Search

Machine to machine communication is an important scenario in a 6G communication network. Random multiple access has recently been revisited and considered a key technology for machine to machine communication scenarios due to many advantages such as without coordination setup time. It is a regret that packet collision probability will be extremely higher for random multiple access when massive devices randomly accessing base station. Decentralized power control is an efficient scheme in random multiple access systems which can support intraslot successive interference cancellation to recover multiple collided packets at receivers. However, existing studies of decentralized power control for random multiple access are with the assumption that blocklength of transmitted packets is infinite, which neglects that machine to machine communication is characterized by finite blocklength transmission (i.e., short packet) in 6G. This paper focuses decentralized power control with short packet transmission in random multiple access systems. First, the closed-form expression of signal to interference plus noise ratio (SINR) threshold for short packets is derived. Then, decentralized transmission power profile is defined based on derived SINR threshold of short packets, which can support intraslot successive interference cancellation deciding at receivers for an ALOHA-type random multiple access system. Further, we propose derivation method to maximize system throughput, which can reduce optimization cost. Theoretical findings in this paper can provide valuable benchmark for short packet transmission with decentralized power control in random multiple access systems.

Intraoperative hypothermia is very common and harmful in adult patients undergoing laparoscopic surgery. A variety of active warming systems has received close attention and has been researched by related scholars. However, the relative efficacy of these systems and which active warming system is preferred for such patients remain unclear. The aim of this study was to compare and rank six active warming systems regarding intraoperative warming efficacy in adult patients undergoing laparoscopic surgery. Following the PRISMA 2020 guidelines, relevant randomized controlled trials (RCTs) on the efficacy of different active warming systems in warming adult patients undergoing laparoscopic surgery were searched from five English databases and three Chinese databases. The quality of the studies was assessed using the Cochrane Risk of Bias tool (RoB2). The outcome was the final intraoperative core temperature. We estimated direct effects by using pairwise meta-analysis, estimated relative effects and ranking with the consistency model to conduct an NetworkMeta-Analysis (NMA). We used GRADE (Grading of Recommendations Assessment, Development, and Evaluation) to assess the certainty of the evidence. Sensitivity analysis was performed to test the robustness of the results. This study is registered with PROSPERO, with number CRD42022309057. In total, 19 RCTs involving 6 active warming systems and comprising 1364 patients were included in this NMA. The NMA once again confirmed the validity of forced-air warming (FAW) systems compared with other active warming systems, and further showed that underbody FAW was associated with more remarkable warming efficacy in different types of FAW systems. NMA was used to perform an exhaustive comparison of the warming efficacy of six active warming systems and indicated that underbody FAW was most likely to be the most effective warming system in adult patients undergoing laparoscopic surgery; however, considering the sparsity of the network, our results should be cautiously interpreted. Furthermore, a large number of high-quality RCTs comparing the warming efficacy of different competitive active warming systems are needed.

Random access systems are potential for Internet of Things in the future wireless communication network for its operational simplicity. Irregular repetition slotted ALOHA (IRSA) system is one of the high-efficiency random access systems. In this paper, performance analysis of the irregular repetition slotted ALOHA systems with short-packet, i.e. finite-blocklength, transmission for the quasi-static Rayleigh fading channel is given. A cumulative distribution function of signal-to-interference power ratio (SIR) is derived and thus a closed-form expression of an average packet error probability (PEP) at the SIR with short packets for the Rayleigh fading channel is given. The closed-form expression makes it possible to optimize the degree distributions at a specific blocklength in the sense that the systems give the maximum system load.

