Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impreg...Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
Based on the observation of outcrops and cores,thin section identification,restoration of paleogeomorphology by residual thickness method,fine description of seismic facies,etc.,the coupling relationships between the ...Based on the observation of outcrops and cores,thin section identification,restoration of paleogeomorphology by residual thickness method,fine description of seismic facies,etc.,the coupling relationships between the development patterns of various types of Cambrian platform margin mound-shoal complexes and paleogeomorphology in the Gucheng area of Tarim Basin have been examined.The Cambrian platform margin mound-shoal complex is divided into mound base,mound core,mound front,mound back and mound flat microfacies,which are composed of dolomites of seven textures with facies indication.The different paleogeomorphology before the deposition of mound-shoal complex in each period was reconstructed,and three types of mound-shoal complex sedimentary models corresponding to the paleogeomorphologies of four stages were established:namely,the first stage of gentle slope symmetric accretion type,the second stage of steep slope asymmetric accretion type and the third and fourth stages of steep slope asymmetric progradation type.Their microfacies are respectively characterized by-mound base-mound back+(small)mound core+mound front-mound flat"symmetric vertical accretion structure,"mound base-(large)mound core+mound front-mound flat"asymmetric vertical accretion structure,"mound base-(small)mound core+mound front-mound flat"asymmetric lateral progradation structure.With most developed favorable reservoir facies belt,the steep slope asymmetric accretion type mound-shoal complex with the characteristics of"large mound and large shoal"is the exploration target for oil and gas reservoir.展开更多
OBJECTIVE:To explore the characteristics of blood glucose excursions of type 2 diabetes mellitus patients with three different Traditional Chinese Medicine(TCM) syndromes.METHODS:One hundred and nine patients with typ...OBJECTIVE:To explore the characteristics of blood glucose excursions of type 2 diabetes mellitus patients with three different Traditional Chinese Medicine(TCM) syndromes.METHODS:One hundred and nine patients with type 2 diabetes mellitus were recruited from the Department of Endocrinology and the Department of TCM of the Sixth People's Hospital affiliated to Shanghai Jiao Tong University.Subjects were divided into three groups according to TCM syndrome:intrinsic Damp(n- 42),Yin deficiency and internal Heat(n = 25),and Qi and Yin deficiency(n- 42).Subcutaneous interstitial glucose was monitored with a continuous glucose monitoring system for 3consecutive days to investigate the glycemic profile in each group.Plasma C-peptide levels were measured,and an arginine test was taken in 10 patients randomly selected from each group.Glucose data and glycemic variability were analyzed to investigate the differences among the groups.The change in C-peptide levels and the results from arginine trial were used to evaluate β cell function.RESULTS:Indicators reflecting blood glucose level were the highest in subjects with Yin deficiency and internal Heat syndrome,and parameters reflecting glycemic variability were the lowest in those with Qi and Yin deficiency syndrome.The change in C-peptide levels showed that subjects with Qi and Yin deficiency syndrome had the best βcell function among the three groups;this was confirmed by the arginine trial.CONCLUSION:Patients with Qi and Yin deficiency syndrome had a more stable blood glucose profile,as glycemic variability was higher in those with intrinsic Damp syndrome and those with Yin deficiency and internal Heat syndrome.展开更多
To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the abs...To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the absence and presence of carboxylic acids. The results show that all the tested organic acids（acetic acid,malonic acid, citric acid, tartaric acid, succinic acid, and malic acid） can promote RE extraction. At relatively high concentrations of organic acids, the activation efficiency of organic acids on RE extraction is generally consistent with their complexation ability; whereas at their low concentrations, the change of zeta potential on the IRE-ore surface with organic acid concentration and p H has a close association with RE extraction, which indicates that organic acids can impact the surface electrical property of IREore via their adsorption/desorption, and thereby increase/decrease the affinity of RE ions to IRE-ore.Therefore the influence of organic acids on the IRE-ore surface electrical property also plays an important role in RE extraction in addition to their complexation with RE ions.展开更多
In this paper we investigate simultaneous approximation for arbitrary system of nodes on smooth domain in complex plane. Some results which are better than those of known theorems are obtained.
