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In order to solve the problems of inconvenient data acquisition and low reliability when data acquisition Instrument are applied in the urban area, a new design of data acquisition instrument based on 5G technology and local storage is introduced in this paper. The instrument is designed to work in two power supply mode-external and internal power supply. Working in external power supply mode, data can be transmitted and backed up in real time; Working in internal power supply mode, data is transmitted in a set time period to realize low power operation. All the data can be saved in the event of a data error or loss by extracting data held by a local storage device.

In this study, the refractory high entropy alloy Al5(TiZrHfNb)95 was diffusion bonded (DB) with the intermetallic compound (IMC) Ti2AlNb under 5 MPa at 970–1100 °C in vacuum. The microstructure and element distribution were analyzed using a scanning electron microscope (SEM) and mechanical properties were evaluated by nanoindentation and shear tests. The typical microstructure of DB joint was Ti2AlNb substrate/solid solution/scattered Al3Zr5/solid solution/Al5(TiZrHfNb)95 substrate, which the discrete brittle Al3Zr5 phase was arranged along a straight line in the bonding surface, and gradually elongated and dissolved as the bonding temperature increased from 970 °C to 1100 °C. The formation of Al3Zr5 was attributed to the lowest Gibbs energy of all the possible IMCs in the range of the welding temperature. In the joining region, the IMC Al3Zr5 had the highest hardness (9.01 GPa) and modulus (143.37 GPa) but the lowest elastic recovery (20.37%), thus, it tended to cause stress concentration at the phase interface and induced crack initiation, which had a detrimental effect on the shear strength of joints. The shear strength of DB joints improved with the increase of bonding temperature and reached the highest (427 MPa) at 1100 °C owing to is lowest Al3Zr5 content. As the bonding temperature increased, the fracture of the joint transformed from intergranular brittle to ductile.

In this paper, the programmable logic controller (PLC) produced the steam cleaning machine controller based on PLC and foundation design, and steam cleaning device controlled the process of the realization .The programmable logic controller PLC programming and logic design, system realizes according to different artifact types, complete cleaning, blowing, drying the corresponding action. This system after careful design, manufacturing and detailed inspection, and after the running test, the experimental results shows that: as long as the proper maintenance and proper use of equipment, the project can improve the efficiency to a great extent.

Mangroves are recognized as one of the richest carbon storage systems. However, the factors regulating carbon sinks in mangrove ecosystems are still unclear, particularly in the subtropical mangroves. The biomass, production, litterfall, detrital export and decomposition of the dominant mangrove vegetation in subtropical (Kandelia obovata) and tropical (Avicennia marina) Taiwan were quantified from October 2011 to July 2014 to construct the carbon budgets. Despite the different tree species, a principal component analysis revealed the site or environmental conditions had a greater influence than the tree species on the carbon processes. For both species, the net production (NP) rates ranged from 10.86 to 27.64 Mg C ha-1 year-1 and were higher than the global average rate due to the high tree density. While most of the litterfall remained on the ground, a high percentage (72%-91%) of the ground litter decomposed within 1 year and fluxed out of the mangroves. However, human activities might cause a carbon flux into the mangroves and a lower NP rate. The rates of the organic carbon export and soil heterotrophic respiration were greater than the global mean values and those at other locations. Only a small percentage (3%-12%) of the NP was stored in the sediment. The carbon burial rates were much lower than the global average rate due to their faster decomposition, indicating that decomposition played a critical role in determining the burial rate in the sediment. The summation of the organic and inorganic carbon fluxes and soil heterotrophic respiration well exceeded the amount of litter decomposition, indicating an additional source of organic carbon that was unaccounted for by decomposition in the sediment. Sediment-stable isotope analyses further suggest that the trapping of organic matter from upstream rivers or adjacent waters contributed more to the mangrove carbon sinks than the actual production of the mangrove trees.

