Two new microporous metal-organic frameworks, [Zn(NH BDC)(HO)]·5DMF (1) and (MeNH)[Cd(NHBDC) ]·2DMF·2.5 HO (2) (NHBDC = 2-amino-1,4-benzenedicarboxylate), based on linear trinuclear secondary building units of Zn(COO) or Cd(COO) that have different connected numbers, have been synthesized and characterized, which exhibit usual pcu and rare hex-like topologies, respectively. Both 1 and 2 are three-dimensional porous frameworks, having solvent accessible volumes of ca. 53 and 39%, respectively. There are unremovable guest MeNH cations clogged in the channels of 2. In contrast, being of good thermo-stability, 1 has a Langmuir surface area about 570 m g and type I isotherm behaviour for nitrogen gas sorption at 77 K, being typical of microporous material. © The Royal Society of Chemistry 2008.

王笑峰    Yuebiao Zhang    程小宁    陈小明    

CrystEngComm

2008

A three-dimensional, highly porous metal-organic framework [Zn O(bdc)(bpz)]·4DMF·6HO (1) (bdc = 1,4-benzenedicarboxylate, bpz = 3,3′,5,5′-tetramethyl-4,4′- bipyrazolate) constructed by ZnO clusters with bdc and bpz linkers, has been prepared and structurally characterized. The N sorption measurements reveal that 1 exhibits high porosity with a Langmuir surface area of 1908 m/g and a pore volume of 0.58 cm/g. Compound 1 features hydrophobic channels with a free passage of ∼8.2 Å defined by the methyl groups from bpz, and it exhibits nice sorption capability for benzene and toluene and interesting two-step sorption behavior for methanol. Meanwhile, 1 also exhibits interesting guest-dependent luminescent properties. © 2008 American Chemical Society.

Lei Hou    Yanyong Lin    陈小明    

Inorganic Chemistry

2008

According to the fractal characters of remote sensing image, the image was segmented with the Local Fractal Dimension (LFD). The pyramid model instead of local window model was used to decrease the computation time in computing local triangular prism. Compared with traditional method, a new recursive procedure was designed to decrease the needed memory capacity. The experiment results on remote sensing image segmentation show that the improved method effectively increases the speed of image segmentation based on the texture, and keeps the accurateness of the fractal dimension with the triangular prism method.

陈小明     Ni Guo-Qiang   

Guangdian Gongcheng/Opto-Electronic Engineering

2008

Two cobalt hydroxysulfates NaCo(OH) (SO)(HO) (1) and Co(OH)(HSO)(SO )(HO) (2) have been prepared and characterized by single-crystal X-ray diffraction, thermal analysis, and magnetic measurements. The structure of 1 consists of helical Co (OH) ferrimagnetic chains that are connected by μ- and μ-sulfates into a two-dimensional anionic [Co(OH)(SO)(HO) ] layer. The adjacent [Co(OH) (SO)(HO)] layers in 1 are further linked by Na ions into a three-dimensional framework. The related compound 2 also consists of helical Co(OH) ferrimagnetic chains but has a two-dimensional layered structure due to the absence of Na ions and partial replacement of sulfates by hydrosulfates. Preliminary magnetic measurements show that 1 and 2 have similar behavior. A detailed magnetic study of 1 reveals a stepped hysteresis loop at 2 K with a coercive field of 1800 Oe and remnant magnetization of 2.8 Nβ attributed to the different anisotropy axes of Co(II) spins in the helical Co(OH) chain. Fieldcooled (FC) and zero-field-cooled (ZFC) magnetization measurements show that 1 has a blocking temperature ca 28 K. The study of frequency dependence of real χ′ component of ac susceptibility by the equation φ = ΔT/[TΔ(log ω] exhibits that 1 is close to a spin glass. The fitting of Arrhenius law reveals that τ seems a little longer but the U/k is normal for a typical single-chain magnet following Glauber dynamics. The -zv value of 3.3 obtained by the conventional critical scaling law of the spin dynamics τ = τ (T -T/T) is out of the range for various spin glasses. The plot of dlog(T)/dlog(χT) versus T eliminates the phase transition to long-range ordering and suggests that 1 is a real one-dimensional system. The unusual slow magnetic relaxation behavior of 1 is tentatively ascribed to be a ferrimagnetic chain with spin-glass-like dynamic relaxation, possibly arising from the movement of the domain walls. © 2008 American Chemical Society.

