Search

We report a bipolar $SiO_{2}$-based selector with threshold switching and self-compliance characteristics. The device turns ON under applied voltage of about $\pm 0.6{V}$, and turns OFF when the applied voltage drops below $\pm 0.04{V}$. Engineering of the copper (Cu) supply film is implemented by alloying Cu with $Ge_{2}Sb_{2}Te_{5}(GST)$. This enables appropriate modulation of the Cu concentration and migration in the active $SiO_{2}$ film, which is responsible for the reliable self-compliance bipolar threshold switching.

New clathrate-based phase-change materials with cage-like structures incorporating Cs and Ba guest atoms, are reported as a means of altering crystallization and amorphization behavior by controlling 'guest-cage' interactions via intra-complex guest vibrational effects. Both a high resistance to spontaneous crystallization, and long retention of the amorphous phase are achieved, as well as a low melting energy. This approach provides a route for achieving cage-controlled semiconductor devices.

Industrial pure aluminum has been widely used in industry. However, it caused great difficulties in welding process due to its characteristics such as easy oxidation, high thermal conductivity and specific volume, low melting point. In order to overcome this problem, improving the welding quality of industrial pure and reducing the welding defects is of great significance. In this paper, the weldability of 1050A industrial pure aluminum plate (5 mm thick) with HS331, SAl-2, 1050A leftover materials and homemade welding wire with Ni-Cr alloy as four different filler materials was studied by using manual TIG welding. Metallographic test and mechanical performance test were used to assess microstructure and mechanical properties of the resulting welding joint. The results show that the microstructure and mechanical properties of the resulting welding joint with homemade welding wire with Ni-Cr alloy is relatively better than the others, which offers important implication for the improvement of the welding properties of industrial pure aluminum.

Compound pearl protein polypeptide (CPPP) was investigated by MTT method as well as detecting alkaline phosphatase (ALP) and mineralized nodes in osteoblasts from SD rats. In vivo the rat models of osteoporosis were induced by ovariectomy and treated with three doses of CPPP (5.0mg.kg-1.d-1, 20.0mg.kg-1.d-1, and 80.0mg.kg-1.d-1). The serum levels of estradiol (E2), osteocalcin (BGP), transforming growth factors (TGF-β1) and ALK, together with the bone mineral density (BMD) and the contents of calcium (Ca) and phosphorus (P) in 24h urine, were detected. The results show that CPPP can enhance cell proliferation, ALK activity and the number of mineralized nodes in rats osteoblasts. CPPP significantly increase the serum level of E2, TGF-β1, and BMD, and decrease the serum level of ALP, BGP and the contents of Ca, P in 24h urine. So, CPPP can increase bone density, and thus it is conductive to osteoporosis prevention and treatment of the elderly.

A new coordination polymer based on cobalt nitrate and 2-4-pyridyl-1H-benzimidazole- 5,6-dicarboxylate (H2pbd), namely [Co (pbd)2·(H2O)2]n·n (H2O)2, have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. The crystal of the complex crystallizes in triclinic, space group P-1 with a=7.6708(6)Å, b=8.0009(8)Å, c=12.8348(12)Å, α=96.4040(10) o, β=102.9480(10) o, γ=112.142(2) o, V=694.11(11)Å3, Z=1, C28H22CoN6O12 and F(000)=376.0. The H2pbd ligand links the Co (II) atoms into a double stranded chain.

In the study, through the addition astaxanthin into the bait for the pearl oyster Pinctada martensii for 3 months, we studied the accumulation and existence form of astaxanthin in pearl oyster through qualitative and quantitative analysis which adopted High Performance Liquid Chromatography method; the transmission of astaxanthin in shells was detected by Micro-Raman spectrometry. The results showed: 6.870±1.356μg/g of astaxanthin existed in the control group of Pinctada martensii, and 74.799±5.907μg/g of astaxanthin existed in the experimental group, some of them were existent in the form of astaxanthin esters. Weak carotenoid characteristic peak occurred in the control group, while the carotenoid characteristic peaks intensity enhanced obviously in the experimental group, which illustrated remarkable increase of carotenoid content in the shell. These findings will not only provide the basis for colorful pearl cultivation via food-borne transmission but also lay a foundation for further artificial regulation and control of pearl color.