Wetting behaviour of a Cu/Ti3SiC2 system was investigated by the sessile drop technique under a vacuum atmosphere. Contact angles between Cu and Ti3SiC2 changed from 95 to 15° as temperatures increased from 1089 to 1270°C. Two distinct reaction layers consisting of different contents of Cu, TiCx, Ti3SiC2 and CuxSiy intermetallics were formed at the interface of Cu and Ti3SiC2. The formation of the interface layers contributes to the improvement of the wettability of the system. The dissolution of Si from theTi3SiC2 into the molten Cu at high temperature plays a dominant role in the wetting behaviour of Cu/Ti3SiC2 systems.

The deleterious effect of Al4C3 on the performance of MAX ceramics has not attracted much attention. In the present study, Al4C3 containing Cr2Al(Si)C and SiC/Cr2AlC ceramics have been prepared. It was found that spontaneous pulverisation of the as synthesised samples took place at room temperature after exposure in air and water for various durations. Volume expansion induced by the interaction of Al4C3 with moisture is held responsible for the disintegration of Al4C3 containing MAX ceramics. Preventive measures to avoid the formation of Al4C3 upon preparing MAX ceramics were herein proposed.

With FPGA as the host controller, a set of hardware system based on digital micro-mirror device (DMD) for compressive imaging (CI) was developed. This paper studies the principle and characteristic of DMD control. First, the data of PC Screen image is transferred to DMD driver by software using binary pulse width modulation (BPWM) technology. The data is then rewritten into a control single which finally directs the DMD. The test results proved that the digital image received can be loaded onto the micro-mirrors excellently and with optics module installed, the system could successfully implement the CS measurement patterns which satisfy CI system.

Weibull distribution was applied to calculate the ground subsidence and deflection value, in order to analysis accurately the influence of ground subsidence caused by underground mining on high voltage electric power lines. The results showed that the effect of reducing surface subsidence was notable and the high power line was working normally. It was accurate enough to calculate ground deformation by using Weibull distribution, and Matlab program can be used to solve the function feasibly.

Aim As liver biopsy has considerable limitations in the assessment of liver fibrosis, non-invasive models have achieved great progress in the past. However, many tests consist of variables that are not readily available, and there are few data about patients with hepatitis B e-antigen (HBeAg) negative chronic hepatitis B (CHB). The aim of this study was to develop a model using routine data to predict liver fibrosis in HBeAg negative CHB patients. Methods We randomly divided 349 patients who underwent liver biopsy into training (n = 200) and validation (n = 149) sets. Multivariable logistic regression and receiver–operator curve (ROC) analyses were used to develop a model for predicting both significant fibrosis (stages 2–4) and cirrhosis (stage 4) in the training set. The model was validated in 149 patients in comparison to FIB-4, Forn's, S and aspartate aminotransferase-to-platelet ratio index indices using ROC. Results Multivariable logistic regression analysis showed that the parameters of the model for predicting both significant fibrosis and cirrhosis included sex, age, prothrombin time, platelet count, cholesterol and γ-glutamyltransferase. In the training set, the areas under the ROC (AUC) for predicting significant fibrosis and cirrhosis were 0.856 and 0.956, respectively. In the validation group, the AUC for predicting significant fibrosis and cirrhosis were 0.889 and 0.937, respectively. Using the best cut-off values, significant fibrosis and cirrhosis can be accurately predicted in 40.9% and 91.3% of patients, respectively. Conclusion Our model can accurately predict both significant fibrosis and cirrhosis and may decrease the need of liver biopsy in a considerable proportion of patients with HBeAg negative CHB.

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.

The ground subsidence due to backfill mining is different from those caused by other mining methods. It’s practically important to analyze the influence of ground deformation due to backfill mining on the buildings above the ground accurately. An example of analysis of ground deformation on an iron mine in the east of Hebei was given in this paper. Then the reason why maximum subsidence angle becomes greater was analyzed by numerical simulation. The second derivative of subsidence curve was obtained by means of numerical method, and then the maximum curvature of ground deformation could be calculated. This quantitative analysis provided reference for safety assessment of buildings on the ground. The method was validated by the analysis on a real case. Comparing with other methods, this analysis method is relatively simple and more efficient.

