Search

Asymmetric electrocarboxylation of aromatic ketones has been achieved over PrCoO3 perovskites with the help of chiral auxiliary t-Bu(R,R)salen(Co[ii]) under CO2 atmosphere.

The perovskite oxides La0.7Sr0.3Fe0.8B0.2O3 (B = Ti, Mn, Co, Ni and Cu) synthesized by sol–gel method were used as cathodes and tested in asymmetric electrocarboxylation of aromatic ketones. The study showed the La0.7Sr0.3Fe0.8Ni0.2O3 (La7Sr3Fe8Ni2) catalyst is more active for asymmetric electrocarboxylation of acetophenone with 95% enantiomeric excess and 85% yield. The high electrocatalytic activity is attributed mainly to several factors, including the increased amount of lattice oxygen and Fe4+ species on the surface of La7Sr3Fe8Ni2, enhanced electrochemically active surface area and faster electron transfer. Furthermore, La7Sr3Fe8Ni2 also exhibited remarkable stability and reusability.

The study reported an electrochemically promoted asymmetric hydrogen transfer reaction of 2,2,2-trifluoroacetophenone with a chiral Ru complex. (R)-α-(Trifluoromethyl) benzyl alcohol with a 96% yield and 94% ee could be obtained with only a 0.5 F mol-1 charge amount at room temperature and normal pressure.

Aromatic thermoset materials have shown great potential applications in various fields owing to their excellent mechanical strengths. However, their poor ductility is still hinders their large-scale applications. In this study, a new class of aromatic thermosets consisting of two types of crosslinks was successfully developed by incorporating the special group imidazole into a type of crosslinked thermoset. One crosslink is constituted of reversible multiple noncovalent interactions containing “face-face” π–π stacking, “point-point” hydrogen bonds, and ion-pair electrostatic interactions, whereas the other is composed of permanent covalent bonds. Most importantly, the synergetic interplay among these reversible multiple noncovalent interactions enables them to evade the restrictions from the aromatic polymer skeletons to proceed with their dynamic dissociating-rebuilding processes, which can timely and effectively dissipate the internal stress. Finally, owing to the coefficient of these two types of crosslinks, a significantly enhanced ductility was successfully obtained on these aromatic thermosets and their tensile strengths were also improved. Such thermosets having simultaneously enhanced strengths and ductility are predicted to be eventually used in a wide range of applications.

Blakeslea trispora is a natural source of carotenoids, including β-carotene and lycopene, which have industrial applications. Therefore, classical selective breeding techniques have been applied to generate strains with increased productivity, and microencapsulated β-carotene preparation has been used in food industry (Li et al., 2019). In B. trispora, lycopene is synthesized via the mevalonate pathway (Venkateshwaran et al., 2015). Lycopene cyclase, which is one of the key enzymes in this pathway, is a bifunctional enzyme that can catalyze the cyclization of lycopene to produce β-carotene and exhibit phytoene synthase activity (He et al., 2017).

Diabetic nephropathy (DN) is one of the leading causes of chronic kidney disease (CKD), during which hyperglycemia is composed of the major force for the deterioration to end-stage renal disease (ESRD). However, the underlying mechanism triggering the effect of hyperglycemia on DN is not very clear and the clinically available drug for hyperglycemia-induced DN is in need of urgent development. Here, we found that high glucose (HG) increased the activity of cyclin-dependent kinase 5 (CDK5) dependent on P35/25 and which upregulated the oxidative stress and apoptosis of mouse podocytes (MPC-5). TFP5, a 25-amino acid peptide inhibiting CDK5 activity, decreased the secretion of inflammation cytokines in serum and kidney, and effectively protected the kidney function in

