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Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the improvement effect and mechanism of the combined of basalt fiber and fly ash on the tensile performance of cementitious soil, basalt fibers of various contents, lengths and fly ash of different contents were selected and incorporated into the cement soil consisting of weak soil in mountainous areas. A series of splitting tensile tests and electron microscopy scanning tests were conducted to study the strength, deformation, toughness, and microscopic mechanism of action. The results indicate that basalt fiber length 6 mm and doping amount 0. 6%, and fly ash content 12% are the combined effect of the two has the best effect on improving the tensile performance and toughness of cement-soil. Compared with ordinary cement-soil, its tensile strength, residual strength, peak strain, and tensile absorption energy have increased by 40. 55%, 134. 68%, 40. 81%, and 132. 22%, respectively. The 18 mm fibers deteriorate the tensile properties of cementitious soil. The mechanism is that fibers reinforce the weak surface inside the cement soil, bear and transmit tensile stress, making the internal stress of the cement soil more uniform. Fly ash pearl particles can fill the pores inside the cement soil, making the cement soil particles fully bond with fibers, and enhancing the integrity of the sample. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The reaction between the acid gases such as H2S and CO2 with the hydrational products of silicates results in serious corrosion to the set cementˈ which is manifested in the increase in the permeability and dramatic reduction in the compressive strength of the set cementˈ negatively affecting the integrity of the wellbore. To deal with this problemˈ a self-crosslinking epoxy resin emulsion is developed to improve the ability of oil well cement to resist the corrosion by H2S and CO2. In laboratory studyˈ the performance and the mechanisms of set cement to resist corrosion are evaluated at H2S partial pressure of 2.0 MPa and H2S partial pressure of 1.5 MPaˈ and the results analyzed. The results of the study show that: 1) Increase the concentration of the self-crosslinking epoxy resinˈ the compressive strength of the set cement increases˗ when the compressive strength of the set cement increases to a certain valueˈ further increase in the concentration of the epoxy resin does not cause the compressive strength of the set cement to increase any moreˈ itˈ on the contraryˈ causes the compressive strength of the set cement to decrease. The elastic modulus in this process decreases significantly. 2) As the concentration of the self-crosslinking epoxy resin increasesˈ the corrosion depth caused by the H2S and CO2 gases in the set cement and the permeability of the set cement decreaseˈ the compressive strength of the set cement first increases and then decreases. 3) The self-crosslinking epoxy resin can wrap up the hydrational products of the set cementˈ thereby isolating the set cement from being contacted with the acid gases and thus improving the corrosion tolerance of the set cement against acid gases. 4) Cement slurries treated with the self-crosslinking epoxy resin have good engineering propertiesˈ leading to reduced sensitivity of the thickening time of a cement slurry to the aging time of cement waterˈ the concentration of the self-crosslinking epoxy resin as well as changes in temperatureˈ and these make the technology easy to use in field operation. The anti-corrosion tough cement slurry has been used in the cementing of 6 wellsˈ more than 90% of the well cementing job is classified as "excellent" and 99% of the well cementing job is classified as "qualified". From the study and the field operation it is concluded that the self-crosslinking epoxy resin emulsion fills and wraps up as a membrane the hydrational products of cementˈ rendering the set cement good anti-corrosion performance and toughnessˈ and this makes the anti-corrosion tough cement very suitable for cementing wells drilled in the high sulfide content blocks in northeast Sichuan. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Petroleum Machinery is the property of China Petroleum Machinery Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Re-dispersible latex powder is the key material for the preparation of steel structure interface mortar. In this paper, the influence of the content of re-dispersible latex powder on the 28 d compressive strength, flexural strength and tensile bond strength of interfacial mortar was researched. At the same time, combined with scanning electron microscopy, X-ray spectroscopy and other microscopic analysis methods, the bonding mechanism of re-dispersible latex powder to enhance the interfacial mortar was analyzed. The results show that the suitable content of re-dispersible latex powder is 15% (mass fraction, same below) in the preparation of steel structure interface mortar. Under the appropriate dosage, the tensile bond strength of the interface mortar reaches 1.12 MPa, and the compressive-flexural strength ratio is 2.3. The addition of latex powder can effectively improve the flexibility of the mortar. The addition of latex powder changes the pore structure of the mortar, and the porosity becomes larger. The hydration products in interfacial transition zone are mainly polymer film encapsulated hydration products C-S-H gel and Ca(OH)2. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Compressed air energy storage (CAES) technology is a large-scale, flexible and low carbon energy storage technology that utilizes compressed air for energy storage. All injectors and producers in the Yunying energy storage are faced with well cementing difficulties such as low formation temperature, large hole diameter, potential losses of cement slurry during well cementing, frequent alternation between injection and production, as well as strict requirements for long-term isolation of the wellbore etc. To solve these difficulties, well cementing techniques suitable for the CASE wells drilled in Yingcheng, Hubei Province are studied. A low-temperature salt-resistant tough cement slurry suitable for cementing the injectors and the producers drilled for the salt cavern energy storage is developed based on the close packing design theory and the induction of crystal phase structure design method. A set of well cementing technique based on this new cement slurry is developed. The density of the cement slurry can be adjusted between 1.88 g/cm3 and 1.93 g/cm³ . The thickening time of the cement slurry is easy to be changed to meet the operation requirements. The cement slurry has no density difference between the top and the bottom, zero free water and API filter loss of less than or equal to 50 mL. Contamination by salt to semi-saturation is of no influence to the performance of the cement slurry. The 7 d elastic modulus is less than 6.13 GPa. At temperatures lower than 30 ℃, the strength of the cement slurry can develop in less than 10 h. The 24 h compressive strength of the set cement is greater than 14 MPa. This cement slurry and the well cementing techniques have been used in the cementing of the surface casing and the production casing of the injectors and the producers drilled for the CAES in the Yunying basin in Hubei. The cementing job is 100% qualified and 95% of which is excellent. [ABSTRACT FROM AUTHOR]