The urea nitrogen adsorbent of complex type, which consists of chitosan coated dialdehyde cellulose （CDAC） and immobilized urease in gelatin membrane （IE）, was prepared. The cellulose, the dialdehyde cellulose （...The urea nitrogen adsorbent of complex type, which consists of chitosan coated dialdehyde cellulose （CDAC） and immobilized urease in gelatin membrane （IE）, was prepared. The cellulose, the dialdehyde cellulose （DAC） and the CDAC were characterized by scanning electronic microscope. The results indicate that the cellulose C2-C3 bond was broken under the oxidation of periodate and it was oxidated to DAC. The DAC was coated with chitosan and the CDAC was obtained. The adsorption of urea nitrogen onto the adsorbent in Na2HPO4-NaH2PO4 buffer solution was studied in batch system. The effects of the experiment parameters, including degree of oxidation of CDAC, initial urea nitrogen concentration, pH and temperature, on the adsorption capacity of urea nitrogen onto the adsorbent at CDAC/IE weight ratio 10：1 were investigated. The results indicate that these parameters affected significantly the adsorption capacity. The adsorption capacity of urea nitrogen onto the adsorbent was 36.7 mg/g at the degree of oxidation of CDAC 88%, initial urea nitrogen concentration 600 mg/L, pH 7.4 and temperature 37℃.展开更多
In the present article, we deal with the so-called overconvergence phenomenon in C of a slightly modified Post-Widder operator of real variable, that is with the extension of its approximation properties from the real...In the present article, we deal with the so-called overconvergence phenomenon in C of a slightly modified Post-Widder operator of real variable, that is with the extension of its approximation properties from the real axis in the complex plane.In this sense, error estimates in approximation and a quantitative Voronovskaya-type asymptotic formula are established.展开更多
The mafic-ultramafic complexes and associated formationsare wide spread within the Ural folded belt,which is located on the boundary of the East European plate and West Siberian sedimentary basin.Two main
In this work,we report three isostructural Fe_(4)Ln_(4)wheel type complexes with molecular formula[{Fe_(4)(dea)_(4)Dy_(4)(deaH)8(μ2-OMe)_(4)}(NO_(3))_(4)]·4(H_(2)O)(1),[{Fe_(4)(dea)_(4)Gd_(4)(deaH)8(μ2-OMe)_(4)...In this work,we report three isostructural Fe_(4)Ln_(4)wheel type complexes with molecular formula[{Fe_(4)(dea)_(4)Dy_(4)(deaH)8(μ2-OMe)_(4)}(NO_(3))_(4)]·4(H_(2)O)(1),[{Fe_(4)(dea)_(4)Gd_(4)(deaH)8(μ2-OMe)_(4)}·(NO_(3))_(4)]·_(4)(H_(2)O)·_(4)(MeOH)(2)and[{Fe_(4)(dea)_(4)Y_(4)(deaH)_(8)(μ2-OMe)_(4)}(NO_(3))_(4)]·_(4)(H_(2)O)·6(MeOH)(3),(where dea=diethanolamine).Detailed structural analysis discloses that the_(4)Ln^(Ⅲ)and_(4)Fe^(Ⅲ)ions are connected alternatively in a cyclic arrangement through the oxo-bridging of methanol and diethanolamine molecules.The detailed magnetic measurements reveal the presence of ferromagnetic exchange interactions between the Ln^(Ⅲ)and Fe^(Ⅲ)centers in complexes 1 and 2,whereas a weak antiferromagnetic interaction is observed between Fe^(Ⅲ)centers in complex 3.In addition,complex 1 shows slow magnetic relaxation behavior(U_(eff)=9.8 K)under zero field and a remarkable entropy change was observed for complex 2 at 7 T magnetic field(magnetocaloric effect=31.15 J kg^(−1)K^(−1)).The ab initio calculations disclose the presence of strong axial anisotropy and a minimum transverse component(gx=0.002_(4),gy=0.0062,and gz=19.82)in the ground state of each Dy^(Ⅲ)ion for complex 1.It was also found that the local anisotropy axis on each Dy^(Ⅲ)ion is arranged in a vortex-like structure as observed in single molecule toroics(SMTs).From BS-DFT calculations,it was found that the exchange interactions between Fe-Ln metal centers mainly follow the charge transfer process between 3d and_(4)f orbitals.展开更多
A series of potentially explosive Werner-type cobalt(Ⅲ)complexes comprising the anions azotetrazolate,nitrotetrazolate,picrate and dipicrylamide were prepared via simple metathetical routes.Treatment of[Co(NH_(3))_(5...A series of potentially explosive Werner-type cobalt(Ⅲ)complexes comprising the anions azotetrazolate,nitrotetrazolate,picrate and dipicrylamide were prepared via simple metathetical routes.Treatment of[Co(NH_(3))_(5)NO_(2)]Cl_(2),trans-[Co(NH_(3))_(4)(py)NO_(2)]Cl_(2)(py=pyridine),trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl,and[Co(NH_(3))_(5)N_(3)]Cl_(2)with equimolar amounts of disodium azotetrazolate,(Na_(2)C_(2)N_(10)·5H_(2)O,1),in aqueous solutions afforded new cobalt(Ⅲ)azotetrazolate salts[Co(NH_(3))_(5)NO_(2)](C_(2)N_(10))·2H_(2)O(2),trans-[Co(NH_(3))_(4)(py)-NO_(2)](C_(2)N_(10))·2H_(2)O_(3),trans-[Co(NH_(3))_(4)(NO_(2))_(2)]2(C_(2)N_(10))(4),and[Co(NH_(3))_(5)N_(3)](C_(2)N_(10))·H_(2)O(5)in moderate to excellent yields(46–88%).Similar treatment of trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl with 1 equiv.of sodium 5-nitrotetrazolate dihydrate(=NaNT,6)afforded the novel cobalt(Ⅲ)5-nitrotetrazolate derivative trans-[Co(NH_(3))_(4)(NO_(2))_(2)](NT)·H_(2)O(7)as orange,rectangular prismatic crystals in 64%yield.Two complex cobalt(Ⅲ)picrates,trans-[Co(NH_(3))_(4)(NO_(2))_(2)](picrate)·H_(2)O(9)and[Co(NH_(3))_(5)N_(3)](picrate)2(10),were prepared in a similar manner from the corresponding chloride precursors and equimolar amounts of sodium picrate.The reaction of trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl with sodium dipicrylamide(=NaDPA)in a 1:1 molar ratio gave the first cobalt(Ⅲ)dipicrylamide,trans-[Co(NH_(3))_(4)(NO_(2))_(2)](DPA)·H_(2)O(12).Finally,the highly explosive,dark blue-green dichroitic non-electrolyte complex mer-[Co(en)(py)(N_(3))_(3)](13)was formed upon treatment of[Co(en)(py)_(2)(NH_(3))Cl]Cl_(2)·H_(2)O with excess NaN_(3)in hot water(93%yield).The molecular and crystal structures of 2,3,4,5,7,9,10,12,and 13 were determined by single-crystal X-ray diffraction.In the solid state,all compounds comprised extensive hydrogen-bonded supramolecular networks.Representative studies of the energetic properties(impact and friction sensitivity,combustion)revealed that some of the new compounds can be classified as primary explosives.展开更多