Three metal-organic frameworks (MOFs), namely, [Mn(CPP)2(H2O)]n (I), [Cd(CPP)2(H2O)]n (II) and {[Zn2(CPP)2(CO3)]·(ClO4)·(H2O)2}n (III) (HCPP = 4'-(4-(4-carboxylphenoxy)-2,2':6′,2′-terpyridine), were successfully achieved under hydrothermal conditions. The as-synthesized coordination polymers have been characterized by IR spectroscopy, elemental analyses and single crystal X-ray diffraction. Single-crystal X-ray diffraction analyses indicate that compounds Ⅰ and Ⅱ display isomorphous and isostructural, in which the central metal ions present distorted octahedral configurations. Ⅰ and Ⅱ feature fascinating 3D frameworks based on π⋯π and C H⋯π interactions between the pyridine rings appertaining CPP− ligands, while compound Ⅲ possesses a 3D net interlinked via C-H⋯π interactions between the phenyl rings belonging to the CPP− ligands. In their 3D frameworks, the {MnN3O3}, {CdN3O3} and {ZnO2N3}–{ZnO2N3} building units are observed, respectively. Luminescent properties of coordination polymer Ⅱ and Ⅲ demonstrate that they may be acted as fluorescent sensors toward Cu2+ cation and Tryptophan, respectively. Furthermore, investigations on magnetic property reveal that coordination polymer Ⅰ presents antiferromagnetic coupling.

Background: To investigate prognostic factors and recurrence patterns in T4 gastric cancer (GC) patients after curative resection. Methods: Between January 2004 and December 2014, 249 patients with T4 gastric cancer undergoing curative resection were recruited. Patient characteristics, survival, prognostic factors and recurrence patterns were analyzed. Results: Our results showed that the median survival time (MST) for T4 gastric cancer after curative resection was 55.47 months, with 59.47 months for T4a (tumor perforating serosa) and 25.90 months for T4b (tumor invasion of the adjacent structure). Multivariate analysis indicated that age (hazard ratio [HR], 1.86; P = 0.006), location of tumor (HR, 1.25, 0.90 - 5.64; P < 0.001) and intraoperative blood loss (HR, 1.85; P = 0.010) were independent prognostic factors for overall survival (OS). After a median follow-up of 25.87 months, a total of 109 (43.8%) patients suffered from recurrence, and 90 patients had been observed specific recurrence sites, among which peritoneal metastasis was the most common recurrence pattern, 59.0% for T4a and 88.3% for T4b, respectively. Conclusions: For T4 gastric cancer patients after curative resection, older age, gastric cancer of the entire stomach and more intraoperative blood loss were associated with poor OS. The recurrence rate after curative resection for T4 was high, and the most common recurrence pattern was peritoneal metastasis.

The use of La1−xSrxFeO3 (x= 0, 0.1, 0.2, 0.3, 0.4 and 0.5) cathodes in asymmetric electrocarboxylation of acetophenone with CO2 induced by chiral auxiliary CoII-(salen) was investigated for the first time. Optically active 2-hydroxy-2-phenylpropionic acid with 94% enantiomeric excess and 68% yield were obtained. The superior asymmetric electrocarboxylation performance may derive from the Fe4+ species and the increased lattice oxygen concentration on the surface of La0.7Sr0.3FeO3 (LSF-0.3) induced by Sr-doping, together with an accelerated electron transfer and an increased electrochemically active surface area. Here, perovskite oxide catalyst has an acid function, which is supplied by Fe4+ ions, can participate in the reaction by coordinating with acetophenone. Moreover, the LSF-0.3 has considerable stability and reusability. By cyclic voltammograms and contrast experiments, a mechanism was proposed for the asymmetric electrocarboxylation reaction.

In order to study magnetocaloric effect, we synthesized five new dinuclear lanthanide (Ⅲ) compounds, namely [Ln(dbm)2HL(CH3OH)]2•2CH3OH (LnⅢ=Nd(1), Gd(2) and Tm(5), dbm =1,3-diphenylpropane-1,3‑dione, HL = N'-[(1E)-[5-(hydroxymethyl)furan-2-yl]methylidene]pyrazine-2-carbohydrazide) and [Ln(dbm)2HL]2 (LnⅢ = Ho(3) and Er(4)), and characterized by elemental analysis, IR, PXRD, UV–vis and single crystal X-ray diffraction. The structures of compounds 1–5 are very similar with a planar [Ln2O2]. Magnetic studies indicated that weak antiferromagnetic interaction are present between the Gd(Ⅲ) ions within 2. Meanwhile, Gd2 compound displays magnetic refrigeration property with the max entropy change (- Δ S m ) of 16.58 J K − 1kg−1 (T = 2.0 K and ΔH = 70 kOe).

