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With the advancement of industrial economies, incidents involving spills of petroleum products have become increasingly frequent. The resulting pollutants pose significant threats to air, water, soil, plant and animal survival, as well as human health. In this study, microcrystalline cellulose served as the matrix and benzoyl peroxide (BPO) as the initiator, while butyl acrylate (BA) and N,N′-methylene bisacrylamide (MBA) were employed as graft monomers. Through free radical graft polymerization, cellulose-graft-poly(butyl acrylate-N,N′-methylene bisacrylamide) [Cell-g-P(BA-MBA)], possessing oil-adsorbing properties, was synthesized. The chemical structure, elemental composition, surface morphology and wetting properties of the graft polymerization products have been characterized, using infrared spectroscopy, elemental analysis, scanning electron microscopy and contact angle testing. The adsorption properties of Cell-g-P(BA-MBA) for various organic solvents and oils were then assessed. The experimental results demonstrated that Cell-g-P(BA-MBA) exhibited a maximum adsorption capacity of 37.55 g/g for trichloromethane. Adsorption kinetics experiments indicated a spontaneous and exothermic process involving physical adsorption, conforming to the Freundlich isotherm model. Furthermore, adsorption kinetics experiments revealed that Cell-g-P(BA-MBA) displayed favorable reuse and regeneration performance, maintaining its adsorption capacity essentially unchanged over fifteen adsorption–desorption cycles. [ABSTRACT FROM AUTHOR]

This study prepared textured (Ti1/3Zr1/3Hf1/3)B2 medium‐entropy ceramics for the first time that maintain enhanced flexural strength up to 1800°C using single‐phase (Ti1/3Zr1/3Hf1/3)B2 powders, slip casting under a strong magnetic field, and hot‐pressed sintering methods. Effects of WC additive and strong magnetic field direction on the phase compositions, orientation degree, microstructure evolution, and high‐temperature flexural strength of (Ti1/3Zr1/3Hf1/3)B2 were investigated. (Ti1/3Zr1/3Hf1/3)B2 grain grows along the a,b‐axes, resulting in a platelet‐like morphology. Pressure parallel and perpendicular to the magnetic field direction can promote the orientation degree and hinder the texture structure formation, respectively. Reaction products of W(B,C) and (Ti,Zr,Hf)C between (Ti1/3Zr1/3Hf1/3)B2 and WC additive can efficiently refine the (Ti1/3Zr1/3Hf1/3)B2 grain size and promote grain orientation. (Ti1/3Zr1/3Hf1/3)B2 ceramics doped with 5 vol.% WC yielded a Lotgering orientation factor of 0.74 through slip casting under a strong magnetic field (12 T) and hot‐pressed sintering at 1900°C. Furthermore, cleaning the boundary by W(B,C) and introducing texture can enhance the grain‐boundary strength and improve its high‐temperature flexural strength. The four‐point flexural strength of textured (Ti1/3Zr1/3Hf1/3)B2‐5 vol.% WC ceramics was 770 ± 59 MPa at 1600°C and 638 ± 117 MPa at 1800°C. [ABSTRACT FROM AUTHOR]

Limited by mining technology, mineral exploitation can produce large amounts of tailings. Heavy summer rainfall or seasonal freeze-thaw can lead to physical and chemical modification of tailing material in mountainous areas, resulting in fluidized tailings flow and severe disaster losses. Therefore, aiming at the problem of tailings fluidization catastrophe, this paper tried to reveal the rheological mechanism of tailings fluidization transformation by combining rheological tests and theoretical analysis. The results show that the yield stress increases with decreasing temperature, and when the density of debris flow (ρ) is more than 1.9 g/cm3, this behavior becomes more pronounced as the density increases. The storage modulus decreases by at least two orders of magnitude at the solid-fluid transition under amplitude test sweep. Storage and loss modulus in the linear viscoelastic range and yield stress have an exponential growth relationship with sediment concentration. In addition, a stress constitutive relation and a new exponential law describing the evolution of yield stress required for solid-liquid transformation were proposed, and the relationship is further strengthened through a comprehensive analysis of existing results, which expands the evaluation application of the rheological characteristics of tailings flow. This paper provides a new insight into the rheological properties of tailing and how they occur through solid-liquid transition under different environments, which is beneficial to geological hazard prevention and the ecological remediation of the mining area. [ABSTRACT FROM AUTHOR]

The tribochemical reactions generated at the relative motion interface are considered to have a positive or negative effect on the performance when lubricating materials are in use. Obviously, these tribochemical reactions are complex and uncontrollable during sliding, resulting in an uncertainty in their performance. To enhance the lubricating properties through tribochemical reactions, herein, we designed an interfacial friction modulation system for the targeted induction of effective substance production. Noteworthily, this system achieves self-adaptive friction modulation through the targeted induction of click chemistry at the interface by copper nanoparticles and friction. In this modulation, active products are generated at the sliding interface and exert their immediate and robust lubricating improvement, avoiding exogenous synthesis and addition. By virtue of the dynamics of the tribochemical reactions, the system exhibits interesting interfacial behaviors and excellent self-adaptive properties. This system overcomes the solubility problem in various base oils and demonstrates superior performance. These important results demonstrate the possibility of regulating the friction state by the ordered design relying on tribochemical reactions. Also, the system provides a new avenue for interfacial friction modulation and the development of lubricating materials. [ABSTRACT FROM AUTHOR]

