Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, F...Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.展开更多
The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the ph...The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the phase field microelasticity(PFM)simulation.The results show a near-attraction and far-repulsion elastic interaction between two inclusions with hydrostatic dilatation.The critical spacing,at which the interaction changes from attraction to repulsion,is on the order of the radius of the rod,dependent on the length and Poisson’s ratio of inclusions.Furthermore,the elastic energy calculations and PFM simulation results indicate that applying the local radial stress on the rod surface can modulate the elastic interaction between inclusions and adjust the periodicity of the superlattice nanowire structure.This can provide some guidelines for the tunable construction of superlattice nanowire structures.展开更多
With a high pH value, soda soil restricts the growth of plants. It had previously been assumed that the inhibition of plant growth by neutral salt stress was partly due to the changes of the ultrastructure and storage...With a high pH value, soda soil restricts the growth of plants. It had previously been assumed that the inhibition of plant growth by neutral salt stress was partly due to the changes of the ultrastructure and storage inclusions of chloroplasts. The aim of this paper is to investigate the effects of alkali-salt mixed stress of soda soil on chloroplasts of higher plant Syringa oblata Lindl. Testing S. oblata plants had grown for more than five years in soda soil, and transmission electron microscope was used for determining the ultrastructure and storage inclusions of chloroplasts. The results showed that some chloroplasts were destroyed, the normal chloroplasts became smaller, and the envelopes of the functional chloroplasts were slightly expanded generally in soda-stressed plants. The most noteworthy fact was that much more starchgrains accumulated in the chloroplasts of S. oblata growing in soda soil than in neutral soil. The total contents of plastoglobules in chloroplasts did not change considerably, and plastoglobules with different electron densities appeared in chloroplasts in the plants growing in soda soil. We presume that the reduction of the volume and number of functional chloroplasts and the occupation of carbon resources by starch grains accumulated in chloroplasts were the possible reasons for the inhibition of S. oblata growth by soda soil. The accumulation of starch grains was one of the adaptive traits of S. oblata, which promoted the survival of plants in soda soil for that the starch grains could serve as a steady source of soluble sugars, which were known as protectors of plant cells under stressed conditions. Soda soil did not significantly change the total content of plastoglobules in chloroplasts, but changed their compositions.展开更多
: The crystal structure of an inclusion compound formed between acetyl-ferrocene pyridine-2, 6-diformylhydrazone and ethanol was report in the present work.The crystal of C33,H35N5O3Fe2 is monoclinic, space group C2/c...: The crystal structure of an inclusion compound formed between acetyl-ferrocene pyridine-2, 6-diformylhydrazone and ethanol was report in the present work.The crystal of C33,H35N5O3Fe2 is monoclinic, space group C2/c with a = 23. 249 (3 ), b=ll. 576(2), c=22. 794(4) A, β=103. 53(l)’, V=5964(1) A3, Mr=66l- 37, Z=8, Dc= 1. 473g/cm3, F (000) = 2752. 00, μ = 10. l5 cm-1. It was found that theethanol molecule present in the crystal lattice depends on the van der Waals force ratherthan hydrogen bonding.展开更多
The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristi...The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.展开更多
X-ray crystal structures of the inclusion complexes of calix[4]arene monomethoxycarboxylic acid 1 (C30H2606) with acetontrile and acetone are reported. The crystal of C30H26O6·CH3CN is of monoclinic, space grou...X-ray crystal structures of the inclusion complexes of calix[4]arene monomethoxycarboxylic acid 1 (C30H2606) with acetontrile and acetone are reported. The crystal of C30H26O6·CH3CN is of monoclinic, space group P2 1/c with a = 11.691(5), b = 13.753(5), c = 17.072(7)A, β = 100.104(7)°, C32H29NO6, Mr = 523.56, V = 2702.4(18)A^3, Z = 4, De= 1.287 g/cm^3, μ(MoKα) = 0.089 mm^-1, T = 293(2) K, 5570 independent reflections with 3220 observed ones (1 〉 2σ(I)), R = 0.0521 and wR = 0.1132 with GOF = 1.042 (R = 0.1055 and wR = 0.1350 for all data). The data for C30H26O6·CH3COCH3: monoclinic, space group P2 1/c, α = 12.366(4), b = 12.119(4), c = 18.796(6) A, β = 90.871(6)°, C33H32O7, Mr = 540.59, V = 2816.6(16)A^3, Z = 4, Dc = 1.275 g/cm^3, μ(MoKα) = 0.089 mm^-1, T = 293(2) K, 5783 independent reflections including 2580 observed ones (I 〉 2σ(I)), R = 0.0555 and wR = 0.1424 with GOF= 0.975 (R = 0.1601 and wR = 0.1884 for all data). Their architectures exhibit one-dimensional inclusion polymers which are mediated head-to-tail by the guests.展开更多
