Microstructure,texture evolution and yield strength symmetry improvement of as-extruded ZK60 Mg alloy via multi-directional impact forging

Multi-direction impact forging(MDIF)was applied to the as-extruded ZK60 Mg alloy,and the microstructure,texture evolution and yield strength symmetry were investigated in the current study.The results showed that the average grain size of forged piece was greatly refined to 5.3μm after 120 forging passes,which was ascribed to the segmenting effect of{10–12}twins and the subsequent multiple rounds of dynamic recrystallization(DRX).A great deal of{10–12}twins were activated at the beginning of MDIF process,which played an important role in grain refinement.With forging proceeding,continuous and discontinuous DRX were successively activated,resulting in the fully DRXed microstructure.Meanwhile,the forged piece exhibited a unique four-peak texture,and the initial<10-10>//ED fiber texture component gradually evolved into multiple texture components composed of<0001>//FFD(first forging direction)and<11–20>//FFD texture.The special strain path was the key to the formation of the unique four-peak texture.The{10–12}twinning and basal slip were two dominant factors to the evolution of texture during MDIF process.Grain strengthening and dislocation strengthening were two main strengthening mechanisms of the forged piece.Besides,the symmetry of yield strength was greatly improved by MDIF process.

Numerical Study on the Leakage and Diffusion Characteristics of Low-Solubility and Low-Volatile Dangerous Chemicals from Ship in Inland Rivers

Considering the accidents of ships for dangerous chemicals transportation in inland rivers,a numerical method for the simulation of the leakage and diffusion processes of dangerous chemicals in inland rivers is proposed in this paper.Geographic information,such as rivers and buildings in the model,is obtained through Google Earth and structures of rivers and buildings are described by Auto CAD.In addition,the Fluent is adopted to simulate the leakage and diffusion processes of the dangerous chemicals where the standard k-εmodel is used to calculate the turbulent flow.Considering the interaction between chemicals and water,the VOF method is used to describe the leakage,drift and diffusion process of dangerous chemicals groups on the water surface.Taking a section of the Yangtze River as an example,the leakage and diffusion processes from a ship carrying 3,000 tons of low-solubility and low-volatile dangerous chemicals are studied,and the characteristics of leakage and diffusion are analyzed in detail.During the simulation,the area of the maximum group of leaked dangerous chemicals reaches up to about 1800 m2,and the number reaches up to 45.Furthermore,the influence of density,viscosity,water velocity and leakage velocity on the leakage and diffusion processes is investigated in this paper.

Robust control for a class of nonlinear networked systems with stochastic communication delays via sliding mode conception

This paper deals with the robust control problem for a class of uncertain nonlinear networked systems with stochastic communication delays via sliding mode conception （SMC）. A sequence of variables obeying Bernoulli distribution are employed to model the randomly occurring communication delays which could be different for different state variables. A discrete switching function that is different from those in the existing literature is first proposed. Then, expressed as the feasibility of a linear matrix inequality （LMI） with an equality constraint, sufficient conditions are derived in order to ensure the globally mean-square asymptotic stability of the system dynamics on the sliding surface. A discrete-time SMC controller is then synthesized to guarantee the discrete-time sliding mode reaching condition with the specified sliding surface. Finally, a simulation example is given to show the effectiveness of the proposed method.

Clinical Application of Primary Suture Following Three-Port Laparoscopic Common Bile Duct Exploration: A Report of 176 Cases

Objective: To investigate the feasibility, safety and the clinical value of primary suture following 3-port laparoscopic common bile duct exploration (LCBDE). Methods: From January 2012 to September 2014, 176 patients suffered from choledocholithiasis were treated with primary suture following 3-port LCBDE and the clinical data were retrospectively analyzed. Results: All cases were operated successfully and none was converted to open surgery. The duration of operation was 92.2 ± 18.8 min and the length of postoperative hospital stay was 4.4 ± 3.7 d. Postoperative bile leakage occurred in 2 cases and these patients recovered by simple drainage for 3 to 7 days without re-operation. All patients recovered smoothly without any serious complications. Conclusions: Primary suture following 3-port LCBDE is safe, effective and mini-invasive, which is worthy of further clinical application.

Feasibility of a novel vermitechnology using vermicast as substrate for activated sludge disposal by two epigeic earthworm species

This study was conducted to investigate the feasibility of vermicomposting by using vermicast as the substrate for the stabilization of municipal activated sludge, called hereafter as direct vermistabilization, in which the pre-treatment and bulking materials required in previous practices were all omitted. For this purpose, two epigeic earthworm species, namely Eisenia foetida and Bimastus parvus, were inoculated into substrate for composting fresh dewatered activated sludge. Direct vermistabilization resulted in significant reductions in pH, TOC, C/N ratio and the content of heavy metals, as well as increases in EC, total N, total P and total K in the final vermicast. Moreover, both Eisenia foetida and Bimastus parvus showed faster growth rate and higher cocoon production. The results of this study suggest that the direct vermistabilization has the advantages of being simple, cost-effective and efficient, and can thus be used as a feasible vermicomposting approach to convert fresh dewatered activated sludge into a valuable product for agricultural use. The results also suggest that Bimastus parvus can be used as a new potential candidate for vermicomposting of municipal activated sludge.

