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Two novel limonoids, chuktabrin A ( 1), featuring the unique motifs of a 1,3-dioxolan-2-one and a 3,4-dihydro-2 H-pyran, and chuktabrin B ( 2), possessing an unprecedented polycyclic skeleton, were isolated from Chukrasia tabularis. The structures of 1and 2bearing a biosynthetically extended C3 and C2 unit at C-15, respectively, were elucidated on the basis of spectroscopic data, and that of 1was confirmed by a single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The umpolung Michael addition of isatin N,N′-cyclic azomethine imine 1,3-dipoles with chalcones is reported. The reaction could be finished within a very short time (0.3–2 min), with 3,3-disubstituted oxindole derivatives obtained in moderate to excellent yields with promising dr values. Unusual Michael adducts were obtained in moderate to high yields (26–98%) with low to high diastereoselectivities (0.8 : 1 to 8.5 : 1 dr). All the synthesized compounds (3, 3′, 4, 5, 5′, 7, 7′, 9 and 9′) were well characterized by FTIR, NMR, and mass spectral analyses and further confirmed by the single-crystal X-ray diffraction analysis of compounds 3aa and 4n. [ABSTRACT FROM AUTHOR]

Summary: Cu-Mn-Si catalysts with copper-manganese oxides as the main constituents and silica dioxide as the supports were prepared by co-precipitation method. The performance of the catalysts for the dehydrogenation reaction of the 2-butanol to methyl ethyl ketone was tested. The effects of Cu and Mn ratios on the catalytic performance were investigated. The catalysts were characterized by XRD, SEM, H2-TPR, TG, BET and XPS, to reveal the catalytic mechanism. The results showed that after adding the manganese, the copper-manganese complexes were formed in the catalysts, which effectively improved the activity of the catalysts. XRD results showed that a new phase of Cu-Mn complex was formed in the fresh catalysts, and reduced copper species appeared in the spent catalysts; TPR results showed that the reduction temperature of the catalysts could be reduced by adding appropriate amount of manganese; XPS results showed that the proportion of Cu ++Cu0 can be increased in the fresh catalyst and that of Cu2+ in the spent catalyst can be decreased after the addition of manganese. When the mole ratio of Cu, Mn and Si in the catalysts was 0.8:0.2:1, the conversion of 2-butanol could reach 94.9%, and the selectivity of methyl ethyl ketone was 98%. [ABSTRACT FROM AUTHOR]

A new polyoxoniobate constructed by four {Nb27} building blocks, K11[Cu(en)2(H2O)2]2[H29{Cu(en)2}4{Cu0.5(en)2}4{Cu(en)2(H2O)}4(OH)4(Nb27O75)4]·103H2O (en = ethanediamine), has been synthesized and characterized. Four {Nb27} inorganic blocks are linked by metal-organic components [Cu(en)2]2+, forming a tetrameric organic–inorganic hybrid. The structure is characterized by IR spectroscopy, XRD, UV–vis, EPR, single crystal X-ray diffraction, thermal gravimetric analysis and elemental analysis. Furthermore, the solution behavior was investigated indicating the integrity of {Nb27} building block, which shows the possibility that it might be an excellent precursor for functionalization. [ABSTRACT FROM AUTHOR]

To elucidate the impact of potato flour (PF) on quality changes and staling characteristics of the composite bread from wheat–potato flour (WPF), the physicochemical (specific volume, colority, sensory value, texture, and viscosity) properties, and staling (X‐ray diffraction and water migration) properties of bread were investigated. The quality of composite bread was comparable to wheat bread when addition level of PF at 20%, but decreased when the addition level increased to 30% or more, and became unacceptable at 50%. A chewy mouthfeel and an elastic and none‐crumbly texture were observed on composite bread, which had higher hardness than wheat bread, and could keep on both longer linear distance and higher linear force during compression test. It indicated that such new parameters other than hardness should be introduced to coordinate with the texture quality of composite bread. During storage, the higher addition level of PF significantly decreased crystallinity of composite bread and slowed water migration rate from the crumb to crust, suggesting that PF had antistaling effect on composite bread, which was further emphasized by the fact that the setback value of the WPF decreased with the increase of PF addition. [ABSTRACT FROM AUTHOR]

In this study, two new mixed-ligand coordination polymers (CPs) {[Cd6(nbta)3(bimb)4(H2O)](H2O)3}n (1, bimb = 4,4′-bis((1H-imidazol-1-yl)methyl)−1,1′-biphenyl) and [Co3(bib)2(nbta)2]n (2, bib = 1,4-bis(benzimidazol-1-yl)−2-butene) have been successfully prepared by reaction of 5-nitro-1,2,3-benzenetricarboxylic acid (H3nbta) with different N-donor ligands under the solvothermal conditions. The as-prepared two CPs have been studied via the elemental analysis along with the single crystal X-ray diffraction. The inhibitory effect of synthesized new mixed-ligand coordination polymers on K562 leukemia cells was evaluated by CCK-8 assay. And the percentage of apoptotic cells after CPs 1 and 2 treatment was assessed by Annexin V-FITC/PI assay. Finally the in vivo effect of CPs on tumor was conducted by tumor volume and mice weight measurement. [ABSTRACT FROM AUTHOR]

This paper presents a quantitative study of the effect of 5 and 7.5% of nano silica (nS), 2.5 and 5% of nanoalumina (nA) and 2.5 and 5% of nanocalcium carbonate (nCC), on the properties of very high-volume fly ash cement composites (VHVFA-CC), replacing 80% of cement. Compressive strength test, thermogravimetry, quantitative X-ray diffraction and scanning electron microscopy were undertaken to study the effect of various nanomaterials on the physicochemical behaviour of VHVFA cement composites. The results show that the addition of nS to VHVFA-CC significantly improves its compressive strength and considerably increases the formation and thermal stability of silica-rich hydrogarnet [Ca3(AlxFe1−x)2(SiO4)y(OH)4(3−y)], which increases with the increase in nS content. The addition of nCC to VHVFA-CC does not show any effect on the pozzolanic reaction at 7 days of curing but at 28 days considerably improves its pozzolanic reaction, which increases with the increase in nCC content. The addition of nA though improves the hydration/pozzolanic reaction of VHVFA-CC, resulting in the improvement of compressive strength, but only if added in small quantities (i.e. 2.5% or less). If it is added in higher amounts, it promotes the formation of Al(OH)3 gel that severely inhibits the hydration/pozzolanic reaction within the cement matrix. [ABSTRACT FROM AUTHOR]

