Search

The effects of traditional heat treatment (quenching and then tempering) and deep cryogenic treatment on the microstructure and mechanical properties of a low-carbon high-alloy martensitic bearing steel were studied by Rockwell hardness test, X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite during cooling, which leads to the hardness of the sample after deep cryogenic treatment higher than that at the quenched state. Also, the carbon content in the martensite matrix after different treatments was calculated and the results indicated that deep cryogenic treatment can promote the segregation of carbon atoms in martensite to dislocations. The segregated carbon atoms act as and grow into nuclei for the formation of fine carbide particles during subsequent tempering. And this resulted in the fact that the hardness of the tempered experimental steel after deep cryogenic treatment is higher than that without deep cryogenic treatment.

The fretting wear performance of high-nitrogen stainless bearing steel (40Cr15Mo2VN) under lubrication conditions was researched. Lithium-based grease was prepared by using MoS2 and carbon nanotubes (CNTs) as additives. AISI 52100 steel ball was used in four-ball test to evaluate the extreme pressure property and wear resistance of grease. After four-ball test, the grease adding 0.8 mass% MoS2 and 0.8 mass% CNTs, respectively, was chosen and used for fretting test. AISI 52100 ball and 40Cr15Mo2VN steel disc were used as the upper and lower samples for fretting test. The results showed that wear power consumption increased with the increase in both sliding velocity and contact stress. When initial contact stress was 2.047 GPa, the main wear mechanisms were abrasive wear and plastic deformation as the velocity increased from 0.028 to 0.112 m/s. When the velocity was 0.028 m/s, the main wear mechanisms changed from abrasive wear to adhesion wear and finally to abrasive wear and adhesion wear as the initial contact stress increased from 1.788 to 2.579 GPa. The volume loss grew sharply because of the changes in wear mechanisms. In this condition, the volume loss growth rate can be divided into three regions according to different wear power consumption ranges corresponding to different wear mechanisms.

The effect of heat treatment and deep cryogenic treatment on microstructural evolution of low carbon martensitic bearing steel was investigated. The experimental results showed that the lath martensite was obtained by quenching and a few twins as substructures formed in some martensitic laths. The rudiment of sub-interfaces of martensitic lath was formed in the high-density dislocation regions after deep cryogenic treatment; meanwhile, the number of twins increased, especially in the high-density dislocation regions. This phenomenon is due to the increase in internal stress caused by cryogenic treatment. After tempering, the rudiment of sub-interface further evolved into the martensitic lath boundary, and thus the original martensitic laths were refined. The twins formed by cryogenic treatment did not disappear after tempering. In addition, small quantities of annealing twins formed in tempering process. Martensitic laths morphology and substructures in different stages of the heat and deep cryogenic treatment were observed by transmission electron microscopy.

The carbides precipitation and their evolution at elevated tempering temperature in Cr15Co10Mo5-alloyed heat-resistant bearing steel were investigated by means of the transmission electron microscope. The results show that there is no carbide precipitated from the martensitic matrix when the sample was tempered at 480 °C. However, when the sample was tempered at 540 °C, a large number of stable spherical M6C carbides precipitated in the test steel. Nevertheless, there are three types of carbides precipitated from the matrix including M6C, M2C and M23C6 carbides when the tempering temperature reached 600 °C. The mechanical properties also present a correlation with the evolution of carbides during tempering at different temperatures. This indicates that the strengthening mechanism of the steel is mainly attributed to the precipitation of carbides and their evolution, including the morphologies and types of carbides at different temperatures. In addition, the austenitic layers with a thickness of about 30 nm have been obtained between the martensite laths after tempering at 600 °C. The austenitic layers will produce transformation-induced plasticity effects to improve the toughness of the steel.

It is evident from controversial statements in the literature that the effects of deep cryogenic treatment on the microstructural evolution of low carbon martensitic steels are not fully understood yet. An investigation has been started to clarify this situation by analyzing the microstructural evolution and alloy precipitation after aging. The results show that the hardness is enhanced after deep cryogenic treatment and this is mainly contributed to the transformation of retained austenite to martensite at low temperature. By comparing with the samples subjected to quenching and deep cryogenic treatment, the hardness behaviors produced different variation tendency and characteristics during aging. According to obtained results and comparing with the characterization of carbides during aging, it showed that deep cryogenic treatment is an advantage for the formation and precipitation of alloy carbides during aging. The results indicated that deep cryogenic treatment increases the diffusion driving force of atoms (especially the carbon atoms) which promotes the formation of fine carbides in the process of aging.

