ti_(6)}and/or{Ti_(3)}units,resulting in fascinating cyclic structures of Ti_(12)Fcdc_(4) and Ti_(18)Fcdc_(2).Notably,ferrocene ligands can not only serve as connectors to induce the geometric assembly of Ti-oxo clusters,but can also act as photosensitizers to greatly improve the light absorption behavior of the resulting compounds.Furthermore,the DFT calculation results suggest that the HOMO→LUMO transition mainly involves ferrocenyl group→Ti-oxo core charge transfer.Using the two ferrocene-containing clusters as electrode precursors,both electrodes exhibited excellent photocurrent responses.Our work opens a new way for the geometric assembly of titanium-oxo clusters and also contributes to the deep understanding of the structure–property relationships of sensitized Ti-based materials.
基金supported by the Natural Science Foundation of China(21701039 and 21473121)the Natural Science Foundation of Hebei Province(B2017201055)the 111 project(B12015)and the Hebei University construction project for comprehensive strength promotion of Midwest colleges and universities.
文摘Two systems of carbonate complexes were constructed by employing a newly prepared Schiff based ligand(H_(2)L;H_(2)L=2-(hydroxyimino)-2-[(3-methoxyl-2-hydroxyphenyl)methylene]hydrazide)and Ln(acac)_(3)·H_(2)O(Hacac=acetylacetone)in different reaction solutions.