Wastewater from the printing and dyeing industry is an area of growing concern. Photocatalysts synthesized using polyaniline (PANI) and certain metal oxides have been increasingly used for the purpose owing to their high photocatalytic potential, ease of synthesis, and ease of recycle and reuse. Herein, a ternary composite α-SiW11Cr/PANI/ZnO was prepared by electrostatic self-assembly, and characterized by infrared (IR) spectroscopy, diffraction of X-rays, scanning electron microscopy, etc. N2 adsorption-desorption showed that the composite had a bimodal pore system for mesoporous materials. Catalytic activity of α-SiW11Cr/PANI/ZnO for photodegradation of organic dye malachite green under UV irradiation was studied. Compared with single materials, ternary composites have better photocatalytic performance. [ABSTRACT FROM AUTHOR]

The study validated the efficacy of methyl cellulose films doped with different concentration of Eu2O3 nanoparticles to inactivate foodborne pathogens. Eu2O3 nanoparticles were added to the methyl cellulose solution with different weight percentages (0.0, 0.5, 0.75, 1.0, 1.25, and 1.5 wt%). X‐ray diffraction patterns for the prepared films were studied. A significant lower count of E. coli, S. typhimurium, and S. aureus (p ≤.05) inoculated in MC films doped with Eu2O3 nanoparticles compared with pure MC film could be achieved. The findings acquired verify the impact of prepared MC films doped with Eu2O3 nanoparticles on the test strains. [ABSTRACT FROM AUTHOR]

The reduction of 2,4,6‐tri(4‐pyridyl)‐1,3,5‐triazine (TPT) with alkali metals resulted in four radical anion salts (1, 2, 4 and 5) and one diradical dianion salt (3). Single‐crystal X‐ray diffraction and electron paramagnetic resonance (EPR) spectroscopy reveal that 1 contains the monoradical anion TPT.− stacked in one‐dimensional (1D) with K+(18c6) and 2 can be viewed as a 1D magnetic chain of TPT.−, while 4 and 5 form radical metal‐organic frameworks (RMOFs). 1D pore passages, with a diameter of 6.0 Å, containing solvent molecules were observed in 5. Variable‐temperature EPR measurements show that 3 has an open‐shell singlet ground state that can be excited to a triplet state, consistent with theoretical calculation. The work suggests that the direct reduction approach could lead to the formation of RMOFs. [ABSTRACT FROM AUTHOR]

Fe-bearing phase E coexisting with ringwoodite and wadsleyite has been synthesized at near-geotherm temperatures in hydrous KLB-1 peridotite compositions held at 18 and 19 GPa, and 1400 °C for 27 h. The long heating duration time of syntheses implies that phase E can be a stable component of the mantle under hydrous conditions. Single-crystal X-ray diffraction analyses show that the M1 octahedral site is 72.1–75.2 at% occupied, whereas the M2 and tetrahedral Si sites are 2.4–2.9 at% and 18.9–19.8 at% occupied, respectively. The M1 site occupancies show a positive correlation with Fe/Mg molar ratios, indicating that Fe mainly occupies the M1 site in the phase E structure. High-pressure Raman spectroscopy shows that the framework Raman frequencies of Fe-bearing phase E increase continuously with increasing pressures up to 19 GPa at room temperature, and there is no indication for a major change in the crystal structure. If transition-zone regions adjacent to subducting slabs are hydrated by fluids generated at the top of the lower mantle, Fe-bearing phase E is expected to occur at wadsleyite-ringwoodite phase transition boundary (about 520 km) as an important phase for incorporating water. [ABSTRACT FROM AUTHOR]

The reaction of the phosphine functionalized chlorogermylene 1 with Ni(COD)2 (COD = 1,5-cyclooctadiene) afforded the bis-chlorogermylene ligated nickel(0) complex 2 in high yield. The dechlorination reaction of 2 with elemental potassium serendipitously yielded the diamidinatogermylene nickel(0) complex 3. Single-crystal X-ray diffraction analysis reveals that the germanium center in 3 features a pyramidalized geometry, suggesting the germylene moiety in 3 acts as a Z-type ligand, which is further supported by theoretical calculations. Complex 3 represents the first example bearing a Z-type diaminogermylene ligand. [ABSTRACT FROM AUTHOR]

Reactions of Ln(acac)3·2H2O (Ln = SmIII (1), EuIII (2), GdIII (3), TbIII (4), DyIII (5), HoIII (6), ErIII (7)) with a bitidentate flexible ligand (HL) in an acetonitrile and dichloromethane mixture solvent result in a family of Ln4 clusters with the formula [Ln4(acac)4(μ2-OH)(L)6]·xCH3CN·yC2H5OH (Hacac = acetylacetone, HL = 5-(4-ethylbenzylidene)-8-hydroxylquinoline). X-ray diffraction studies reveal that clusters 1–7 are isostructural and possess a rhombus-shaped tetranuclear Ln4 core. All the LnIII ion centers adopt a distorted square-antiprismatic coordination geometry. Magnetic investigations reveal that cluster 3 displays magnetic refrigeration properties with a significant entropy change (−ΔSm) of 23.37 J kg−1 K−1 (−ΔH = 7.0 T, T = 2.0 K), whereas cluster 5 shows remarkable SMM behavior with two distinct slow magnetic relaxation processes (ΔE/kB = 124.8 K and τ0 = 1.12 × 10−8 s for FR, and ΔE/kB = 39.5 K, τ0 = 6.95 × 10−7 s for SR). Furthermore, the solid-state luminescence property indicates that clusters 1, 2, 4 and 5 display the characteristic lanthanum luminescence at room temperature. [ABSTRACT FROM AUTHOR]