A new coordination polymer based on cadmium nitrate and 2-（4-pyridyl-1H-benzimidazole- 5,6-dicarboxylate (H2pbd) , namely [Cd( pbd)2•(H2O)2]n•n(H2O)2, have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. The crystal of the complex crystallizes in triclinic, space group P-1 with a = 7.7200 Å, b = 8.1029Å, c = 13.0801Å, α= 96.1270(10) º, β = 102.1280(10)º, γ= 112.479(2) º, V = 723.15(12) Å3, Z =1, C28 H22 Cd N6 O12 and F(000) = 376.0. The H2pbd ligands links the Cd(II) atoms into a double stranded chain.

Three new coordination polymers based on 2-ethyl-imidazole-4,5-dicarboxylate with 1,10-phenanthroline as ligands, Pb(HEIDC)(phen)2 (1), [Zn(EIDC)(phen)] n (2), and {[Ba(H2EIDC)2(phen)] · (phen)2 · [Ba(H2EIDC)(HEIDC)(phen)]} n (3) (H3EIDC = 2-ethyl-1-Himidazole-4,5-dicarboxylate; phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Complex 1 displays a tetranuclear square constructed of four Pb(II) centers, four HEIDC, and eight phen, resulting in a 3-D network with a 1-D open channel along the c-axis via C–H ··· O hydrogen bonds, C–H ··· π, and π–π stacking interactions. Complex 2 is an infinite zigzag chain resulting in the final 3-D supramolecular framework via C–H ··· O and π–π stacking interactions. Complex 3 is composed of two individual Ba chains, exhibiting a 3-D framework via O–H ··· O, O–H ··· N hydrogen bonds, and π–π stacking interactions....

Two new isostructural coordination polymers, namely, [Ln(nbtc)·2H2O]n [Ln = Eu (1), Tm (2)] (H3nbtc = 5-nitrobenzene-1,2,3-tricarboxylic acid), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. Both compounds are sandwich-like 2D layered network built by the 1D Ln-carboxylate chains and nbtc3− linkers, displaying the same 3D supramolecular network via intermolecular hydrogen bonds. The photoluminescence and lifetime of 1 in the solid state has also been investigated.

In the present study, through a transmission experiment, the effects of europium complex and Eu3+ on the pearl colour in the pearl oyster Pinctada martensii were evaluated. Europium complex and europium salt were respectively enriched by dietary green algae platymonas subcordiformi, and their toxicity to algae were analysed by the 96-h acute toxic experiment. Then, the green algae enriched europium complex and europium salt were respectively fed pearl oysters for 2 months, and the surface microstructures of cultured pearls were presented with scanning electron microscopy (SEM) and atomic force microscope(AFM). The results show that toxicity of europium complex to algae is much lower than Eu3+ from lowest no observable effect concentration LNOEC values and 96h-EC50 values and two compounds can modify pearl structure and optimize pearl colour from SEM and AFM images. Taken together, our results, for the first time, show that rare earth complex can improve the pearl quality. This study provides an innovative approach for additional investigation of the influence of rare earth elements on pearls.

The 3D heterometallic 3d–4f coordination polymer, [EuZn(gly)(ox)2(H2O)2]n, 1, (gly = glycinate, ox = oxalate), was the product of the hydrothermal synthesis of glycinate from the reaction of tetrazole-1-acetic acid, sodium oxalate, zinc and europium salts in the presence of a trace quantity of nitric acid. Coordination polymer 1 exhibits an unusual 3D heterometallic coordination framework that is built up by heterometallic dinuclear EuZn secondary building units and mixed ox and gly linkers in a uninodal 6-connected vme {33.43.58.6} net. The solid-state photoluminescence and lifetime characteristics of 1 reveal intense red luminescence.