Raising the configurational entropy in a solid solution ceramic is regarded as a promising strategy to improve the mechanical properties of ceramics, especially when five or more elements are mixed to form so‐called high‐entropy ceramics. However, in this study, we report that the binary (TiZr)C solid solution ceramics can demonstrate high hardness comparable or even superior to high‐entropy ceramics. Followed by a carbothermal reduction synthesis of carbide powders, the bulk ceramics were synthesized by hot pressing. Via increasing the hot pressing temperature to 2200°C, a full solid solution of equimolar (TiZr)C was obtained in contrast to phase separation at lower sintering temperatures, for example, 2000 and 2100°C. The dislocation networks are observed in the single‐phase (TiZr)C ceramic and should be the product of competition between enthalpy and entropy in a binary full solid solution. These defects finally contribute to the high nano‐hardness of 41.9 ± 1.4 GPa (H) and the Vickers hardness of 22.0 ± 0.6 GPa (HV at 49 N). [ABSTRACT FROM AUTHOR]

Lubrication failure under heavy load condition due to the limited carrying capacity of base lubricants usually results in catastrophic failure of mechanical systems. In this work, a class of perfluorinated gel lubricants (PFGs) is prepared, retaining excellent lubricity and load‐carrying performances under high load. Self‐assembly mechanism confirmed by molecular dynamics simulation indicates that the gelators in PFGs self‐assemble into a 3D network structure through intermolecular hydrogen bonds. The confinement effect of gelator self‐assembly in the base oil contributes to avoiding lubrication failure and environmental pollution caused by base oil creeping and leakage. Simple synthesis, creep recovery, and high sol–gel phase transition temperatures confer more benefits for PFGs applications. Moreover, X‐ray photoelectron spectroscopy and transmission electron microscopy techniques are employed to investigate the lubrication mechanism of PFGs, revealing that lubricants can interact with the friction interface to form two layers of tribofilm which are formed by adsorption and tribochemical reaction. PFGs provide an eco‐friendly solution for lubricating under heavy load condition. [ABSTRACT FROM AUTHOR]

The currently available heat-sink materials cannot meet the requirements for the 5G and beyond technology. Copper (Cu)/diamond composites have been proposed because Cu and diamond are excellent thermal conductors, while diamond has a very low coefficient of thermal expansion. Mixing Cu and diamond to form a composite seems a straightforward approach. However, this simple approach has never succeeded because, chemically, Cu does not wet diamond. Therefore the Cu-diamond interface cannot be tightly bonded, leading to an inferior thermal conductivity. This study presents a modified press and sinter process for depositing Cu submicronic particles onto diamond reinforcements prior to densification by hot pressing. The initial results obtained from microstructural observations and x-ray photoelectron spectroscopy have shown that our strategy can lead to successful Cu deposition onto diamond particles. The Cu deposition leads to a well-bonded interface between the copper matrix and diamond reinforcement, ultimately resulting in excellent thermal conductivity. [ABSTRACT FROM AUTHOR]

We report for the first time the synthesis of a core‐shell structured composite powder with a core of Zr(Ti,Ta)C and a shell of Ti,Ta(Zr)C at 1700°C and investigate the formation mechanism for the core‐shell structure. The medium‐entropy (Ti,Zr,Ta)C ceramics with fine grains (1.1 ± 0.4 μm) and relative density of 94.8% was prepared by hot‐pressing at 2100°C. The flexural strength of (Ti,Zr,Ta)C at 1000°C (493 ± 21 MPa) was close to the room temperature (511 ± 52 MPa). As the temperature increased from 1600°C to 1800°C, the flexural strength was increased significantly, with an ultra‐high flexural strength of 725 ± 32 MPa at 1800°C. The existence of the core‐shell structure in the powder suppressed the grain growth due to the sluggish diffusion effect. The ultra‐high strength of (Ti,Zr,Ta)C ceramics was attributed to its fine microstructures, high fracture toughness, and the reinforced the grain boundary strength. [ABSTRACT FROM AUTHOR]

Whereas loess-mudstone landslides are widely distributed and frequently occurred at the loess Plateau, this type of landslides is hard to detect due to its particularity, and easily generates serious losses. To clarify the shear characteristics and formation mechanism of loess-mudstone landslides, field investigations, ring shear tests and numerical simulation analyses were performed on the loess specimens collected from the Dingjiagou landslide in Yan'an city, China. The test results showed that both the peak strength and residual strength of slip zone soils have a decreasing tendency with moisture content, while the increasing of normal stress caused an increase in the shear strength. These phenomena indicate that the rise in the moisture content induced by precipitation or the decreasing of normal stress due to excavation activities would result in the weakening of slip zone soils. Numerical simulations of the evolution process of slope failure using the finite element method were conducted based on the Mohr-Coulomb criterion. It was found that the heavy precipitation played a more important role in the slope instability compared with the excavation. In addition, the field investigation showed that loess soils with well-developed cracks and underlying mudstone soils provide material base for the formation of loess-mudstone landslides. Finally, the formation mechanism of this type of landslides was divided into three stages, namely, the local deformation stage, the penetration stage, the creeping — sliding stage. This study may provide a basis for understanding the sliding process of loess-mudstone landslides, as well as guidelines for the prevention and mitigation of loess-mudstone landslides. [ABSTRACT FROM AUTHOR]