A series of [2 × 2] square grid LnIII4 clusters based on a multidentate chelating ligand N′-(2-hydroxybenzylidene)-6-(hydroxymethyl)picolinohydrazide (H3L), namely [Ln4(HL)4(μ2-CH3O)4]·4CH3OH (LnIII = Gd (1), Tb (2), Dy (3), and Ho (4)), were successfully synthesized and characterized by single-crystal X-ray diffraction and SQUID magnetometry. The X-ray structural analysis reveals that clusters 1–4 are mainly composed of four LnIII ions which are interconnected through four μ-O bridging picolinoyl hydrazine ligands and four μ-O bridging methoxide ions. Magnetic studies show that cluster 1 exhibits antiferromagnetic exchange interactions between nearby GdIII centers and displays a large magnetic entropy (−ΔSm = 34.46 J kg−1 K−1 for ΔH = 7.0 T at 2.0 K). Alternating current (ac) magnetic susceptibility measurements demonstrate that slow relaxation behavior occurs in 3 under a zero direct-current (dc) field, with an effective energy barrier (ΔE/kB) of 42.76 K and a pre-exponential factor of τ0 = 1.02 × 10−6 s, while in clusters 2 and 4, no out-of-phase (χ′′) signals are observed. [ABSTRACT FROM AUTHOR]

This study investigated the influence of the main metal materials of transformers on the oil-paper insulation performance. Ten types of insulating specimens were subjected to accelerated thermal aging at 120°C. Some aging parameters, including oil acid number, furfural content and degree of polymerization (DP) of insulating paper, were measured and compared. At the same time, we conducted frequency domain spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry on the insulating paper. The following conclusions were drawn: silicon lamination slightly deteriorates the insulating oil, copper increases the acidity and accelerates the production of furfural, metal materials can decrease DP of insulating paper and the effect of copper is greater than that of silicon lamination. During thermal aging, the dielectric dissipation factor of insulating paper increases and the carbon content of insulating paper increases. Metal materials can significantly increase the dielectric dissipation factor and carbon content of insulating paper and the effect of copper is greater than that of silicon lamination. [ABSTRACT FROM AUTHOR]

Identification of fractures is an important guide for the selection of well location as well as improvement of single-well recovery. In this paper, large-scale fractures of Su 48 block (target well) located in Sulige gas field were predicted using the coherence, curvature and anti-tracking analysis while small-fractures prediction were performed using R/S fractal statistical method. The observations revealed that, development of large-scale fractures were not that significant, whilst those of a smaller scale were distributed across the near-wellbore formation constituted of mudstone. Moreover, predicted results using the multi-scale fusion fracture developed model showed good agreement of the existence of fractures during horizontal well drilling in real time. Furthermore, the predicted fractures matched well with those observed in the field. Hence, reflecting the significance of tight gas sandstone reservoir fracture identification method. [ABSTRACT FROM AUTHOR]

We studied the impact of in situ post-growth annealing process on cadmium telluride (CdTe) polycrystalline thin film in this work. Samples of different annealing times have been characterized by x-ray diffraction (XRD) and a scanning electron microscope (SEM). The optoelectronic properties of CdTe film were deeply studied with light I-V testing, external quantum efficiency (EQE) and photoluminescence (PL)/time-resolved photoluminescence (TRPL) measurements. It is found that the in situ post-growth annealing treatment has a great effect on cadmium sulfide (CdS)/CdTe intermixing as well as interface pinholes. Elementary correlations between annealing time, film and junction morphology, carrier lifetime and device performance were investigated, and the annealing time turns out to be crucial to CdTe device performance. Solar cells with CdTe polycrystalline thin film annealed in situ at 550°C/550°C for 10 min show the best performance. With the help of precisely controlled annealing time, better CdTe film microstructure and morphology can be realized after in situ post-growth annealing. [ABSTRACT FROM AUTHOR]

Nd3+, as one of the most important rare-earth (RE) ion, has been playing a significant role in pumping the infrared (IR) light. Depending on different synthesis strategies, doping content, and crystal lattice, however, Nd3+ always shows different IR intensity. In this work, we have fabricated two series of Nd3+ doped nanocrystallines that share with the same crystal structure, i.e., Nd3+ doped Y3Al5O12 (YAG) and Yb3Al5O12 (YbAG), through using the co-precipitation synthesis method while the ammonium bicarbonate as the precipitant agent. To reveal the influence of the synthesis conditions (e.g., synthetic temperature and pH value) on structural and florescent properties of Nd3+ doped YAG and YbAG nanocrystallines, several techniques have been performed in this work, including the X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric-differential scanning calorimeter (TG-DSC), Fourier transform infrared (FT-IR) spectroscopy, Raman and florescent spectroscopy spectra. Our results reveal that the optimal synthesis conditions are 1000 °C and pH 8 for YAG:Nd3+ and 900 °C and pH 9 for YbAG:Nd3+. Moreover, we also find the optimal Nd3+ doping contents of the YAG:Nd3+ and YbAG:Nd3+ nanocrystallines are 3% and 1.5%, which correspond to the strongest fluorescent intensity upon excitation at 808 nm and 980 nm, respectively. Typically, we reveal that substitution of Y with Yb ions could allow to enhancing the Nd3+ fluorescent intensity upon excitation at 808 nm. This work provides new insights into designing excellent crystal materials that can allow us to realize the laser transparent ceramics. [ABSTRACT FROM AUTHOR]

SnO2/TiO2 composites have been widely studied as efficient photoanodes by various research groups around the globe. However, in this work, we display a novel and low cost strategy to synthesize thin films of such composites. According to the synthesizing strategy, various amounts of Degussa TiO2 P25 nanopowder ranging from 0.25 to 1.0 g were mixed to a fixed volume of SnO2 sol-gel solution. Then, the mixtures were spin-coated on doped tin oxide glass substrates. After a slow annealing at 500 °C, we obtained nanostructured SnO2/TiO2 composite thin films (CTFs). As-prepared CTFs were characterized by the scotch tape test, scanning electron microscope, X-ray diffraction and photoluminescence spectra. Furthermore, photoelectrochemical properties, photocatalytic activities and stability of all SnO2/TiO2 composite based PAs were studied. Results showed that composites with medium TiO2 amount exhibits more compact and adherent films than bare TiO2 films. We recorded an optimum situation for films prepared with 0.75 g of TiO2. It was proved that the SnO2 sol-gel method enabled compactness and adhesion of the processed composites. We correlated the photoluminescence intensity to the photocurrent density Jsc. The optimum Jsc, almost equal to 0.9 mA, was obtained in the case of 0.75 g amount of TiO2. This electrical performance is nearly nine times higher than that recorded with bare TiO2 photo-anodes. Moreover, replacing bare TiO2 photocatalyst by SnO2/TiO2 CTFs brought remarkable improvements to the photocatalytic degradation of methyl orange. Finally both morphological and mechanical properties of the composites were correlated to the stability and reusability of the CTF PAs. [ABSTRACT FROM AUTHOR]