Two novel 2D coordination polymers, namely, {[Cu2(L)2][Cu(H2O)3]}n (1) and {Pb3(O2N-btb)2}n (2) (O2N-H3btb = 5-nitro-benzene-1, 2, 3-tricarboxylic acid, L = 5-nitro-2-oxidoisophthalate), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, X-ray diffraction, and thermogravimetric analysis. Compound 1 is an infinite 2D layer exhibiting an extended 3D supramolecular network structure. O–H···O hydrogen bonding interactions play a key role in forming the final 3D supramolecular framework. It is noted that 5-nitro-benzene-1, 2, 3-tricarboxylic acid (O2N-H3btb) was in situ transformed to 5-nitro-2-oxidoisophthalate in 1. Compound 2 is a 2D microporous lead-containing metal-organic framework made up of interconnected Pb-carboxylate chains, involving three independent lead atoms with three different coordination arrangements. Furthermore, the solid-state photoluminescence and lifetime characteristics of 2 reveal intense blue luminescence.

Room temperature ferromagnetism in both transition-metals doped and undoped semiconductor thin films and nanostructures challenges our understanding of the magnetism in solids. In this report, we performed the magnetic measurement and Andreev reflection spectroscopy study on undoped Indium–Tin oxide (ITO) thin films and bulk samples. The magnetic measurement results of thin films show that the total magnetization/cm2 is thickness independent. Prominent ferromagnetism signal was also discovered in bulk samples. Spin polarized electron transports were probed on ITO thin film/superconductor interface and bulk samples surface/superconductor interface. Based on the magnetic measurement results and spin polarization measurement data, we propose that the ferromagnetism in this material originates from the surface spin polarization and this surface polarization may also explain the room temperature ferromagnetism discovered in other undoped oxide semiconductor thin films and nanostructures.

A series of new coordination polymers, namely, [Sr(H2EIDC)2(H2O)2]n (1),{[Pb(H2EIDC)2(H2O)](H2O)3}n (2), [Ag(H2EIDC)]n (3), and [Ba(H2EIDC)2(H2O)]n (4) (H2EIDC = 2-ethyl-1H-imidazole-4,5-dicarboxylate), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, X-ray diffraction and thermogravimetric analyses. Complex 1 is a 2D infinite gridlike (4,4)topological layer structure. Complex 2 is a 2D corrugated layer constructed by PbII atoms and H2EIDC– anions. Complex 3 is a 2D corrugated sheet consisting of 1D chains linked by short Ag···Ag interactions, and the three complexes are extended into 3D supramolecular structures by weak intermolecular forces such as hydrogen bonds and π–π stacking interactions. Complex 4 exhibits a 3D framework with 1D channels. Furthermore, the luminescent properties of complexes 1, 2, and 3 are also investigated.

The apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, ash, phosphorus, gross energy and amino acids of 10 selected ingredients for juvenile hybrid tilapia (7.05 ± 0.09 g) were determined using 0.5% Cr2O3 as an inert indicator. The feed ingredients tested in this study were corn gluten meal (CGM), corn byproduct, corn germ meal (CG), soybean meal (SBM), fermented soybean meal (FSM), soy protein concentrate (SPC), soy protein isolate, malt sprouts (MS), fish meal (FM) and earthworm meal (EM). The test diets were prepared by incorporation of 30% test ingredients into the reference diet. Reference and test diets were fed to the fish and the faecal samples were collected using a faecal collection column attached to the fish-rearing tanks. The ADCs for dry matter, crude protein, crude lipid, ash, phosphorus and gross energy were 41.7–98.9%, 90.6–99.6%, 73.1–98.8%, 34.1–98.6%, 49.5–99.6% and 45.4–99.7% respectively. Soy protein isolate, FM and EM had higher dry matter, crude protein and gross energy ADCs. Corn byproduct and EM had higher crude lipid ADCs, and CG and EM had higher phosphorus ADCs. Corn germ meal had the highest ash ADC, while CGM had the highest value for gross energy. The lowest dry matter, crude protein, lipid and gross energy ADCs occurred in MS, while the lowest ash and phosphorus ADCs occurred in SPC. The amino acid ADCs ranged from 83.3% to 100%, exhibiting a positive correlation with crude protein digestibility for a given test ingredient. The feed ingredient digestibility of this study may provide useful information about nutrient and energy utilization to facilitate formulation of least-cost practical diets for hybrid tilapia.

