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Tensile stiffness of interfacial layered rock is the basis of studying the law of interlaminar propagation of hydraulic cracks. We used similar materials to make simulated specimens of sand-mud layered rock with prefabricated cracks, and used the digital image correlation (DIC) technique together with the three-point bending (TPB) test to obtain the strain field near the prefabricated crack tip in tensile state. Combined with the tensile stress in the corresponding area calculated by the load of the tester, the tensile stress-displacement curve at the interface of layered rock is obtained, and the tensile stiffness and interfacial fracture law at the interface of layered rock is calculated by the curve. The results show that in the process of tensile failure, before reaching its peak value, the interfacial tension stress of layered rock has a linear elastic deformation stage followed by a short hardening stage. Upon reaching the peak value, it is accompanied by interfacial failure and macro-cracks, and then the load decreases and enters the softening stage, which results in the complete destruction of the interface. The tensile stiffness values of layered rock with different sizes vary greatly, which indicates that the interfacial tensile stiffness values are sensitive to the specimen size and have a size effect. The results are of great significance to the study of the law of hydraulic fracture propagation in the interface of layered rock.

The cement sheath plays a vital role in preventing gas channelling. It is important to understand the interfacial bonding between the casing and cement sheath when the downhole temperature and pressure change. This paper demonstrates the results of an experimental study to investigate the effect of high temperature and high pressure and their variations on the cement sheath interfacial bonding strength (CSIBS). An experimental device was developed that is used to test the shear and hydraulic bonding strength with the method of uniaxial compression and gas channelling. The results show that both temperature and pressure have a significant influence on the CSIBS. As the curing temperature increases with a constant curing time or as the curing time increases with a constant curing temperature, the CSIBS first increases and then converges to a stable value. The casing roughness has a crucial effect on the shear bonding strength but little effect on the hydraulic bonding strength. Though the CSIBS decreases obviously with the decrease in temperature, it undergoes little change when the temperature first increases and then recovers to the initial value. When the internal casing pressure decreases to a certain value or first increases to a certain value followed by recovery to the initial state, the hydraulic bonding strength tends to be 0 MPa, which means that the interface undergoes debonding between the casing and cement.

The microstructures have been investigated in steel plates with different rolling processes to find the reasons of yield ratio overseted standard in few high strength building steel plates produced in Echeng Iron and Steel Corporation. The effects of rolling path, rolling path depress ratio on microstructure and properties. Some reasons of yield ratio overseted standard have been analyzed. The results show that decreasing rolling paths and increasing depress ratio refined grains but unchanged area ratio and interlamellar spacing of pearlite. Yield strength excessively increased but tensile strength unchanged increased yield ratio. So, excellent properties can be obtained by applying the optimization process.

The effects of controlled rolling and controlled cooling parameters on the microstructure and mechanical properties of 550MPa grade engineering mechanism steel were investigated in the industrial trial conditions. The results show that the mechanical properties of 550MPa grade engineering mechanism steel are obviously improved by controlling finishing rolling temperature ranged from 780°Cto 850°C, and by using accelerate cooling after rolling, ferrite grains are refined markedly of the steel which possess excellent strength and toughness behaviors.

The microstructure, tensile and impact property of a 600 MPa HSLA steel plate at different temperature were investigated by tensile and impact tests, metallographic observation, SEM and EDX analysis. The results indicated that the microstructures of the steel after tensile tests were mainly the bainites. As the temperature increased from 300°C to 650°C, the yield strength and tensile strength decreased, the elongation and reduction of area increased, but this steel had a relatively stable tensile property below 400°C. Moreover, as the temperature reduced from 20°C to -80°C, the impact toughness was gradually decreased, and the ductile-brittle transition temperature of this steel was obtained at -57.75°C by using Boltzmann function fitting.

The effect of intercritical quenching temperature on the microstructure and performance of a 650 MPa low-carbon structural steel was investigated by optical microscope and mechanical test. The results showed that the obtained microstructures at different temperature were mainly bainites, the volume fraction of the bainites was gradually increased and the size of which became finer with the increase of the quenching temperature. Moreover, as the temperature increased, the yield strength and tensile strength gradually increased; the yield ratio decreased initially and then increased; the impact energy increased among the temperature range of T3°C and T4°C, subsequently dropped significantly at T5°C, and then increased atT6°C. The best comprehensive performance was obtained at T4°C in this study.