Medium‐entropy (Ti,Zr,Hf)C ceramics were prepared by hot pressing a dual‐phase medium‐entropy carbide powder with low oxygen content (0.45 wt%). The results demonstrate that the medium‐entropy (Ti,Zr,Hf)C ceramics sintered at 2100°C had a relative density of 99.2% and an average grain size of 1.9 ± 0.6 μm. The flexural strength of (Ti,Zr,Hf)C carbide ceramics at room temperature was 579 ± 62 MPa. With an increase in temperature to 1600°C, the flexural strength showed an increase up to 619 ± 57 MPa, and had no significant degradation even up to 1800°C. The high‐temperature flexural strengths of (Ti,Zr,Hf)C were obviously higher than those of the monocarbide ceramics (TiC, ZrC, and HfC). The primary strengthening mechanism in (Ti,Zr,Hf)C could be attributed to the high lattice parameter mismatch effects between TiC and ZrC, which not only inhibited the fast grain coarsening of (Ti,Zr,Hf)C ceramics, but also increased the grain‐boundary strength of the obtained ceramics. [ABSTRACT FROM AUTHOR]

Rock creep properties can be used to predict the long-term stability in rock engineering. In reservoir bank slopes, sandstones which are frequently used in the bank slope undergoing long-term effects of dry-wet (DW) cycles due to periodic water inundation and drainage may gradually accumulate creep deformation, resulting in rock structure's damage or even geological hazards such as landslides. To fully investigate the effect of DW cycles on the creep damage properties of sandstone, triaxial creep tests were conducted on saturated sandstone with different DW cycles by using a triaxial rheometer apparatus. The experimental results show that both the instantaneous strain and the stabilized strain increase with the DW cycles. In addition, using the Burgers model, four kinds of functions including an exponentially decreasing function, a linearly decreasing function, a linearly increasing function and an exponentially increasing function were proposed to express the relationships between the shear modulus, viscoelastic parameters of the Burgers model and the deviatoric stress under different DW cycles. Through comparative analysis, it is found that the theoretical curves generated using proposed four kinds of functions are in good agreement with the experimental data. Furthermore, macromorphological and microstructural observations were performed on specimens after various triaxial rheological tests. For samples with small number of DW cycles, approximately X-shaped fracture surfaces were observed in shear failure zones, whereas several shear fractures including obvious axial and horizontal tensile cracks, and flaws were found for samples with relatively large DW cycles due to long-term propagation and evolution of micro-fissures and micro-pores. Furthermore, as the DW cycles increases, the variation in micro-structure of samples after creep failure was summarized into three stages, namely, a stage with good and dense structure, a stage with pore and fissure propagation, and a stage with extensive increase of pores, fissures and loose particles. It is concluded that the combination effect of permeation of water molecules through pores and fissures within sandstone, and the propagation of preexisting pores and fissures owing to the dissolution of mineral particles leads to further deterioration of the mechanical properties of sandstone as the number of DW cycles increases. This study provides a fundamental basis for evaluating the long-term stability of reservoir bank slopes under cyclic fluctuations of water level. [ABSTRACT FROM AUTHOR]

Background: During the process of shearing the ligamentum flavum, rotating the working channel, and manipulating the annulus fibrosis, the sinuvertebral nerve and the spinal nerve root can be irritated, inducing intolerable back and leg pain. Thus, general anesthesia is recommended and well accepted by most surgeons when performing percutaneous endoscopic lumbar discectomy (PELD) via the interlaminar approach. The aim of our study was to explore the efficacy and safety of percutaneous endoscopy interlaminar lumbar discectomy with gradient local anesthesia (LA) in patients with L5/S1 disc herniation. Methods: This retrospective study was conducted between December 2017 and June 2018. The study included 50 consecutive patients who met the study criteria, had single-level L5/S1 disc herniation, and underwent PELD via the interlaminar approach under gradient LA. Different concentrations of local anesthetic compound (LAC) were injected into different tissues inside and outside the ligamentum flavum to complete gradient LA. The evaluation criteria included the intraoperative satisfaction score, visual analog scale (VAS) score, Oswestry Disability Index (ODI), complications, and adverse reactions. Results: The intraoperative satisfaction score was consistently over 7, with an average score of 9.3 ± 0.7, indicating that LAC can achieve satisfactory pain control throughout the PELD operation without additional anesthesia. The postoperative VAS score and ODI were dramatically improved at each follow-up interval (P < 0.001, respectively). There was no serious complication such as dural rupture caused by puncture, dural laceration caused by manipulation under endoscopy, total spinal anesthesia, iatrogenic nerve root injury, epidural hematoma, infections, or local anesthetic-related adverse reactions. Three patients experienced transient postoperative dysesthesia of the lower limbs that gradually recovered within 24 h. Conclusions: Gradient local anesthesia can satisfactorily and safely control intraoperative pain during the PELD via the interlaminar approach. It can not only improve intraoperative satisfaction, but also reduce local anesthesia-related adverse reactions and surgery-related complications. [ABSTRACT FROM AUTHOR]