Three lanthanide coordination polymers, [Ln4(BDC)6(H2O)2] n (Ln = Er, 1; Ln = Tm, 2; BDC = 1,2-benzenedicarboxylate) and {[Nd2(BDC)(EDTA)(H2O)2] · 1.5H2O} n , 3, were prepared by hydrothermal synthesis and characterized by elemental analysis, IR spectra, as well as single-crystal X-ray diffraction. The isostructural coordination polymers 1 and 2 exhibit four different coordination modes, which are rarely found in one lanthanide complex. Complex 3 displays a 2-D wave-like network assembled by two polycarboxylate ligands.

One new metal-organic complex formulated as {[Co(bipy)3][Co2(μ2–ox)3]}n 1 (bipy = 2,2′-bipyridyl; ox = oxalate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV–visible spectra. The complex 1 contains helical chains composed of left-handed and right-handed helices interlaced in pairs. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 5.75 × 10−30 esu for 1 in a 2.36 × 10−4 mol dm−3 DMF solution.

The homometal cluster [Fe(DMF)6][W2(μ2-S)2S4] (I) was successfully synthesized by low-temperature solid-state reactions. X-ray single-crystal diffraction studies suggest that compound I is a dinuclear anion cluster. The compound was characterized by elemental analyses, IR spectra, and UV-Vis spectra. The third-order nonlinear optical (NLO) properties of the cluster were also investigated and exhibited nice nonlinear saturation absorption (α2 0) and self-defocusing property (n 2 < 0) and self-defocusing performance with modulus of the hyperpolarizabilities (9.547 × 10−31 esu) for I.

Two-dimensional (2D) metal-organic supramolecular polymer [Co2(μ2-4,4′-bipy)2(μ2-be)2(be)2]n 1 (4,4′-bipy = 4,4′-bipyridine, be = benzoate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, TGA, IR spectra and UV–visible spectra. The 2D structure is built from the linkage of secondary building units of binuclear [Co2(μ2-4,4′-bipy)2(μ2-be)2(be)2] clusters by a mixed connector of 4,4′-bipyridine and benzoate. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 8.30 × 10−30 esu for 1 in a 2.70 × 10−4 mol dm−3 DMF solution.

A novel manganese(II) coordination polymer [Mn(bpy)2(μ2-S6)]n 1 (bpy = 2,2′-bipyridine) has been synthesized by low-temperature solid-state reaction. Single crystal X-ray analyses reveal that compound 1 possesses a new type of two-dimensional (2-D) framework structure. Each Mn(II) ion, located on an inversion center of distorted octahedron, is six-coordinated by four nitrogen atoms from the bpy ligands and two sulfur atoms from the μ2-S6 ligands. The compound 1 was characterized by elemental analyses, IR spectra and UV–visible spectra. The third-order non-linear optical (NLO) properties were also investigated and they exhibit nice non-linear absorption and self-defocussing performance with modulus of the hyperpolarizability (γ) 6.56 × 10−30 esu for 1 in a 2.5 × 10−4 mol dm−3 DMF solution.