In the lighting field, it is essential to seek the phosphor materials with tunable emission for warm white light-emitting diodes (wLEDs). Herein, we reported a new type of Eu3+, Bi3+ doped calcium germanate phosphor, which can exhibit a broad emission tuning from blue, white and to red. According to the XRD results, the structure purity of all as-obtained germanate phosphors are revealed to feature a trigonal structure with the space group of R3(No. 146). Structural analysis shows that the dopants of Eu3+ and Bi3+ should tend to substitute the Lu sites in the crystal host. The photoluminescence (PL) spectroscopy shows that the Eu3+ and Bi3+ ions can emit the blue emission and the red emission upon excitation at 297 nm and 393 nm, respectively. In view of the significant spectral overlapping between the excitation wavelength of Eu3+ and the emission wavelength of Bi3+, we study the energy transfer from Bi3+ and Eu3+ ion and reveal that the energy transfer is happened via an electric dipole-dipole (d-d) interaction. Remarkably, when the doping content of Bi3+ ions is fixed, changing the doping content of Eu3+ ions can induce the emission color tuning from blue, white and to red. To explain better the PL observation, a mechanistic pattern, which bases on the energy transfer from Bi3+ and Eu3+ ion, has been also constructed, which is expected to provide a general idea for achieving the energy-transfer-controlled tunable phosphor materials for phosphor-converted wLEDs. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we analyze the role of a thin Cr spacer between Fe and Gd layers on the structure and magnetic properties of a [Fe(35 Å)/Cr(tCr)/Gd(50 Å)/Cr(tCr)]12 superlattice. Samples without the Cr spacer (tCr = 0) and with a thin spacer (tCr = 4 Å) are investigated using X-ray diffraction, polarized neutron and resonance X-ray magnetic reflectometry, static magnetometry, magneto-optical Kerr effect, and ferromagnetic resonance techniques. Magnetic properties are studied experimentally in a wide temperature range 4-300 K and analyzed theoretically using numerical simulation on the basis of the mean-field model. We show that a reasonable agreement with the experimental data can be obtained considering temperature dependence of the effective field parameter in gadolinium layers. The analysis of the experimental data shows that besides a strong reduction of the antiferromagnetic coupling between Fe and Gd, the introduction of Cr spacers into Fe/Gd superlattice leads to modification of both structural and magnetic characteristics of the ferromagnetic layers. [ABSTRACT FROM AUTHOR]

This paper is mainly concerned with the design problem of two-step model predictive control (MPC) for nonlinear systems represented by Hammerstein model, where the network-induced time delays exist between sensor to controller (S2C) and controller to actuator (C2A) links. We assume that the system state is not measurable, so the state observer is employed to estimate the state. The intermediate variable for the linear part of the system is calculated by minimising the quadratic performance function. The time-delay compensation algorithm of two-step output feedback predictive control (TSOFPC) for Hammerstein systems is presented and validated by a numerical example. [ABSTRACT FROM AUTHOR]

The Nanyang Sag in the Nanxiang Basin, eastern China, has a large petroleum resource, although the genetic potential of source rocks and oil–rock correlation in the Paleogene Hetaoyuan Formation is unclear. Organic geochemistry and molecular geochemistry analyses of mudstone and oil samples were performed to evaluate source rock potential, classify oil groups, and establish accurate oil–source rock correlation. The results suggest that the second member (Eh2) and the third member (Eh3) of the Hetaoyuan Formation are good source rocks, contain abundant organic matter and oil‐prone kerogen, and are thermally mature. Oil samples from Eh2 and Eh3 were separated into 3 groups derived from different source rocks. Group I oils are mainly distributed in the Eh2 and Eh3 members around the Dongzhuang (Dongz) structure belt and are characterized by a low saturated hydrocarbon content (SAT, 39.07–49.54%), high total resin (RE) and asphaltene (ASP) content (17.22–22.80%), low gammacerane index (gammacerane/C3017α(H)‐hopane < 0.60), and low Pr/Ph (<0.7). The organic matter is in an early mature stage and is mainly sourced from algae and land plants. The oils of this group are derived from the Eh2 and Eh3 source rocks around the Dongz secondary sag. Group II oils occur in the Eh2 around the Weigang–Beimazhuang (Weig–Beimz) structure belt and north of the Zhangdian–Heilongmiao (Zhangd–Heilm) structure belt and have intermediate SAT, RE, and ASP contents, a low gammacerane index (<0.47), and high Pr/Ph (0.72–1.25). The organic matter includes mainly algae and land plants. The source rocks should be the Eh2 and Eh3 in the Dongz and Niusanmen (Niusm) secondary sags. Group III oils are located in the Eh3 just north of the Weig–Beimz and Zhangd–Heilm structure belts, with a high SAT (55.62–78.42%), low RE and ASP proportion (3.60–6.16%), high gammacerane index (>0.88), and low Pr/Ph (<0.72). This organic matter is composed of mostly land plants. The oils in this group are mainly derived from the Eh3 near Baiqiu (Baiq). [ABSTRACT FROM AUTHOR]

A large number of rare earth element mining and application resulted in a series of problems of soil and water pollution. Environmental remediation of these REE-contaminated sites has become a top priority. This paper explores the use of Bacillus licheniformis to adsorb lanthanum and subsequent mineralization process in contaminated water. The maximum adsorption capacity of lanthanum on bacteria was 113.98 mg/g (dry weight) biomass. X-ray diffraction (XRD) and transmission electron microscopy (TEM) data indicated that adsorbed lanthanum on bacterial cell surface occurred in an amorphous form at the initial stage. Scanning electron microscopy with X-ray energy-dispersive spectroscopy (SEM/EDS) results indicated that lanthanum adsorption was correlated with phosphate. The amorphous material was converted into scorpion-like monazite (LaPO4 nanoparticles) in a month. The above results provide a method of using bacterial surface as adsorption and nucleation sites to treat REE-contaminated water. [ABSTRACT FROM AUTHOR]