This report described the first DMAP and PivOH-promoted ortho-C–H amination and ipso-allenization reaction of iodobenzenes realized by Pd/norbornene cooperative catalysis. Based on control experiments and DFT calculations, we speculated that the three ligands have different functions and mechanism paths in the reaction. [ABSTRACT FROM AUTHOR]

It is well known that the hydromechanical behavior of both saturated and unsaturated loess soils is significantly influenced by the soil fabric. However, there is limited understanding of how the soil fabric or structure evolves due to mechanical, hydraulic and chemical changes on loess soils. Information of the microstructural evolution or change in pore-size distribution (i.e., PSD) of loess soils along different stress paths is valuable for proposing an advanced constitutive model that considers the microstructure and can better model the hydromechanical behavior of loess soils. For this reason, in the present study, the microstructure is characterized on intact and saturated loess specimens before and after oedometer consolidation tests, using scanning electron microscopy and mercury intrusion porosimetry methods. The results suggest that the loading-induced change in PSD varies with stress level and saturation state of the loess soil. A reduction arises in the cumulative intrusion void ratio due to an increase in vertical stress, which accounts for compression of inter-aggregate pores greater than 6 μm. However, loading saturated loess leads to transformation from a bimodal PSD into a trimodal one that defines three major pore series, namely large-pore series (i.e., more than 6 μm), medium-pore series (i.e., between 0.1 and 6 μm) and small-pore series (i.e., less than 0.1 μm). The trimodal nature of PSD is, however, destructed under higher vertical stresses. Both large pores and medium pores are compressed under higher vertical stresses (i.e., > 600 kPa). The inundating-induced change in PSD is dependent on loading condition and can be discerned to take place in the same three pore series. Not only large pores but also medium pores collapse upon inundating under higher vertical stresses (i.e., > 600 kPa). The microstructural evolution is consistent with the mechanical responses of both intact and saturated loess. [ABSTRACT FROM AUTHOR]

Visible-light-induced C–H phosphorylation of para-CAr–H and heteroarenes was realized using cost-effective RuCl3 as a catalyst. The reaction conditions are green and environmentally friendly, using water as a solvent at room temperature and without ligands. A broad range of highly functional organophosphorus compounds were obtained via a cross-dehydrogenation-coupling (CDC) reaction. In addition, we also proved that RuCl3 is a photocatalyst via its absorption spectrum and on/off light experiments. [ABSTRACT FROM AUTHOR]

Since it is difficult to obtain a large number of failure data in a short time, performance degradation analysis is a reliability analysis method which can effectively compensate for the lack of data. Linear degradation process is used to describe the performance degradation process of mechanical systems. Considering the extreme impact and operation impact of products, the threshold effect of performance degradation process on sudden failure is analyzed. Based on the performance degradation process of variable failure threshold and the impact process of variable failure threshold, a competitive failure reliability model with both sudden failure and performance degradation failure is established. The reliability model is analyzed with an example. The results show that the reliability of the product is overestimated if the invalidation threshold is fixed and the change of the invalidation threshold is neglected. [ABSTRACT FROM AUTHOR]

Previous studies have reported that short-term statin loading effectively protects statin-naive patients with mild renal insufficiency from contrast-induced acute kidney injury (CI-AKI). The aim of the present study was to determine whether patients with more advanced chronic kidney disease (CKD) and long-term statin therapy also benefit from high-loading statin pretreatment. A total of 256 consecutive patients with moderate-to-severe CKD receiving long-term statin therapy and undergoing percutaneous coronary intervention (PCI) or coronary artery angiography (CAG) were divided into the statin-loading group (n=34) and the no statin-loading group (n=222), depending on whether the respective patient received high-dose statin within 24 h prior to the intervention. The primary endpoint was the percent change in serum creatinine (SCr) levels. Additional endpoints included absolute change in SCr levels, estimated glomerular filtration rate (eGFR) at 48–72 h after contrast exposure, incidence rate of CI-AKI and composite in-hospital adverse events. The mean SCr decreased from baseline in either of the two groups, and the differences in the percent (P=0.930) and absolute change (P=0.990) in SCr levels were not significant between the two groups. Furthermore, no significant difference in the post-procedural eGFR was observed between the two groups. The incidence rates of CI-AKI (2.9 vs. 4.1%, P>0.999) and in-hospital adverse events (0.0 vs. 3.6%, P=0.602) were also similar between the two groups. Stratified analyses were then performed, which yielded results consistent with the above. Multiple linear regression indicated that the baseline eGFR value and current smoking status were independent factors affecting the post-procedural eGFR value, while high-dose statin loading was not. Therefore, statin reloading prior to intervention may not provide any further renal protection or decrease the occurrence of in-hospital adverse events in patients with moderate-to-severe CKD receiving long-term statin therapy, which warrants validation in prospective trials. [ABSTRACT FROM AUTHOR]