Two polymorphs of the inclusion compound [(n-C4H9)4N]+'(C13H903)H2O have been prepared and characterized by X-ray crystallography. Polymorph 1: triclinic P1, a = 13.4982(2), b = 13.5743(2), c = 17.1996(2)...Two polymorphs of the inclusion compound [(n-C4H9)4N]+'(C13H903)H2O have been prepared and characterized by X-ray crystallography. Polymorph 1: triclinic P1, a = 13.4982(2), b = 13.5743(2), c = 17.1996(2) A, at = 67.045(1),β = 77.845(1), γ= 88.762(1)°, V = 2830.43(7) A3, Z = 4, R = 0.0491, wR= 0.1276; Polymorph 2: tetragonal P43, a = b = 13.53690(1) A, c = 30.8491(8) A, V = 5653.02(16) A3, Z = 8, R = 0.0448, wR = 0.0984. In these two crystal structures, the hydrogen-bonded ribbons built of 4,4'-dihydroxybenzophenone (DHBP, C13H1003) anions and water molecules are orderly arranged to generate two-dimensional host layers, with tetrabutylammonium cations contained between the layers to form the sandwich-like inclusion compounds. The structures of 1 and 2, which exist as two polymorphs, both display the similar packing pattern and hydrogen-bond linking model.展开更多
The X-ray crystal structure of the inclusion complex of p-tert-butylcalix [4] crown-6 with actonitrile is reported. C54H70O10·3CH3CN, Mr=1002. 3 ,monoclinic, space group C2/c with cell dimensions of a=23.587(7),b...The X-ray crystal structure of the inclusion complex of p-tert-butylcalix [4] crown-6 with actonitrile is reported. C54H70O10·3CH3CN, Mr=1002. 3 ,monoclinic, space group C2/c with cell dimensions of a=23.587(7),b=21.153(6),c=15.608(8) A,β=116.99(3)°,V=6939.2 A3,Z=4, F(000)=2160,Dc=0.959 g/cm3,μ=1.114 cm-1; R=0.088 for 2066 reflections with I>3σ(I).The calixarene subunit exists in a distorted cone conformation. One of the three acetonitrile molecules is located in the intracavity of the calixarene subunit and the other two in the intermolecular channels.展开更多
THE Kuranakh gold deposit is located in the Aldan shield, in the southern portion of Siberian platform.Sub-horizontal, blanket-or ribbon-like ore bodies up to 50 m thick occur along and above the contact between Cambr...THE Kuranakh gold deposit is located in the Aldan shield, in the southern portion of Siberian platform.Sub-horizontal, blanket-or ribbon-like ore bodies up to 50 m thick occur along and above the contact between Cambrian calcareous footwall rocks and overlaying Jurassic clastic rocks within a narrow zone, about30 km long, bounded by several south-north trending faults. To date the deposit is estimated to have produced more than 200 tonnes of gold at an average grade of 3.57 g/t Au extending over 41 years of production. Cambrian rock is predominantly composed of limestone and dolomite. The limestone contains a smallamount (1%-3%) of clastic material. The limestone is thin-bedded, platy, fractured, brecciated,cavernous, and porous. Its composition varies from pure limestone to spotted-banded dolomitic limestoneor "zebra" rock. The "zebra rock is characterized by the presence of finely disseminated organic materi-展开更多
Two inclusion complexes of β-cyclodextrin-7-hydroxycoumarin (1) and ,β-cyclodextrin-4-hydroxycoumarin (2) were prepared and their crystal structures were investigated by single crystal X-ray crystallography unde...Two inclusion complexes of β-cyclodextrin-7-hydroxycoumarin (1) and ,β-cyclodextrin-4-hydroxycoumarin (2) were prepared and their crystal structures were investigated by single crystal X-ray crystallography under cryogenic condition. Both structures consist of stacks of face-to-face cyclodextrin dimers arranged in brickwork-like pattern along the crystallographic a-axis. For complex 1, each of the two dimeric β-cyclodextrins includes one 7-hydroxycoumarin molecule that penetrates deeply into the cyclodextrin dimer and locates its lactonering at the center of the dimer cavity. For complex 2, each cyelodextrin dimer accommodates three 4-hydroxycoumarin molecules. One of them is sandwiched between two units of the cyclodextrin dimer, the other two are shallowly included in the cavities of the dimeric cyclodextrins respectively and protrude their lactone rings from the primary end of the cyclodextrin. The substituent effects of guest molecules on inclusion geometry of various coumarin molecules in fl-cyclodextrin were examined.展开更多