In the present study, the PLC characteristic parameters and DSA mechanism of Al-(2.86~9.41) Mg alloy sheets were investigated during tensile testing at room temperature with a tensile rate of 1 × 10−3 s−1. On the basis of the solution Mg concentrations in the α-Al matrix, the initial vacancy concentration, the second-phase particle configuration and the recrystallized grain configuration are almost the same by quenching treatment. The results show that the type of room-temperature tensile stress–strain curves of quenched Al-(2.86~9.41) Mg alloy sheets varied according to the Mg content. The type of stress–strain curve of the Al-2.86 Mg alloy sheet was B + C, while the type of stress–strain curve of the Al-(4.23~9.41) Mg alloy sheets was C. When the quenched Al-(2.86~9.41) Mg alloy sheets were stretched at room temperature, the strain cycle of the rectangular waves corresponding to the high stress flow ΔεTmax and stress drop amplitude Δσ on the zigzag stress–strain curve of alloy sheets increased with increasing the Mg content. Moreover, the strain cycle of ΔεTmax and Δσ on the stress–strain curve of alloy sheets increased gradually with increasing tensile deformation. The yield stress of quenched Al-(2.86~9.41) Mg alloy sheets increased gradually with increasing the Mg content. Moreover, the critical strain corresponding to yield stress εσ and the critical strain corresponding to the occurrence of the PLC shearing band εc of alloy sheets both increased with increasing the Mg content. However, the difference in flow strain value Δεc−σ between εc and εσ of alloy sheets decreased gradually with increasing the Mg content.

Based on the characteristics of modern weapon injury, a repetitive model of traumatic systemic inflammatory response syndrome (SIRS) and an evaluation system were established. The models were treated with GFP-labeled tree shrew umbilical cord mesenchymal stem cells (UCMSCs). Forty out of 50 tree shrews were used to make a unilateral femoral comminuted fracture. Lipopolysaccharide was injected intravenously to create a traumatic SIRS model. The other 10 shrews were used as normal controls. After the model was established for 10 days, 20 tree shrews were injected intravenously with GFP-labeled UCMSCs, and 18 tree shrews were not injected as the model control group. The distribution of GFP-labeled cells in vivo was measured at 2 and 10 days after injection. Twenty days after treatment, the model group, the normal control group, and the treatment group were taken to observe the pathological changes in each tissue, and blood samples were taken for the changes in liver, renal, and heart function. Distribution of GFP-positive cells was observed in all tissues at 2 and 10 days after injection. After treatment, the HE staining results of the treatment group were close to those of the normal group, and the model group had a certain degree of lesions. The results of liver, renal, and heart function tests in the treatment group were returned to normal, and the results in the model group were abnormally increased. UCMSCs have a certain effect on the treatment of traumatic SIRS and provide a new technical solution for modern weapon trauma treatment.

Background Age-related macular degeneration (AMD) may lead to irreversibly vision loss among aging populations. In this work, in an in vitro AMD cell model, we examined the expression and function of long non-coding RNA, Prader-Willi Region Non-Protein Coding RNA 2 (PWRN2) in injured human retinal pigment epithelial cells. Method ARPE-19 cell line was maintained in vitro and treated with multi-module stressful conditions, including hydrogen peroxide (H2O2) tert-butylhydroperoxide (t-BuOOH) and ultraviolet B (UVB). Multi-module-stressor-induced cell death was monitored by a viability assay, and PWRN2 expression by qRT-PCR. PWRN2 was either downregulated or upregulated in ARPE-19 cells. The effects of PWRN2 downregulation or upregulation on t-BuOOH-induced cell death, cellular apoptosis and mitochondrial injuries were then quantitatively evaluated. Results Multi-module stressful conditions induced cell death and PWRN2 upregulation in ARPE-19 cells in vitro. We created ARPE-19 subpopulations with either downregulated or upregulated PWRN2 expressions. Quantitative assays demonstrated that, PWRN2 downregulation effectively alleviated t-BuOOH-induced cell death, apoptosis and various-type of mitochondrial injuries. On the other hand, PWRN2 upregulation worsened t-BuOOH-induced cellular damages in ARPE-19 cells. Conclusion We demonstrated that downregulating PWRN2 protected multi-module-stressor-induced cell death, apoptosis and mitochondrial injuries in human retinal pigment epithelial cells, suggesting PWRN2 may be an active factor in human AMD.