The effect of W addition on densification, microstructure, and mechanical properties of ZrC ceramics was investigated. W reacted with carbon in ZrC to form WC, which resulted in the formation of ZrC1‐x at 1300‐1700°C, while WC was further dissolved in ZrC to form a (Zr1‐yWy)C1‐x solid solution at 1800‐2000°C. The relative density of ZrC with 5 mol% W (ZW5, 96.8%) was markedly higher than that of pure ZrC (Z0, 94.8%). ZW5 exhibited a fine homogeneous microstructure with a grain size (2.6 ± 0.5 μm) much smaller than that of Z0 (10.9 ± 3.0 μm), while excess W addition (10 mol%) in ZrC adversely affected the densification and the microstructure. The flexure strength of Z0 was 446 ± 46 MPa at room temperature, which almost linearly decreased to 281 ± 10 MPa at 1800°C in a high‐purity flowing argon atmosphere. The flexure strength of ZW5 was 512 ± 40 MPa at room temperature, and had no degradation even up to 1800°C. The fine and homogeneous microstructure of ZW5 and the removal of oxygen impurity from the grain boundaries promoted the enhancement of high‐temperature mechanical properties. [ABSTRACT FROM AUTHOR]

Application of an oxidative amination reagent (di-tert-butyldiaziridinone) to the Ru3(CO)12-catalyzed ortho-selective CAr–H amination reaction is described. This strategy shows good functional group compatibility with various phenyl-substituted N-heterocycles, including biologically active substrates, thus providing synthetic potential for this methodology. Mechanistic studies showed that the reaction process involves an octahedral ruthenium species, and the carbon monoxide ligand plays a crucial role in the C–H activation. [ABSTRACT FROM AUTHOR]

A ruthenium-catalyzed alternative para- and meta-difluoroalkylation of anilines is herein reported. The reaction tolerates a broad range of aniline derivatives and provides a convenient approach for accessing the corresponding para/meta-selective difluoroalkylated products. Mechanism studies demonstrated that the initial CAr–H and N–H cycloruthenation is the pivotal step in achieving remote C–H difluoroacetylation. [ABSTRACT FROM AUTHOR]

Background/Aims: Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Our study investigated the functional role of miR-212-5p in TNBC. Methods: Realtime PCR was used to quantify miR-212-5p expression levels in 30 paired TNBC samples and adjacent normal tissues. Wound healing and Transwell assays were used to evaluate the effects of miR-212-5p expression on the invasiveness of TNBC cells. Luciferase reporter and Western blot assays were used to verify whether the mRNA encoding Prrx2 is a major target of miR-212-5p. Results: MiR-212-5p was downregulated in TNBC, and its expression levels were related to tumor size, lymph node status and vascular invasion in breast cancer. We also observed that the miR-212-5p expression level was significantly correlated with a better prognosis in TNBC. Ectopic expression of miR-212-5p induced upregulation of E-cadherin expression and downregulation of vimentin expression. The expression of miR212-5p also suppressed the migration and invasion capacity of mesenchymal-like cancer cells accompanied by a morphological shift towards the epithelial phenotype. Moreover, our study observed that miR-212-5p overexpression significantly suppressed Prrx2 by targeting its 3’-untranslated region (3’-UTR) region, and Prrx2 overexpression partially abrogated miR-212-5p-mediated suppression. Conclusions: Our study demonstrated that miR-212-5p inhibits TNBC from acquiring the EMT phenotype by downregulating Prrx2, thereby inhibiting cell migration and invasion during cancer progression. [ABSTRACT FROM AUTHOR]

Background/Aims: Epithelial-mesenchymal transition (EMT) is recognized as a crucial mechanism in breast cancer progression and metastasis. Paired-related homeobox 2 (Prrx2) has been identified as a new EMT inducer in cancer, but the underlying mechanisms are still poorly understood. Methods: The expression of Prrx2 was assessed by immunohistochemistry in breast cancer tissues to evaluate the clinicopathological significance of Prrx2, as well as the correlation between Prrx2 and EMT. Short hairpin RNA knockdown of Prrx2 was used to examine cellular effects of Prrx2, detecte the expression of Wnt/β-catenin signaling and EMT-associated proteins, and observe cell proliferation, invasion and migration abilities in vitro and in vivo. Results: Clinical association studies showed that Prrx2 expression was related to tumor size, lymph node metastasis, tumor node metastasis stages, EMT and poor survival. Results also showed that knockdown of Prrx2 could alter cell morphology, suppressed the abilities of cell proliferation, invasion and migration in breast cancer. Moreover, silencing of Prrx2 induced the mesenchymal-epithelial transition and prevented nuclear translocation of β-catenin, inhibited wnt/β-catenin signaling pathway. Conclusion: Our study indicated that Prrx2 may be an important activator of EMT in human breast cancer and it can serve as a molecular target of therapeutic interventions for breast cancer. [ABSTRACT FROM AUTHOR]