The heterogeneous chiral catalyst L-cysteine-CuPt prepared by the bonding between the natural and inexpensive L-cysteine and CuPt obtained by a simple method in a green process exceled in this work. L-cysteine showed strong chemisorption through the bonding of the sulfhydryl group with the CuPt, so it could be firmly present on the surface of the alloy. Detailed surface analysis were carried out on the as-prepared L-cysteine-CuPt which was further applied to catalyze the asymmetric electroreduction of aromatic ketones. (R)-α-(trifluoromethyl) benzyl alcohol with 73% yield and 43% ee was obtained on the L-cysteine-CuPt cathode under the optimized electrolytic reaction conditions. In addition to owning the activity capable of efficiently catalyzing the substrate to produce optically active products, the L-cysteine-CuPt also exhibited strong stability such that the catalytic results did not significantly change on it after repeated use.

Three novel coordination polymers, namely, {[Pr(TTTPC)·(H2O)2]·2Cl·NO3·4H2O}n (I), {[Gd(TTTPC)·(H2O)2]·2Cl·NO3·4H2O}n (II) and {[Yb(TTTPC)·(H2O)2]·3Cl·NO3·0.5DMA·6H2O}n (III) were synthesized in conventional aqueous solutions with H3TTTPC ligands (H3TTTPC = 1,1′,1″-(2,4,6-trimethylbenzene-1,3,5-triyl(methylene))-tris(pyridine-4-carboxylic acid), DMA = N,N-dimethylacetamide) and characterized by infrared spectrometry and single crystal X-ray diffraction. Experimental results show that these MOFs are isomorphous and isostructural, containing the unit of cavate 14-membered cages (Pr2(OCO)4), based on which to generate a one-dimensional (1D) infinite linear metallic chain through the linkage of two COO− groups that are further interlinked reciprocally to polymerize into three-dimensional (3D) porous frameworks. Coordination polymer III shows remarkable selectivity toward Pb2+ and it can be considered as potential selective luminescent probes for Pb2+ ion. Additionally, magnetic analysis indicates coordination polymer I presents antiferromagnetism. Besides, lanthanide contraction effect exists in as-synthesized coordination polymers.

Context: Epidermal cells play an important role in regulating the regeneration of skin after burns and wounds. Objective: The aim of our study is to explore the role of Tanshinone IIA (Tan IIA) in the apoptosis of epidermal HaCaT cells induced by H2O2, with a focus on mitochondrial homeostasis and inverted formin-2 (INF2). Materials and methods: Cellular viability was determined using the MTT assay, TUNEL staining, western blot analysis and LDH release assay. Adenovirus-loaded INF2 was transfected into HaCaT cells to overexpress INF2 in the presence of Tan IIA treatment. Mitochondrial function was determined using JC-1 staining, mitochondrial ROS staining, immunofluorescence and western blotting. Results: Oxidative stress promoted the death of HaCaT cells and this effect could be reversed by Tan IIA. At the molecular levels, Tan IIA treatment sustained mitochondrial energy metabolism, repressed mitochondrial ROS generation, stabilized mitochondrial potential, and blocked the mitochondrial apoptotic pathway. Furthermore, we demonstrated that Tan IIA modulated mitochondrial homeostasis via affecting INF2-related mitochondrial stress. Overexpression of INF2 could abolish the protective effects of Tan IIA on HaCaT cells viability and mitochondrial function. Besides, we also reported that Tan IIA regulated INF2 expression via the ERK pathway; inhibition of this pathway abrogated the beneficial effects of Tan IIA on HaCaT cells survival and mitochondrial homeostasis. Conclusions: Overall, our results indicated that oxidative stress-mediated HaCaT cells apoptosis could be reversed by Tan IIA treatment via reducing INF2-related mitochondrial stress in a manner dependent on the ERK signaling pathway.