The density functional theory(DFT)method and natural bond orbital(NBO)analysis have been employed to investigate the electronic structures and second-order nonlinear optical(NLO)properties for tricarbonyl metal deriva...The density functional theory(DFT)method and natural bond orbital(NBO)analysis have been employed to investigate the electronic structures and second-order nonlinear optical(NLO)properties for tricarbonyl metal derivatives of a Lindqvist-type polyoxometalate,[Nb_(2)W_(4)O_(19)M(CO)_(3)]^(3−/2−)(M=Mn^(Ⅰ),Tc^(Ⅰ),Re^(Ⅰ),Fe^(Ⅱ),Ru^(Ⅱ)and Os^(Ⅱ)).The position of the tricarbonyl metal ligand and the substitution of different metal atoms M have an influence on the electronic absorption spectra and NLO responses of all complexes.Among the three isomers of[Nb_(2)W_(4)O_(19)Mn(CO)_(3)]^(3−),theβ_(0)value of isomer 1^(a)is the largest,which is 1.4 times and 2.3 times larger than those of isomers 1^(b)and 1^(c),respectively.Theβ_(0)value also depends on the tricarbonyl metal M,theβ_(0)value decreases in the order M=Ru>Re>Fe>Os>Mn>Tc.In addition,the analysis of the main transition orbitals shows that the tricarbonyl metal ligand acts as an electron donor in[Nb_(2)W_(4)O_(19)M(CO)_(3)]^(3−/2−)(M=Mn^(Ⅰ),Tc^(Ⅰ),Re^(Ⅰ),Ru^(Ⅱ)and Os^(Ⅱ)),while the[Fe(CO)_(3)]^(2+)ligand acts as an electron acceptor in[Nb_(2)W_(4)O_(19)Fe(CO)_(3)]^(2−).展开更多
A series of new sandwich type lanthanide complexes containing both boratabenzene and cyclooctatetraenyl ligands,[(C5H5BR)Ln(COT)](1Er:R=H,Ln=Er;2Er:R=Me,Ln=Er;3Er:R=NEt2,Ln=Er;4Dy:R=H,Ln=Dy;5Dy:R=Me,Ln=Dy;6Dy:R=NEt_(2...A series of new sandwich type lanthanide complexes containing both boratabenzene and cyclooctatetraenyl ligands,[(C5H5BR)Ln(COT)](1Er:R=H,Ln=Er;2Er:R=Me,Ln=Er;3Er:R=NEt2,Ln=Er;4Dy:R=H,Ln=Dy;5Dy:R=Me,Ln=Dy;6Dy:R=NEt_(2),Ln=Dy;7Y:R=NEt2,Ln=Y),were synthesized.The structures of 1Er-7Y were all characterized by single crystal X-ray diffraction.Dynamic susceptibility experiments showed that the erbium complexes 1Er-3Er exhibited slow magnetic relaxation under zero dc field while the dysprosium complexes 4Dy-6Dy did not.For the erbium complexes,the magnetic properties were influenced by the substituent on the boron atom.1Er exhibited hysteresis up to 8 K,and 2Er featured the highest energy barrier(300 cm^(-1))among all the reported erbium single-ion magnets(SIMs).The influence of the boron substituent on the magnetic properties was highlighted by ab initio calculations.展开更多
Tunnel stability control is a world-wide difficult problem. For the sake of solving it,the new theory of soft rock engineering mechanics has been estabilished. Some key points,such as the definition and classification...Tunnel stability control is a world-wide difficult problem. For the sake of solving it,the new theory of soft rock engineering mechanics has been estabilished. Some key points,such as the definition and classification of soft rock, mechanical deformation mechanism of a soft rock tunnel, the critical support technique of soft rock tunnel and the new theory of the soft rock tunnel stability control are proposed in this paper.展开更多
In this paper, push-over analysis for tall concrete structures was made and a corresponding computer program was given. Several kinds of elements in the program were considered to meet the demand of tall buildings wit...In this paper, push-over analysis for tall concrete structures was made and a corresponding computer program was given. Several kinds of elements in the program were considered to meet the demand of tall buildings with complex structural type. These elements included beam-column element for beams and columns, single slice wall element and three vertical line element for walls, and tube-wall element for tubes. Computational example for verifying the models indicates that the result obtained by this method is identical with a well-known test result and the program can be used to search for the full process of structural reaction, even the softening stage of the structure. With this push-over analysis method, an actual tall building with complex structural type was analyzed, and the result has been put into practice of the structural design of the building. Key words push-over analysis - tall structure - complex type - nonlinearity - earthquake level - weak storey MSC2000 74S05 - 74L99 Project supported by the National Natural Science Foundation of China (Grant No. 50025821)展开更多
With the scale of programs becoming increasingly bigger, and the complexity degree higher, how to select program fragments for slicing has become an important research topic. A new type of criterion called interesting...With the scale of programs becoming increasingly bigger, and the complexity degree higher, how to select program fragments for slicing has become an important research topic. A new type of criterion called interesting index is proposed for selecting parts of procedures or procedure fragments to do program slicing. This new criterion considers not only the subjective aspects in users, namely users' emphasis on the time efficiency, storage capacity or readability, but also the objective aspect in large procedures. It also represents the benefit of the users, while displaying the many-faceted roles that program slicing plays. In this way users call proceed with program slicing to large systems or unfinished systems.展开更多
Objective To study the relationship between human leukocyte antigen (HLA) DRB1 and DQ alleles and the genetic susceptibility of type 1 diabetes in North Chinese children Methods Polymerase chain reaction (PCR) tec...Objective To study the relationship between human leukocyte antigen (HLA) DRB1 and DQ alleles and the genetic susceptibility of type 1 diabetes in North Chinese children Methods Polymerase chain reaction (PCR) techniques were used to amplify the second exon of DRB1 and DQ alleles, after which sequence specific olignucleotide probe (SSOP) dot blot hybridization techniques were used to analyze the amplified products Results DRB1*0301, DQA1*0301, DQB1*0201 alleles and DRB1*0301 DQA1*0501 DQB1*0201 haplotype were significantly increased in patients, while DQA1*0103 and DQB1*0601 alleles were significantly increased in controls The distribution of DR4 and DR9 haplotypes in patients and controls were not significantly different, but DR3/DR4 and DR4/DR9 heterozygotes were significantly increased in patients Conclusions DRB1*0301, DQA1*0301 and DQB1*0201 confer susceptibility while DQA1*0103 and DQB1*0601 confer protection to type 1 diabetes DRB1*0301 DQA1*0501 DQB1*0201 haplotype offers a predisposition to type 1 diabetes in North Chinese Although the distribution of DR4 and DR9 in patients and controls had no significant difference, DR3/DR4 and DR3/DR9 heterozygotes were significantly increased in patients, showing that the susceptive effects of DR3 and DR4 or DR4 and DR9 haplotypes could be added up展开更多