After water is impounded in a reservoir, rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturationdehydration circulation (WSDC). To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers (1, 5, 10, 15, and 20) of simulated WSDC cycles. Based on the curves derived from these tests, a modified Hoek- Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hoek-Brown failure criterion is useful. Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion. [ABSTRACT FROM AUTHOR]

Reconfigurable digital filter is being widely used in applications such as communication and signal processing. Its performance, power consumption, and logic resource utilization are the major factors to be taken into consideration when designing the filters. This paper proposes a concise canonic signed digit coefficient grouping method aiming at reducing the number of common subexpressions (CSs). Further, we statistically analyze every CS occurance for numerous sorts of the finite-impulse response (FIR) filters and obtain characterization of the distribution behavior for all the possible CS patterns in a 16-bit coefficient. Thus, a novel processing element structure is proposed to form a medium-grain array for computationally efficient realization of reconfigurable FIR filter. The experiment results suggest such design implementations typically achieve 21% reduction in silicon area, 20% decrease in power consumption, and 14% improvement in operation speed in comparison to other conventional FIR architectures. [ABSTRACT FROM AUTHOR]

To investigate the formation mechanism and the stability of Wanjia middle school slope in Wenchuan Earthquake Area, the macroscopic geological characteristics and the failure process of the landslide are researched by engineering geology analysis method, limit equilibrium method, and finit element method. The results show that after the Wenchuan Earthquake, retaining walls, houses and other infrastructure on the foot of Wanjia middle school slope were severely destroyed, 10 cm wide tension fracture appeared at the trailing edge of the slope. Wanjia middle school slope is a type of medium-sized soil landslide. The area of the deformation body is about 19,314 m, the total volume of the deformation body is about 23 × 10 m. There may be two potential sliding surfaces in the unstable slope: shallow and deep landslide. The analysis results of the limit equilibrium method and the finite element method show that: under dead weight, dead weight + rainstorm, dead weight + earthquake conditions, the plastic zone occurs mainly at the middle part or the trailing edge of the slope, and it doesn't fully cut through the deep landslide body, so the deep landslide is stable. However, under rainstorm or earthquake conditions, the plastic zone almost completely cut thorough the shallow landslide body, it shows that the shallow landslide is in the understable-basic stable state. It is found that the results of finite element method is concordant with the results of the limit equilibrium method ( F = 1.06-1.29, the shallow landslide is in the basic stable-stable state). The calculation results show that shallow landslides are likely to occur in Wanjia middle school slope during a rainstorm or an earthquake, so monitoring and control of the slope should be strengthened. The shallow landslide should be managed by some measures, such as anti slide pile retaining structures and drainage works, and the dangerous rock bodies on the slope surface should be cleaned up. [ABSTRACT FROM AUTHOR]

Tetragonal KCu7S4 nanobelts (NBs) with width of 200–600 nm and length of up to hundreds of micrometers were facially synthesized via a solution-based method. Electrical analysis reveals that the as-fabricated NB exhibits typical p-type semiconducting characteristics with an exceptionally high carrier mobility of ∼870 cm2 V−1 s−1, which may be attributed to the quasi-1D conduction path along the c axis in the structure of KCu7S4. A further study of a device based on the Cu/KCu7S4 NB/Au Schottky junction shows a stable memory behavior with a set voltage of about 0.6 V, a current ON/OFF ratio of about 104, and a retention time ＞104 s. Such resistive switching characteristics, according to our analysis are due to the interfacial oxide layers that can efficiently trap the electrons by the oxygen vacancies. This study will offer opportunities for the development of high-performance memory devices with new geometries. [ABSTRACT FROM AUTHOR]

A novel oriented linear porous metal (OLPM) with high porosity was fabricated through solid-sintering method with cutting copper fibers. In this study, tensile experiments were conducted to investigate the fracture process of the OLPM and the effects of porosity and sintering parameters on the tensile properties. The typical tensile stress-strain plot of this material was obtained based on a large number of tensile test results. The plot can be divided into three stages, namely, initial linear elastic stage, plastic deformation stage, and tensile fracture stage. Based on the results, the fracture mechanism of the OLPM was further studied. Moreover, the porosity and sintering parameters were also varied to investigate their influence on the tensile properties. Tensile strength and plastic deformation were found to decrease with increasing porosity ranging from 70% to 90%. A higher sintering temperature produced a higher tensile strength for the OLPM sintered in the temperature range of 700°C–900°C, but the strength decreased at 1000°C. In addition, the extension of holding time could also slightly affect the tensile strength. Finally, the tensile properties of the OLPM are significantly higher than those of commercial porous metal and porous metal fiber sintered sheet. [ABSTRACT FROM AUTHOR]