Background: Psoriasis is an immune-mediated polygenic hereditary skin disease quality of the patients’ life because of the great trouble it causes to patients. Whereas there is variability when we regard the selection of acupuncture treatments in practice and most choices are made based on personal experience or preference of clinician. This study uses network meta-analysis to compare the effectiveness of different forms of acupuncture for psoriasis and assesses the evidence with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Methods: We will search for PubMed, Cochrane Library, AMED, EMbase, WorldSciNet; Nature, Science online and China Journal Full-text Database (CNKI), China Biomedical Literature CD-ROM Database (CBM), and related randomized controlled trials included in the China Resources Database. The time is limited from the construction of the library to April 2019. The quality of the included RCTs will be evaluated by the risk of bias (ROB) tool and the evidence will be evaluated by GRADE. STATA 13.0 and WinBUGS 1.4.3 through the GeMTC package will be used to perform a network meta-analysis to synthesize direct and indirect evidence. Results: The results of this network meta-analysis (NMA) will be submitted to a peer-reviewed journal for publication. Trial registration number: PROSPERO CRD42019123437

Objective Conversion surgery is a surgery with a purpose of R0 resection in primary advanced gastric cancer (GC) that responded well to systemic chemotherapy. This study aimed to explore the efficacy of conversion surgery for advanced GC. Methods A total of 618 advanced GC patients receiving systemic chemotherapy were stratified into low-, moderate- and high-risk groups based on a nomogram-predicted probability of overall survival. The survival of conversion surgery and chemotherapy alone groups was compared using the log-rank test and Cox regression analysis after propensity score matching (PSM). Results A nomogram with good discrimination (concordance index: 0.65) and accurate calibration was constructed. After PSM, the median survival time (MST) of conversion surgery was 26.80 months, compared with 16.60 months of chemotherapy alone (P

A novel tetranuclear Gd(III)-based cluster, namely [Gd4(HL)4(CH3O)4] •3CH3OH (1), has been successfully synthesized by using a polydentate Schiff base ligand (H3L) reacted with Gd(acac)3•2H2O. The crystal structure and magnetic property of cluster 1 have been completely studied. Crystal structure study reveals that cluster 1 is a tetranuclear compound and the four center Gd(III) ions display a tetrahedral arrangement. The magnetic research suggests that cluster 1 shows cryogenic magnetic refrigeration property with a larger magnetic entropy (−ΔSm = 30.42 J K−1 kg−1, T = 2.0 K and ΔH = 7.0 T).

The optical and EPR data of Cr 3+ -doped colquiriite-type fluoride crystals LiSrGaF 6 , LiSrAlF 6 and LiCaAlF 6 are computed from the complete diagonalization of energy matrix method based on the two-spin-orbit-parameter model. This model takes account of the contributions due to both the spin-orbit parameter of central d n ion (in the traditional crystal field theory) and that of ligand ions via covalent effect. The computed results indicate that the observed five optical band positions and three spin-Hamiltonian parameters ( g factors g // , g ⊥ and zero-field splitting D ) can be explained reasonably with only four adjustable parameters. The defect structures of Cr 3+ centers in these crystals are also achieved from the calculations. It is suggested that the trigonal MF 6 octahedra in LiSrMF 6 : Cr 3+ (M = Al, Ga) crystals change from the compression (along C 3 axis) in the host crystals to the elongation in the Cr 3+ impurity centers. The results are discussed.

Precipitation is a very important input variable for numerous models in many scientific fields such as hydrology, agriculture, ecology, and environmental sciences. However, precipitation often exhibits considerable spatial variability and cannot be adequately modeled by commonly used geostatistical techniques, particularly in terms of the prediction uncertainty accuracy, which is of great significance to determine the effects on various models’ prediction uncertainty. In this paper, a moving-window copula-based geostatistical method was proposed to assess the local spatial uncertainty of precipitation. By incorporating non-stationary, non-Gaussian, and distance-weighted spatial statistics, many geostatistical techniques can be regarded as a special case of the proposed method. Especially, in this paper, the marginal distribution in each window was fitted using Legendre polynomials. Although the proposed method has the potential to improve both prediction accuracy and the prediction uncertainty accuracy, the case study showed that the prediction accuracy of the proposed method was not better than commonly used geostatistical techniques (i.e., ordinary kriging, moving window kriging, and the global copula-based method). However, the prediction uncertainty accuracy was the best of all. The moving-window copula-based geostatistical method allows the estimation of the full conditional distribution of the precipitation at any ungauged site. With the full conditional distributions, various analyses and decisions can be conducted and made. Moreover, in the sense of statistics, more accurate results could be expected.