Intra-site prophylactic vancomycin in spine surgery is an effective method of decreasing the incidence of postsurgical wound infection. However, there are differences in the prophylactic programs used for various spinal surgeries. Thus, this systematic review and meta-analysis aimed to evaluate the effectiveness of using intra-wound vancomycin during spinal surgery and to explore the effects of dose-dependence and the method of administration in a subgroup analysis. A total of 628 citations or studies were searched in PubMed, Ovid, Web of Science, and Google Scholar that were published before August 2016 with the terms "local vancomycin", "intra-wound vancomycin", "intraoperative vancomycin", "intra-site vancomycin", "topical vancomycin", "spine surgery", and "spinal surgery". Finally, 19 retrospective cohort studies and one prospective case study were eligible for inclusion in the systematic review and meta-analysis. The odds of developing postsurgical wound infection without prophylactic local vancomycin use were 2.83-fold higher than the odds of experiencing wound infection with the use of intra-wound vancomycin (95% confidence interval, 2.03-3.95; P = 0.083; I2 = 32.2%). The subgroup analysis including the dosage and the method of administration, revealed different results compared to previous research. The value of I2 in the 1-g group was 27.2%, which was much lower than in the 2-g group (I2 = 57.6%). At the same time, the value of I2 was 0.0% (P = 0.792, OR = 2.70) when vancomycin powder was directly sprinkled into all layers of the wound. However, there is high heterogenicity (I2 = 60.0%, P = 0.007, OR = 2.83) when vancomycin powder is not exposed to the bone graft and instrumentation. There are differences found with the method of local application of vancomycin for reducing postoperative wounds and further studies are necessary, including investigations focusing on the dose-dependent effects during spinal or the topical pharmacokinetic and other orthopaedic surgeries.

The microstructural changes and thermal stability of a cobalt-containing martensitic heat resistance bearing steel have been investigated in this paper. The hardness variation showed a progressive hardness decrease associated with coarsening of fine carbides at elevated temperatures. The precipitation of secondary phases during tempering at 500 °C for 10 h and 100 h has been characterized and identified in detail using transmission electron microscopy. The results revealed that the aging treatment induced very fine secondary M6C precipitates which were responsible for the secondary hardening peak when tempered at 500 °C for 30 h. But the hardness gradually decreased due to the coarsening of M6C carbide and other secondary phases (such as μ phase, σ phase, and χ phase) precipitation when the samples were tempered over 30 h at 500 °C.

Wear behavior and mechanism of plasma nitrided steel oscillating against a heat-treated and an untreated aluminum bronze alloy were investigated using an Optimol SRV tribometer. The influence of heat treatment on the mechanical properties of the alloy was evaluated. Furthermore, the wear debris was also examined to understand the wear mechanisms. The results show that a 220–230 μm nitrided layer, which was harder than the substrate, was obtained on the steel surface. The tensile strength and hardness of the alloy are found to be significantly improved by the heat treatment associated with low impact toughness. The heat treatment of the alloy did not obviously decrease the friction coefficient of the nitrided steel-bronze couple. However, the wear loss of the nitrided steel increased when it mated with the treated bronze by a severe three-body abrasion. The nitrided steel was mainly damaged by fatigue spalling. Under plane contact conditions, the wear debris was mainly generated from the bronze part and can escape from the interface before being oxidized, leading to the phase structure of all the debris being copper rather than copper oxides.

The dynamic recrystallization and carbides precipitation of the Cr-Co-Mo-Ni bearing steel were investigated by hot compression tests performed at temperatures ranging from 850 °C to 1080 °C with strain rate of 1-20 s-1. The activation energy (Q) for the tested steel is calculated to be around 682.99 kJ/mol at a deformation strain of 0.6. Microstructural analysis by SEM shows that the dynamic recrystallization (DRX) behavior is dependent sensitively on the deformation strain, temperature and strain rate, while an exponential relationship between DRX grain size and Z parameter is obtained from the computational formula. Moreover, the M6C-type carbides (

Utilizing Pro-cast software, the whole vacuum arc remelting process of high-alloy bearing steel ingot (the diameter was 160 mm and the high was 600 mm) was simulated. And moving face quality and moving boundary conditions were added to the simulation. Purposes of the simulation were to explore the influence of smelting powers on the temperature field, pool shape and solidification microstructure in vacuum arc remelting process. The depth of molten bath gradually increased and stabilized finally and the pool shape transferred from flat to funnel. When smelting power increased, the depth of molten pool became deeper and the width of mushy zone slightly reduced; the size of primary dendrite and secondary dendrite spacing increased significantly; the percentage and size of columnar crystals also increased. A reasonable power-time cure was given to guide industrial melting after simulation, the size of molten pool morphology and microstructure were controlled in an ideal range under the reasonable cure. The simulated grain morphology agreed well with the experimental pickling result.