Introduction: Deep burn wounds undergo a dynamic process known as wound progression that results in a deepening and extension of the initial burn area. The zone of stasis is more likely to develop more severe during wound progression in the presence of hypoperfusion. Hydrogen has been reported to alleviate injury triggered by ischaemia/reperfusion and burns in various organs by selectively quenching oxygen free radicals. The aim of this study was to investigate the possible protective effects of hydrogen against early burn-wound progression. Methods: Deep-burn models were established through contact with a boiled, rectangular, brass comb for 20 s. Fifty-six Sprague-Dawley rats were randomly divided into sham, burn plus saline, and burn plus hydrogen-rich saline (HS) groups with sacrifice and analysis at various time windows (6 h, 24 h, 48 h) post burn. Indexes of oxidative stress, apoptosis and autophagy were measured in each group. The zone of stasis was evaluated using immunofluorescence staining, ELISA, and Western blot to explore the underlying effects and mechanisms post burn. Results: The burn-induced increase in malondialdehyde was markedly reduced with HS, while the activities of endogenous antioxidant enzymes were significantly increased. Moreover, HS treatment attenuated increases in apoptosis and autophagy postburn in wounds, according to the TUNEL staining results and the expression analysis of Bax, Bcl-2, caspase-3, Beclin-1 and Atg-5 proteins. Additionally, HS lowered the level of myeloperoxidase and expression of TNF-α, IL-1β, and IL-6 in the zone of stasis while augmenting IL-10. The elevated levels of Akt phosphorylation and NF-κB p65 expression post burn were also downregulated by HS management. Conclusion: Hydrogen can attenuate early wound progression following deep burn injury. The beneficial effect of hydrogen was mediated by attenuating oxidative stress, which inhibited apoptosis and inflammation, and the Akt/NF-κB signalling pathway may be involved in regulating the release of inflammatory cytokines. [ABSTRACT FROM AUTHOR]

Ferrocenylethynyl-terminated derivatives 8-12 have been synthesized and characterized by electrochemistry and UV/Vis spectroscopy. The electrochemical and photophysical studies indicate that the electronic communication in ferrocenylethynyl-substituted derivatives is strongly influenced by the substituted position of the ferrocenylethynyl moiety. In situ electrochemical oxidation or chemical oxidation caused a characteristically weak ligand-to-metal charge-transfer (LMCT) band to appear at 700-1000 nm. Subsequent electrochemical reduction or chemical reduction recovered the most of the original curve and the color of the solution as well. Among the derivatives, compound 8 exhibits the highest cis/trans molar ratio (64:36) in the photostationary state (PSS) upon light irradiation at 365 nm. Compound 8 exhibits excellent fatigue resistance and reversibility under several repeated reversible isomerization cycles. [ABSTRACT FROM AUTHOR]

High-strength ZrC ceramics with relative density above 98% were prepared by reactive hot pressing of ZrC and Al at 1900°C. The reaction between ZrC and Al resulted in the formation of ZrC1− x, Zr3 Al3 C5 and Zr- Al compound such as AlZr3 and Al- C- Zr. The intermediate product AlZr3 below 1600°C and remained Al- C- Zr phase could form liquid phase and promoted the first stage of densification process. The improvement in densification behavior at higher temperatures (1800°C-1900°C) could be attributed to the formation of nonstoichiometric ZrC1− x. Adding 5 wt% and 7.5 wt% Al to ZrC, the formed ZrC0.85- Zr3 Al3 C5 and ZrC0.80- Zr3 Al3 C5 based ceramics had 3-point bending strength as high as 757 ± 79 MPa and 967 ± 50 MPa, respectively, with hardness and fracture toughness being 16.2-18.3 GPa and 3.3-3.5 MPa m1/2, respectively. [ABSTRACT FROM AUTHOR]

Restoring soil quality is the main evaluation norm of the reclamation. In order to reveal the effects of mushroom waste on the quality improvement of reclaimed soil in coal mining areas, the physical, chemical and microbial characteristics of soil are studied. The results show clear improvement in the soil after using mushroom waste. Because of human cultivation and fertilization, cultivated soil after reclamation exhibits high comprehensive quality and the index of quality of surface soil reaches 0.64 and 0.73. The average index of surface soil quality is as high as 0.52 and 0.54. In comparison, the quality of reclaimed soil of forest land is low, with average index of 0.40. The effects of mushroom waste are mainly on the surface soil in the first 2 years after the application. After that period, with the decomposition of mushroom waste, soil quality index tends to be the same as the original soil. The quality of surface soil is higher than that of subsoil, especially after the application of mushroom waste, at which point the soil quality reaches a peak at about 15 cm. Cultivated soil after reclamation has great variance in quality, after the coefficient of 24.74%. Mushroom waste can reduce such variation, particularly with long-term use. The variance efficient falls to 3.59% after 3-year application. [ABSTRACT FROM AUTHOR]