The floor heave is one of soft rock roadway distortion. Based on soft rock supporting theory and engineering practice, the program bolt-mesh-anchors and floor corner, bolts coupling support to control floor heave of the soft rock roadway is proposed. Numerical simulation results show that bolt-anchors can mobilize the strength of the deep adjacent rock, at the same time, and properly arranged floor corner bolts with high bending rigidity can cut the slip-line field and achieve the goal of controlling floor heave effectively.

Take a typical cross-section of rockfill embankment slope in Yaan-Luku highway as the research object, reliability analysis is studied under the condition of water table of 840.85m, 851.50m, and loading condition of natural state and horizontal seismic acceleration of 0.2g, respectively. Raw data use Kolmogorov-Smirnov test (K-S test) to determine the distribution type of parametric variation. And the parameters were sampling with Latin hypercube sampling (LHS) method and Monte Carlo (MC) method, respectively, to obtain state function and determine safety factors and reliability indexes. A conclusion is drawn that the times of simulation based on LHS method were less than Monte Carlo method. Also the convergence of failure probability is better than the Monte Carlo method. The safety factor is greater than one and the failure probability has reached to 35.45% in condition of earthquake, which indicating that the instability of rockfill embankment slope is still possible.

Highly pure and dense bulk Ti2AlC was prepared by hot-pressing a mixture of the “312” phase Ti3AlC2 powders, and the element Ti and Al powders. Different ratios of the starting materials and different sintering temperature were attempted in order to obtain a highly pure and dense bulk Ti2AlC sample. Phase analysis and microstructures observing were performed by using by XRD, SEM as well as an X-ray fluorescence spectrometer. The results show that a nearly full dense bulk Ti2AlC sample can be prepared at 1300°C and 30MPa for 30 minutes in argon atmosphere. A dominant mechanism to form the “211” phase Ti2AlC can be attributed to the directly connecting between Al and Ti6C octahedron, which is as an intermediate phase in the Al-rich liquid mediator during the hot pressing.

BACKGROUND There has been continuous debate as to whether Y chromosome loss is an age related phenomenon or a cytogenetic marker indicating a malignant change. This study aimed to investigate the frequency of Y chromosome loss in the specific patients in order to determine whether it is an age related phenomena or a cytogenetic marker indicating a malignant change. METHODS Five hundred and ninety-two male patients with a median age of 59 years old (22 - 95 years) were included in this study. These patients were divided into two groups: the study group, including 237 patients who had hematological disorders included myeloproliferative disorder (MPD), myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), multiple myeloma (MM), and lymphoma and the control group including 355 patients with no evidence of hematological disease. Both conventional cytogenetics and fluorescence in situ hybridization using DNA probes specific for the centromere of chromosomes X or Y were performed according to our standard laboratory protocols. RESULTS Twenty-four out of 237 patients with hematological disorders (10.1%) had Y chromosome loss. Of these 24 patients, 2 patients had AML (5.0% of all AML patients), 2 patients had CML (5.7% of all CML patients), 2 patients had MPD (8.0% of all MPD patients), 3 patients had MM (10.0% of all MM patients), 5 patients had lymphoma (10.6% of all lymphoma patients) and 10 patients had MDS (16.7% of all MDS patients). Twenty-one out of these 24 patients had a loss of Y chromosome as the sole anomaly and the remaining three had a loss of Y chromosome accompanied with other structural changes detected by conventional cytogenetic analysis. Fluorescence in situ hybridization (FISH) analysis confirmed the routine cytogenetic results. All 24 patients had a loss of Y chromosome with a range of 17.5% - 98.5% of cells. Two of the patients, one with AML and another with CML, had karyotype and FISH testing done both at the initial diagnosis and during remission. The results showed a loss of Y chromosome at initial diagnosis but a normal 46, XY karyotype during remission. Only 9 out of 355 patients (2.5%) without evidence of hematological disease had Y chromosome loss, among them 7 patients had cardiovascular diseases and 2 patients had kidney diseases. Comparison of the incidence of Y chromosome loss in patients with hematological disorders or without evidence of hematological disease using statistical analysis showed a statistically significance difference (P < 0.05). CONCLUSIONS The present study demonstrated that the frequency of Y chromosome loss is significantly higher in patients with hematological disorders than in patients without hematological disorders, which indicates that the loss of Y chromosome is associated with a neoplastic change.