The effects of Si content on the microstructure and yield strength of Al−(1.44−12.40)Si−0.7Mg (wt.%) alloy sheets under the T4 condition were systematically studied via laser scanning confocal microscopy (LSCM), DSC, TEM and tensile tests. The results show that the recrystallization grain of the alloy sheets becomes more refined with an increase in Si content. When the Si content increases from 1.44 to 12.4 wt.%, the grain size of the alloy sheets decreases from approximately 47 to 10 μm. Further, with an increase in Si content, the volume fraction of the GP zones in the matrix increases slightly. Based on the existing model, a yield strength model for alloy sheets was proposed. The predicted results are in good agreement with the actual experimental results and reveal the strengthening mechanisms of the Al−(1.44−12.40)Si−0.7Mg alloy sheets under the T4 condition and how they are influenced by the Si content.

Background The tumorigenesis of infused umbilical cord mesenchymal stem cells (UC-MSCs) is being preclinically evaluated. Methods We observed tumor formation in NOD SCID mice after a single subcutaneous injection of hUC-MSCs and the effect of these cells on tumor growth in tumor-bearing mice. Three generations (P5, P7, and P10) of hUC-MSCs (1 × 107) from two donors (hUC-MSC1 and hUC-MSC2) were inoculated subcutaneously into NOD SCID mice. Subcutaneous transplantation models were established in NOD SCID mice with human cervical cancer HeLa cells (solid tumor) and human B cell lymphoma Raji cells (hematological tumor). Then, the animals were euthanized, gross dissection was performed, and tissues were collected. Various organs were observed microscopically to identify pathological changes and tumor metastasis. Results In the tumorigenesis experiment, no general anatomical abnormalities were observed. In the tumor promotion experiment, some animals in the HeLa groups experienced tumor rupture, and one animal died in each of the low- and medium-dose hUC-MSC groups. The results may have occurred due to the longer feeding time, and the tumor may have caused spontaneous infection and death. Pathological examination revealed no metastasis to distant organs in any group. In the Raji tumor model, some animals in each group experienced tumor rupture, and one animal in the medium-dose hUC-MSC group died, perhaps due to increased tumor malignancy. Thus, hUC-MSCs neither promoted nor inhibited tumor growth. No cancer cell metastasis was observed in the heart, liver, spleen, lungs, kidneys or other important organs, except that pulmonary venule metastasis was observed in 1 animal in the model group. Conclusions Injected hUC-MSCs were not tumorigenic and did not significantly promote or inhibit solid or hematological tumor growth or metastasis in NOD SCID mice.

Friction stir additive manufacturing (FSAM) can be potentially used for fabricating high-performance components owing to its advantages of solid-state processing. However, the inhomogeneous microstructures and mechanical properties of the build attributed to the complex process involving restirring and reheating deserve attention. This study is based on the previous research of the underwater FSAMed 7A04 aluminum alloy and adopts a quasi in situ experimental method, i.e., after each pass of the underwater FSAM, samples were taken from the build for microstructural observation to investigate the restirring and reheating effects on microstructural evolution during the underwater FSAM. Fine-grain microstructures were formed in the stir zone during the single-pass underwater FSAM. After restirring, the grain size at the bottom of the overlapping region decreased from 1.97 to 0.87 μm, the recrystallization degree reduced from 74.0% to 29.8%, and the initial random texture transformed into a strong shear texture composed of the C {110}. After reheating, static recrystallization occurred in the regions close to the new additive zones, increasing the grain size and recrystallization degree. This study not only revealed the microstructural evolution during the underwater FSAM but also provided a guideline for further optimization of the mechanical properties of the Al–Zn–Mg–Cu alloy build.