THE Yindongpo gold deposit, situated in northern Tongbei County, northern Qinling orogenic belt, is alarge-scale one controlled by the Heqianzhuang anticline that plunges northwestwards and dips northeastwards. The or...THE Yindongpo gold deposit, situated in northern Tongbei County, northern Qinling orogenic belt, is alarge-scale one controlled by the Heqianzhuang anticline that plunges northwestwards and dips northeastwards. The ore-bodies locates in the carbon layers belonging to the Neoproterozoic Waitoushan Formation.Two ore-forming periods can be distinguished: the pre-Mesozoic epithermal mineralization in primary sediment with metamorphic superposition and the Mesozoic epithermal-mesothermal mineralization related totectonomagmatic activities. The principal ore-forming period can be divided into four stages. The ore bodies consist of networked and brecciated quartz veins. Gold is mainly rich in the veinlet-type quartz veinsthat formed during the diagentic-metamorphism or syn-metamorphic hydrothermal period, but a little inthe coarse veins related to later tectonomagmatic activities. The phenomenon that the fracturing degree展开更多
The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-c...The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered guest molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The guest inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-guest stoichiometries are different,i.e.,2:1 for m-nitrophenoxyacetic acid and 1:1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.展开更多
To avoid coarse crystallization of glassy inclusions in Si–Mn deoxidized steel during hot rolling, the effect of MgO on the structure and crystallization behavior of CaO–SiO_(2)–Al_(2)O_(3) inclusions was investiga...To avoid coarse crystallization of glassy inclusions in Si–Mn deoxidized steel during hot rolling, the effect of MgO on the structure and crystallization behavior of CaO–SiO_(2)–Al_(2)O_(3) inclusions was investigated. The results showed that the crystallization temperature of the oxide melts decreased with increasing MgO content from 0 to 15.7 wt.%, which suggested that the addition of MgO would increase the temperature range of the crystalline transition. The increase in MgO content could decrease the crystallization activation energy of inclusions. With the increase in MgO content, the relative fractions of O_(Si)^(0) and O_(Si)^(1) structure units increased, and those of structure units O_(Si)^(2), O_(Si)^(3), and O_(Si)^(4) decreased, increasing the depolymerization degree of the silicate structure. The crystallization ratio of glassy inclusions in the steel crucible increased from 19.7% to 98.3% with increasing MgO content from 0 to 15.7 wt.%. The addition of MgO improved the crystallization ability of inclusions, because MgO provides free oxygen O_(2−) to destroy the bridging oxygens and form non-bridging oxygens O^(−), which depolymerizes silicate network structure and simplifies the [SiO_(4)]-tetrahedral structure. In addition, MgO would promote the precipitation of the Mg-containing phases with a high melting point. When the MgO content was increased above 12.1 wt.%, MgO·Al_(2)O_(3) and 2MgO·SiO_(2) crystalline phases would precipitate from the inclusions.展开更多
The mechanisms of La in heavy rail steel were studied by means of experimental measurements, microstructure observation and theoretical analysis in the present work. For heavy rail steel, the state and the content of ...The mechanisms of La in heavy rail steel were studied by means of experimental measurements, microstructure observation and theoretical analysis in the present work. For heavy rail steel, the state and the content of La were measured, and the mechanisms and the effects of La on sulfide inclusions, microstracture and properties of steel were determined. Strip-like sulfides disappear in heavy rail steel with La/(O+S)〉3.50, which is shown that the metallurgical function of modifying sulfide inclusions has been achieved by La. La can fine the grain size of the austenite in heavy rail steel. Under the experimental condition, the plasticity and the impacting toughness of heavy rail steel with 0.005wt% La can evidently be improved.展开更多