To strengthen NADH regeneration in the biosynthesis of L-2-aminobutyric acid (L-ABA).L-Threonine deaminase (L-TD) from Escherichia coli K12 was modified by directed evolution and rational design to improve its endurance to heat treatment. The half-life of mutant G323D/F510L/T344A at 42 °C increased from 10 to 210 min, a 20-fold increase compared to the wild-type L-TD, and the temperature at which the activity of the enzyme decreased by 50% in 15 min increased from 39 to 53 °C. The mutant together with thermostable L-leucine dehydrogenase from Bacillus sphaericus DSM730 and formate dehydrogenase from Candida boidinii constituted a one-pot system for L-ABA biosynthesis. Employing preheat treatment in the one-pot system, the biosynthesis of L-ABA and total turnover number of NADBy using the engineered L-TD during endured preheat treatment, the one-pot system has achieved a higher productivity of L-ABA and total turnover number of coenzyme.

Background The molecular mechanism for the formation of the P1/P2 blood groups remains unsolved. It has been shown that the P1/P2 polymorphism is connected to the different A4GALT gene expression levels in P1 and P2 red blood cells. Study Design and Methods The present investigation conducted a pilot investigation that involved the detailed and stepwise screening of single-nucleotide polymorphisms (SNPs) in the A4GALT gene, followed by a larger-scale association study. The transcription-inducing activity by the different genotypes of SNPs was analyzed using reporter assays. Results A total of 416 different SNP sites in the A4GALT genes from four P1 and four P2 individuals were analyzed in the pilot investigation, and 11 SNP sites, distributed in the A4GALT Intron 1 region, exhibited an association with the P1/P2 phenotypes. In the follow-up association study, the genotypes at the 11 SNPs of a total of 338 individuals across four different ethnic populations were determined, and the results show that two SNPs, rs2143918 and rs5751348, are consistently associated with the P1/P2 phenotypes. Reporter assays demonstrated significantly higher transcription-inducing activity by the SNPs bearing the P1-allele genotype than by the SNPs bearing the P2-allele genotype and that the difference in transcriptional activity was determined by the different genotypes at SNP rs5751348. Conclusion The results of this investigation demonstrate a consistent association of A4GALT SNPs rs2143918 and rs5751348 with the P1/P2 phenotypes and suggest that SNP rs5751348 may lead to allelic variations in A4GALT gene expression and consequently leads to the formation of the P1/P2 phenotypes.

The proton conductivity of phosphoric acid (PA) doped polybenzimidazole (PBI) membrane is improved through imbibing antimony pentachloride before doping PA. The antimony involvement diminishes the temperature dependence of proton conductivity in the targeted temperature range 160–260 °C. Among the compositions being prepared, the most conductive one exhibits 8.08 × 10−2 S cm−1 at 180 °C, with a small temperature sensitivity 6.3 × 10−5 S cm−1 °C−1. Several membrane-electrode assemblies (MEAs) have been prepared with the Pt/C catalyst layers to evaluate the practicality of co-doped PBI membrane. After proper activation, the hydrogen/air cell generates substantial electric power, denoted by its peak value over 500 mW cm−2 at 180 °C. Impedance analysis indicates carbon monoxide poisoning affects overall MEA kinetics, as evidenced in the rising resistances of electrolyte, cathode, and anode. But the poisoned performance due to 3% CO/H2 fuel can be rejuvenated after the fuel is switched back to pure hydrogen in one or two hours.

In order to establish a succession law of every phase in sintered Nd–Fe–B magnets marked as 38/38H/38SH/38UH, four alloys of Nd33−x Dy x Al0.7Nb0.6Cu0.1B1.05Febal. (at%) were investigated after smelting processing, sintering processing, high-temperature tempering processing, and high- and low-temperature tempering processing. It is found that the four phases: the Nd2Fe14B matrix phase, Nd-rich phase, B-rich phase, and defect phase can be inherited by means of the subsequent processing. These phases might have the special constitution and appearance in the different states. Magnetic properties also have succession law. In every processing except smelting one, the values of remanence and maximum energy product hardly alter, but the value of coercive force increases gradually.