This paper analyzes the adaptability of process of alloy structural steel 50Mn2V by simulating research. Through the high temperature tensile test、the multi-pass deformation test we study the deforming resistance characteristics of 50Mn2V steel, and carry on the contrast with high strength steels P20（3Cr2Mo）of a factory; Through thermo-plasticity test the high temperature thermoplastic of 50Mn2V steel is studied. The test result indicates a factory has ability to produce the high strength 50Mn2V steel completely with present equipment.

The Effect of slab quality on the microstructure and performance of Q345C hot rolling strip for pipe pile foundation were studied by SEM, EBSD, mechanical test and corrosion test. The results showed that the dendrite size of the slab had a great impact on the grain size of the steel. The fine grain structure can significantly improve the mechanical properties of the steel, but to some extent, reduce its corrosion resistance. In the early and later stage of the corrosion reaction, the coarse grain structure can improve the corrosion resistance. However, in the middle stage of the corrosion reaction, the grain size had no significant effect on the corrosion resistance. The rust layer included the inner layer and the outer layer, in which the inner layer was relatively compact, and they were mainly composed of the oxide of iron.

A steel plate with thickness（3~12）mm named 30CrMo（%：0.29~0.34C、0.17~0.37Si、0.40~0.70Mn、≤0.015P、≤0.010S、≤0.30Mo、0.80~1.10Cr）was developed by converter melting and hot continuous rolling. Good metallurgical quality, mechanical properties and strip shape are ensured by accurately control of smelting, rolling, coiling and decoiling process. The results show that 30CrMo steel has high purity, uniform structure and stable properties, perfect plate shape, and meets requirements of consumer.

The flaws in a heavy bridge-making steel plate (Q370qE) were detected by ultrasonic test, the types and formation reasons of which were studied by metallographic examination, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectrometer. The results showed that the types of the flaws were mainly crack, micropore and inclusion. The formation of crack and micropore was attributed to the center segregation, porosity, as well as the role of structural stress and thermal stress. Moreover, the inclusions were mainly composite oxides (MgO, Al2O3, CaO, etc.) and MnS, the former came from the raw materials and impurity oxides, however, the latter came from the center segregation of the alloying elements. Besides, some improvement measures to reduce detecting flaws were also proposed.

Bacterial induced infection is a major complication associated with the use of medical implants. Degradable antibacterial ciprofloxacin-polyurethanes (CFPU) have been synthesized in attempts to address this problem. It is supposed that the material may be sensitively hydrolyzed by inflammatory enzyme, cholesterol esterase (CE), and the drug could be released according to the state of infection. The enzyme biodegradation experiments showed an extra release of ciprofloxacin when CFPU was incubated by enzyme solutions than by phosphate-buffer saline (PBS). Results showed that the drug release was enhanced as the concentration of the enzyme increased. The antimicrobial activities of degradation solutions were tested by broth dilution assay. The enzyme degradation solutions exhibited an ability to kill bacteria. The cell cytotoxicity assay indicated that the degradation products were hypotoxicity to human beings according to the cytotoxicity grade of United States Pharmacopoeia (USP).

Corundum–mullite based ceramic foams were prepared by adopting foam impregnation process with raw talc and kyanite as modifiers. By comparing the sinters strength among the original formula with and without talc and kyanite added, it can be seen that when 6wt% raw talc was added, the compressive and flexural strength of the sintered foam ceramic bodies are increased by 108.9% and 33% respectively more than the original formula. Adding 4wt% ball-milled kyanite on this basis, the compressive and flexural strength were further elevated 20.1% and 29.1%, respectively, and meanwhile, the sintering shrinkage rate was dropped by 54.2%.

This work evaluated the method of manufacturing bimaterial composite parts by semisolid metal processing (SSP) through strain-induced melt-activated thixo-forging. Sn-15 pct Pb and Pb-30 pct Sn semisolid alloys were chosen as model alloys. Bimetal composite parts were manufactured successfully by forging the semisolid alloys into the same die simultaneously. Optical photography, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Vickers hardness were employed to characterize the samples. The results showed that the composite semisolid fluid flowed in a laminar way. Globular primary grains in the two semisolid alloys maintained their respective geometry and constitutions. The mixture of two liquid phases was limited in a thin layer beneath the interface between the two semisolid alloys. The absence of an oxide-enriched layer at the interface suggests that the oxide skins of the feedstock were torn during the processing, leading to the formation of metallurgical bonding at the composite interface. This work showed that SSP is a promising technology for bimaterial/multimaterial composite manufacturing. The bimaterial composite parts achieved by SSP have a good composite interface and well-located material distribution.