Objective: To investigate the therapeutic effect of human umbilical cord mesenchymal stem cells (hUCMSCs) on diabetic retinopathy (DR) in diabetic rats, and to study the mechanism of hUCMSCs in treating diabetic retinopathy by tert-butylhydroquinone (tBHQ) regulation of the Nrf2/HO-1 pathway.Methods: The diabetic rat model was induced by intraperitoneal injection of streptozotocin (STZ). The experimental animals were divided into six groups: Normal, diabetes mellitus (DM), hUCMSCs, tBHQ, combined tBHQ-hUCMSCs, and all-trans-retinoid acid (ATRA)-hUCMSCs combined group. Visual function experiments and histological analyses were performed eight weeks post intravitreal injection. Biochemical and molecular analyses were used to assess the hUCMSCs composition and its biological effects.Results: Improvements in systemic oxidative stress and inflammation were found in the tBHQ group. Although hUCMSCs had no significant effect on oxidative stress, retinal structure was improved, visual defects reduced and expression of local retinal inflammatory factors were inhibited following its application. The effect of combined therapy was better than that of single therapy. Inhibition of the Nrf2/HO-1 pathway can promote the expression of systemic inflammatory factors and inhibit the therapeutic effect of hUCMSCs in the retina.Conclusions: Intravitreal administration of hUCMSCs triggers an effective cytoprotective microenvironment in the retina of diabetic mice. Alone, however, it may not significantly improve the systemic inflammatory response of diabetes. In combination with tBHQ it may promote Nrf2expression, systemic antioxidant stress and therapeutic effects of hUCMSCs.

Diabetic retinopathy (DR) is a major cause of visual deficits and blindness in the working-age population and inflammatory response is a key event during DR. In this study, we investigated the anti-inflammatory properties of small extracellular vesicles (sEVs) derived from human umbilical cord mesenchymal stem cells (hUCMSCs) in a diabetic rat model and human retinal microvascular endothelial cells. After development of DR in rats subjected to diabetes induction with streptozotocin (STZ), the DR rats were treated with different concentrations of hUCMSC-sEVs. Our results showed that the treatment of the retinas of DR rats with hUCMSC-sEVs not only reduced the level of vascular leakage in the retinas of rats but also decreased the retinal thickness as well as the associated inflammation. Further, our in vitro evidences suggest that hUCMSC-sEVs repress high glucose (HG)-induced cell inflammation and apoptosis. Subsequently, we analyzed the differentially expressed microRNAs (miRNAs) in the hUCMSC-sEVs by microarray and performed in silico studies to predict the target mRNA of miR-18b. Our findings also revealed that the expression of miR-18b was significantly elevated in the retina of diabetic rats after sEV treatment. In addition, miR-18b was found to target mitogen-activated protein kinase kinase kinase 1 (MAP3K1), thereby inhibiting NF-κB p65 phosphorylation to alleviate DR. Overall, this study highlights the potential of hUCMSCs-sEVs as biomaterials for anti-inflammatory and anti-apoptotic effects in DR by transferring miR-18b.

7475 aluminium alloy is widely used in aerospace industry and military field. There are many dispersoid former elements in 7475 aluminium alloy, such as Mn, Cr, Ti, Zr and Sc. And the dispersoid configuration has important effect on the performance of alloy wrought. The characteristic of dispersoids in the semi-continuous casting ingot of 7475 aluminum alloy and the evolution of their distribution during rolling have been investigated. The size, shape and distribution of dispersoids are controlled by pre-treatment before homogenization. The results show that there are many coarse triangular, irregular block and spindly rod-like dispersoids which contain some of Cr and Mg and a little of Cu and Zn in the 7475 aluminum alloy which subject to conventional one-step homogenization treatment. The size and the distribution of the Cr-containing dispersoids is not uniform. The width of the coarse dispersoids is close to 1 micron and the length of the spindly rod-like dispersoids is more than 4 microns. There is no dispersoids in the center of the dendritic grains, but the nonuniform distribution of dispersoids is eliminated when the hot rolling reduction exceed 80%. The dispersoids can be significantly refined and homogenously distributed by pre-treated before the conventional one-step homogenized. The pre-treatment can stimulate the nucleation of Cr-containing dispersoids, narrow down the dispersoids free zone. The size of the dispersoids is dramatically reduced by pre-treated before the conventional homogenization, and the width of the coarse dispersoids and length of the spindly rod-like ones are less than 300 nm and 1 micron.