The Chang 7 Member of the Yan-Chang Formation (Yan-Chang #7 Member), which is located in the central south of the Ordos Basin (China), is assessed for its potential as a shale gas resource. The characteristics and spatial variability of mineral components in this continental shale formation play a crucial role in evaluating and characterising the shale reservoirs. We collected 64 shale core samples from 30 representative sampling sites located in the central south of the Ordos Basin using X-ray diffraction and field emission scanning electron microscopy to study the mineral compositions, vertical/planar variations of minerals, and the major controlling factors that result in such variations. Based on the relative fractions of the dominant minerals, the shale rocks can be classified into four categories: quartz-rich (type #1), illite/chlorite-rich (type #2), illite-smectite mixed-layer-rich (type #3) and feldspar-rich (type #4). In general, type #1 is mainly located in the northwest of the study area, type #4 is mainly located in the south of the study area, and types #2 and #3 are sandwiched between types #1 and #4. In the centre of the basin, the illite content increases with burial depth and the conversion from smectite to illite, which is experimentally confirmed in this study, enhances the surface porosity of shale. The major factors influencing the properties and spatial variability of the mineral components include sedimentary environment, provenance and diagenesis. Compared with marine shales in China (e.g. Longmaxi marine shales), the Yan-Chang #7 Member continental shale has a higher clay content, but lower calcite, dolomite and pyrite contents. The brittleness indexes of type #1 shale in Wuqi and its surrounding areas are marginally higher than that of Longmaxi marine shales, which makes the type #1 shale in the Wuqi and its surrounding areas slightly easier to fracture than the Longmaxi marine shales. [ABSTRACT FROM AUTHOR]

In this paper, poly(vinyl chloride)/graphene (PVC/G) composite fibers are extruded through a set of wet spinning unit for the purpose of properties improvement, including mechanical strength, thermal stability, and electrical conductivity. PVC/G composite membranes are also prepared using a spin-coating method for the analysis on the distribution of graphene in PVC composite. The PVC/G composite fibers are systematically characterized by means of Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and X-ray Diffraction. The mechanical, thermal, and electrical properties of the prepared PVC/G composite fibers are also analyzed. The experimental results show that the graphene sheets at a low concentration of 1-5 wt% can be distributed homogeneously in the PVC matrix; the mechanical properties, thermal stability, and electrical conductivity of PVC can be enhanced significantly by the blending of graphene sheets. [ABSTRACT FROM AUTHOR]

A series of Ln-sulfoterephthalate coordiantion polymers, namely, [Ln(2-stp)(4,4'-bbpi) (H2O)2]⋅H2O [Ln = Eu (1), Tb (2), Dy (3)] (2-H3stp = 2-sulfoterephthalate; 4,4'-bbpi = 4,4'-bisbiphenylimidazole), were prepared by hydrothermal method and characterizatied by EA, IR, TGA, and PXRD technologies. Single crystal X-ray diffraction analyses show that the three complexes are isostructral twodimensional network featuring helical chain structures. The fluorescence studies show that the emissions of the coordination polymers exhibit the characteristic peaks of lanthanide ions, which means they could be potential fluorescence materials. [ABSTRACT FROM AUTHOR]

Epoxy composites comprising modified graphene oxide and copper nanowires as hybrid fillers were prepared, in which dopamine (DA) is used as modifier for copper nanowires and graphene oxide (GO). Dopamine is easily oxidized to self-polymerize into adherent polydopamine (PDA) coating on all sorts of substrates in alkaline aqueous solution. In this paper, CuNWs@PDA and GO@PDA have been prepared successfully and confirmed by TEM, SEM and XRD, which indicates that the coating layer of PDA is uniformly capped on the copper nanowires and GO nanosheets. Meanwhile, the properties of epoxy composite were obtained by testing the thermal properties, volume resistivity and dielectric constant. The different proportions of hybrid fillers prepared by two modified fillers result in different thermal conductivities and other properties. The experimental results show that the epoxy composites possess higher thermal conductivity for 0.36 W/m K and excellent electrical insulation properties when the proportion of filler CuNWs@PDA:GO@PDA is 7:3. This is mainly attributed to the good interfacial adhesion between CuNWs@PDA/GO@PDA and resin as well as the synergetic effect between CuNWs@PDA and GO@PDA. [ABSTRACT FROM AUTHOR]

In this study, a surface functionalization process was designed for the preparation of Au nanoparticles-strewn MnOOH nanorods with enhanced catalytic performance for reduction of aromatic nitro compounds. (3-Aminopropyl) triethoxysilane was used as a modifier to link MnOOH nanorods and Au nanoparticles. The as-obtained nanocomposite was characterized by powder X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy (TEM/HRTEM), selected area electron diffraction, energy dispersive X-ray spectrometry, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Our results showed that the MnOOH/Au nanocomposite can be used as a highly efficient catalyst for the reduction of aromatic nitro compounds in the presence of NaBH solution. [ABSTRACT FROM AUTHOR]