规模化猪场三周批次管理要点

文章主要结合猪场的实践经验,从猪场管理、批次化方案选择及优势,阐述了规模猪场在实施三周批次过程中出现的问题以及操作要点,以期为规模猪场批次化生产提供帮助。

P-band center theory guided activation of MoS_(2) basal S sites for pHuniversal hydrogen evolution

The edge S sites of thermodynamically stable 2H MoS_(2)are active for hydrogen evolution reaction(HER)but the active sites are scarce.Despite the dominance of the basal S sites,they are generally inert to HER because of the low p-band center.Herein,we reported a synergistic combination of phase engineering and NH_(4)^(+) intercalation to promote the HER performance of MoS_(2).The rational combination of 1T and 2H phases raises the p-band center of the basal S sites while the intercalated NH4+ions further optimize and stabilize the electronic band of these sites.The S sites with regulated band structures afford moderate hydrogen adsorption,thus contributing to excellent HER performance over a wide pH range.In an acid medium,this catalyst exhibits a low overpotential of 169 mV at 10 mA·cm^(−2)and Tafel slope of 39 mV·dec^(−1)with robust stability,superior to most of recently reported MoS_(2)-based non-noble catalysts.The combined use of in/ex-situ characterizations ravels that the appearance of more unpaired electrons at the Mo 4d-orbital reduces the d-band center which upshifts the p-band center of the adjacent S for essentially improved HER performance.This work provides guidelines for the future development of layered transition-metal-dichalcogenide catalysts.

Exploring the efficacy of(R)-PFI-2 hydrochloride in mitigating noise-induced hearing loss by targeting NLRP3 inflammasome and NF-κB pathway to reduce inner ear inflammation

Noise-induced hearing loss(NIHL)is primarily driven by inflammatory processes within the cochlea,where noise exposure triggers the activation of the NOD-like receptor protein 3(NLRP3)inflammasome,leading to an inflammatory cascade.The interaction between increased NLRP3 expression and NF-κB activity can further amplify cochlear inflammation.Our findings reveal that(R)-PFI-2 hydrochloride,a selective inhibitor of the SETD7 enzyme,effectively inhibits the activation of the cochlear NF-κB pathway,suppresses the release of proinflammatory factors,and prevents inflammasome assembly.This intervention disrupts the perpetuating cycle of inflammation,thereby alleviating damage to cochlear hair cells attributed to acoustic trauma.Consequently,(R)-PFI-2 hydrochloride emerges as a promising pharmacological candidate for NIHL,targeting and moderating the excessive immune and inflammatory responses implicated in the pathology of hearing loss.

Analyses of levels of thyroid hormones and its receptor expression in puerperants and newborns from an e-waste dismantling site

In this study,the serum levels,including thyr-oid hormones free triiodothyronine(FT3),free thyroxine(FT4),thyroid stimulating hormone(TSH)among the sub-jects from the exposed group(n 548)and the control group(n 545)were detected by immuno radiometric assay(IRMA).The expression levels of TRa1,TRb1,TSHR mRNA in placentas and umbilical cords were detected by fluorescent quantitative real-time PCR(FQ-PCR).The correlations between the thyroid hormone levels in maternal serum and umbilical serum,and between the expression levels of its receptors mRNA in placentas and umbilical cords were determined.We found that the FT4 levels of both maternal serum and umbilical cord serum in the exposed group were lower than those in the control(P<0.05).However,the increased TSH levels in the exposed group had statistically significance com-pared to those in the control group(P<0.05).The TRa1 and TRb1 mRNA levels both in placentas and umbilical cords in the exposed group were lower than those in the control group(P<0.05 and 0.01).How-ever,the TSHR mRNA levels in the exposed group were significantly different compared to those in the control group(P<0.01).The serum FT4 and TSH levels of par-turient women were positively correlated with those of the newborns in both groups(P<0.05 and 0.01).The mRNA levels of TRa1,TRb1 and TSHR in the placentas were positively correlated with those in umbilical cords in both groups(P<0.01).The findings suggest that some envir-onmental pollutants existing in the electronic waste(e-waste)dismantling region may affect the health of local parturient women and newborns,representing changes both in serum levels of thyroid hormones and in mRNA expression of its receptors.

Abnormal expression of c-Myc in human bronchial epithelial cells malignantly transformed by anti-BPDE

Anti-benzo[a]pyrene-7,8-diol-9,10-epoxide(anti-BPDE)is a metabolite of benzo[a]pyrene(B[a]P)and acts as a potent mutagen in mammalian systems.However,molecular mechanisms related to anti-BPDE-induced carcinogenesis are poorly understood.Here,we investigated the expression of proto-oncogene c-myc in human bronchial epithelial cells(16HBE-T)transformed by exposure to anti-BPDE.The levels of mRNA and pro-tein of c-Myc were examined in the 16HBE-T and vehicle-treated control cells(16HBE-N)by using different meth-ods respectively,including reverse transcriptase-polymer-ase chain reaction(RT-PCR),quantitative real-time PCR(Q-PCR),western blot and immunocytochemical meth-ods.The level of c-myc mRNA appeared to be signifi-cantly increased in 16HBE-T,as compared with those of the 16HBE-N.Likewise,the expression of c-Myc protein was significantly enhanced as compared with those of the control cells.Moreover,the localization of c-Myc protein shows mainly nuclear staining in 16HBE-T.In conclu-sion,the abnormal expression of c-Myc was present in anti-BPDE malignantly transformed 16HBE cells,which may be involved in the carcinogenesis molecular mech-anism of anti-BPDE.