The wrought Mg-containing high-silicon aluminum alloy has become more attractive as an ideal structural material, because it has moderate strength and the ductility, high wear and corrosion resistance, low thermal expansion coefficient and low cost. However, as structural material, the fatigue properties and the fatigue fracture behavior of it should be paid much more attention to, especially the effect of Si content on the fatigue properties of wrought Mg-containing Al-Si alloy. In this paper, the wrought Al-(1.44%, 4.92%, 6.61%, 8.81% and 12.4%)Si-0.7%Mg alloy were prepared through DCC and homogenization treatment, and then hot-rolled and cold-rolled into 1.3mm sheets. The microstructure and fatigue fracture morphology of Al-(1.44~12.4)Si-0.7Mg-T4 alloy sheet after fatigue test were investigated by LSCM and SEM. The results showed that the size of Si particles in Al-(1.44~12.4)Si-0.7Mg alloy sheets was approximately the same, but the number of Si particles increased as the Si content increased. The size of recrystallization grain in Al-(1.44~12.4)Si-0.7Mg alloy sheets decreased from 47μm to 10μm when Si content increased from 1.44% to 12.4%, which indicates that increasing of Si content can refine the grain of Al-(1.44~12.4)Si-0.7Mg alloy sheets. With the increasing of Si content the propagation area of fatigue fracture surface of Al-(1.44~12.4)Si-0.7Mg alloy sheets in T4 temper became rougher, and crack propagation became more difficult. Moreover, dimples in the fast fracture area became larger in amount, smaller in size and more uniform in distribution.

The microstructure of Al-1.01Mg-1.11Si-0.38Cu-0.69Mn aluminum alloy plate hot-rolled from homogenization and homogenization-free ingots were investigated by optical microscopy and scanning electron microscopy assisted with energy dispersive spectroscopy (SEM/EDS). The results showed that there are 3 main kinds of constituents such as Mg2Si, AlCuMgSi and AlFeMnSi in the as-cast Al-1.01Mg-1.11Si-0.38Cu-0.69Mn aluminum alloy ingot. After homogenization treated at 545°C for 24h, the black Mg2Si and the white bright AlCuMgSi particles in the ingot dissolved into matrix, but the grey AlFeMnSi phase partly dissolved, contracted into sphere and become coarse, many ultrafine dispersoids appear in the dendritic arms. The constituents in the plates hot-rolled from the homogenization and homogenization-free ingots are both distributed as broken chains along the rolling direction. However, compared with the particles configuration in the plate that hot-rolled from homogenization ingot, the particles in the plate that hot-rolled from the homogenization-free ingot are finer, more numerous and more homogenous, and with insufficient recrystallization when the plates are solution treated at 545°C for 2 h and then water quenched.

The effects of quenching in different ways following solid-solution treatment on properties and precipitation behaviors of 7050 alloy were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), hardness and electrical conductivity tests. Results show that after quenching in different ways, electrical conductivity of the alloy decreases rapidly in the first 48 h of natural aging. The electrical conductivity of 7050 alloy in natural aging state is determined by the size and density of GP zones, and the size of GP zones is the main factor. After natural aging for 70 d, the size of GP zones is 1.8–2.6 nm in matrix of the immersion quenched sample and it is 1.4–1.8 nm in matrix of both water mist and forced air quenched samples. After natural and artificial peak aging, the hardness of the water mist quenched sample is HV 193.6 and its electrical conductivity is 30.5% (IACS) which are both higher than those of the immersion quenched sample. Therefore, water mist quenching is an ideal quenching method for 7050 alloy sheets after solid-solution treatment.