Herein four inclusion compounds of 2,2′-dithiosalicylic acid and tetraalkylammonium, 2(CH3)4N+·C14H8O4S22−·H2O (1), (C2H5)4N+·C14H9O4S2−·0.25H2O(2), (n-C3H7)4N+·C14H9O4S2− (3) and (n-C4H9)4N+·C14H9O4S2−(4) are prepared and characterized by X-ray single crystal diffraction. As shown in the results, compounds 1 and 3 belong to orthorhombic crystal system with different space groups of P212121 and Pca21, and 2 and 4 are monoclinic system with similar groups of P21/n and P21/c. The crystallography data are displayed below: 1: a = 10.5903(7) Å, b = 10.6651(7) Å, c = 21.9476(13) Å, V = 2478.9(3) Å3, Z = 4, R1 = 0.0359; 2: a = 8.13340(1) Å, b = 22.0741(3)Å, c = 13.2143(2)Å, β = 101.6360(1) °, V = 2323.70(6) Å3, Z = 1, R1 = 0.0385; 3: a = 15.7857(2) Å, b = 8.24830(1) Å, c = 20.2599(2) Å, V = 2637.94(5) Å3, Z = 4, R1 = 0.0308degree4: a = 11.7476(2) Å, b = 17.1346(1) Å, c = 16.3583(3)Å, β = 109.4560(1) °, V = 3104.74(9)Å3, Z = 4, R1 = 0.0562. Interestingly, although the carbon chains of the guest templates vary from methyl group to butyl group, the host molecules of 2,2′-dithiosalicylic acid all construct the similar 2D hydrogen-bonded host layers with or without the existence of water molecules to contain the guest templates to yield analogous sandwich-like inclusion compounds. Obviously, although the guest templates will have certain effects on the ultimate formation of these crystal structures, the host molecule of 2,2′-dithiosalicylic acid is a controlling factor to form these four inclusion compounds. [ABSTRACT FROM AUTHOR]

A novel 1D organic–inorganic hybrid phase transition material {[(C4H4N2)Co(H2O)4]SO4·2H2O}n (1) was prepared and characterized. Differential scanning calorimetry indicated that 1 underwent a reversible phase transition at 181.3 K. Single crystal X-ray diffraction analysis revealed transition from a room temperature phase with the space group C2/c to a low temperature phase with the space group P21/c. The SO42− anions, located in the free cavities formed by vertically staggered [(C4H4N2)Co(H2O)4]n2+ chains, are dynamically disordered in the room temperature phase. The disorder–order transition of SO42− anions and the distortion of [(C4H4N2)Co(H2O)4]2+ chains with the decrease of temperature synergistically drove the phase transition. The step-like dielectric anomaly makes 1 a promising switchable dielectric material. [ABSTRACT FROM AUTHOR]

Highly improved catalytic reductive degradation of different organic dyes, in the presence of excess NaBH over Au/CeO-TiO nano-hybrid as the catalyst is reported in this study. CeO-TiO nanocomposite was prepared by a facile co-precipitation method using ultra-high dilute aqueous solutions. Small amount of Au (only 1 wt%) was loaded onto the nanocomposite material by deposition-precipitation with urea (DPU) method to fabricate the ternary Au/CeO-TiO nano-hybrid. The catalysts were characterized by the representative techniques like XRD, BET surface area, ICP-AES, UV-Vis diffuse reflectance spectroscopy, TEM and XPS. The Au/CeO-TiO nano-hybrid along with NaBH exhibited remarkable catalytic activities towards all the probed dyes, namely Methylene Blue, Methyl Orange, Congo Red, Rhodamine B and Malachite Green, with a degradation efficiency of ∼100% in a short reaction time. The degradation reaction followed pseudo-first-order kinetics with respect to the concentration of the dye. Different parameters that affect the rate of the reaction are discussed. A plausible mechanism for methylene blue degradation has also been proposed. [ABSTRACT FROM AUTHOR]

Six known quassinoids were isolated from the bark of Ailanthus altissima. Their structures were elucidated by spectroscopic methods. Compounds 1-6 were screened for their antitumor activities evaluated by MTT assay. [ABSTRACT FROM AUTHOR]

The self-assembly of three giant hexagonal 3d-4f metallocycles with inner diameters of 16.4, 16.5, and 16.4 Å, is described. Hexagonal metallocycles were stacked along the crystallographic c axis, producing unique hexagonal macroscopic tubular single crystals. The assembly mechanism of the tubular crystals was investigated. Remarkably, all three hexagonal metallocycles show typical single-molecule magnet behavior, benefiting from the ferromagnetic couplings between the 3d and 4f ions. [ABSTRACT FROM AUTHOR]

Mg-Zn-Y alloys solidified under high pressure were characterized using XRD, DTA, SEM, and TEM. After solidification at atmospheric pressure, Mg-6Zn-1Y consisted of α-Mg, MgZn, and MgYZn, while Mg-6Zn-3Y consisted of α-Mg, MgYZn, and MgYZn. After solidification at 6 GPa pressure, both alloys consisted of α-Mg, MgZn, and MgYZn. The size and the shape of the second-phase particles formed for atmospheric solidification were significantly different to those formed for solidification at 6 GPa pressure. In Mg-6Zn-1Y, the second-phase size decreased from 300 to 50 nm, and the shape changed from needle like to blocky. In Mg-6Zn-3Y, the size decreased from 100 to 50 nm and the shape changed from short rod like to small and round. After aging at 200 °C for 12 h, the new MgZn phase transformed into the intermediate MgZn phase. Increasing the aging time to 24 h caused the intermediate MgZn phase to transform into MgZn with a size of 50 nm, while the MgYZn phase remained unchanged. [ABSTRACT FROM AUTHOR]

Bismuth oxychloride materials were synthesized by a one-step procedure with high purity precursors with variation of the pH from 1 to 6. The materials were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer Emmett Teller measurements, and photoluminescence. Photocatalytic properties were characterized by the degradation of methylene blue with visible light from a 100 W lamp and natural sunlight. All samples contained the tetragonal phase with platelet structures. The thickness of the platelets was sensitive to pH during synthesis and increased from 97 to 227 nm with an increase in pH. The photoactivity of the sample decreased with an increase in pH. The highest photocatalytic activity of 0.00295 min-1 for the 100 W electric lamp and 0.00316 min-1 for sunlight was observed for the material prepared at pH 1. The photocatalytic activity values of these materials were approximately one order or magnitude higher than titanium dioxide in the visible region. Photoluminescence studies confirmed the presence of mid-band gap states that enabled the material to absorb light in the 400 to 450 nm region. [ABSTRACT FROM AUTHOR]

An inorganic–organic hybrid compound, (C3H12N2)2[Cu(H2O)4(SO4)2](HSO4)2 (1), was synthesized by slow evaporation based on 1,3-propanediamine as the template. Differential scanning calorimetry measurement showed that compound 1 underwent a reversible phase transition at 277 K with a hysteresis width of 3 K. The temperature dependence of the dielectric permittivity also confirmed the phase transition. Single crystal X-ray diffraction demonstrated that the disorder–order transformation of the C atoms in the (C3H12N2)2+ cation may drive the structural phase transition. The dielectric permittivity of 1 can be switched between two states, which will be used in switchable dielectric devices. [ABSTRACT FROM AUTHOR]