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The shear behavior of ultra-high-performance concrete (UHPC) beams without stirrups was investigated through the single-point loading. Four UHPC beams with different steel fibers were tested until shear failure. The shear capacity, crack, deflection, and toughness were investigated in detail. The results show that the end-hook steel fiber has the better influence on the shear capacity, crack development and deformation, followed by smooth and straight steel fibers. The end-hook type Ⅱ steel fibers are better than end-hook type Ⅰ steel fibers. End-hook type Ⅰ steel fibers and smooth and straight steel fibers have better toughening effect, but share less longitudinal reinforcement tension. The wavy steel fibers share more longitudinal reinforcement tension. The wavy steel fibers improve the crack resistance of UHPC beams better without stirrups, but toughening effect is poorer. By comparison and analysis, the equation by Chen Xuan provides the best prediction accuracy. [ABSTRACT FROM AUTHOR]

Carbon nanotubes were selected as the reinforcing phase and a carbon nanotube toughened Al-Mg alloy composite material was prepared by stirring casting method. The effects of the amount of carbon nanotubes added on the mechanical properties, microstructure and toughness of the composite materials were studied, and the toughening mechanism of carbon nanotubes on Al-Mg alloy was explored. The results showed that the addition of an appropriate amount of carbon nanotubes refined the grain size of the Al-Mg alloy composite material, with a grain size of approximately 80/im. When the addition amount of carbon nanotubes was 0.8 wt%, the fracture morphology of the composite material was the most uniform. As the amount of carbon nanotubes added increased, the tensile strength, elongation at break, and hardness of the composite material showed a trend of first increasing and then decreasing. When the addition amount of carbon nanotubes was 0.8 wt%, the tensile strength, elongation at break, and hardness all reach their maximum values, which were 208.6 MPa, 15.8% and 53.1 HB, respectively. The addition of appropriate amount of carbon nanotubes significantly improves the toughness of Al-Mg alloy, gradually increasing the fracture elongation, prolonging the yield stage, and improving the toughness. This is because an appropriate amount of carbon nanotubes can bind well with the alloy and penetrate the cracks of the alloy, exerting a bridging effect and hindering the initiation and propagation of cracks, thereby improving the toughness of Al-Mg alloy composites, delaying the failure process of the alloy, and extending the yield stage of the alloy. Based on the above analysis, it can be concluded that the optimal addition amount of carbon nanotubes is 0.8 wt%. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The unique crystalline structure and strong covalent bonding of TiB2 coating give it ultra-high hardness and chemical stability, but it also suffers from poor toughness and weak bonding with metal substrates. Herein, Ni-doped TiB2 coating was prepared by combining high-power pulse magnetron sputtering technology and radio frequency magnetron sputtering technology. Additionally, SEM, EPMA, XRD, XPS, nanoindentation instrument, scratch tester, high-temperature friction and wear testing machine were used to comparatively study the micromorphology, chemical composition, phase structure, mechanical properties, and tribological properties of TiB2-Ni coatings with different Ni contents. Results showed that the Ni-doped TiB2-Ni coating possessed a small amount of Ni element solidly dissolved in the TiB2 lattice, and the excess Ni element existed in the form of a metallic phase, forming a nanocomposite structure at the grain boundaries, which restricted the growth of TiB2 grains, and caused the refinement and nanometerization of the columnar grains of the coating. Besides, the Ni doping brought about a significant decrease in the hardness and elastic modulus of the TiB2 coatings. With the increase of the Ni content, the adhesion strength between the coating and the substrate and the toughness of coatings continuously increased, while the friction coefficient of the coating decreased first and then increased. Moreover, the wear morphology indicated the wear of the coating belonged to abrasive wear and adhesive wear. In conclusion, Ni doping improved the toughness of the TiB2-Ni coatings by generating Ni metal phase in the grain boundaries, which could absorb the fracture energy through deformation during crack expansion. The TiB2-Ni coating with a Ni content of 4.9% (atomic fraction) exhibited good hardness and toughness.