A cobalt(II) thiocyanate complex [Co(py)4(NCS)2] 1 (py = pyridine) has been synthesized by low-temperature solid-state reaction. Single crystal X-ray analysis reveals that 1 possesses a one-dimensional (1-D) zigzag chain structure. Each Co ion is symmetrically coordinated by four pyridine ligands and also coordinates with two NCS− anions. Compound 1 was characterized by elemental analyses, IR spectra and UV-visible spectra. The third-order non-linear optical (NLO) properties were also investigated and they exhibit non-linear absorption and self-defocusing performance with modulus of the hyperpolarizability 9.46 × 10−30 esu for 1 in a 3.6 × 10−4 mol dm−3 DMF solution.

The homometal cluster [Fe(DMF)6][Mo2(μ2-S)2S4] 1 (DMF = dimethylformamide) was successfully synthesized by low-temperature solid-state reactions. X-ray single-crystal diffraction studies suggest that compound 1 is dinuclear anion cluster. The compound was characterized by elemental analyses, IR spectra and UV–vis spectra. The third-order non-linear optical (NLO) properties of the cluster were also investigated and exhibited nice non-linear absorption and self-defocusing performance with modulus of the hyperpolarizabilities 4.20 × 10−30 esu for 1.

Keywords: organic-inorganic hybrid materials; luminescent property; 2-Chlorobenzeneacetic acid Abstract. One new organic-inorganic hybrid materials of complex Ag2ClO5N5C28H22 (1) was synthesized by evaporation methods using 2-Chlorobenzeneacetic acid(2-CBAA), 4,4'-dipyridyl (4,4'-bipy), and AgNO3. And the complex was characterized by elemental analysis, FT-IR, thermogravimetrie analysis(TGA), XRD, X-ray single-crystal structure analysis and fluorescence properties have been studied. As a result, complex 1 are one-dimensional structure. Among others, Ag(I) ion is surrounded by two nitrogen atoms from two bipy ligands form an infinite chain, and adjacent Ag-bipy chains produce "rungs" of a ladder by silver ions contacts. Complex 1 emits the intensely luminescence with the fluorescence of 486 nm in a solid state at room temperature. CCDC

The title complex mol­ecule, [Mn2(C7H4ClO2)4(C12H8N2)2(H2O)], possesses crystallographically imposed C2 symmetry. Each MnII atom is coordinated by three carboxyl O atoms from three 4-chloro­benzoate ligands, two N atoms from one 1,10-phenanthroline ligand and one bridging water mol­ecule in a distorted octa­hedral coordination geometry. The Mn⋯Mn separation is 3.512 (3) A. Symmetrically related dinuclear mol­ecules form chains parallel to the c axis via π–π stacking inter­actions.

In the title complex, [Co(C7H4ClO2)2(C12H8N2)(H2O)2], the CoII atom is six-coordinated in a distorted octa­hedral geometry by two O atoms from two 4-chloro­benzoate ligands, two N atoms from one 1,10-phenanthroline ligand and two water mol­ecules. The mol­ecules form O—H⋯O hydrogen-bonded centrosymmetric dimers that are extended by additonal intra- and inter­molecular hydrogen-bonding inter­actions to form infinite chains of dimers parallel to the a axis.

The molecular structure of the title compound, [Zn(C8H7O2)2(C7H6N2)2]·2C8H8O2, is composed of a mononuclear ZnII complex, which possesses twofold rotation symmetry, and two uncoordinated 4-methylbenzoic acid molecules. The ZnII atom displays a four-coordinate distorted tetrahedral configuration, formed by two carboxylate O atoms of two monodentate 4-methylbenzoate ligands and two N atoms of two benzimidazole molecules. In the crystal structure, complex molecules are linked by the 4-methylbenzoic acid molecules via N—H...O and O—H...O hydrogen bonds, giving rise to the formation of a supramolecular structure.