The linear component of starch,amylose,has the ability to interact with hydrophobic molecules forming inclusion complexes(ICs).These structures have gained a particular interest for potential food applications,either ...The linear component of starch,amylose,has the ability to interact with hydrophobic molecules forming inclusion complexes(ICs).These structures have gained a particular interest for potential food applications,either as dietary fiber or as delivery systems of bioactive compounds.In the second case,the complexation of sensitive molecules is directed to protect them from processing,storage and stomach conditions and to guarantee a sustained release in the gastrointestinal tract.The present review covers the analytical and technological aspects of inclusion complexes,with focus on their potential application in the development of functional foods.It was addressed by first explaining the methodologies used for the analytical assessment of their structural,thermal,and functional properties,followed by the study of the functionality of ICs as carrier agents of different bioactive compounds and food ingredients,including alpha-lipoic acid,α-linolenic and linoleic fatty acids,conjugated linoleic acid,ascorbyl palmitate,phenolic compounds,and flavors.It also covers the application of ICs in food products and the analysis of the potential industrial scalability of the formation process.The analytical methodologies allowed a complete characterization of the ICs.These structures have shown suitable functional properties as delivery systems of the bioactive compounds and flavors covered in this review.The incorporation of ICs in food has led to the development of products with improved nutritional and/or functional value.The successful formation of complexes using methods suitable for an industrial scale represents promising preliminary results to achieve the scalability of the ICs production in the near future.展开更多
Oxide inclusions widely exist in additively manufactured components due to the native oxide layer on the powder surface,together with gas impurities during the printing process.Using in-situ tensile tests combined wit...Oxide inclusions widely exist in additively manufactured components due to the native oxide layer on the powder surface,together with gas impurities during the printing process.Using in-situ tensile tests combined with electron backscatter diffraction(EBSD)and electron channeling contrast imaging(ECCI)techniques,we propose an asymmetrical cracking mechanism around the oxide inclusions in a selective laser melted 316L stainless steel.The heterogeneous sub-micro cellular structures lead to different twinning tendencies around the inclusions due to the size-related critical twinning stresses,and the deformation-induced nano-twin clusters can resist the cracking propagation,therefore resulting in the asymmetrical cracking behaviors around the inclusions.展开更多
In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning...In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic microscope.The results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation alone.The inclusions were spheroidizing.The size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was dispersed.Ce played a role in purifying molten steel through desulphurization and deoxidization.Meanwhile,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar crystals.The average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled plate.In addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was obtained.When rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening effect.Mechanical properties such as tensile,yield,and low-temperature impact toughness were significantly improved.展开更多
An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two...An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two opposite orientations, i.e. the amine group of α-aminopyridine pointing to the primary side (1a, occupancy: 41.2%) or the secondary side (1b, occupancy: 58.8%) of β-cyclodextrin, forming two scalelike supramolecular aggregations. The studies of 2D NMR and circular dichroism spectra indicated that the α-aminopyridine molecule is deeply embedded in the β-cyclodextrin cavity to form host-guest inclusion complex, showing a circular dichroism spectrum induced by the chiral cavity of cyclodextrin. The results obtained are helpful for understanding the molecular recognition and aggregation mechanism between the host and guest.展开更多