Due to the difficulty of manufacturing complex small pieces ofthe new bearing steel0.30C-Cr-W with high-performance in the aviation industry, the electron beam welding process are usually used for preparing the complex parts.Thewelding performance of 0.30C-Cr-W steelwas calculated by theory and confirmedby actual experiments.The base metal was preheated,then welded and heattreated for weldments.The purpose of this work is to study the properties and the microstructure changes of base metal after heat treatment, weldments before heat treatment and weldments after heat treatment.The results show that the base metalafter heat treatment is sorbitic,weldzone of weldments after heat treatmentismartensite and austenite, theprecipitated M23C6 and M6C in latter (the weld zoneof weldmentsafter heat treatment) were more thanthe former (the base metalafter heat treatment), and the strengthof the latter is 23.4%lower than the former, theroom temperature impact absorbing energy and hardness of the latter increased 13.5% and 6.6%. It may be considered that0.30-C-Cr-W steel is not suitablefor welding by the theoretical calculations, but after reasonable preheat and post-weld heat treatment, the mechanical properties of the weld afterheat treatment can satisfy the requirements.

Microstructural transformations and mechanical properties of a low carbon martensite stainless bearing steel treated with different heat treatment parameters and cryogenic treatment (-82°C) were investigated. The function of microstructural transformations on strengthening and toughening process was quantitatively characterized as well. These analyses were performed by the optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and electron back scattering diffraction (EBSD) technique. The obtained results show that with execution of cryogenic treatment and tempering, the tensile strength increase owing to the reduction of retained austenite and fine carbides precipitating respectively. The effect of martensitic microstructure on yield strength increment can be regarded as packet size and block width which conform to Hall-Petch relationship. Meanwhile, the results suggest that the block width is the key structural controlling unit when analyzing the strength-structure relationship of lath martensite in low carbon martensite stainless bearing steel. In addition, packet size can be related to toughness controlling as well because of the same size as cleavage plane.

The low-carbon Cr-Ni-Mo carburizing bearing steel was tested with different heat treatment processes. Quenching-tempering temperature and cryogenic treatment (-73°C) wasstudied respectively onthe mechanical properties and microstructure.Results show thatthe increase of quenching temperature causes the micron-sized Cr-rich carbide re-dissolution and smaller quantity of retained austenite, makingthe strength and hardness of the tested steel increase and the impact toughness decrease. The tempering temperaturerising causesthe reduction of micro-residual stresses and smallerdegree of lattice distortion andlower dislocation density, resulting in the decrease of strength and the increase of impact toughness. Cryogenic treatment contributes to the refinement of martensite lath and precipitation of nanosized carbide and lowest quantity of retained austenite, improving the strength and impact toughness of the steel.The good comprehensive mechanical propertieswith the hardness of HRC41.3, tensile strength of 1413MPa,yield strength of 1168MPa, and impact toughness of 162J/cm2 can be obtainedby optimizing the heat treatment process parameters.

In order to make a further promotion and development of photovoltaic power generation project, this paper brings the extension theory in photovoltaic power generation project quality evaluation and builds the photovoltaic power generation project extension evaluation index system and model on the basis of matter-element theory and extension analysis. Ranking the evaluating projects by calculating the indicators compared with the correlation of evaluation degrees. The paper takes three photovoltaic power generation project in Shaanxi in 2012 as an example, expounding the model is reasonable and reliable. The empirical results give a best reflection on the quality of the photovoltaic power generation project, which provide a scientific basis for project decision. The paper results provide a new thought for quality assessment of photovoltaic power generation project, enriching the photovoltaic power generation project evaluation method.

Intra‐site prophylactic vancomycin in spine surgery is an effective method of decreasing the incidence of postsurgical wound infection. However, there are differences in the prophylactic programs used for various spinal surgeries. Thus, this systematic review and meta‐analysis aimed to evaluate the effectiveness of using intra‐wound vancomycin during spinal surgery and to explore the effects of dose‐dependence and the method of administration in a subgroup analysis. A total of 628 citations or studies were searched in PubMed, Ovid, Web of Science, and Google Scholar that were published before August 2016 with the terms “local vancomycin”, “intra‐wound vancomycin”, “intraoperative vancomycin”, “intra‐site vancomycin”, “topical vancomycin”, “spine surgery”, and “spinal surgery”. Finally, 19 retrospective cohort studies and one prospective case study were eligible for inclusion in the systematic review and meta‐analysis. The odds of developing postsurgical wound infection without prophylactic local vancomycin use were 2.83‐fold higher than the odds of experiencing wound infection with the use of intra‐wound vancomycin (95% confidence interval, 2.03–3.95; P = 0.083; I (2) = 32.2%). The subgroup analysis including the dosage and the method of administration, revealed different results compared to previous research. The value of I (2) in the 1‐g group was 27.2%, which was much lower than in the 2‐g group (I (2) = 57.6%). At the same time, the value of I (2) was 0.0% (P = 0.792, OR = 2.70) when vancomycin powder was directly sprinkled into all layers of the wound. However, there is high heterogenicity (I (2) = 60.0%, P = 0.007, OR = 2.83) when vancomycin powder is not exposed to the bone graft and instrumentation. There are differences found with the method of local application of vancomycin for reducing postoperative wounds and further studies are necessary, including investigations focusing on the dose‐dependent effects during spinal or the topical pharmacokinetic and other orthopaedic surgeries.