Spaceborne photon-counting LiDAR is significantly affected by noise,and existing denoising algorithms cannot be universally adapted to different surface types and topographies under all observation conditions.Accordin...Spaceborne photon-counting LiDAR is significantly affected by noise,and existing denoising algorithms cannot be universally adapted to different surface types and topographies under all observation conditions.Accordingly,a new denoising method is presented to extract signal photons adaptively.The method includes two steps.First,the local neighborhood radius is calculated according to photons’density,then thefirst-step denoising process is completed via photons’curvature feature based on KNN search and covariance matrix.Second,the local photonfiltering direction and threshold are obtained based on thefirst-step denoising results by RANSAC and elevation frequency histogram,and the local dense noise photons that thefirst-step cannot be identified are further eliminated.The following results are drawn:(1)experimental results on MATLAS with different topographies indicate that the average accuracy of second-step denoising exceeds 0.94,and the accuracy is effectively improves with the number of denoising times;(2)experiments on ICESat-2 under different observation conditions demonstrate that the algorithm can accurately identify signal photons in different surface types and topographies.Overall,the proposed algorithm has good adaptability and robustness for adaptive denoising of large-scale photons,and the denoising results can provide more reasonable and reliable data for sustainable urban development.展开更多
A tetranuclear cubane-type complex[Co_(4)(ntfa)_(4)(CH_(3)O)_(4)(CH_(3)OH)_(4)](1)with a{Co_(4)O_(4)}core,and a mononuclear complex[Co(ntfa)_(2)(CH_(3)OH)_(2)](2)have been rationally obtained by adjusting the ratio of...A tetranuclear cubane-type complex[Co_(4)(ntfa)_(4)(CH_(3)O)_(4)(CH_(3)OH)_(4)](1)with a{Co_(4)O_(4)}core,and a mononuclear complex[Co(ntfa)_(2)(CH_(3)OH)_(2)](2)have been rationally obtained by adjusting the ratio of theβ-diketonate and Co(II)ions,with the synthetic processes being monitored by in situ microcalorimetry.Then,following synthetic conditions to obtain 2,but using three distinct N-donor coligands-2,2’-bipyridyl(bpy),6,6’-dimethyl-2,2’-bipyridyl(6,6-(CH_(3))_(2)-bpy)and 5,5’-dimethyl-2,2’-bipyridyl(5,5-(CH_(3))_(2)-bpy)-three novel mononuclear complexes have been obtained,[Co(ntfa)_(2)(bpy)_(2)](3),[Co(ntfa)_(2)(6,6-(CH_(3))_(2)-bpy)_(2)](4)and[Co(ntfa)_(2)(5,5-(CH_(3))_(2)-bpy)_(2)](5).The introduction of different capping coligands-as singlecrystal X-ray crystallography ascertains-fine-tunes the structures,with changes in both the distortion degree of the coordination geometry and the intermolecular interactions,which have a direct impact on the magnetic properties of these complexes.Magnetic investigations reveal field-induced single-ion magnet behavior in all complexes with distinct energy barriers(Ueff)-39.06(1),36.65(2),36.32(3),28.26(4)and 15.85 K(5).Magnetic experiments together with HF-EPR measurements and theoretical calculations demonstrate that 2 features easy-axis magnetic anisotropy(D=-60.48 cm^(-1)),whereas 3-5 show easy-plane magnetic anisotropies-D=+70.77 cm^(-1) for 3,+35.71 cm^(-1) for 4,and+51.28 cm^(-1) for 5.To our knowledge,such reversal of anisotropic nature driven by coligands is unprecedented.展开更多
In this paper,we give certain homotopy and diffeomorphism versions as a generalization to an earlier result due to W.S.Cheung,Bun Wong and Stephen S.T.Yau concerning a local rigidity problem of the tangent bundle over...In this paper,we give certain homotopy and diffeomorphism versions as a generalization to an earlier result due to W.S.Cheung,Bun Wong and Stephen S.T.Yau concerning a local rigidity problem of the tangent bundle over compact surfaces of general type.展开更多
Nerve-tissue interactions are critical.Peripheral nerve injuries may involve intraneural and extraneural scar formation and affect nerve gliding planes,sometimes leading to complex clinical presentations.All of these ...Nerve-tissue interactions are critical.Peripheral nerve injuries may involve intraneural and extraneural scar formation and affect nerve gliding planes,sometimes leading to complex clinical presentations.All of these pathological entities involve pain as the main clinical symptom and can be subsumed under the term“painful scar neuropathy”.The authors review the literature on treatment approaches to peripheral nerve scar neuropathy and the outcomes of neurolysis-associated procedures and propose a simple classification and a therapeutic approach to scar neuropathy.The search retrieved twenty-one papers,twenty of which reported pain reduction or resolution with various techniques.There is no consensus on the best therapeutic approach to neuropathic pain due to scar tethering.Most authors report good or excellent results with different techniques,from nerve wrapping with anti-adhesion devices to nerve coverage or wrapping with vascularized tissue.The authors’classification of and therapeutic approach to peripheral nerve scar lesions aims at promoting a logical approach based on the analysis of lesion type(perineural,or endoneural and perineural),pain type(due to traction or external trauma,pain at rest),and number of previous operations.Patients need to be informed that multiple procedures may be required,that outcomes may be partial,and that surgery can potentially worsen preoperative conditions.The review found no evidence for the best therapeutic approach to scar neuropathy,but there is consensus on a multidisciplinary approach.展开更多
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