The structures of closo-hedral cluster (HAlNH)12 and endohedral complexes X@(HAlNH)12 (X = He, Ne, Ar, Kr) have been studied by using density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natura...The structures of closo-hedral cluster (HAlNH)12 and endohedral complexes X@(HAlNH)12 (X = He, Ne, Ar, Kr) have been studied by using density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency, energetic parameters, magnetic shielding constants and nucleus independent chemical shifts (NICS) were discussed. The potential surface of guest X shifting from the cage center to a face of six- membered ring was calculated at the same level. The exit transition state was demonstrated with IRC calculations. It is found that X@(HAlNH)12 complexes are dynamically stable, and Ne@(HAlNH)12 is more energetically favorable than the other complexes in thermodynamics.展开更多
文摘Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB22040502)the National Natural Science Foundation of China(No.11672285)and the Fundamental Research Funds for the Central Universities of China(No.WK2090050043)。
文摘The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the phase field microelasticity(PFM)simulation.The results show a near-attraction and far-repulsion elastic interaction between two inclusions with hydrostatic dilatation.The critical spacing,at which the interaction changes from attraction to repulsion,is on the order of the radius of the rod,dependent on the length and Poisson’s ratio of inclusions.Furthermore,the elastic energy calculations and PFM simulation results indicate that applying the local radial stress on the rod surface can modulate the elastic interaction between inclusions and adjust the periodicity of the superlattice nanowire structure.This can provide some guidelines for the tunable construction of superlattice nanowire structures.
文摘With a high pH value, soda soil restricts the growth of plants. It had previously been assumed that the inhibition of plant growth by neutral salt stress was partly due to the changes of the ultrastructure and storage inclusions of chloroplasts. The aim of this paper is to investigate the effects of alkali-salt mixed stress of soda soil on chloroplasts of higher plant Syringa oblata Lindl. Testing S. oblata plants had grown for more than five years in soda soil, and transmission electron microscope was used for determining the ultrastructure and storage inclusions of chloroplasts. The results showed that some chloroplasts were destroyed, the normal chloroplasts became smaller, and the envelopes of the functional chloroplasts were slightly expanded generally in soda-stressed plants. The most noteworthy fact was that much more starchgrains accumulated in the chloroplasts of S. oblata growing in soda soil than in neutral soil. The total contents of plastoglobules in chloroplasts did not change considerably, and plastoglobules with different electron densities appeared in chloroplasts in the plants growing in soda soil. We presume that the reduction of the volume and number of functional chloroplasts and the occupation of carbon resources by starch grains accumulated in chloroplasts were the possible reasons for the inhibition of S. oblata growth by soda soil. The accumulation of starch grains was one of the adaptive traits of S. oblata, which promoted the survival of plants in soda soil for that the starch grains could serve as a steady source of soluble sugars, which were known as protectors of plant cells under stressed conditions. Soda soil did not significantly change the total content of plastoglobules in chloroplasts, but changed their compositions.
文摘: The crystal structure of an inclusion compound formed between acetyl-ferrocene pyridine-2, 6-diformylhydrazone and ethanol was report in the present work.The crystal of C33,H35N5O3Fe2 is monoclinic, space group C2/c with a = 23. 249 (3 ), b=ll. 576(2), c=22. 794(4) A, β=103. 53(l)’, V=5964(1) A3, Mr=66l- 37, Z=8, Dc= 1. 473g/cm3, F (000) = 2752. 00, μ = 10. l5 cm-1. It was found that theethanol molecule present in the crystal lattice depends on the van der Waals force ratherthan hydrogen bonding.
基金financially supported by National Natural Science Foundation of China(42272106,41202067)Open Fund of State Key Laboratory for Mineral Deposits Research,Nanjing University(2019-LAMD-K12)China Geological Survey(DD20211386,DD20211392,DD20179603).
文摘The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.