SiC/AZ31 inverse nacre structured composite was prepared by mechanical ball milling and thermal deformation, and the microstructure of the composite was effectively controlled by process control. The microstructure was characterized by X-ray diffraction（XRD）and scanning electron microscopy（SEM）, the mechanical properties of the material were tested by quasi-static tensile test, and the strengthening and toughening mechanism and failure mechanism were preliminarily analyzed by combining the microstructure. The results show that the inverse nacre structure obtained by hot deformation process can significantly improve the tensile properties. When the strain hardening ability of the matrix in the inverse nacre structured composite is improved, it can better compensate for the softening effect caused by crack propagation in the hard phase, and the strain hardening ability of the composite is improved. The tensile properties can be controlled by adjusting the size of the lamellar soft phase in the inverse nacre structured composite. When the size of lamellar soft phase is large, the composite has better toughness. When the size of lamellar soft phase is small, the composite has higher strength. The excellent strength and toughness of the inverse nacre structure composite are arising from its structural characteristics, and the continuous hard phase plays a good role in bearing, while the dispersed lamellar soft phase benefits for improving the toughness of the composite. The main strengthening mechanisms of this material include dispersion strengthening, fine grain strengthening, and heterogeneous deformation induced strengthening, and the improvement of toughness are attributed to the crack blunting and deflection induced by lamellar soft phase. In summary, the architecture design of inverse nacre structure is an effective way to obtain high-strength and tough magnesium matrix composite.

Cyclic olefin copolymer (COC) is produced through the copolymerization of ethylene and cyclic olefins, and has been used for the manufacturing of optical devices and diagnostic containers due to its high transparency and excellent water vapor barrier. However, COC with high glass-transition temperature usually needs high cycloolefin insertion in copolymer and has increased brittleness, which has significantly hampered its many end uses. The introduction of α -olefin into ethylene/cycloolefin binary copolymers that have been extensively studied is expected to expand the application of cyclic olefin copolymers. In this paper, we report the terpolymerization of ethylene/norbornene/1-octene and ethylene/dicyclopentadiene/1-octene catalyzed by modified cyclopentadienyl scandium complexes 1−3 activated with [Ph3C] [B (C6F5 ) 4 ] and Ali Bu3 because rare earth catalysts have shown excellent catalytic performance towards olefin polymerization. These rare earth catalysts exhibit high catalytic activities (4. 4×105 ~21. 4×105 g/ (mol (Sc) ·h·bar) ) . The resultant terpolymers show moderate number average molecular weight (Mn=3. 8×104 ~20. 3×104 ) and relatively narrow polydispersity index (PDI=1. 2~2. 4) . The introduction of 1-octene significantly improves the toughness of ethylene/norbornene/1-octene terpolymers, and the P3 sample (Mn 13. 7×104, norbornene 37. 1%, 1-octene 11. 0%) exhibits 2. 0 times higher elongation at break (29. 9% vs. 9. 9%) than the P1 sample (Mn 14. 0×104, NB 42. 6%, OCT 6. 4%) [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to obtain films with better mechanical properties and fracture toughness, the (TiAlCrZrNb)- Six-N (x=0, 4%, 8%, 12% and 16%) high entropy ceramic nanocomposite films with different Si contents were deposited on Si substrate by magnetron sputtering technology. The effects of Si doping on the microstructure, mechanical properties! and fracture toughness of the films were investigated by X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy and Nano indentation apparatus. The results show that the mechanical properties and fracture toughness of the films increase first and then decrease with the addition of Si element, which can be attributed to the formation of nanocomposite structures. When Si content is 4%, (TiAlCrZrNb)-Six-N film has the best comprehensive mechanical properties, and Us maximum hardness and elastic modulus are 22.7 GPa and 192.0 GPa, respectively. In this case, the fracture toughness reaches the best, and the radial crack length C as 6.760 µm, The K1C was 1.77 MPa • m1/2. [ABSTRACT FROM AUTHOR]