Using corundum, quartz, kaoline, etc, as base components and CeO2-rich mixed rare earth as modifier, foam ceramics were fabricated adopting the organic foam impregnation process. The mixed rare earth addition had much improving effects on the matrix mechanical properties owing to much glass phase and acerate mullite growing. While 3wt% was considered to be the optimal addition, in this case, homogeneous and compact ceramic microstructure with maximal glass condensation and minimal porosity formed, with the matrix compressive strength and the flexural strength at room temperature reached 0.87MPa and 0.66MPa respectively, which were 52.6% and 73.7% higher than the original samples respectively. As the mixed rare earth addition exceeded further, the compressive strength increased slowly and the flexural strength descended gradually. XRD and SEM were used to structure strengthening mechanism analysis.

Two kinds of bi-metal composite parts (Sn-15% Pb and Pb-22%Sn bi-metal system, and Al-7%Si and SiCp/6061 MMC bi-metal system) were prepared by the strain-induced melt activated thixo-forging. The interfaces of the bi-metal composites were observed by OM and SEM. The observations show that the semisolid metals keep independence during thixo-forging. The solid phases in the semisolid slurries maintain their original morphologies after thixo-forging. The liquid phases near the interface mix together and form a thin layer. The interfaces are bonded firmly with the metallurgical bonding. No oxide layers are found at the interfaces. Strengths of the interfaces were investigated by the micro-hardness test. The experimental results show that the composite interfaces have high strength. However, the agglomerated enhancing particles cause fine defect on the interface of the Al-7%Si and SiC(subscript p)/6061 MMC bi-metal composite.

Fine-grained Al–Cu–Fe–(B) icosahedral poly-quasicrystals (IQCs) as the main materials and fine-grained Al–Pd–Mn IQCs as the supplements, both prepared by powder metallurgy, are uniaxially deformed at various temperatures and strain rates. The systematic study shows the dependences of curves of the true stress versus true strain on several parameters, such as temperature, strain rate and grain size. For Al–Cu–Fe IQCs with grain sizes of about 10–30 μm, QC-specific intra-granular softening drop appears in the deformation curves at lower temperatures and/or faster strain rates, but disappears in those curves at higher temperatures and/or slower strain rates, which suggests that the inter-granular effects such as grain-boundary sliding should be taken into account to interpret the continuous hardening, similarly to conventional poly-crystals. For Al–Cu–Fe-B IQCs with smaller grain sizes of about 1 μm and fine-grained Al–Pd–Mn IQCs with grain sizes of about 10 μm, QC-specific intra-granular softening drop is absent for all the deformation curves at the possible lowest temperature and fastest strain rate. This implies that the smaller the grain size, the more the inter-granular contribution. At the same time, due to the rapid recovery caused by intense diffusion in small-sized grains, the intra-granular quasicrystal lattice reorders rapidly from disordering, which also inhibits the intra-granular softening drop to some extent.

Raman spectroscopy is a powerful diagnostic method for gas analysis due to its advantages like non-invasiveness and fast speed. However, its applications are greatly restricted because of the weak signal level caused by small scattering cross section. In order to enhance the Raman signal level and improve the detection sensitivity, a sample cell of confocal cavity is designed and the enhanced Raman signal of ambient air based on this cavity is demonstrated experimentally. The confocal cavity is constructed with a pair of plano-concave reflectors with a curvature radius of 150 mm and reflectivity of 92%. This low reflectivity design not only allows for bandwidth matching with the line-width of excitation laser but also makes the resonant condition satisfied easily. The measured output power of the confocal cavity is over 42 mW in resonant condition, which gives a coupling efficiency of 87.5% when divided with the input power 48 mW. The high coupling efficiency enables the output power efficiently to reach 11 times that for the intra-cavity laser power in one direction. Raman scattering of ambient air is tested to verify the performance of the confocal cavity. In our experiments, the Raman signals are collected in a forward scattering configuration by an imaging Raman spectrometer which is connected to a CCD camera. Strong Raman signals of O2 and N2, even H2O are observed with 1 s exposure time in resonant condition, and rotational lines (O-branch and S-branch) of O2 and N2 are also clearly detected when exposure time is set to be 10 s. Compared with the results obtained without confocal cavity, the Raman signal level is enhanced 17 times and the signal-to-noise ratio is improved twice. In addition, a limit of detection (3) at a magnitude of 200 ppm for CO2 in ambient air is achieved for the resonant confocal cavity. These results indicate that the system can significantly enhance the spontaneous Raman scattering signal level and improve the detection sensitivity. Furthermore, the confocal cavity is applicable to the Raman analyses of other gas samples.