Polycrystalline bulk samples of ternary carbide Ti3AlC2 ceramics were fabricated by reactively hot-pressing a mixture of Ti, Al, and graphite powders with and without Sn additive. The effects of sintering temperature, time and addition of Sn on the purity, mechanical properties and microstructure of Ti3AlC2 were investigated. The result showed that the TiC content was strongly influenced by sintering temperature for the Ti3AlC2 samples without Sn additive, and the most suitable sintering temperature to create the lowest TiC content was 1400°C. The addition of Sn additive led to a distinct decrease in TiC content. The flexural strength of the testing materials had close relation with the TiC content and sintering time. A certain content of TiC second phase and longer sintering time were helpful to improving the flexural strength. The sample sintered at 1400°C for 2 h possessed the highest flexural strength.

Thin-walled 316L stainless steel seamless pipes with different diameters are fabricated by extrusion technology. An aqueous solution of water-soluble hydroxypropyl methylcellulose (HPMC) is used as binder. The effect of the binder content on the extrusion behavior of the pipe is discussed. The green products are debound and pressureless sintered at vacuum atmosphere. Good thin-walled pipes have been obtained after sintering at 1100 °C, and at that temperature, a microstructure with the battle-necks forming between the round particles has formed that guarantees the thin-walled pipes having the pores with homogeneous size distribution. Scanning electron microscope is used to observe the microstructure.

An Al2O3 matrix composites, i.e. partially stabilized zirconia toughening alumina (ZTA) reinforced by SiC particle (ZTA-SiCP), was prepared by hot pressing (HP). Fatigue behavior of ZTA-SiCP under cyclic compressive loads was investigated on different loading conditions. The application of cyclic compressive loads to a notched specimen led to a stable crack growth along the notch plane in a direction normal to the far-field compressive axis. Irreversible damages in the main form of microcrack were induced at the stress concentration zone during compression loading, and it led to high residual tensile stresses ahead of the notch root upon unloading. Nucleation and growth of a model I fatigue crack were caused by the residual tensile stresses at the notch root. Along with propagation of the fatigue crack, a gradual decrease in crack growth rate was shown due to the crack closure caused by accumulating of debris particles within the wake of growing crack, and thus led to the crack arrested at last. The fatigue crack length was investigated as a function of notch length, the maximum compressive stress, stress range and load frequency.

Microscale plasticity of Ti3SiC2 was investigated by Vickers hardness indentation. The surface layer of the hardness indentations was removed by acid solution to observe microstructure beneath the indentations, where a large number of bending, delamination and kinking grains were found. These features suggest that Ti3SiC2 is able to consume microdamage around the indentations. Numerous basal plane dislocations and stacking faults lying in Ti3SiC2 grains or accumulating at grain boundaries were observed. The basal plane dislocations play an important role in the microscale plastic deformation. The plasticity and damage tolerance for Ti3SiC2 at room temperature should be attributed to multiple energy absorbing mechanisms: grains bending, delamination, kink-band formation, and the basal plane slip, etc.

A novel process – multi-billet extrusion was employed to produce a three-layer W/Cu functionally graded material, which is comprised of superfine W–15%Cu, W–25%Cu and W–35%Cu composite powders fabricated by mechanical alloying. An aqueous solution of water-soluble hydroxypropyl methylcellulose was used as binder. The effect of the content of binder on the quality of extrusion products is discussed. The extrusion behavior for W–Cu extrudates is analyzed. W/Cu green products were pressureless sintered at temperatures in the range of 1150–1300 °C for 1 h in hydrogen atmosphere. Three-layer W/Cu samples with a high density and a highly homogeneous microstructure were attained after sintering at 1250 °C for 1 h in hydrogen atmosphere. The mechanisms for enhancement of sinterability and improvement of density of the mechanically alloyed W–Cu powder products have been discussed. X-ray diffraction and scanning electron microscope respectively were used to identify and observe phase constitution and microstructure.