AIM To evaluate the treatment effects of recombinant human interleukin-12 (rhIL-12) on radiotherapy complications, such as severe myelosuppression or pancytopenia, the decline or imbalance of immune function, etc. METHODS The patients received high-dose and short-course precise radiotherapy, such as Cyber knife and image-guided radiotherapy (IGRT), which can cause myelosuppression or pancytopenia and immune function decline within a short time. One-hundred subjects were enrolled in the study, and 50 were randomized to a treatment group which used rhIL-12 and 50 were randomized to a control group which used symptomatic and supportive therapy after radiotherapy. The 50 subjects in the treatment group were further divided into five subgroups and intervened with rhIL-12 at a dose of 50, 100, 150, 200 or 250 ng/kg respectively. The dose-effect relationship was observed. RESULTS RhIL-12 significantly attenuated the decrease of peripheral blood cells in the treatment group, and immune function was improved after treatment. Due to the different radiation doses, there was a fluctuation within 12 h after treatment but mostly showing an increasing trend. As to the clinical manifestations, 2 patients in the 250 ng/kg subgroup showed low fever after administration, 1 patient in the 200 ng/kg subgroup and 2 patients in the 250 ng/kg subgroup showed mild impairment of liver function during the observation period. CONCLUSION RhIL-12 has effective therapeutic and protective effects on complications following radiotherapy, such as the decline of blood cells, myelosuppression and the decline or imbalance of immune function, which indicated good prospects for development and application.

The reasons of the chalking on concrete pavement were discussed according to the project case. The effects of water to cementitious material ratios (W/C ratios), mineral powder contents and construction curing conditions on the concrete chalking were investigated. The technical measures were proposed to prevent or reduce chalking at the concrete surface. The results indicate that the major compositions of chalking material are mineral powder, quartz and part of hydration products of cement. The bleeding of concrete, which mainly caused by lower cement amount, higher surface water to cementitious material ratio and excessive vibration during the construction, is the main cause of concrete chalking. The concrete chalking can be prevented or reduced under the conditions of lower W/C ratios (

Luminescent Ln3+ (Ce3+, Tb3+) doped hydroxyapatite (HAp: Ce, Tb) phosphors were successfully fabricated via the modified hydrothermal process. The structure, morphology, and luminescent properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra respectively. The XRD results reveal that the obtained HAp: Ce, Tb phosphors show the characteristic peaks of hydroxyapatite in a hexagonal lattice structure and the import of Ce3+and Tb3+ causes small change in the crystalline structure and leads to the peaks shifting and declining. It is observed that the as-prepared luminescent samples exhibit nearly equiaxial morphology of dispersed particles about 50-150 nm in size. Under 254 nm UV radiation excitation, the phosphors demonstrate the characteristic 5D47F36 emission lines of Tb3+and the excitation of Tb3+ is mainly caused by the energy transfer from Ce3+. PL intensity of Tb3+ doped HAp remarkably strengthened with increment of Ce3+ concentration and reached the maximum at the concentration of 4 mol%.

Well-aligned ZnO nanorod arrays on Chaleted Sol-Gel-Derived ZnO thin films was achieved at a temperature of 90°C by a surfactant-assisted soft chemical approach. The nanorod arrays were characterized by XRD, SEM, XPS, and UV-Vis absorbance spectra. The ZnO nanorod arrays are wurtzite crystal stuctures preferentially orienting in the direction of the c-axis and ZnO nanorods are grown verticallyon the substrate. The XPS analysis shows the Zn:O ratio of ZnO nanorod arrays near is 1:1. The UV-Vis absorbance spectra indicate that ZnO nanorod arrays have absorption of visible-light as well as ultraviolet-light. Therefore, the ZnO nanorods may be good candidates for visible-light photocatalysis materials from the viewpoint of practical applications.