张献明    Li Cui-Rui    Zhang Xu-Hui    Weixiong Zhang    陈小明    

Chemistry of Materials

2008

Two three-dimensional coordination polymers, namely [Co(na)(ina)] (1) and [Co(na)(1,4-chdc)] (2) (Hna =nicotinic acid, Hina =isonicotinic acid, 1,4-Hchdc=cyclohexane-1,4-dicarboxylic acid), with 8-connected CsCl-like topology, have been solvothermally synthesized. The temperature-dependent magnetic susceptibilities were also determined, showing antiferromagnetism in both compounds. CCDC: 688479, 1; 688480, 2.

Jianbin Lin    陈小明    

Chinese Journal of Inorganic Chemistry

2008

The self-assembly of Zn(II) and Cd(II) ions with a bis-bidentate ligand 3,5-bis(benzimidazol-2-yl)pyrazole (HL) was studied by Electrospray ionization mass spectrometry, H NMR measurements, and single-crystal X-ray diffraction analyses. Reaction of Zn(ClO)· 6HO and Cd(ClO)·6HO with HL in DMF gave two pentanuclear complexes [(Zn(μ -O)(HL))(ClO) ·DMF·9.5HO (1) and [Cd(μ -O)(HL)](ClO)(OH)·4. 75DMF·0.25EtOH·10.5HO (2), in which the trigonal-bipyramidal core structures are bridged by μ-oxo and pyrazolate rings of the monodeprotonated HL. When Na PO·12HO was used in the reaction system of CdBr·4HO and HL, [Cd (μ-O)(HL)]-Br ·4.5DMF·6.5HO (3) and [Cd (μ-PO)(μ-Br)(H L)](HPO)·DMF·10HO (4) were isolated. 3 displays the same core structure as that of 2, whereas 4 exhibits a turbinate, heptanuclear core which is bridged by a μ-PO, three μ-Br, and three pyrazolate rings. All of the pentanuclear and heptanuclear cores are surrounded by three pairs of bis-bidentate HL ligands with offset π-π stacking, showing propeller-like molecular structures and triple-stand helicates. Electrospray ionization mass spectrometry studies and H NMR measurements demonstrate that the pentanuclear complexes have different stability in the solution, depending on the metal ions and the counteranions. Furthermore, both 1 and 2 emit blue fluorescence with nanosecond luminescent lifetimes in DMF at room temperature. © 2008 American Chemical Society.

Zhu Ai-Xin    Jiepeng Zhang    Yanyong Lin    陈小明    

Inorganic Chemistry

2008

An universal serial bus (USB)-based high-speed real-time pulse signal detecting system is developed. The hardware and application software of the system is presented. The integrated polyvinylidene difluoride (PVDF) piezoelectric pulse sensor is used to pick-up the pulse signals of examined person and turn to the electric signal under processing. Because the signal is very weak, only after passing through the enlargement can the regular pulse profile be allowed to be obtained. The in-phase amplifier circuit is used to magnify the weak signal from the sensor. The magnified pulse signal is converted digital pulse signal through system-on-chip single-chip microcomputer C8051F130. The digitalized pulse signal is delivered to personal computer under USB interface protocol. The pulse signal is then shown, recorded, saved and processed through computer software. This inspecting system for pulse signal has many advantages, such as its structure is simple, it works steadily and reliably, its low cost, high application value and it can also realize rapid collection and storage of pulse signal.

陈小明    

Journal of Clinical Rehabilitative Tissue Engineering Research

2008

Silica inverse opal photonic crystals (PCs) were fabricated by using a sacrificial polymer template method, and were characterized by scanning electron microscopy and reflection spectra. The fluorescence of tricolor fluorescent powders has been enhanced obviously by silica inverse opals as the emission wavelengths of the tricolor fluorescent powders are in the range of stop bands of the inverse opal PCs, which demonstrates that the PCs will be efficient and selective reflection mirrors. A promising application of the strategy would be in novel effective lighting devices. © Springer-Verlag 2007.

Yuqi Zhang    jun Wang    陈小明     Jie Liang    江雷    宋延林    朱道本   

Applied Physics A: Materials Science and Processing

2007

Yuqi Zhang    jun Wang    陈小明     Jie Liang    江雷    宋延林    朱道本   

Applied Physics A: Materials Science and Processing

2007

Reaction of copper powder with Mn(OAc)·4HO and triethanolamine in DMF solution in air yields a high nuclearity, mixed-valent CuCuMnMnMn cluster. X-ray crystallography shows that 1 contains an unprecedented adamantane-like Mn core connected wholly by MnO cubane units. Magnetic susceptibility data indicate a S = 51/2 ground state in low magnetic field with a S = 63/2 excited state only 5 K in energy above the ground state. Copyright © 2007 American Chemical Society.

Wang Wen-Guo    Zhou Ai-Ju    Weixiong Zhang    童明良    陈小明     Motohiro Nakano    Beedle    Hendrickson   

Journal of the American Chemical Society

2007