Composites of ZrC- SiC with relative densities in excess of 98% were prepared by reactive hot pressing of ZrC and Si at temperature as low as 1600°C. The reaction between ZrC and Si resulted in the formation of ZrC1− x, SiC, and ZrSi. Low-temperature densification of ZrC− SiC ceramics is attributed to the formed nonstoichiometric ZrC1− x and Zr- Si liquid phase. Adding 5 wt% Si to ZrC, the three-point bending strength of formed ZrC0.8-13.4 vol% SiC ceramics reached 819 ± 102 MPa with hardness and toughness being 20.5 GPa and 3.3 MPa·m1/2, respectively. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between renal function and clinical outcomes among patients with acute ST-segment elevation myocardial infarction (ASTEMI), who were treated with emergency percutaneous coronary intervention (PCI). Methods: 420 patients hospitalized in Peking University First Hospital, diagnosed with ASTEMI treated with emergency (PCI) from January 2001 to June 2011 were enrolled in this study. Estimated glomerular filtration rate (eGFR) was used as a measure of renal function. We compared the clinical parameters and outcomes between ASTEMI patients combined renal insufficiency and the patients with normal renal function. Results: There was a significant increase in the concentrations of fibrinogen and D-Dimer ( P<0.05) and a much higher morbidity of diabetes mellitus in the group of patients with chronic kidney disease (CKD; eGFR<60 ml/(min·1.73 m)) ( P<0.01). CKD (eGFR<60 ml/(min·1.73 m)) was an independent predictor of in-hospital mortality for patients hospitalized with ASTEMI receiving PCI therapy rapidly ( P=0.032, odds ratio (OR) 4.159, 95% confidence interval (CI) 1.127-15.346). Conclusions: Renal insufficiency is an independent predictor of in-hospital mortality for patients hospitalized with ASTEMI treated with primary PCI. [ABSTRACT FROM AUTHOR]

Based on the random perturbation technique for reliability sensitivity design, some realistic reliability-based sensitivity issues are discussed, some of which have a structure of high nonlinear performance functions. Combining the related theories of the moment method of the reliability analysis, the matrix differential, and the Kronecker algebra, the reliability-based sensitivity method based on the perturbation method is modified if the first four moments of random variables are given. Meanwhile, a reliability-based sensitivity computation method is proposed. Some examples are used to show that using this method can effectively improve the accuracy of the reliability-based sensitivity computation and offer a reliable theoretic basis in engineering. [ABSTRACT FROM AUTHOR]

We study dynamical behaviors in coupled nonlinear oscillators and find that under certain conditions, a whole coupled oscillator system can cease oscillation and transfer to a globally nonuniform stationary state [i.e., the so-called oscillation death (OD) state], and this phenomenon can be generally observed. This OD state depends on coupling strengths and is clearly different from previously studied amplitude death (AD) state, which refers to the phenomenon where the whole system is trapped into homogeneously steady state of a fixed point, which already exists but is unstable in the absence of coupling. For larger systems, very rich pattern structures of global death states are observed. These Turing-like patterns may share some essential features with the classical Turing pattern. [ABSTRACT FROM AUTHOR]

By a small-size complex network of coupled chaotic Hindmarsh-Rose circuits, we study experimentally the stability of network synchronization to the removal of shortcut links. It is shown that the removal of a single shortcut link may destroy either completely or partially the network synchronization. Interestingly, when the network is partially desynchronized, it is found that the oscillators can be organized into different groups, with oscillators within each group being highly synchronized but are not for oscillators from different groups, showing the intriguing phenomenon of cluster synchronization. The experimental results are analyzed by the method of eigenvalue analysis, which implies that the formation of cluster synchronization is crucially dependent on the network symmetries. Our study demonstrates the observability of cluster synchronization in realistic systems, and indicates the feasibility of controlling network synchronization by adjusting network topology. [ABSTRACT FROM AUTHOR]

Background: Early acute kidney injury (AKI) in severely burned patients predicts a high mortality that is multi-factorial. Hydrogen has been reported to alleviate organ injury via selective quenching of reactive oxygen species. This study investigated the potential protective effects of hydrogen against severe burn-induced early AKI in rats.Methods: Severe burn were induced via immersing the shaved back of rats into a 100°C bath for 15 s. Fifty-six Sprague-Dawley rats were randomly divided into Sham, Burn + saline, and Burn + hydrogen-rich saline (HS) groups, and renal function and the apoptotic index were measured. Kidney histopathology and immunofluorescence staining, quantitative real-time PCR, ELISA and western blotting were performed on the sera or renal tissues of burned rats to explore the underlying effects and mechanisms at varying time points post burn.Results: Renal function and tubular apoptosis were improved by HS treatment. In addition, the oxidation-reduction potential and malondialdehyde levels were markedly reduced with HS treatment, whereas endogenous antioxidant enzyme activities were significantly increased. HS also decreased the myeloperoxidase levels and influenced the release of inflammatory mediators in the sera and renal tissues of the burned rats. The regulatory effects of HS included the inhibition of p38, JNK, ERK and NF-κB activation, and an increase in Akt phosphorylation.Conclusion: Hydrogen can attenuate severe burn-induced early AKI; the mechanisms of protection include the inhibition of oxidative stress induced apoptosis and inflammation, which may be mediated by regulation of the MAPKs, Akt and NF-κB signalling pathways. [ABSTRACT FROM AUTHOR]