he well Xingtan-1 is a deep horizontal well drilled in the Shuangyang district of Changchun city by the Jilin Oilfield. This well has a total depth of 5,758 m and horizontal section of 2,015 m. Studies were conducted on two problems, which are mud losses and strict requirement for the impact resistance of the cement sheath to withstand the effects of large scale fracturing jobs. A toughness enhancing anti-channeling agent TA-1 is developed. TA-1 is a product with “core-shell” structure, and is used to formulate an anti-channeling cement slurry with good toughness. The molecules of TA-1 have elastic cores and flexible molecular chains, and are able to improve the toughness of the cement slurry and form films. Test results of the performance of the cement slurry show that the slurry has good stability, with thickening time adjustable between 150 min and 350 min. The SPN value of the cement slurry is 1.15, indicating the cement slurry has good anti-channeling capacity. TA-1 reduces the elastic modulus of the set cement by 29.5% and enhances the impact resistance of the set cement by 16.4%. A cement slurry treated with TA-1 has 24-hour strength of greater than 20 MPa. Well cementing with this anti-channeling cement slurry on the well Xingtan-1 is successful, helping solve the problems of gas channeling through the cement sheaths and cracking of set cement during fracturing operation. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a kind of environment-friendly cementing material, the low toughness of alkali-activated slag cement limits its wide application. The graphene oxide (GO) was prepared by modified Hummers' method in this study. The effects of different amounts of GO on the hydration heat release, flexural strength, compressive strength, and toughness of alkali-activated slag cement were studied. The results show that GO can increase the latter hydration release and hydration degree of alkali-activated slag cement. In addition, GO significantly improves the flexural strength of alkali-activated slag mortar but slightly decreases compressive strength, indicating its toughness can be significantly enhanced. At 60d, when the addition of GO is 0.03%, the toughness of alkali-activated slag mortar can be enhanced by 51.9% compared to that of the reference sample. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The reservoir formations in the Baran Hetao Basin have the characteristics of low maturity, high permeability, low strength and high shale content. The formations drilled have high water sensibility, instability and leaking potential. Deep well cementing is faced with many difficulties, such as long cementing section, low displacement efficiency, low bonding strengths of the two interfaces and high requirements on the mechanical performance of the cement sheath in late fracturing jobs, etc. To solve these problems, a batch-mixing batch-injecting DRJ-2S flushing spacer and a slight-expansion high strength rough cement slurry DRE have been developed with two key cementing materials, which are an interface strengthening agent DRJ-2S and an expanding toughening agent DRE-4S. Laboratory studies show that the DRJ-2S flushing space has a flushing efficiency of more than 96%, which is 30% higher than that of clean water, and a spacer of density 1.60 g/cm³ has 7 d compressive strength of 9.6 MPa. The DRE2S flushing spacer has the ability of remarkably enhancing the compressive strength of mixed fluids and the bonding strengths of the interfaces of a cement sheath. At 90 ℃ and 21 MPa, a high strength tough slight-expansion cement slurry treated with 4% – 6% DRE-4S has compressive strength of at least 24 MPa, elastic modulus of equal to or less than 7 GPa, and linear ratio of expansion of at least 0.02%, indicating that the cement slurry has good adaptability to mechanical alternation. The DRE cement slurry and the DRJ-2S spacer have been used on more than 40 wells in the Bayan Hetao basin, with average well cementing pass rate of 96.5% or higher, greatly improving the quality of well cementing job in the basin. The application of the DRE and the DRJ-2S has provided a powerful technical support for the safe and efficient development of the complex oil and gas wells, and is worth promoting. [ABSTRACT FROM AUTHOR]