In this paper, tribological tests for Ti3SiC2 sliding against low carbon steel were made on a block-on-disc type friction tester, with the normal pressures from 0.1 to 0.8 MPa and the sliding speed of 30 to 50 m/s. The surface state was observed and analyzed by SEM and XRD. A definite tribo-glazing layer was found over the worn surface of the Ti3SiC2 block, which seems to be primary reason for Ti3SiC2 to have comparatively lower friction coefficient and wear rate, because the tribo-glazing layer would be fusible under high frictional temperature. The tribo-glazing layer was the results of tribo-chemical oxidation reaction and the cause forming it could be the high frictional temperature and the mechanical catabolism in the surface of Ti3SiC2 during sliding friction. Due to the tribo-oxidation reaction is un-reversible and self-adaptive, the tribo-glazing layer in area and thickness are function of normal pressures and sliding speed.

The friction behavior of a high-purity bulk titanium aluminum carbide (Ti3AlC2) material dryly sliding against low carbon steel was investigated. Tests were performed using a block-on-disk type high-speed friction tester under sliding speed of 20 m/s and 60 m/s, several normal pressures from 0.1 to 0.8 MPa. The results showed that the friction coefficient is as low as about 0.18 for sliding speed of 20 m/s and only 0.1 for 60 m/s, and that almost not changes with the normal pressure. The reason could be related with the presence of a surface layer on the friction surface. The layer was analyzed to consist of Ti, Al and Fe oxides, which played a lubricate part inducing the friction coefficient decrease on the friction surface.

W/Cu functionally gradient materials (FGMs) are fabricated by a novel process—multi-billet extrusion (MBE). Different W/Cu superfine powders made by mechanical alloying (MA) are used to improve the sinterability of W/Cu compacts. Good quality of three-layer W/Cu extrudes are obtained after confirming the extrusion parameters and the type and the content of binder during extrusion process. The green products are pressureless sintered at the temperature range of 1100-1300 oC for 1 h. W/Cu FGMs with relatively high density and high homogeneous microstructure are attained after sintering at 1200 oC for 1 h. The mechanisms for the enhance of sinterability and improvement of density of the mechanical alloyed (MAed) W-Cu powder products have been discussed. X-ray diffraction and scanning electron microscope are used to identify and observe phase constitution and microstructure, respectively.

Various toughening methods, i.e. partially stabilized zirconia transformation toughening, transformation- SiC whisker reinforcing and transformation-SiC particle reinforcing were used to improve the mechanical properties of alumina ceramic. Influence of various toughening methods on microstructure and mechanical properties of the alumina-matrix composites were studied. On the basis of transformation toughening, by which the strength and toughness of Al2O3 ceramic improved simultaneously, the addition of SiC whisker substantially enhanced the toughness, whereas the addition of SiC particle increased both toughness and strength to a certain degree. Mechanical properties of the testing materials were closely related with their morphologies of fracture surfaces. Toughening mechanisms of the composites were also studied. In the transformation-whisker reinforced composite or the transformation-particle reinforced composite, the two toughening methods affected with each other and produced a cooperative toughening effect.