The effects of different heat treatment parameters and cryogenic treatment (−75 °C) on microstructural changes and mechanical properties of a low-carbon martensitic stainless bearing steel were investigated. These analyses were performed via the optical microscope (OM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The obtained results showed that the execution of cryogenic treatment on quenched and tempered bearing steel increases hardness, tensile strength and decreases toughness with the increment of cryogenic treatment and tempering cycles. This paper also showed that the cryogenic cycle׳s treatment incorporating tempering can refine the martensite laths resulting in improvement of tensile strength. In addition, cryogenic treatment further reduces the retained austenite content but it cannot make retained austenite transform into martensite completely even tempering at high temperature.

The carburizing behavior of low-carbon Cr-Ni-Mo, the nitriding behavior of C-Cr-W bearing steel and the carburizing process prior to nitriding of low-carbon Cr-Ni-Mo bearing steel were mainly investigated in this paper through the contrastive analysis of microstructures and properties by employing scanning electron microscope (SEM), transmission electron microscope (TEM) and X-Ray Diffraction XRD, etc. The result indicated that compared to the simple carburizing and nitriding process, the material that experienced the duplex surface finishing process could obtain a good infiltrated layer’s microstructure and excellent mechanical properties. The thickness of infiltrated layer was 1.8mm. The hardness of surface could reach 1100HV, and the infiltrated layer had a reasonable hardness gradient distribution. Meanwhile the test materials through duplex surface finishing process exhibited good friction properties in the aspect of point contact in dry friction.

To reveal the effect of deformation ratio on high nitrogen martensitic stainless steel, the room temperature mechanical properties, microstructures and precipitates morphology were studied by using optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM) as well as mechanical tests. The results indicate that the tensile strength, yield strength and impact energy were raised 241MPa, 180MPa and 10.0J respectively, at a higher deformation ratio. While, the average original austenite grain size was refined from 14.93μm to 9.57μm when the deformation ratio was increased from 0.65 to 0.83 as well as the martensite lath width thinned from 400nm to 250nm. Furthermore, at various deformation ratios, the precipitates morphology was different in quantity, grain size and dispersion. There are more eutectic precipitates and secondary precipitates dispersed along the grain boundary as continuous chains with lower deformation ratio. On the contrary, the precipitates in specimen with higher deformation ratio were uniform and fine without chain or network. It can be inferred that the improvements on mechanical properties, microstructures and precipitates morphology are mainly due to the deformation ratio.

Land planning is plans and arrangements to a certain of areas the ahead of future land use, and involving social, economic, resource and environmental and other aspects of the planning area, to social economic development and ecological environment will have a profound impact,Land planning environmental impact assessment is analysis, pre-monitoring and evaluation after the implementation of land use planning producting the potential environmental impact, and on this basis from the environment point of view ,raised the best solution for planning and adjustment proposal, so it carried out environmental impact assessment to guarantee the correctness of decisions is essential as soon as possible.

Accelerating urbanization is China's "The Fifth" period of economic and social development of an important part of the overall strategy.Urbanization construction process speeded up in Guan- zhong region in recent years.At the same time, many problems appeared, Guanzhong area of farmland for construction land increased year by year, while the Guanzhong area in northern and central located in the Loess Plateau and the Weihe Plain, is the most serious soil erosion in China, the ecological envi- ronment of the most vulnerable areas. Urban sprawl compressed natural environment space, and destr- oyed undermined the balance of the ecosystem.To under the premise of ensuring food security and ecological security, only to improve land use efficiency. It adopts the PSR framework model to build urbanization index system of intensive use of land.It used the matter-element extension theory to evaluate, designed to evaluate land use efficiency and benefit, To find out the problems existing in the current land use and seek the most effective use way of land and to achieve sustainable land use.

The influence of deformation and quenching temperature on microstructure and properties for high nitrogen stainless bearing steel was studied using the calculation of Thermo-Calc software and relevant Fe-based database and some experiments. The results showed that there was a small precipitation amount of carbide in the sample after a large deformation. The value of impact toughness (AKU) was increased from 2.0 J to 12.0 J with the deformation increasing from 71% to 83%. When the quenching temperature reached 1050, the value of the hardness was up to the tiptop. Additionally, according to the calculation, it was found that there was a linear functional relation between the precipitation of carbide M23C6(M) and quenching temperature (T). And the relational model could be expressed as:MM23C6=55.34 - 0.05T(T1000).

The solidification microstructure and crystallization of Cr-Co-Mo-Ni bearing steel were simulated in solidification process based on CAFE methods in the electro-slag remelting process. The optimization of the intensity of cooling and molten pool temperature was simulated for Cr-Co-Mo-Ni bearing steel. The result shows that raising the cooling intensity to 7.5 m3/h and reducing the superheat temperature to 1600 can increase the grain nucleation number about 13.83%, and reduce the average columnar grain radius about 10.61%, to have a very good effect on refining the grains and get dense uniform solidification, which improve the homogeneity of the solidification structure, and reduce the performance differences of the materials.