In the title complex, [Mn(C7H2N2O7)(C10H8N2)] n , the MnII atom has a distorted octahedral coordination geometry, defined by two N atoms from the 2,2′-bipyridine ligand and four O atoms from two 3,5-dinitrosalicylate dianions. One carboxylate O atom acts as a bridge between adjacent metal centres to form a one-dimensional chain. The Mn...Mn distance is 4.315 (6) Å. The crystal packing is stabilized by intermolecular C—H...O hydrogen interactions.

In the title coordination polymer, [Ca(C7H2N2O7)(H2O)]n, the CaII atom is seven-coordinate by six O atoms from four 3,5-dinitro­salicylatate ligands and one water mol­ecule, and displays a distorted penta­gonal–bipyramidal geometry. Centrosymmetrically related dinuclear calcium units with a Ca⋯Ca separation of 3.8665 (8)A form layers which are self-assembled into a three-dimensional network by inter­molecular O—H⋯O hydrogen bonds.

In the title coordination polymer, [Zn(C7H2N2O7)(C12H8N2)]n, the ZnII atom has a distorted trigonal–bipyramidal coordination geometry, defined by two N atoms from one phenanthroline ligand and three O atoms from two different 3,5-dinitro­salicylate ligands. The crystal packing is governed by weak intra- and inter­molecular C—H⋯O hydrogen bonds.

The CoII atom in the mononuclear title complex, [Co(C8H5Cl2O3)2(C3H4N2)2(H2O)2], lies on an inversion center. The CoII atom has an octa­hedral coordination, involving two carboxylate O atoms of two monodentate 2,4-dichloro­phenoxy­acetate ligands, two N atoms of imidazole ligands and two water mol­ecules. Inter­molecular O—H⋯O hydrogen bonds give rise to chains, which are linked by N—H⋯O hydrogen bonds, forming a sheet structure. The mol­ecules are further linked by π–π stacking inter­actions, generating a two-dimensional supra­molecular network.

The title complex, [Mn(C8H5Cl2O3)2(H2O)2]n, is a coordination polymer containing the flexible 2,4-dichloro­phenoxy­acetate ligand. The MnII atom, which lies on a centre of inversion, is coordinated by four O atoms from two 2,4-dichloro­phenoxy­acetate ligands and two water mol­ecules and displays an octa­hedral geometry. An ideal three-dimensional framework is formed by the flexible phenoxy­acetate ligands via intra­molecular hydrogen-bond inter­actions.

In the title coordination polymer, [Cd(C8H5Cl2O3)2(H2O)2]n, each CdII atom lies on an inversion center. The CdII atom exists in a slightly distorted octa­hedral coordination polyhedron, involving four carboxyl O atoms from different 2,4-dichloro­phenoxy­acetate ligands and two water mol­ecules. The CdII ions are bridged by carboxyl­ate groups in a bis­(mono­dentate) mode, leading to a two-dimensional layer structure. This supra­molecular network is consolidated by inter­molecular hydrogen-bonding inter­actions.

Control of octahedral rotations in the ABO${}_{3}$ perovskite oxides has been of great interest due to its potential in rationally discovering and designing new multifunctional phases. In this study, we show that octahedral rotations of the SrRuO${}_{3}$ films can be controlled by oxygen vacancies as well as by interfacial coupling, which further determines the physical properties. Half-integer reflections using high-resolution synchrotron x-ray diffraction were carried out to determine the octahedral rotation pattern of SrRuO${}_{3}$ films on SrTiO${}_{3}$ substrates. The transition of RuO${}_{6}$ rotation pattern accompanied by the structural change from monoclinic $P$2${}_{1}/m$ to tetragonal $F$4/mmc can be understood from the preference of oxygen vacancies in the SrO atomic plane and the coupling of octahedra across the interface between film and substrate. The field angle dependence of magnetoresistance further confirmed the structural phase transition with changes in octahedral rotations. The monoclinic phase has the uniaxial magnetic easy axis 30\ifmmode^\circ\else\textdegree\fi{} away from the [001] direction towards the [010] direction while the tetragonal phase has uniaxial magnetic easy axis along the fourfold axis which is perpendicular to the film surface. This study demonstrates the ability to control the octahedral rotations in perovskite films and its importance when designing thin films and multilayers with desired functional property.