基金Supported by the National Natural Science Foundation of China(41772103)China National Science and Technology Major Project(2016ZX05007-002)Petrochina Science and Technology Major Project(2016E-0204)。
文摘Based on the observation of outcrops and cores,thin section identification,restoration of paleogeomorphology by residual thickness method,fine description of seismic facies,etc.,the coupling relationships between the development patterns of various types of Cambrian platform margin mound-shoal complexes and paleogeomorphology in the Gucheng area of Tarim Basin have been examined.The Cambrian platform margin mound-shoal complex is divided into mound base,mound core,mound front,mound back and mound flat microfacies,which are composed of dolomites of seven textures with facies indication.The different paleogeomorphology before the deposition of mound-shoal complex in each period was reconstructed,and three types of mound-shoal complex sedimentary models corresponding to the paleogeomorphologies of four stages were established:namely,the first stage of gentle slope symmetric accretion type,the second stage of steep slope asymmetric accretion type and the third and fourth stages of steep slope asymmetric progradation type.Their microfacies are respectively characterized by-mound base-mound back+(small)mound core+mound front-mound flat"symmetric vertical accretion structure,"mound base-(large)mound core+mound front-mound flat"asymmetric vertical accretion structure,"mound base-(small)mound core+mound front-mound flat"asymmetric lateral progradation structure.With most developed favorable reservoir facies belt,the steep slope asymmetric accretion type mound-shoal complex with the characteristics of"large mound and large shoal"is the exploration target for oil and gas reservoir.
基金Supported by the State Administration of Traditional Chinese Medicine plan projects:Base Construction of Traditional Chinese Medicine Clinical Research(No.JDZX2012129)Shanghai Science and Technology Commitment plan projects:Science and Technology Support Project(No.12401905000)
文摘OBJECTIVE:To explore the characteristics of blood glucose excursions of type 2 diabetes mellitus patients with three different Traditional Chinese Medicine(TCM) syndromes.METHODS:One hundred and nine patients with type 2 diabetes mellitus were recruited from the Department of Endocrinology and the Department of TCM of the Sixth People's Hospital affiliated to Shanghai Jiao Tong University.Subjects were divided into three groups according to TCM syndrome:intrinsic Damp(n- 42),Yin deficiency and internal Heat(n = 25),and Qi and Yin deficiency(n- 42).Subcutaneous interstitial glucose was monitored with a continuous glucose monitoring system for 3consecutive days to investigate the glycemic profile in each group.Plasma C-peptide levels were measured,and an arginine test was taken in 10 patients randomly selected from each group.Glucose data and glycemic variability were analyzed to investigate the differences among the groups.The change in C-peptide levels and the results from arginine trial were used to evaluate β cell function.RESULTS:Indicators reflecting blood glucose level were the highest in subjects with Yin deficiency and internal Heat syndrome,and parameters reflecting glycemic variability were the lowest in those with Qi and Yin deficiency syndrome.The change in C-peptide levels showed that subjects with Qi and Yin deficiency syndrome had the best βcell function among the three groups;this was confirmed by the arginine trial.CONCLUSION:Patients with Qi and Yin deficiency syndrome had a more stable blood glucose profile,as glycemic variability was higher in those with intrinsic Damp syndrome and those with Yin deficiency and internal Heat syndrome.
基金Project supported by National Natural Science Foundation of China(51604128)
文摘To examine the activation of organic acids on the leaching process of ion-adsorption type rare earth ore（IRE-ore）, the leaching behavior of rare earth（RE） and zeta potential of IRE-ore were investigated in the absence and presence of carboxylic acids. The results show that all the tested organic acids（acetic acid,malonic acid, citric acid, tartaric acid, succinic acid, and malic acid） can promote RE extraction. At relatively high concentrations of organic acids, the activation efficiency of organic acids on RE extraction is generally consistent with their complexation ability; whereas at their low concentrations, the change of zeta potential on the IRE-ore surface with organic acid concentration and p H has a close association with RE extraction, which indicates that organic acids can impact the surface electrical property of IREore via their adsorption/desorption, and thereby increase/decrease the affinity of RE ions to IRE-ore.Therefore the influence of organic acids on the IRE-ore surface electrical property also plays an important role in RE extraction in addition to their complexation with RE ions.
文摘In this paper we investigate simultaneous approximation for arbitrary system of nodes on smooth domain in complex plane. Some results which are better than those of known theorems are obtained.
基金SUPPORTED BY NATURAL SCIENCE FOUNDATION OF TIANJIN ( NO. 033802011).
文摘The urea nitrogen adsorbent of complex type, which consists of chitosan coated dialdehyde cellulose （CDAC） and immobilized urease in gelatin membrane （IE）, was prepared. The cellulose, the dialdehyde cellulose （DAC） and the CDAC were characterized by scanning electronic microscope. The results indicate that the cellulose C2-C3 bond was broken under the oxidation of periodate and it was oxidated to DAC. The DAC was coated with chitosan and the CDAC was obtained. The adsorption of urea nitrogen onto the adsorbent in Na2HPO4-NaH2PO4 buffer solution was studied in batch system. The effects of the experiment parameters, including degree of oxidation of CDAC, initial urea nitrogen concentration, pH and temperature, on the adsorption capacity of urea nitrogen onto the adsorbent at CDAC/IE weight ratio 10：1 were investigated. The results indicate that these parameters affected significantly the adsorption capacity. The adsorption capacity of urea nitrogen onto the adsorbent was 36.7 mg/g at the degree of oxidation of CDAC 88%, initial urea nitrogen concentration 600 mg/L, pH 7.4 and temperature 37℃.