To investigate the coordination nature of the pyridyl-N-oxide phosphonate ligands with rare earth metals, two series of nine lanthanide complexes, namely, {[Ln(HL)((C2O4)0.5)2(H2O)]·3H2O}n {Ln = Eu(1), Gd(2), Tb(3), Dy(4) and Ho(5)} and {[Ln2(L)(C2O4)2(H2O)3]·H2O}n {Ln = Er(6), Tm(7), Yb(8) and Lu(9)} {H2L = 2-(pyridyl-N-oxide)methylphosphonic acid; H2C2O4 = oxalic acid }, have been hydrothermally synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and powder and single-crystal X-ray diffraction. Complexes 1–5 are isomorphic, featuring a three-dimensional (3D) porous structure with a dia topological framework, while the isomorphic complexes 6–9 show a 3D 3,4-connected topological framework with a point symbol of {72·8}2{73·83}. Photoluminescence spectra of complexes 1 and 3 exhibit the strong luminescence characteristic of Eu(iii) and Tb(iii) ions, respectively, suggesting that HL− and L2− anions are able to efficiently sensitize the luminescence of lanthanide ions. The magnetic analyses of complexes 2–5 show the characteristic magnetic susceptibilities of isolated Gd(iii), Tb(iii), Dy(iii) and Ho(iii) ions, respectively. [ABSTRACT FROM AUTHOR]

( R)-3-(2′-hydroxyprop-1-yl) adenine 4 was obtained by of adenine 1 with R-propylene carbonate 2 in the presence of pulverized in the synthetic process of tenofovir. The elucidation of the structure of 4 was confirmed by single crystal X-ray diffraction and NMR experiments such as 1D 1H, 13C, and DEPT, as well as 2D COSY, HSQC, and HMBC spectra. [ABSTRACT FROM AUTHOR]

BiMoO nanomaterials are synthesized by a facile solvothermal method. Morphology and structure of the BiMoO nanomaterials are analyzed by SEM, XRD, N adsorption techniques and XPS. Gas-sensing properties of the as-prepared BiMoO sensors are also systematically investigated. The results show the BiMoO nanomaterials consist of nanosheets and demonstrate good crystallinity. The optimal operating temperature of the BiMoO sensors is 240 °C. At this operating temperature, The BiMoO sensor exhibits a fast response-recovery to ethanol, suggesting its excellent potential application as a gas sensor for ethanol gas-sensing applications. [ABSTRACT FROM AUTHOR]

In this paper, the alkali hydrolyzed polyester fabric was treated with functional single-wall and multi-wall carbon nanotubes, nanocarbon black without and with nano-TiO2 and citric acid as a cross-linking agent through exhaustion method and post-curing. Electrical conductivity, methylene blue degradation, UV protection, and thermal stability of the treated fabrics were investigated. The loading of various carbon nanostructures and nano-TiO2 on the polyester fabric confirmed with SEM images and energy-dispersive X-ray spectroscopy. Further, X-ray diffraction, remaining ash percentage via furnace and thermogravimetric analysis, proved the presence of nano-TiO2 on the polyester fabric. The UV protection verified with UV–Vis reflection spectra indicated the highest protection on the nanocarbon black/nano-TiO2/CA-treated fabric. The highest discoloration of methylene blue solution and electrical conductivity obtained on the treated fabric with functional single-wall carbonnano tube/nano-TiO2/citric acid and functional nanocarbon black/nano-TiO2/citric acid. This is related to enhance photocatalytic activities of nano-TiO2 with cooperation of single-wall carbon nanotubes and more surface coating of nanocarbon black on the polyester fabric. [ABSTRACT FROM AUTHOR]

In this study, the iron oxide/silver (FeO/Ag) nanocomposite has been successfully prepared by a facile one-step method using goethite (α-FeOOH) rods as support. The diameter of the as-synthesized goethite rods was between 250 and 500 nm and the silver nanoparticles sizes were about 10-50 nm. By varying the concentrations, the FeO/Ag nanocomposite with different Ag contents are successfully obtained. The FeO/Ag nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy dispersive spectroscopy, respectively. Due to the unique nanostructure, these nanocomposites can catalyze degradation of both aromatic nitro compounds and organic dyes only within a few minutes, which show high catalytic performance. [ABSTRACT FROM AUTHOR]

Bi1-xHoxFeO3(BHFO, x = 0, 0.05, 0.10, 0.15, 0.20) nanoparticles were successfully synthesized via a simple double solvents based sol-gel route. X-ray diffraction analysis shows the BHFO samples with x = 0-0.10 are pure-phased perovskite structure. Scanning electron microscopy images reveal that the BHFO particles are in nano scale. UV-Vis measurement was taken to determine the band gap of BHFO samples, suggesting the band gap of BHFO samples can be modulated by Ho doping. The absorption spectra of RhB solution show that the BHFO nanoparticles have photocatalytic effect of degrading RhB organic dye which reaches a maximum of 42% for x = 0.10. Well-shaped M–H hysteresis loops of BHFO nanoparticles were observed at 300 K. The magnetism at room temperature is obviously enhanced by Ho doping. For x = 0.10, the BHFO sample performed the strongest ferromagnetism (Ms= 5.3 emu/g, Mr= 1.5 emu/g). The result confirms the contribution of Ho3+towards enhancement of ferromagnetic properties of BiFeO3. [ABSTRACT FROM AUTHOR]

Bi1-xCexFe1-yCoyO3(BCFCO, x = 0, 0.05, 0.1, 0.15; y = 0, 0.05, 0.1, 0.15) particles were synthesized by a sol-gel method to enhance the electrical and magnetic properties of BiFeO3. The structure and morphology properties of Bi1-xCexFe1-yCoyO3particles were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM). XRD patterns show that the BCFCO particles are main single-phase perovskite structure with R3c space group. The enhancement of room-temperature ferromagnetism was obtained in the BCFCO particles. Obvious hysteresis loops of BCFCO were observed, which indicate ferromagnetic order. BCFCO particles exhibit reduction in leakage current density. [ABSTRACT FROM AUTHOR]