The girth welds of natural gas pipelines applied by self-shielded flux cored semi-automatic welding process in multiple layers and passes are prone to failure, and the main reasons include the number of welding layers is less than that required by the process, the single-pass welding layer is too thick, and welding principles are not met. These problems can cause excessive input of welding heat, which affects the weld structure and leads to the decline of girth weld toughness. Hence, the study was performed based on the X80 pipeline steel by the semi-automatic welding process using the self-shielded flux cored wire. Specifically, the toughness test results, metallographic structure and fracture of the girth weld zone and heat affected zone with different welding layers were analyzed comparatively. The results show that, with the increase of welding layers, the impact toughness of weld is greatly improved and the dispersion is reduced, the toughness ratio of fracture morphology increases, the grains are continuously refined and staggered with each other, which can effectively prevent the crack propagation. Generally, the research results could play a guiding role in formulating the welding procedure specification of natural gas pipeline and strengthening the quality management of construction on site.

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the embrittlement problem of coarse grain zone (CGHAZ) of deep-sea X70 pipeline steel in actual welding,the thermal simulation study of X70 pipeline steel was carried out under different thermal cycle processes.X70 pipeline steel CGHAZ was simulated by Gleeble-3800 thermal simulator to study the microstructure and toughness of CGHAZ under different heat input (HI) conditions in the range of 10~60 kJ/cm.The microstructure and toughness of CGHAZ were characterized by means of optical microscope (OM),scanning electron microscope (SEM) and Charpy impact test.The results show that the microstructure of the test steel under different heat input is mainly composed of granular bainite (GB),bainite ferrite (BF) and martensite-austenite component(M-A component).When HI increases continuously,the proportion of BF decreases,the proportion of GB increases,the M-A component coarsens,and the impact absorption energy first increases and then decreases.In the case of 20 kJ/cm,the excellent combination of BF and GB is obtained,the fracture is ductile fracture,and the impact absorption energy reaches [BF]173.8[BFQ] J;when HI is greater than 20 kJ/cm,the fracture is dissociated and fractured,and the impact absorption energy decreases obviously,with the lowest of [BF]18.8[BFQ] J.Therefore,lower heat input can improve the toughness of CGHAZ,make X70 pipeline steel have high strength,high toughness and good weldability,and provide some theoretical guidance for the optimization of welding process.[HQ]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studied here in the paper is the influence by the heat treatment process on the residual austenite content and the mechanical properties of the expandable casing. As a result, it is revealed that compared with the heat treatment process of quenching + hi-temperature annealing, employment of the heat treatment process of quenching + critical section normalization + hi-temperature annealing is capable of bringing about more residual austenite structure, and thus proper residual austenite content gets the comprehensive mechanical properties of the steel improved, the strength ratio reduced, the plasticity and toughness of the expandable casing enhanced, and the uniform elongation increased from 12% up to 23% so as to meet the requirement for the expansion. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, the spatial game between production, living and ecological land is constantly escalating. How to maintain regional ecological security and build a life community of mountains, rivers, forests, farmlands, lakes and grasslands has become the key to the transformation, upgrading and integrated development of urban and rural areas. Taking Baodi District of Tianjin as the study area, this paper applied the comprehensive index evaluation, spatial conflict index model and GIS spatial mutual exclusion matrix to conduct the ecological space regulation zoning based on the internal and external constraints of ecological space suitability and spatial conflict. The results showed that: 1) Under the consideration of suitability and conflict, Baodi District could be divided into six types of ecological regulation space, of which the stable ecological area, protective ecological area, control ecological area, restoration ecological area, reserve ecological area, and non-ecological area accounted for 5. 12%, 4. 59%, 0. 20%,2. 20%,36. 59% and 51. 30%, respectively. 2) A high degree of coincidence was found between the stable ecological area with the ecological protection red line. The overall coincidence rate of them was 71. 64%, indicating that the existing ecological protection red line played an obvious role in the protection of ecological security in Baodi District in terms of scale. 3) There were areas with an abrupt change of high and low ecological suitability levels, and areas with a serious overlap between high suitability and high conflict Meanwhile, most of the ecological protection red lines were directly adjacent to the reserve and non-ecological areas. These patterns indicated that it was difficult to carry out ecological protection according to the spatial distribution of ecological land in Baodi District, for there was a lack of necessary resilient space as a buffer. In conclusion, the ecological space regulation zoning can provide new ideas for increasing the resilience of ecological space, breaking through the bottom-line thinking of ecological protection and realizing the harmonious coexistence of production-living-ecological space. [ABSTRACT FROM AUTHOR]