Ti3SiC2/SiC composite has been synthesized by in situ displacement reaction of Si and TiC powders. Its relative density is >98%. Its Vickers hardness was measured to be 8.7 GPa. Its flexural strength and the fracture toughness were 505 MPa and 5.3 MPa·m1/2, respectively. Scanning electron micrograph (SEM) and transmission electron micrograph (TEM) were used to observe the microstructure of the composite. Mechanisms for its high flexural strength and fracture toughness were discussed, respectively. The composite shows a better oxidation resistance than monolithic Ti3SiC2 at high temperatures. The oxidation layers were comprised of an outer layer with coarse TiO2 grains and an inner layer with a mixture of fine-grained SiO2 and TiO2. Its weight gain is only about 7.9 mg/cm2 at 1200 °C in air for 21 h. However, that of Ti3SiC2 is 30 mg/cm2. The results suggested that the in situ formation of SiC improved its oxidation resistance.

The oxidation behavior of Ti3SiC2 with additive-Al2O3 was studied over the temperature range of 1000–1500 °C in air. Ti3SiC2 based composite has a good oxidation resistance at below 1100 °C. The oxidation kinetics followed a parabolic and a linear law respectively at different oxidation stages. Morphology of oxidation products was observed from the oxidized surface by scanning electron microscope (SEM). Oxides were identified by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS). The existence of additive-Al2O3 influenced the morphology of oxides and the oxidation behavior of Ti3SiC2. The formation of pores or cavities at high temperature provided the channels for diffusion of oxygen and accelerated the oxidation behavior of Ti3SiC2 based composite. The effects related to the morphology and microstructure features on the oxidation kinetics are discussed.

Platelets in situ reinforced Ti–B–C composite was synthesized by hot-pressed 4.8:1 Ti/B 4 C at 1800 °C under 35 MPa. The composite is comprised of TiB 2 and TiC x phases that determined by X-ray diffraction (XRD) and energy dispersive spectroscope (EDS). The platelet phases are TiB 2 as reinforced particles. TiB 2 –TiC x composite possesses a high relative density of >98%, and good mechanical properties with a flexural strength of 680 MPa and a fracture toughness of 12 MPa m 1/2 , respectively. The reasons of the composite with high mechanical properties were discussed. The microstructure was observed by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

The oxidation behavior of ternary compound Ti 3 SiC 2 is investigated in the temperature range of 1000–1500 °C for up to 20 h exposure. The scales formed on the Ti 3 SiC 2 matrix were duplex, consisting of an outer layer and an inner layer over the temperature ranges. The outer layer was pure TiO 2 (rutile), and the inner layer consisted of SiO 2 and TiO 2 . At the temperature 1300 °C and below, the oxidation kinetics of Ti 3 SiC 2 followed the parabolic law. When the temperature rose to 1400 °C, the oxidation behavior followed the parabolic-linear law. The activation energy was calculated to be 325 kJ mol −1 over the temperature range of 1000–1400 °C. A number of pores existing in the boundary of the outer layer and the inner layer provide the cannel for oxygen diffusion. The effect of pores and impurities on oxidation behavior was analyzed, and the morphology of oxidation products was observed through scanning electron microscope.

The dense ceramic Ti3SiC2 was fabricated by hot-pressing of TiH2, Si and C powders. The new layered material Ti3SiC2 possesses some unique properties such as low hardness, damage tolerance, and high fracture toughness and flexural strength at room temperature. The flexural strength and fracture toughness of Ti3SiC2, which were measured by three-point bending test, were 427 MPa and 7.20 MPa m1/2, respectively. The mechanisms of this material with the high fracture toughness and strength are discussed based on the observation of microstructure. This layered material has a low hardness of about 4 GPa. The features are observed by scanning electron microscopy (SEM) around hardness indentations suggesting that Ti3SiC2 is a damage-tolerant material able to contain the extent of microdamage at room temperature. The damage tolerance should be due to the multi-absorbing energy mechanisms: grain pull out, grain deformation, delamination, crack deflection and grain buckling.