Ni, Co, and Zn are widely distributed in the Earth's mantle as significant minor elements that may offer insights into the chemistry of melting in the mantle. To better understand the distribution of Ni.sup.2+, Co.sup.2+, and Zn.sup.2+ in the most abundant silicate phases in the transition zone and the upper mantle, we have analyzed the crystal chemistry of wadsleyite (Mg.sub.2SiO.sub.4), ringwoodite (Mg.sub.2SiO.sub.4), forsterite (Mg.sub.2SiO.sub.4), and clinoenstatite (Mg.sub.2Si.sub.2O.sub.6) synthesized at 12-20 GPa and 1200-1400 °C with 1.5-3 wt% of either NiO, CoO, or ZnO in starting materials. Single-crystal X-ray diffraction analyses demonstrate that significant amounts of Ni, Co, and Zn are incorporated in octahedral sites in wadsleyite (up to 7.1 at%), ringwoodite (up to 11.3 at%), olivine (up to 2.0 at%), and clinoenstatite (up to 3.2 at%). Crystal structure refinements indicate that crystal field stabilization energy (CFSE) controls both cation ordering and transition metal partitioning in coexisting minerals. According to electron microprobe analyses, Ni and Co partition preferentially into forsterite and wadsleyite relative to coexisting clinoenstatite. Ni strongly prefers ringwoodite over coexisting wadsleyite with [Formula omitted] = 4.13. Due to decreasing metal-oxygen distances with rising pressure, crystal field effect on distribution of divalent metal ions in magnesium silicates is more critical in the transition zone relative to the upper mantle. Analyses of Ni partitioning between the major upper-mantle phases implies that Ni-rich olivine in ultramafic rocks can be indicative of near-primary magmas., Author(s): Li Zhang [sup.1] [sup.2] , Joseph R. Smyth [sup.2] , Takaaki Kawazoe [sup.3] [sup.4] , Steven D. Jacobsen [sup.5] , Shan Qin [sup.1] Author Affiliations: (Aff1) 0000 0001 2256 [...]

In this study, we reported successful fabrication of the carbon nanofibers/gold nanoparticles (CNFs/Au) nanocomposite by noncovalent assembly, which was accomplished via two steps, firstly noncovalent functionalization of CNFs with polysiloxane and then noncovalent assembly of Au nanoparticles on the functionalized CNFs. The CNFs/Au nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy dispersive spectroscopy, respectively. The property of the synthesized CNFs/Au nanocomposite was explored by its catalytic reduction for 4-nitrophenol (4-NP). Our results demonstrate that the CNFs/Au nanocomposite can catalyze degradation of 4-NP from 100 to 11 % during 240 min. In addition, compared with the CNFs and Au nanoparticles, the CNFs/Au nanocomposite has higher catalytic activity during the reduction of 4-NP. [ABSTRACT FROM AUTHOR]

A series of homochiral metal–organic cages (MOCs) have been obtained from self-assembly of Cu(ii) salts with chiral N,N′-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-amino acids. Single-crystal X-ray diffraction analyses reveal that these compounds show a lantern-type cage structure, in which one pair of Cu2(CO2)4 paddlewheels is linked by four diacid ligands. The resulting homochiral cages have been fully characterized by EA, TOF-MS, TGA, VTPXRD, IR, UV, and CD measurements. The catalytic tests reveal that these Cu(ii) cages are effective in cyclopropanation with excellent diastereoselectivity (up to 99 : 1 E/Z). In addition, the cage catalysts can promote the aziridination reaction with PhI=NNs. [ABSTRACT FROM AUTHOR]

The Bam machinery, which is highly conserved from bacteria to humans, is well recognized as the apparatus responsible for the insertion and folding of most outer membrane proteins in Gram-negative bacteria. In Escherichia coli, the Bam machinery consists of five components ( i.e. BamA, BamB, BamC, BamD and BamE). In comparison, there are only four partners in Haemophilus influenzae: a BamB homologue is not found in its genome. In this study, the recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis of H. influenzae BamD and BamCD complex are reported. The genes encoding BamC and BamD were cloned into a pET vector and expressed in E. coli. Affinity, ion-exchange and gel-filtration chromatography were used to obtain high-purity protein for further crystallographic characterization. Using the hanging-drop vapour-diffusion technique, BamD and BamCD protein crystals of suitable size were obtained using protein concentrations of 70 and 50 mg ml−1, respectively. Preliminary X-ray diffraction analysis showed that the BamD crystals diffracted to 4.0 Å resolution and belonged to space group P212121, with unit-cell parameters a = 54.5, b = 130.5, c = 154.7 Å. The BamCD crystals diffracted to 3.8 Å resolution and belonged to space group I212121, with unit-cell parameters a = 101.6, b = 114.1, c = 234.9 Å. [ABSTRACT FROM AUTHOR]

Through the combination of x-ray diffraction, electrical transport, magnetic susceptibility, and heat capacity measurements, we studied the effect of Ce doping in the newly discovered SrFBiS2 system. It is found that Sr0.5Ce0.5FBiS2 undergoes a second-order transition below ∼7.5 K, followed by a superconducting transition with the critical temperature Tc∼2.8 K. Our transport, specific heat, and dc-magnetization results suggest the presence of bulk ferromagnetic correlation of Ce ions below 7.5 K that coexist with superconductivity when the temperature is further lowered below 2.8 K. [ABSTRACT FROM AUTHOR]

Three dixanthones ( 1- 3) and an unprecedented C3h-symmetric trixanthone ( 4) were synthesized through a three-step approach in overall yields above 63 %. These compounds possessed a planar π-conjugated system and formed tight face-to-face columnar stacks, as confirmed by single-crystal structural analysis. In comparison with xanthone, the fluorescence emissions of compounds 1- 4 showed significant red-shifts, with improved quantum yields. Moreover, the fluorescence emissions of compounds 1- 4 could be modulated in a strongly acidic environment without decomposition, which led to a further red-shift of the emissions, as well as enhancement of the emission intensities. These compounds have potential applications as optoelectronic materials and/or chemosensors. [ABSTRACT FROM AUTHOR]