基金supported by the 973 program (2006CB932900)NNSFC (Nos. 20572048 and 20421202)NSF of Tianjin (07QTPTJC29700)
文摘X-ray crystal structures of the inclusion complexes of calix[4]arene monomethoxycarboxylic acid 1 (C30H2606) with acetontrile and acetone are reported. The crystal of C30H26O6·CH3CN is of monoclinic, space group P2 1/c with a = 11.691(5), b = 13.753(5), c = 17.072(7)A, β = 100.104(7)°, C32H29NO6, Mr = 523.56, V = 2702.4(18)A^3, Z = 4, De= 1.287 g/cm^3, μ(MoKα) = 0.089 mm^-1, T = 293(2) K, 5570 independent reflections with 3220 observed ones (1 〉 2σ(I)), R = 0.0521 and wR = 0.1132 with GOF = 1.042 (R = 0.1055 and wR = 0.1350 for all data). The data for C30H26O6·CH3COCH3: monoclinic, space group P2 1/c, α = 12.366(4), b = 12.119(4), c = 18.796(6) A, β = 90.871(6)°, C33H32O7, Mr = 540.59, V = 2816.6(16)A^3, Z = 4, Dc = 1.275 g/cm^3, μ(MoKα) = 0.089 mm^-1, T = 293(2) K, 5783 independent reflections including 2580 observed ones (I 〉 2σ(I)), R = 0.0555 and wR = 0.1424 with GOF= 0.975 (R = 0.1601 and wR = 0.1884 for all data). Their architectures exhibit one-dimensional inclusion polymers which are mediated head-to-tail by the guests.
文摘Two polymorphs of the inclusion compound [(n-C4H9)4N]+'(C13H903)H2O have been prepared and characterized by X-ray crystallography. Polymorph 1: triclinic P1, a = 13.4982(2), b = 13.5743(2), c = 17.1996(2) A, at = 67.045(1),β = 77.845(1), γ= 88.762(1)°, V = 2830.43(7) A3, Z = 4, R = 0.0491, wR= 0.1276; Polymorph 2: tetragonal P43, a = b = 13.53690(1) A, c = 30.8491(8) A, V = 5653.02(16) A3, Z = 8, R = 0.0448, wR = 0.0984. In these two crystal structures, the hydrogen-bonded ribbons built of 4,4'-dihydroxybenzophenone (DHBP, C13H1003) anions and water molecules are orderly arranged to generate two-dimensional host layers, with tetrabutylammonium cations contained between the layers to form the sandwich-like inclusion compounds. The structures of 1 and 2, which exist as two polymorphs, both display the similar packing pattern and hydrogen-bond linking model.
文摘The X-ray crystal structure of the inclusion complex of p-tert-butylcalix [4] crown-6 with actonitrile is reported. C54H70O10·3CH3CN, Mr=1002. 3 ,monoclinic, space group C2/c with cell dimensions of a=23.587(7),b=21.153(6),c=15.608(8) A,β=116.99(3)°,V=6939.2 A3,Z=4, F(000)=2160,Dc=0.959 g/cm3,μ=1.114 cm-1; R=0.088 for 2066 reflections with I>3σ(I).The calixarene subunit exists in a distorted cone conformation. One of the three acetonitrile molecules is located in the intracavity of the calixarene subunit and the other two in the intermolecular channels.
文摘THE Kuranakh gold deposit is located in the Aldan shield, in the southern portion of Siberian platform.Sub-horizontal, blanket-or ribbon-like ore bodies up to 50 m thick occur along and above the contact between Cambrian calcareous footwall rocks and overlaying Jurassic clastic rocks within a narrow zone, about30 km long, bounded by several south-north trending faults. To date the deposit is estimated to have produced more than 200 tonnes of gold at an average grade of 3.57 g/t Au extending over 41 years of production. Cambrian rock is predominantly composed of limestone and dolomite. The limestone contains a smallamount (1%-3%) of clastic material. The limestone is thin-bedded, platy, fractured, brecciated,cavernous, and porous. Its composition varies from pure limestone to spotted-banded dolomitic limestoneor "zebra" rock. The "zebra rock is characterized by the presence of finely disseminated organic materi-
基金Project supported by the Natural Science Foundation of Hainan Province (No. 808145).