Rod-like phase TiB 2 , formed by reaction of B 4 C and Ti, in situ toughened Ti–B–C composites, and improved the mechanical properties of composites. But additives as added to system of B 4 C–Ti damaged the mechanical properties of Ti–B–C composites and restrained the formation of rod-like TiB 2 . The particles of TiB 2 , β-SiC and Ti(C, N) were produced by addition of 20 vol.% Si 3 N 4 that reacted with B 4 C and Ti. The thermodynamic processing of the reaction of B 4 C, Ti, and Si 3 N 4 was studied. Each of grain size is about 2 μm and distributes uniformly in composites. TiB 2 did not develop into rod-like microstructure, but equiaxial crystal owing to restraint of interrelated unfavorable factors. The crystalline phases were determined by X-ray diffractometry (XRD) and the microstructure of composite was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite possesses high density (>99%) and the fracture toughness of composites by addition of 20% Si 3 N 4 is 7.11 MPa √m. We discussed the effect of Si 3 N 4 on the mechanical properties of composites and analyzed the mechanisms of toughening.

In situ toughened TiB 2 –TiC x composites were fabricated using reaction synthesis of B 4 C and Ti powders at high temperatures. The resulting materials possessed very high relative densities and well developed TiB 2 plate-like grains, leading to a rather high fracture toughness, up to 12.2 MPa⋅m 1/2 . The microstructure was examined by means of XRD, SEM, TEM and EDAX. The reaction products mainly consisted of TiB 2 and TiC x . No other phases, e.g. Ti 3 B 4 , TiB, Ti 2 B 5 and free Ti, were observed regardless of whether the starting composition was Ti:B 4 C=3:1 or 4.8:1, and whether the sintering temperature was 1700 or 1800°C. The microstructural morphology is characterised by TiB 2 plate-like grains distributed uniformly in the TiC x matrix. Some inclusions and defects were found in TiB 2 grains. The very high reaction temperature was believed to be responsible for the formation of plate-like grains, which, in turn, is responsible for the much improved mechanical properties. The main toughening mechanisms were likely to be crack deflection, platelet pull-out and the micro-fracture of TiB 2 grains.

Joining of Cu/Ti3AlC2 cermet by an argon-arc welding technique without filler was firstly investigated. The results show that the Cu/Ti3AlC2 cermet can be joined firmly. The joining strength at room temperature was measured to be 851 MPa after optimization of the welding parameters with 2.6 A/mm2 for arc current density, 5 s for arc time, 10.8 kPa for applied pressure and 12 V for arc voltage. The microstructure in welded zone shows that fine TiCx particles uniformly dispersed in a network structure of Cu-Al alloys. This feature endows the Cu/Ti3AlC2 cermet with the high joining strength.

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.

A search for Ti3Si1.2-xAlxC2 (x=0~1.2) solid solution was undertaken using precise X-ray diffraction measurements. The samples covering the whole concentration range were studied. Except very ends of the concentration range, the samples contained two phases, identified as Ti3Si1.2-xAlxC2 solid solution and TiC respectively. Lattice parameter, a increased, c increased, c/a increased, and cell volume increased with the increasing of Al concentration.

Ti2SnC has been fabricated from Ti, Sn and graphite elemental powders by mechanically activated low-temperature synthesis (MALS) technique. Superfine powders were obtained after milling the elemental powders for only 1 h with a charge ratio of 20:1. The mechanically alloyed powders were then pressureless sintered at different temperatures at Ar atmosphere for 0.5 h. High content of Ti2SnC was obtained at 950 oC, which is lower than the previously reported temperatures of above 1200 oC by sintering the conventional mixture powders. The microstructure shows that Ti2SnC grains with plate-like shape and smooth surface are less than 5 μm in size. The result demonstrates that the MALS is a novel method for the synthesis of Ti2SnC or other ceramic powders.

Slope stability evaluation is one of the most effective countermeasures to improve the safety in open-pit mine. Bayesian network is a popular tool for modeling many kinds of statistical problems. The method is applied to the stability evaluation of slope system in one open-pit mine of Sanyou Group Corporation Ltd in Hebei province, China. Through the result of the analysis we pointed out the most important factors influencing the stability state. The corresponding countermeasures are put forward.