In order to inhibit its decomposition and improve its compatibility with the metal matrix during laser cladding, WS2 powder was encapsulated with a layer of micro Ni–P by electroless plating. The microstructure and tribological properties of the NiCr–Cr3C2/30%WS2 and NiCr–Cr3C2/30%WS2(Ni–P) high temperature self-lubricating wear-resistant composite coatings at RT (room temperature), 300 °C and 600 °C were investigated, respectively. It was found that the NiCr–Cr3C2/30%WS2(Ni–P) coating had a microstructure consisting of primary Cr7C3 dendrite, γ-(Fe,Ni)/Cr7C3 eutectic and solid lubricant particles WS2 and CrS, Ni–P electroless plating had decreased the decomposition of WS2 to some extent, the WS2 solid lubricant particles dispersed in the ductile γ-(Fe,Ni)/Cr7C3 matrix. Friction and wear experiments indicated that the tribological properties of the NiCr–Cr3C2/30%WS2(Ni–P) coating was better than that of NiCr–Cr3C2/30%WS2 coating, the NiCr–Cr3C2/30%WS2(Ni–P) coating presents lower friction coefficient at RT and 300 °C and lower wear rate from RT to the elevated temperature of 600 °C.

One type of spatial new parallel mechanism with two degree of freedom is proposed.. The position and velocity analytic equation are constructed based on the coordinate transformations. Finally, the singular configuration of the tilter is analyzed by the forward and the inverse Jacobian matrix.

This paper is analyzed based on extension learn matter-element theory, combined with urban subway traffic service status, constituting the urban subway service level evaluation model and AHP. Taking Xi'an Metro Line 2 as the object of study determine the weight coefficient of each index and establish correlation function, in order to calculate the index of correlation and give a quantitative numerical representation of evaluation results. Finally, we can get the result that the Metro Line 2 of the traffic service level is good. This evaluation system can also be applied to other urban subway transportation service level evaluation.

Based on the extensible matter-element theory, this paper constructs the evaluation model of construction lands combined the analysis of current situation of construction lands in towns of northern area Shaanxi province. Also, by using combination method of entropy weight and level analysis, we find out the weighted coefficient of each indicator and the correlation degree of correlation functions. Through the empirical analysis from Shenmu, Qingjian, Zizhou town in Yulin city, Shaanxi Province, We confirm the feasibility and advantages of the extensible matter-element evaluation in the evaluation study of the construction land.

Based on extension theory, combined with the existing problems of urban land intensive use, evaluation system of urban land intensive use was established. According to the present situation of urban land use in Xi’an, combined with the model, this paper takes extension method to determine the index weight and makes an empirical analysis of urban land intensive use in Xi’an.

Data on the utilization of immunosuppressants and incidences of cardiovascular complications after kidney transplantation are generally lacking in China. The objectives of this systematic review and analysis were to investigate the hypothesis that tacrolimus and cyclosporine have different effects on the incidences of cardiovascular complications among Chinese patients after kidney transplantation. A comprehensive database research was performed in PubMed and CMB-disc. Random effect models and meta-regression were used for data analysis. Eleven eligible studies were retrieved (7 comparative studies and 4 conversion studies). There were 838 participants from the eligible studies. The incidences of drug-related hypertension, dyslipidemia and hyperglycemia were compared between tacrolimus and cyclosporine groups. Significant different odds ratios for dyslipidemia (40 vs. 20 %, OR 2.72) and hypertension (63 vs. 37 %, OR 2.93), but not for hyperglycemia (11 vs. 15 %, OR 0.705) were noted between patients receiving cyclosporine and tacrolimus containing regimens. The secondary analysis including comparative studies revealed a similar acute rejection rate, but significantly improved renal functions, lipid profiles and lower liver toxicity associated with tacrolimus. Significant reversal of hypertension and dyslipidemia was also noted in the analysis of the conversion studies. A significant association between immunosuppressant use and cardiovascular complications was identified among Chinese patients after kidney transplantation. Patients receiving cyclosporine-containing regimens and/or with chronic allograft nephropathy should be closely monitored for potential cardiovascular complications.