文摘In the present article, we deal with the so-called overconvergence phenomenon in C of a slightly modified Post-Widder operator of real variable, that is with the extension of its approximation properties from the real axis in the complex plane.In this sense, error estimates in approximation and a quantitative Voronovskaya-type asymptotic formula are established.
基金supported by the Program of UD RAS (project № 15-18-5-24)
文摘The mafic-ultramafic complexes and associated formationsare wide spread within the Ural folded belt,which is located on the boundary of the East European plate and West Siberian sedimentary basin.Two main
基金the SRF fellowship and S.K.thanks CSIR(project no.01(2974)/19/EMR-II)SERB(project no.CRG/2018/000072)Government of India and IISER Bhopal for generous financial support.
文摘In this work,we report three isostructural Fe_(4)Ln_(4)wheel type complexes with molecular formula[{Fe_(4)(dea)_(4)Dy_(4)(deaH)8(μ2-OMe)_(4)}(NO_(3))_(4)]·4(H_(2)O)(1),[{Fe_(4)(dea)_(4)Gd_(4)(deaH)8(μ2-OMe)_(4)}·(NO_(3))_(4)]·_(4)(H_(2)O)·_(4)(MeOH)(2)and[{Fe_(4)(dea)_(4)Y_(4)(deaH)_(8)(μ2-OMe)_(4)}(NO_(3))_(4)]·_(4)(H_(2)O)·6(MeOH)(3),(where dea=diethanolamine).Detailed structural analysis discloses that the_(4)Ln^(Ⅲ)and_(4)Fe^(Ⅲ)ions are connected alternatively in a cyclic arrangement through the oxo-bridging of methanol and diethanolamine molecules.The detailed magnetic measurements reveal the presence of ferromagnetic exchange interactions between the Ln^(Ⅲ)and Fe^(Ⅲ)centers in complexes 1 and 2,whereas a weak antiferromagnetic interaction is observed between Fe^(Ⅲ)centers in complex 3.In addition,complex 1 shows slow magnetic relaxation behavior(U_(eff)=9.8 K)under zero field and a remarkable entropy change was observed for complex 2 at 7 T magnetic field(magnetocaloric effect=31.15 J kg^(−1)K^(−1)).The ab initio calculations disclose the presence of strong axial anisotropy and a minimum transverse component(gx=0.002_(4),gy=0.0062,and gz=19.82)in the ground state of each Dy^(Ⅲ)ion for complex 1.It was also found that the local anisotropy axis on each Dy^(Ⅲ)ion is arranged in a vortex-like structure as observed in single molecule toroics(SMTs).From BS-DFT calculations,it was found that the exchange interactions between Fe-Ln metal centers mainly follow the charge transfer process between 3d and_(4)f orbitals.
文摘A series of potentially explosive Werner-type cobalt(Ⅲ)complexes comprising the anions azotetrazolate,nitrotetrazolate,picrate and dipicrylamide were prepared via simple metathetical routes.Treatment of[Co(NH_(3))_(5)NO_(2)]Cl_(2),trans-[Co(NH_(3))_(4)(py)NO_(2)]Cl_(2)(py=pyridine),trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl,and[Co(NH_(3))_(5)N_(3)]Cl_(2)with equimolar amounts of disodium azotetrazolate,(Na_(2)C_(2)N_(10)·5H_(2)O,1),in aqueous solutions afforded new cobalt(Ⅲ)azotetrazolate salts[Co(NH_(3))_(5)NO_(2)](C_(2)N_(10))·2H_(2)O(2),trans-[Co(NH_(3))_(4)(py)-NO_(2)](C_(2)N_(10))·2H_(2)O_(3),trans-[Co(NH_(3))_(4)(NO_(2))_(2)]2(C_(2)N_(10))(4),and[Co(NH_(3))_(5)N_(3)](C_(2)N_(10))·H_(2)O(5)in moderate to excellent yields(46–88%).Similar treatment of trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl with 1 equiv.of sodium 5-nitrotetrazolate dihydrate(=NaNT,6)afforded the novel cobalt(Ⅲ)5-nitrotetrazolate derivative trans-[Co(NH_(3))_(4)(NO_(2))_(2)](NT)·H_(2)O(7)as orange,rectangular prismatic crystals in 64%yield.Two complex cobalt(Ⅲ)picrates,trans-[Co(NH_(3))_(4)(NO_(2))_(2)](picrate)·H_(2)O(9)and[Co(NH_(3))_(5)N_(3)](picrate)2(10),were prepared in a similar manner from the corresponding chloride precursors and equimolar amounts of sodium picrate.The reaction of trans-[Co(NH_(3))_(4)(NO_(2))_(2)]Cl with sodium dipicrylamide(=NaDPA)in a 1:1 molar ratio gave the first cobalt(Ⅲ)dipicrylamide,trans-[Co(NH_(3))_(4)(NO_(2))_(2)](DPA)·H_(2)O(12).Finally,the highly explosive,dark blue-green dichroitic non-electrolyte complex mer-[Co(en)(py)(N_(3))_(3)](13)was formed upon treatment of[Co(en)(py)_(2)(NH_(3))Cl]Cl_(2)·H_(2)O with excess NaN_(3)in hot water(93%yield).The molecular and crystal structures of 2,3,4,5,7,9,10,12,and 13 were determined by single-crystal X-ray diffraction.In the solid state,all compounds comprised extensive hydrogen-bonded supramolecular networks.Representative studies of the energetic properties(impact and friction sensitivity,combustion)revealed that some of the new compounds can be classified as primary explosives.