As liver biopsy has considerable limitations in the assessment of liver fibrosis, non-invasive models have achieved great progress in the past. However, many tests consist of variables that are not readily available, and there are few data about patients with hepatitis B e-antigen (HBeAg) negative chronic hepatitis B (CHB). The aim of this study was to develop a model using routine data to predict liver fibrosis in HBeAg negative CHB patients.We randomly divided 349 patients who underwent liver biopsy into training (n = 200) and validation (n = 149) sets. Multivariable logistic regression and receiver-operator curve (ROC) analyses were used to develop a model for predicting both significant fibrosis (stages 2-4) and cirrhosis (stage 4) in the training set. The model was validated in 149 patients in comparison to FIB-4, Forn's, S and aspartate aminotransferase-to-platelet ratio index indices using ROC.Multivariable logistic regression analysis showed that the parameters of the model for predicting both significant fibrosis and cirrhosis included sex, age, prothrombin time, platelet count, cholesterol and γ-glutamyltransferase. In the training set, the areas under the ROC (AUC) for predicting significant fibrosis and cirrhosis were 0.856 and 0.956, respectively. In the validation group, the AUC for predicting significant fibrosis and cirrhosis were 0.889 and 0.937, respectively. Using the best cut-off values, significant fibrosis and cirrhosis can be accurately predicted in 40.9% and 91.3% of patients, respectively.Our model can accurately predict both significant fibrosis and cirrhosis and may decrease the need of liver biopsy in a considerable proportion of patients with HBeAg negative CHB.

To investigate the clinical significance of the expression of serum differential protein in patients with chronic hepatitis B (CHB) related liver fibrosis.One hundred and ten CHB patients confirmed by liver biopsies were enrolled, 83 for modeling and 27 for verification. According to Ishak staging, 55 patients in the modeling group were with significant liver fibrosis ( F is more than or equal to 3 ) and 28 patients with normal/mild liver fibrosis ( F0-F2 ). While that in the verification group were 15 ( F is more than or equal to 3 ) and 12 ( F0-F2 ), respectively. MALDI-TOF-MS/MS was used to detect serum proteins and the spectrum for each sample was analyzed in FlexAnalysis3.0 to produce the spectrum of differential proteins. The results were compared with clinicopathologic diagnosis and the diagnosis model based on genetic algorithm was established and evaluated.There were 15 proteins differentially expressed in significant liver fibrosis group and normal/mild fibrosis group ( P value is less than 0.01), in which the differences on proteins 2081.73 m/z and 1944.41 m/z were the most significant. Based on these two proteins, the coordinate system was set up and the diagnosis model based on genetic algorithm was established by six characteristic peaks. After detecting 12 cases of normal/mild liver fibrosis and 15 cases of significant liver fibrosis, the results showed that the diagnostic model could identify significant fibrosis ( F is more than or equal to 3 ) and normal/mild liver fibrosis ( F0-F2 ) at 100% recognition, 94.14% prediction and 100% accuracy.Serum differential proteins examination can be used for early prediction of CHB related fibrosis. The study provides the basis for non-invasive diagnosis of hepatic fibrosis according to identifying the potential differences of the serum samples from patients with HBV related fibrosis.

To gain a broad spectrum on allelic loss of specific loci in ovarian tumors, we initially examined DNA from 23 pairs of ovarian tumors and matched peripheral blood lymphocyte samples from the same patients, using 27 polymorphic DNA markers distributed on 13 chromosomes. Significant high frequency of allelic deletion (22%-44%) at chromosome 13 loci (D13S31, D13S32, D13S33, and D13S34) at bands q12-q34 was observed in tumor tissues. These results led us to investigate the loss of heterozygosity at the retinoblastoma (RB) locus in ovarian tumors, because the RB gene is a tumor-suppressor gene located at 13q14. Analysis of the variable number of tandem repeat sequence polymorphism in intron 20 in the RB gene revealed that 6 (30%) of 20 patients with informative samples showed allelic loss at the RB locus in their tumor tissues. This loss, of relatively high frequency, suggests that the RB gene, or a closely linked gene, seems to be involved in the development of ovarian cancer.