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The effects of inclusions on the microstructure and toughness of the heat-affected zone (HAZ) in steel plates with Mg deoxidation after high-heat-input welding were investigated in the present study. The results indicate that the morphologies of MgO–MnS complex inclusions in steel are changed obviously with the addition of Al. When containing 0.001% Al (mass fraction), the inclusions consist of a central single MgO particle and an outside MnS phase. When containing 0.020% Al, they are comprised of several small MgO particles entrapped by the MnS phase. Because the former inclusion can nucleate intragranular acicular ferrites (IAFs) and the latter is non-nucleant, the main intragranular microstructures in the HAZs are ductile IAFs and brittle ferrite side plates, respectively. Therefore, the HAZ toughness of the steel plate without Al addition after a high-heat-input welding of 400 kJ·cm−1 is significantly better than that of the steel plate with Al addition.

As the use of high-strength thick plates is increasing in marine engineering, bridge engineering, petroleum pipelines, and other fields, the required performance level of thick welded plates is also increasing. Oxide metallurgy technology, which is used to improve the toughness of heat-affected zones by controlling the formation and dispersion of high-melting-temperature oxide particles in steel, has attracted increasing attention by researchers in recent years. The effect of cerium on the welding performance of industrial quenched and tempered high-strength steel was investigated. Using a Gleeble 3500 thermal simulator, the coarse-grained heat-affected zones of high-strength steel were simulated with different cerium contents. The microstructures, austenite grains, and mechanical properties of the heat-affected zone were investigated by using optical microscopy, scanning electron microscopy equipped with energy dispersive spectrometry, and hardness testing. The results show that when the heat inputs are 25 kJ·cm−1 and 50 kJ·cm−1, the impact energies of the heat-affected zone of Ce-undoped steel are 84.8 J and 24.5 J, respectively. When the mass fraction of Ce is 0.0018%, the impact energies of the heat-affected zone are 110.0 J and 112.0 J, respectively. The different degrees of toughness of the two experimental steels indicate that the appropriate content of rare earth element can effectively improve welding performance. By comparing and analyzing the microstructures and prior-austenite grain sizes of the two experimental steels, it can be seen that with increases in the welding heat input, the microstructure of the heat-affected zone of the high-strength steel gradually transforms from martensite and lower bainite to upper bainite and granular bainite, and the average size of the prior-austenite grains in the heat-affected zone obviously increases. However, at the same welding heat input, the size of the prior-austenite grains in the heat-affected zone of Ce-doped high-strength steel is significantly smaller. The observed microstructure of Ce-doped steel is finer with a reduced content of brittle upper bainite, which significantly improves the welding performance of 700 MPa high-strength steel.

Polymer matrix composites (PMCs) have become one of the most important structure materials in the new generation of civil turbofan aeroengine due to their advantages of high specific strength, high specific stiffness, good designability, excellent vibration damping performance and feasible integrity fabrication. The PMCs application in aeroengine abroad based on fan blade, fan casing, acoustic liner and bushing was introduced firstly in this paper. The advantages of PMCs in structure optimization, economy and environmental friendliness were also illustrated. Moreover, new progress of PMCs including micro/nano material hybridization, 3D printing process and metamaterials in aeroengine was analyzed in details. Finally, some suggestions about PMCs application based on the relationship of "design-material-process-evaluation" were proposed for further development of civil turbofan aero engine in China.

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas & Oil is the property of Editorial Department of Natural Gas & Oil and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)