文摘Two inclusion complexes of β-cyclodextrin-7-hydroxycoumarin (1) and ,β-cyclodextrin-4-hydroxycoumarin (2) were prepared and their crystal structures were investigated by single crystal X-ray crystallography under cryogenic condition. Both structures consist of stacks of face-to-face cyclodextrin dimers arranged in brickwork-like pattern along the crystallographic a-axis. For complex 1, each of the two dimeric β-cyclodextrins includes one 7-hydroxycoumarin molecule that penetrates deeply into the cyclodextrin dimer and locates its lactonering at the center of the dimer cavity. For complex 2, each cyelodextrin dimer accommodates three 4-hydroxycoumarin molecules. One of them is sandwiched between two units of the cyclodextrin dimer, the other two are shallowly included in the cavities of the dimeric cyclodextrins respectively and protrude their lactone rings from the primary end of the cyclodextrin. The substituent effects of guest molecules on inclusion geometry of various coumarin molecules in fl-cyclodextrin were examined.
文摘THE Yindongpo gold deposit, situated in northern Tongbei County, northern Qinling orogenic belt, is alarge-scale one controlled by the Heqianzhuang anticline that plunges northwestwards and dips northeastwards. The ore-bodies locates in the carbon layers belonging to the Neoproterozoic Waitoushan Formation.Two ore-forming periods can be distinguished: the pre-Mesozoic epithermal mineralization in primary sediment with metamorphic superposition and the Mesozoic epithermal-mesothermal mineralization related totectonomagmatic activities. The principal ore-forming period can be divided into four stages. The ore bodies consist of networked and brecciated quartz veins. Gold is mainly rich in the veinlet-type quartz veinsthat formed during the diagentic-metamorphism or syn-metamorphic hydrothermal period, but a little inthe coarse veins related to later tectonomagmatic activities. The phenomenon that the fracturing degree
文摘The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered guest molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The guest inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-guest stoichiometries are different,i.e.,2:1 for m-nitrophenoxyacetic acid and 1:1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.
基金supported by the National Natural Science Foundation of China(Nos.52274341 and 51974210).
文摘To avoid coarse crystallization of glassy inclusions in Si–Mn deoxidized steel during hot rolling, the effect of MgO on the structure and crystallization behavior of CaO–SiO_(2)–Al_(2)O_(3) inclusions was investigated. The results showed that the crystallization temperature of the oxide melts decreased with increasing MgO content from 0 to 15.7 wt.%, which suggested that the addition of MgO would increase the temperature range of the crystalline transition. The increase in MgO content could decrease the crystallization activation energy of inclusions. With the increase in MgO content, the relative fractions of O_(Si)^(0) and O_(Si)^(1) structure units increased, and those of structure units O_(Si)^(2), O_(Si)^(3), and O_(Si)^(4) decreased, increasing the depolymerization degree of the silicate structure. The crystallization ratio of glassy inclusions in the steel crucible increased from 19.7% to 98.3% with increasing MgO content from 0 to 15.7 wt.%. The addition of MgO improved the crystallization ability of inclusions, because MgO provides free oxygen O_(2−) to destroy the bridging oxygens and form non-bridging oxygens O^(−), which depolymerizes silicate network structure and simplifies the [SiO_(4)]-tetrahedral structure. In addition, MgO would promote the precipitation of the Mg-containing phases with a high melting point. When the MgO content was increased above 12.1 wt.%, MgO·Al_(2)O_(3) and 2MgO·SiO_(2) crystalline phases would precipitate from the inclusions.
基金supported by the National Natural Science Foundation of China(No.50374029)and(No.50204005).
文摘The mechanisms of La in heavy rail steel were studied by means of experimental measurements, microstructure observation and theoretical analysis in the present work. For heavy rail steel, the state and the content of La were measured, and the mechanisms and the effects of La on sulfide inclusions, microstracture and properties of steel were determined. Strip-like sulfides disappear in heavy rail steel with La/(O+S)〉3.50, which is shown that the metallurgical function of modifying sulfide inclusions has been achieved by La. La can fine the grain size of the austenite in heavy rail steel. Under the experimental condition, the plasticity and the impacting toughness of heavy rail steel with 0.005wt% La can evidently be improved.
基金supported by the Universidad Nacional de La Plata(UNLP)(11/X756,X907)the Agencia Nacional de Promoci´on Científicay Tecnol´ogica(PICT 2016-0323,2020-01274)(Argentina)the la ValSe-Food Project CYTED 119RT0567(Spain).