Using iron tailings from northern Tangshan region of China as the main material, fly ash and clay as the accessories, fired bricks were prepared. The influences of iron tailings content, heating rate, firing temperature and holding time on water absorption and compressive strength of bricks were investigated. the phases of fired bricks was characterized by XRD. The most suitable conditions is as follows: the range of the iron tailings content is 80%~ 95%, no more than 8°C/min has little effect on the properties of fired bricks, the range of feasible calcined temperature could be adjusted in 1020 ~ 1050°C for 1.5~2h, which make the physical properties and durability of fired bricks accorded with Chinese Fired Common Bricks Standard (GB/T5101-2003). The main mineral phases mainly constituted the mechanical strength of fired product are hematite, quartz, anorthite and augite.

The effects of amounts of the kiln dust-activated coal gangue on the setting time and compressive strength of high-content slag cement were investigated. The performance of sulphate resistance of cement with 30 wt.% kiln dust-activated coal gangue was evaluated. The results reveal that the setting time of high-content slag cement is prolonged. Appropriate kiln dust-activated coal gangue amounts can increase the compressive strength, while too much activated coal gangue (>30 wt.%) leads to the decrease in compressive strength. Cement with 10 wt.% kiln dust-activated coal gangue exhibits a good compressive strength. The performance of sulphate resistance of Portland cement with 30 wt.% kiln dust-activated coal gangue is distinctly enhanced, while that of high-content slag cement is improved to some extent.

The effects of Si3N4 addition on the room temperature physical properties and thermal shock resistance properties of corundum based refractory castables were investigated using brown corundum, white corundum and alumina micropowder as the starting materials and pure calcium aluminate as a binder. The phase composition, microstructure, mechanical properties of corundum based castables were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that as the increase in Si3N4 addition, the bulk density decreased and apparent porosity increased, the cold strength deduced. However, the residual strength rate increased. That is, the thermal shock resistance was improved. This is because even though the introduction of Si3N4 inhibited the sintering of material and deduced the compactness, microcracks were produced in the materials due to a difference in thermal expansion coefficient. So the thermal shock resistance of corundum based castable was improved.

Optical stimulated luminescence (OSL) study on sand and fossil soils from Hulun Buir Dunefield in Eastern China is reported in this paper. Aeolian dune sequences responded to the climate change by alternations of aeolian sand and dark sandy soils, which corresponded to arid and humid conditions, respectively. Optical dating using the single aliquot regeneration technique with quartz was applied to the deposits. The results indicate that the soils and underlying aeolian sand correspond to the Holocene optimum (HO) and the last late glacial, respectively. Combined with studies of OSL dating of 13 profiles and grain-size, magnetic susceptibility, total organic carbon, sediment color and scanning electron microscopy measurements for two representative sections, indicate the expansion in the last late glacial sand was 10 times that of today. The dune field was not totally stabilized by vegetation cover until HO (10–5 ka BP).

Air temperature is the input variable of numerous models in agriculture, hydrology, climate, and ecology. Currently, in study areas where the terrain is complex, methods taking into account correlation between temperature and environment variables and autocorrelation of regression residual (e.g., regression Kriging, RK) are mainly adopted to interpolate the temperature. However, such methods are based on the global ordinary least squares (OLS) regression technique, without taking into account the spatial nonstationary relationship of environment variables. Geographically weighted regression-Kriging (GWRK) is a kind of method that takes into account spatial nonstationarity relationship of environment variables and spatial autocorrelation of regression residuals of environment variables. In this study, according to the results of correlation and stepwise regression analysis, RK1 (covariates only included altitude), GWRK1 (covariates only included altitude), RK2 (covariates included latitude, altitude and closest distance to the seaside) and GWRK2 (co-variates included altitude and closest distance to the seaside) were compared to predict the spatial distribution of mean daily air temperature on Hainan Island on December 18, 2013. The prediction accuracy was assessed using the maximum positive error, maximum negative error, mean absolute error and root mean squared error based on the 80 validation sites. The results showed that GWRK1's four assessment indices were all closest to 0. The fact that RK2 and GWRK2 were worse than RK1 and GWRK1 implied that correlation among covariates reduced model performance.

A practical synthesis of 4-acetoxy-2-azetidinone useful for the preparation of carbapenem- and penem-type antibiotics is described. The synthesis has advantages such as avoiding the tedious and costly column chromatographic or recrystallized separation steps for diastereomers. The overall yield of the product is greatly improved and the process is also more economical for large-scale production. In addition, the mechanism for oxidative decarboxylation is also present.