基金financial support by NSFC(21131001)the Program for New Century Excellent Talents in University(NCET-10-318)+1 种基金the Doctoral Fund of Ministry of Education of China(20100043120007)the Science and Technology Development Planning of Jilin Province(20100104,20100320).
文摘The density functional theory(DFT)method and natural bond orbital(NBO)analysis have been employed to investigate the electronic structures and second-order nonlinear optical(NLO)properties for tricarbonyl metal derivatives of a Lindqvist-type polyoxometalate,[Nb_(2)W_(4)O_(19)M(CO)_(3)]^(3−/2−)(M=Mn^(Ⅰ),Tc^(Ⅰ),Re^(Ⅰ),Fe^(Ⅱ),Ru^(Ⅱ)and Os^(Ⅱ)).The position of the tricarbonyl metal ligand and the substitution of different metal atoms M have an influence on the electronic absorption spectra and NLO responses of all complexes.Among the three isomers of[Nb_(2)W_(4)O_(19)Mn(CO)_(3)]^(3−),theβ_(0)value of isomer 1^(a)is the largest,which is 1.4 times and 2.3 times larger than those of isomers 1^(b)and 1^(c),respectively.Theβ_(0)value also depends on the tricarbonyl metal M,theβ_(0)value decreases in the order M=Ru>Re>Fe>Os>Mn>Tc.In addition,the analysis of the main transition orbitals shows that the tricarbonyl metal ligand acts as an electron donor in[Nb_(2)W_(4)O_(19)M(CO)_(3)]^(3−/2−)(M=Mn^(Ⅰ),Tc^(Ⅰ),Re^(Ⅰ),Ru^(Ⅱ)and Os^(Ⅱ)),while the[Fe(CO)_(3)]^(2+)ligand acts as an electron acceptor in[Nb_(2)W_(4)O_(19)Fe(CO)_(3)]^(2−).
基金the National Basic Research Program of China(2013CB933401,2011CB808705)the National Science Foundation of China(21321001,91422302,21272256,21325210)the Chinese Academy of Sciences for support.
文摘A series of new sandwich type lanthanide complexes containing both boratabenzene and cyclooctatetraenyl ligands,[(C5H5BR)Ln(COT)](1Er:R=H,Ln=Er;2Er:R=Me,Ln=Er;3Er:R=NEt2,Ln=Er;4Dy:R=H,Ln=Dy;5Dy:R=Me,Ln=Dy;6Dy:R=NEt_(2),Ln=Dy;7Y:R=NEt2,Ln=Y),were synthesized.The structures of 1Er-7Y were all characterized by single crystal X-ray diffraction.Dynamic susceptibility experiments showed that the erbium complexes 1Er-3Er exhibited slow magnetic relaxation under zero dc field while the dysprosium complexes 4Dy-6Dy did not.For the erbium complexes,the magnetic properties were influenced by the substituent on the boron atom.1Er exhibited hysteresis up to 8 K,and 2Er featured the highest energy barrier(300 cm^(-1))among all the reported erbium single-ion magnets(SIMs).The influence of the boron substituent on the magnetic properties was highlighted by ab initio calculations.
文摘Tunnel stability control is a world-wide difficult problem. For the sake of solving it,the new theory of soft rock engineering mechanics has been estabilished. Some key points,such as the definition and classification of soft rock, mechanical deformation mechanism of a soft rock tunnel, the critical support technique of soft rock tunnel and the new theory of the soft rock tunnel stability control are proposed in this paper.
文摘In this paper, push-over analysis for tall concrete structures was made and a corresponding computer program was given. Several kinds of elements in the program were considered to meet the demand of tall buildings with complex structural type. These elements included beam-column element for beams and columns, single slice wall element and three vertical line element for walls, and tube-wall element for tubes. Computational example for verifying the models indicates that the result obtained by this method is identical with a well-known test result and the program can be used to search for the full process of structural reaction, even the softening stage of the structure. With this push-over analysis method, an actual tall building with complex structural type was analyzed, and the result has been put into practice of the structural design of the building. Key words push-over analysis - tall structure - complex type - nonlinearity - earthquake level - weak storey MSC2000 74S05 - 74L99 Project supported by the National Natural Science Foundation of China (Grant No. 50025821)
文摘With the scale of programs becoming increasingly bigger, and the complexity degree higher, how to select program fragments for slicing has become an important research topic. A new type of criterion called interesting index is proposed for selecting parts of procedures or procedure fragments to do program slicing. This new criterion considers not only the subjective aspects in users, namely users' emphasis on the time efficiency, storage capacity or readability, but also the objective aspect in large procedures. It also represents the benefit of the users, while displaying the many-faceted roles that program slicing plays. In this way users call proceed with program slicing to large systems or unfinished systems.
基金ThisstudywassupportedbygrantsofNationalNaturalScienceFoundationofChina (No 3 93 70 717)
文摘Objective To study the relationship between human leukocyte antigen (HLA) DRB1 and DQ alleles and the genetic susceptibility of type 1 diabetes in North Chinese children Methods Polymerase chain reaction (PCR) techniques were used to amplify the second exon of DRB1 and DQ alleles, after which sequence specific olignucleotide probe (SSOP) dot blot hybridization techniques were used to analyze the amplified products Results DRB1*0301, DQA1*0301, DQB1*0201 alleles and DRB1*0301 DQA1*0501 DQB1*0201 haplotype were significantly increased in patients, while DQA1*0103 and DQB1*0601 alleles were significantly increased in controls The distribution of DR4 and DR9 haplotypes in patients and controls were not significantly different, but DR3/DR4 and DR4/DR9 heterozygotes were significantly increased in patients Conclusions DRB1*0301, DQA1*0301 and DQB1*0201 confer susceptibility while DQA1*0103 and DQB1*0601 confer protection to type 1 diabetes DRB1*0301 DQA1*0501 DQB1*0201 haplotype offers a predisposition to type 1 diabetes in North Chinese Although the distribution of DR4 and DR9 in patients and controls had no significant difference, DR3/DR4 and DR3/DR9 heterozygotes were significantly increased in patients, showing that the susceptive effects of DR3 and DR4 or DR4 and DR9 haplotypes could be added up
基金supported by the National Key R&D Program of China under[grant number 2021YFF0704600]the National Natural Science Foundation of China under[grant number 42171352,42271365,U22A20566]the High-Level Talent Aggregation Project in Hunan Province,China-Innovation Team under[grant number 2019RS1060].