文摘The linear component of starch,amylose,has the ability to interact with hydrophobic molecules forming inclusion complexes(ICs).These structures have gained a particular interest for potential food applications,either as dietary fiber or as delivery systems of bioactive compounds.In the second case,the complexation of sensitive molecules is directed to protect them from processing,storage and stomach conditions and to guarantee a sustained release in the gastrointestinal tract.The present review covers the analytical and technological aspects of inclusion complexes,with focus on their potential application in the development of functional foods.It was addressed by first explaining the methodologies used for the analytical assessment of their structural,thermal,and functional properties,followed by the study of the functionality of ICs as carrier agents of different bioactive compounds and food ingredients,including alpha-lipoic acid,α-linolenic and linoleic fatty acids,conjugated linoleic acid,ascorbyl palmitate,phenolic compounds,and flavors.It also covers the application of ICs in food products and the analysis of the potential industrial scalability of the formation process.The analytical methodologies allowed a complete characterization of the ICs.These structures have shown suitable functional properties as delivery systems of the bioactive compounds and flavors covered in this review.The incorporation of ICs in food has led to the development of products with improved nutritional and/or functional value.The successful formation of complexes using methods suitable for an industrial scale represents promising preliminary results to achieve the scalability of the ICs production in the near future.
基金financially supported by the National Key Research and Development Program of China(No.2017YFB0702300)National Natural Science Foundation of China(No.51871028)+1 种基金Fundamental Research Funds for the Central Universities(No.FRF-TP-19-003B2)the China Scholarship Council for financial support。
文摘Oxide inclusions widely exist in additively manufactured components due to the native oxide layer on the powder surface,together with gas impurities during the printing process.Using in-situ tensile tests combined with electron backscatter diffraction(EBSD)and electron channeling contrast imaging(ECCI)techniques,we propose an asymmetrical cracking mechanism around the oxide inclusions in a selective laser melted 316L stainless steel.The heterogeneous sub-micro cellular structures lead to different twinning tendencies around the inclusions due to the size-related critical twinning stresses,and the deformation-induced nano-twin clusters can resist the cracking propagation,therefore resulting in the asymmetrical cracking behaviors around the inclusions.
基金financially supported by National Natural Science Foundation of China (No. 51774031)Open Project of State Key Laboratory of Advanced Special Steel, Shanghai University (SKLASS 2017-12)
文摘In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic microscope.The results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation alone.The inclusions were spheroidizing.The size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was dispersed.Ce played a role in purifying molten steel through desulphurization and deoxidization.Meanwhile,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar crystals.The average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled plate.In addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was obtained.When rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening effect.Mechanical properties such as tensile,yield,and low-temperature impact toughness were significantly improved.
基金supported by the National Natural Science Foundation of China (Grant Nos. 20272028 and 90306009).
文摘An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two opposite orientations, i.e. the amine group of α-aminopyridine pointing to the primary side (1a, occupancy: 41.2%) or the secondary side (1b, occupancy: 58.8%) of β-cyclodextrin, forming two scalelike supramolecular aggregations. The studies of 2D NMR and circular dichroism spectra indicated that the α-aminopyridine molecule is deeply embedded in the β-cyclodextrin cavity to form host-guest inclusion complex, showing a circular dichroism spectrum induced by the chiral cavity of cyclodextrin. The results obtained are helpful for understanding the molecular recognition and aggregation mechanism between the host and guest.
基金This work was supported by the National Natural Science Foundation of China (No. 20341005), Natural Science Foundation of Shanxi Province (No. 20011015) and the Foundation for University Key Teachers by the Ministry of Education
文摘The structures of closo-hedral cluster (HAlNH)12 and endohedral complexes X@(HAlNH)12 (X = He, Ne, Ar, Kr) have been studied by using density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency, energetic parameters, magnetic shielding constants and nucleus independent chemical shifts (NICS) were discussed. The potential surface of guest X shifting from the cage center to a face of six- membered ring was calculated at the same level. The exit transition state was demonstrated with IRC calculations. It is found that X@(HAlNH)12 complexes are dynamically stable, and Ne@(HAlNH)12 is more energetically favorable than the other complexes in thermodynamics.