The high temperature self-lubricating wear-resistant NiCr/Cr3C2–30%WS2 coating and wear-resistant NiCr/Cr3C2 coating were fabricated on 0Cr18Ni9 austenitic stainless steel by laser cladding. Phase constitutions and microstructures were investigated, and the tribological properties were evaluated using a ball-on-disc wear tester under dry sliding condition at room-temperature (17 °C), 300 °C and 600 °C, respectively. Results indicated that the laser clad NiCr/Cr3C2 coating consisted of Cr7C3 primary phase and γ-(Fe,Ni)/Cr7C3 eutectic colony, while the coating added with WS2 was mainly composed of Cr7C3 and (Cr,W)C carbides, with the lubricating WS2 and CrS sulfides as the minor phases. The wear tests showed that the friction coefficients of two coatings both decrease with the increasing temperature, while the both wear rates increase. The friction coefficient of laser clad NiCr/Cr3C2–30%WS2 is lower than the coating without WS2 whatever at room-temperature, 300 °C, 600 °C, but its wear rate is only lower at 300 °C. It is considered that the laser clad NiCr/Cr3C2–30%WS2 composite coating has good combination of anti-wear and friction-reducing capabilities at room-temperature up to 300 °C.

Considering that energy-saving of public building is affected by many complicated factors, and there exists difference energy-saving methods from the building project design stage, construction stage and operational stage. This article has firstly made an analysis from the point of the systems engineering, pointing out that the public building energy systems is based on the life cycle of the theory, and then set up the evaluation target system of public building energy systems. The evaluation target system includes energy consumption target, economic target, sustainable development target, environmental target, technical target and function target. Finally, we applied Extension evaluation method to evaluate public building energy-saving, and adopt AHP to make the weight of targets.

In order to assess the standardization of safety accurately and objectively, this paper establishes the safety evaluation index system for the building construction according to engineering experience. The weight of each index is decided reasonably by the Analytic Hierarchy Process. Based on extension theory, the evaluation matter —element model for evaluation of construction safety is established, and the extensional evaluation method with correlative functions is put forward. Thus, construction safety is systematically evaluated. Finally it verified by project example, the result proves its feasibility.

This paper makes a detailed analysis of the four dimensions of influencing factors and composition index, namely, financial return, resource consumption, environment load and external benefit. On the basis of such an analysis, the paper establishes a comprehensive assessment on the green value of ecological energy-saving buildings. And discusses the concept of ecological energy-saving buildings, and reveals the content of the green value.

In order to improve the high-temperature wear resistance of austenitic stainless steel, a wear resistant composite coating reinforced with hard (Cr,Fe)7C3 carbide and toughened by ductile γ-(Ni,Fe)/(Cr,Fe)7C3 eutectic matrix was fabricated by a novel central hollow laser cladding technique. The constituent phases and microstructure as well as high-temperature tribological behaviors of the Ni-based coating were investigated, respectively, and the corresponding wear mechanisms were discussed. It has been found that the composite coating exhibits superior wear resistance than substrate either at ambient or high temperatures. The coating shows better sliding wear resistance at 600 °C than 300 °C owing to high-temperature stability of the reinforced carbide and polishing effect as well as formation of continuous lubricious films, which implied it has large potential industrial applications at relatively higher temperatures.

In order to deal with the striking booming process of urbanization in the situation of urban housing demolition expanding and its major contradictions, the interactive fair game theory model is used to solve these contradictions and presented some suggestion. By analyzing the existing contradictions of demolition, the leads interactive justice theory establishes the model to analyze the game among the Government, the demolition, the developers and the demolition, which finally comes to the conclusion of the contradictory solutions and supplies suggestions for the government and developers demolition work. What’s more, it’s helpful to build a harmonious and stable society.

To replicating the associations of type 2 diabetes (T2D) and six novel reported variants in Han Chinese lean individuals of first episode T2D, a total of six high risk single nucleotide polymorphisms (SNPs) from the BCL11A, DUSP9, IRS1, CENTD2, ADRA2A, and CDKAL1 genes were examined. Candidate six SNPs were genotyped in 761 T2D patients and 433 control subjects, and associations between the six SNPs and Body Mass Index (BMI), Fasting Plasma Glucose (FPG) and Two Hours Oral Glucose Tolerance Test (2hOGTT) were also investigated. CDKAL1 provided the strongest evidence for replication, where rs7754840 was associated with T2D (odds ratio = 1.54, per copy of the risk C allele, P = 8.10 × 10(-7)). SNP rs5945326 at DUSP9 showed modest significance (odds ratio = 0.81, per copy of the protective G allele, P = 0.02). After adjusting the confounders of age, gender and BMI, the above results remain significant for both rs7754840 (P1.0 × 10(-4)) and rs5945326 (P = 0.043) respectively. After correcting for multiple testing, however, only the association between T2D and rs7754840 at CDKAL1 (P1×10(-4)) remains significant. In addition, the risk C allele of CDKAL1 rs7754840 was significantly associated with increased FPG levels (P = 3.8 × 10(-4)). The association between genetic variant in CDKAL1 gene was detected in the Han Chinese lean individuals. The correlation between rs7754840-C allele and increased FPG levels is consistent with the potential function of CDKAL1 gene in pancreatic islets.