文摘Spaceborne photon-counting LiDAR is significantly affected by noise,and existing denoising algorithms cannot be universally adapted to different surface types and topographies under all observation conditions.Accordingly,a new denoising method is presented to extract signal photons adaptively.The method includes two steps.First,the local neighborhood radius is calculated according to photons’density,then thefirst-step denoising process is completed via photons’curvature feature based on KNN search and covariance matrix.Second,the local photonfiltering direction and threshold are obtained based on thefirst-step denoising results by RANSAC and elevation frequency histogram,and the local dense noise photons that thefirst-step cannot be identified are further eliminated.The following results are drawn:(1)experimental results on MATLAS with different topographies indicate that the average accuracy of second-step denoising exceeds 0.94,and the accuracy is effectively improves with the number of denoising times;(2)experiments on ICESat-2 under different observation conditions demonstrate that the algorithm can accurately identify signal photons in different surface types and topographies.Overall,the proposed algorithm has good adaptability and robustness for adaptive denoising of large-scale photons,and the denoising results can provide more reasonable and reliable data for sustainable urban development.
基金support from the National Natural Science Foundation of China(21863009,U20A2073)the Natural Science Foundation of Ningxia Province(2020AAC02005)+5 种基金the Discipline Project of Ningxia(NXYLXK2017A04)the Guizhou Education Department Youth Science and Technology Talents Growth Project(No.KY[2020]158)the 2019 Post-doctoral Junior Leader-Retaining Fellowship,la Caixa Foundation(ID100010434 and fellowship code LCF/BQ/PR19/11700011)the“Generalitat Valenciana”(SEJI/2020/034)the“Ramón y Cajal”program(J.F.-S.)support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme/ERC Grant Agreement No.814804,MOF-reactors.
文摘A tetranuclear cubane-type complex[Co_(4)(ntfa)_(4)(CH_(3)O)_(4)(CH_(3)OH)_(4)](1)with a{Co_(4)O_(4)}core,and a mononuclear complex[Co(ntfa)_(2)(CH_(3)OH)_(2)](2)have been rationally obtained by adjusting the ratio of theβ-diketonate and Co(II)ions,with the synthetic processes being monitored by in situ microcalorimetry.Then,following synthetic conditions to obtain 2,but using three distinct N-donor coligands-2,2’-bipyridyl(bpy),6,6’-dimethyl-2,2’-bipyridyl(6,6-(CH_(3))_(2)-bpy)and 5,5’-dimethyl-2,2’-bipyridyl(5,5-(CH_(3))_(2)-bpy)-three novel mononuclear complexes have been obtained,[Co(ntfa)_(2)(bpy)_(2)](3),[Co(ntfa)_(2)(6,6-(CH_(3))_(2)-bpy)_(2)](4)and[Co(ntfa)_(2)(5,5-(CH_(3))_(2)-bpy)_(2)](5).The introduction of different capping coligands-as singlecrystal X-ray crystallography ascertains-fine-tunes the structures,with changes in both the distortion degree of the coordination geometry and the intermolecular interactions,which have a direct impact on the magnetic properties of these complexes.Magnetic investigations reveal field-induced single-ion magnet behavior in all complexes with distinct energy barriers(Ueff)-39.06(1),36.65(2),36.32(3),28.26(4)and 15.85 K(5).Magnetic experiments together with HF-EPR measurements and theoretical calculations demonstrate that 2 features easy-axis magnetic anisotropy(D=-60.48 cm^(-1)),whereas 3-5 show easy-plane magnetic anisotropies-D=+70.77 cm^(-1) for 3,+35.71 cm^(-1) for 4,and+51.28 cm^(-1) for 5.To our knowledge,such reversal of anisotropic nature driven by coligands is unprecedented.
文摘In this paper,we give certain homotopy and diffeomorphism versions as a generalization to an earlier result due to W.S.Cheung,Bun Wong and Stephen S.T.Yau concerning a local rigidity problem of the tangent bundle over compact surfaces of general type.
文摘Nerve-tissue interactions are critical.Peripheral nerve injuries may involve intraneural and extraneural scar formation and affect nerve gliding planes,sometimes leading to complex clinical presentations.All of these pathological entities involve pain as the main clinical symptom and can be subsumed under the term“painful scar neuropathy”.The authors review the literature on treatment approaches to peripheral nerve scar neuropathy and the outcomes of neurolysis-associated procedures and propose a simple classification and a therapeutic approach to scar neuropathy.The search retrieved twenty-one papers,twenty of which reported pain reduction or resolution with various techniques.There is no consensus on the best therapeutic approach to neuropathic pain due to scar tethering.Most authors report good or excellent results with different techniques,from nerve wrapping with anti-adhesion devices to nerve coverage or wrapping with vascularized tissue.The authors’classification of and therapeutic approach to peripheral nerve scar lesions aims at promoting a logical approach based on the analysis of lesion type(perineural,or endoneural and perineural),pain type(due to traction or external trauma,pain at rest),and number of previous operations.Patients need to be informed that multiple procedures may be required,that outcomes may be partial,and that surgery can potentially worsen preoperative conditions.The review found no evidence for the best therapeutic approach to scar neuropathy,but there is consensus on a multidisciplinary approach.