Objective To study the extraction system of hirudin emulsion liquid membrane with the Poecilobdella manillensis as raw material, di-(2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as emulsifier, octane and D2EHPA mixed to constitute membrane solution, diluted HCl solutions as internal aqueous phase. Method Using the orthogonal experiment to optimize the extraction conditions of hirudin reference substance such as membrane phase, internal aqueous phase volume ratio (MIPVR), external aqueous phase pH, internal aqueous phase pH, mobile carrier concentration and so on, and then using hirudin crude extracts to do purifying experiment, and gaining experimental samples. Result The optimal conditions of hirudin extraction were as follows: MIPVR 10: 3, internal aqueous phase pH 2.6, external aqueous phase pH 3.4, the mass fraction of carrier D2EHPA 2%. In the optimal extraction conditions, when the initial concentration of hirudin was one anti-thrombin activity units (ATU) x mL(-1), ATU recovery rate of the reference substance was 83.06%. In the purifying experiment of crude extracts, ATU recovery rate was 82.99%, and the specific activity of sample was 3 289.48 the ATU x mg(-1). Discontinuous polyacrylamide gel electrophoresis and spectral scanning, the results showed that the purity and reference substance were considerable. Conclusion The method of preparation hirudin was relatively simple, the purity of the experimental samples and ATU recovery were both high.

The title molecule, C13H8N4, is is essentially planar [r.m.s. deviation for all non-H atoms = 0.025 (3) Å]. In the crystal, molecules are connected through one weak bifurcated N—H...(N,N) hydrogen bond and three π–π stacking interactions between pyridine and imidazole rings [centroid–centroid distance = 3.631 (8) Å] and between pyridine and benzene rings [centroid–centroid distances = 3.675 (5) and 3.666 (2) Å].

In the title compound, [Cd(C(10)H(7)N(6))(2)(H(2)O)(2)], the Cd(II) atom lies on an inversion centre and is coordinated by four N atoms from 5-[4-(1H-imidazol-1-yl)phen-yl]tetra-zol-1-ide ligands and two O atoms from the coordinated water mol-ecules in an octa-hedral arrangement. The complex polymeric chains are inter-connected via inter-molecular water O-H⋯N hydrogen bonds into a three-dimensional network.

The intrinsic ferromagnetism (FM) in phase-change (PC) magnetic materials was studied by first-principle calculations and experiments. The doped Fe or other transition metals tend to substitute at the Sb site of Ge${}_{2}$Sb${}_{2}$Te${}_{5}$. An asymmetric coupling, between ${p}_{\mathrm{x}}$ and ${p}_{\mathrm{y}}$ rather than ${p}_{\mathrm{z}}$ states of Te and $d$ states of Fe, creates magnetic moments and holes in the $p$ band. The findings reveal a strong dependence of FM interaction on Fe-Fe pair distances and crystallographic orientation. A design principle with three criteria is proposed for exploring new PC magnetic materials.

In the title complex, [Cd(C(8)H(9)N(2)O(4))(2)(H(2)O)(2)]·2C(3)H(7)NO, the six-coordinate Cd(II) ion is in a slightly distorted octa-hedral environment, defined by two O atoms from two coordinated water mol-ecules and two carboxyl-ate O atoms and two N atoms from two N,O-bidentate 5-carb-oxy-2-propyl-1H-imidazole-4-carboxyl-ate ligands. In the crystal, complex mol-ecules and dimethyl-formamide solvent mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds into a two-dimensional supra-molecular structure. The propyl groups of the ligands are disordered over two conformations with refined occupancies of 0.680 (7) and 0.320 (7).