The lipoprotein lipase (LPL) gene encodes a rate-limiting enzyme protein that has a key role in the hydrolysis of triglycerides. Hypertriglyceridemia, one widely prevalent syndrome of LPL deficiency and dysfunction, may be a risk factor in the development of dyslipidemia, type II diabetes (T2D), essential hypertension (EH), coronary heart disease (CHD) and Alzheimer's disease (AD). Findings from earlier studies indicate that LPL may have a role in the pathology of these diseases and therefore is a common or shared biological basis for these common complex diseases. To examine this hypothesis, we reviewed articles on the molecular structure, expression and function of the LPL gene, and its potential role in the etiology of diseases. Evidence from these studies indicate that LPL dysfunction is involved in dyslipidemia, T2D, EH, CHD and AD; and support the hypothesis that there is a common or shared biological basis for these common complex diseases.

Background Gene expression data and association analyses in two Chinese samples implicate chitinase 3-like 1 (CHI3L1), a cellular survival gene, in schizophrenia susceptibility. Methods We tested whether the association data are robust to replication in a Caucasian schizophrenia sample and performed a comprehensive investigation of common genetic variation at the locus. Results In a sample of 375 case and 812 control subjects we identified significant association with the same risk allele at the promoter single nucleotide polymorphism (SNP) associated in the original study (rs10399805; p = .018) and with another SNP at intron 7 of CHI3L1 (rs2275351; p = .008). The rs10399805 SNP is located at position -247 and disrupts the C/EBP-AML-1 binding site in the gene promoter; the risk allele is predicted to increase CHI3L1 expression, as has been reported in several postmortem schizophrenia studies. Carriers of the risk variant presented with fewer positive symptoms and relatively spared cognitive performance compared with other schizophrenia patients. Conclusions These findings support a functional mechanism for involvement of CHI3L1 in schizophrenia susceptibility, possibly contributing to a less severe illness. The associated variants in this study are not well tagged by all Whole-Genome Association (WGA) platforms, suggesting additional genotyping may be necessary despite the imminent availability of WGA data from large SZ samples. Because CHI3L1 may be involved in transmission of stress-induced cellular responses, studies of interaction with known environmental risk factors may also be warranted.

Autism is a neurodevelopmental disorder with high heritability and a likely complex genetic architecture. Much genetic evidence has accumulated in the last 20 years but no gene has been unequivocally identified as containing risk variants for autism. In this article we review the past and present literature on neuro-pathological, genetic linkage, genetic association, and gene expression studies in this disorder. We sought convergent evidence to support particular genes or chromosomal regions that might be likely to contain risk DNA variants. The convergent evidence from these studies supports the current hypotheses that there are multiple genetic loci predisposing to autism, and that genes involved in neurodevelopment are especially important for future genetic studies. Convergent evidence suggests the chromosome regions 7q21.2-q36.2, 16p12.1-p13.3, 6q14.3-q23.2, 2q24.1-q33.1, 17q11.1-q21.2, 1q21-q44 and 3q21.3-q29, are likely to contain risk genes for autism. Taken together with results from neuro-pathological studies, genes involved in brain development located at the above regions should be prioritized for future genetic research.

BACKGROUND: High blood pressure can cause kidney damage, which can increase blood pressure, leading to a vicious cycle. It is not clear whether the protective effects of T-type calcium channel blockers (T-type CCBs) on renal function are better than those of L-type CCBs or renin-angiotensin system (RAS) antagonists in patients with hypertension. METHODS AND FINDINGS: PUBMED, MEDLINE, EMBASE, OVID, Web of Science, Cochrane, CNKI, MEDCH, VIP, and WANFANG databases were searched for clinical trials published in English or Chinese from January 1, 1990, to December 31, 2013. The weighted mean difference (WMD) and 95% confidence interval (CI) were calculated and reported. A total of 1494 reports were collected, of which 24 studies with 1,696 participants (including 809 reports comparing T-type CCBs versus L-type CCBs and 887 reports comparing T-type CCB versus RAS antagonists) met the inclusion criteria. Compared with L-type CCBs, T-type CCBs resulted in a significant decline in aldosterone (mean difference = -15.19, 95% CI -19.65 - -10.72, p

BACKGROUND: Hypertension is a major risk factor for the development of stroke. It is well known that lowering blood pressure decreases the risk of stroke in people with moderate to severe hypertension. However, the specific effects of calcium channel blockers (CCBs) against stroke in patients with hypertension as compared to no treatment and other antihypertensive drug classes are not known. METHODS AND FINDINGS: This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CCBs effect on stroke in patients with hypertension in studies of CCBs versus placebo, angiotensin-converting-enzyme inhibitors (ACEIs), β-adrenergic blockers, and diuretics. The PUBMED, MEDLINE, EMBASE, OVID, CNKI, MEDCH, and WANFANG databases were searched for trials published in English or Chinese during the period January 1, 1996 to July 31, 2012. A total of 177 reports were collected, among them 31 RCTs with 273,543 participants (including 130,466 experimental subjects and 143,077 controls) met the inclusion criteria. In these trials a total of 9,550 stroke events (4,145 in experimental group and 5,405 in control group) were reported. CCBs significantly decreased the incidence of stroke compared with placebo (OR = 0.68, 95% CI 0.61-0.75, p

Objective Many studies have suggested that certain types of lipids such as phospholipids, fatty acids, and cholesterols are involved in the pathology of nervous system diseases. Lipoprotein lipase (LPL), as the key enzyme of triglyceride hydrolysis, is expressed in the brain regions functionally relevant to learning, memory, and other cognitive functions. In addition, both genome-wide linkage and association studies in schizophrenia have implicated the chromosome 8p22 region, in which the LPL gene is located. Therefore, LPL is an attractive candidate gene for schizophrenia and we tested this hypothesis in a case-control sample. Methods In this study, we investigated allele and genotype frequencies distributions of nine single nucleotide polymorphisms (SNPs) within the LPL gene in Han Chinese patients with schizophrenia (n = 319) and healthy controls (n = 575). Results Significant differences were detected between case and control groups in the frequencies of rs253 alleles [odds ratio (OR): 1.74; 95% confidence interval (CI): 1.43-2.11; P = 3.21 x 10(-8)] and genotypes (OR: 3.08; 95% CI: 2.07-4.56; global P = 7.88 x 10(-9)), respectively. Interestingly, this association was observed only in the male (P = 5.87 x 10(-9) for allele; P = 1.79 x 10(-11) for genotype) and not in the female samples (P>0.05). After correcting for multiple testing, the above association remains to be significant (P-c Conclusion Our study lends support to the potential role of lipid metabolism in schizophrenia and further investigations are warranted. Psychiatr Genet 21: 307-314 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Psychiatric Genetics 2011, 21: 307-314

Tumor necrosis factor-alpha (TNF-α) has been regarded as a candidate gene for Crohn’s disease (CD) based on its inflammatory function in immune reaction and the clinical effectiveness of anti-TNF-α therapy. However, studies to date have reported inconsistent findings for the association between TNF-α and CD. The PubMed, EMBASE, and Medline databases were systematically reviewed from all English language publications up to April, 2011. A total of twenty-nine studies concerning the association between CD and the TNF-α promoter polymorphisms of −308G/A, −857C/T and −238G/A were identified, among of them only twenty-three studies match the inclusion criteria (including 3,843 cases and 6,260 controls) and were selected for the statistical test. We found that neither the G allele of −308G/A (OR 1.02, 95% CI 0.87–1.19, P = 0.84), C allele of −857C/T (OR 0.97, 95% CI 0.86–1.09, P = 0.57) and G allele of −238G/A (OR 0.91, 95% CI 0.70–1.18, P = 0.48), and nor their GG (OR 1.05, 95% CI 0.88–1.25, P = 0.59), CC (OR 0.98, 95% CI 0.86–1.12, P = 0.76) and GG (OR 0.92, 95% CI 0.70–1.21, P = 0.55) genotypes were associated with CD susceptibility, respectively. Our meta-analysis demonstrates that three promoter polymorphisms of TNF-α above may not confer susceptibility to CD.

Cyclin-dependent kinase inhibitor-2A/B (CDKN2A/B) has been reported as a candidate gene of type 2 diabetes (T2D) based on its chromosomal position and its important role in β-cell function and regeneration. However, studies to date have reported inconsistent findings regarding the association between T2D and CDKN2A/B. To clarify this inconsistence, we conducted a meta-analysis based on alleles and genotypes prevalence of rs10811661 and rs564398 in CDKN2A/B. The PubMed, EMBASE, and Medline databases were systematically reviewed for studies published between January, 2006, and November, 2010. A total of 35 reports were collected, among of them only 16 studies (including 24,407 cases and 33,937 controls) match the inclusion criteria and were selected for the statistical test. In the meta-analysis of published data, our results suggest that the rs10811661 T allele (OR 1.28, 95% CI 1.21–1.36, P

The etiology of recurrent miscarriage (RM) is extremely heterogeneous, including genetic, immunologic, anatomic, endocrinological, and infectious anomalies. About 50% of RM is unexplained or poorly understood, which is called idiopathic recurrent miscarriage (IRM). The primary aim of this study was to identify the genetic loci that might be susceptible to IRM. Forty-four Han Chinese patients with IRM during the first trimester of their pregnancies and 44 healthy sex- and ethnic-matched controls were enrolled in this study. A case—control and genome-wide study was performed and 430 polymorphic microsatellite markers were analyzed. Three loci, 6q27 (D6S446, P = .028), 9q33.1 (D9S1776, P = .037), and Xp22.11 (DXS1226, P = .008), significantly associated with IRM were found. This work identified 3 genetic regions that might harbor genes predisposed to IRM and provided new insights for future genetic and etiological study of IRM. Further study is required to confirm it.