The hepatitis C virus (HCV) subgenomic replicon is a valuable tool for studying virus replication and HCV drug development. Despite the fact that HCV genotype 1a (HCV1a) is the most prevalent genotype in the United States, few HCV1a reporter replicon constructs have been reported, and their replication capacities are not as efficient as those of HCV1b or 2a, especially in transient expression. In this study, we selected efficient HCV1a replicons and characterized the novel adaptive mutations derived from stable HCV1a (strain H77) replicon cells after G418 selection. These novel adaptive mutations were scored in NS3 (A1065V, C1073S, N1227D, D1431Y, and E1556G), NS4A (I1694T and E1709V), and NS4B (G1871C). The D1431Y mutation alone or combinations of other adaptive mutations introduced into the parental HCV1a replicon construct was observed to differentially enhance either transient or stable expression of replicon. In particular, two replicon mutants VDYG (A1065V, N1227D, D1431Y, and E1556G within NS3) and VDYGRG, VDYG with two additional adaptive mutations (NS4A-K1691R and NS4B-E1726G), displayed robust replication and exhibited no impairment in the susceptibility of replicon activity to various known HCV inhibitors.

In the present work, continuous cooling curves were accurately measured by the modified Jominy specimen of 7B50 alloy during water-spray quenching tests. Besides, the time–temperature–properties (TTP) curves of this alloy were obtained during isothermal treatments. Based on the accurate cooling curves and TTP curves, the hardness distribution along the thickness direction of 7B50 alloy thick plates was predicted by quench factor analysis method. It is found that the quench sensitive temperature range of 7B50 alloy is 240–410 °C, the nose temperature is 335 °C, and the incubation period at the nose temperature is about 0.87 s. When 7B50 alloy was isothermal treated at 180–400 °C after solid solution treatment (470 °C for 1 h followed by 483 °C for 2 h), the exponent (n) in the Johnson–Mehl–Avrami equation is close to 1 until transformed fraction of new precipitates is up to 60%, indicating that new precipitates first grow into rodlike shape and then coarsen or thicken. When the distance is less than 65 mm from the spray quenching surface of the modified Jominy specimen, the deviation between the predicted and measured hardness is less than 2.7%, confirming the quench factor analysis method as the feasible way to predict the hardness distribution along the thickness direction of 7B50 alloy thick plates. When the distance from the spray quenching surface is 25 mm, the average cooling rate in quench sensitive temperature range is 9.93 °C·s−1, while the quench factor (τ) is 9.89 and the corresponding predicted hardness is HV 185.1 equivalent to 97.3% of the maximum measured hardness of 7B50 alloy in T6 temper.

According to inverse heat transfer theory, the evolutions of synthetic surface heat transfer coefficient (SSHTC) of the quenching surface of 7B50 alloy during water-spray quenching were simulated by the ProCAST software based on accurate cooling curves measured by the modified Jominy specimen and temperature-dependent thermo-physical properties of 7B50 alloy calculated using the JMatPro software. Results show that the average cooling rate at 6 mm from the quenching surface and 420–230 °C (quench sensitive temperature range) is 45.78 °C/s. The peak-value of the SSHTC is 69 kW/(m2·K) obtained at spray quenching for 0.4 s and the corresponding temperature of the quenching surface is 160 °C. In the initial stage of spray quenching, the phenomenon called “temperature plateau” appears on the cooling curve of the quenching surface. The temperature range of this plateau is 160–170 °C with the duration about 3 s. During the temperature plateau, heat transfer mechanism of the quenching surface transforms from nucleate boiling regime to single-phase convective regime.

This paper investigates how anticorruption measures affect corporate governance, especially the executive incentive mechanism. The results of empirical tests show that in the short term, alleviating corruption does not enhance executives incentive, however, it significantly escalates pay-performance sensitivity. It is also found reductions in executive incentive in state-owned companies are more salient than in non-state-owned companies. The suggestion is that anticorruption measures at firm level should be a long-term strategy and focus on state-owned companies. It provides a new perspective for understanding how anticorruption affects firm behavior and performance and for the literature on executive incentives with political intervention.

Unavoidably, Fe impurities are mixed into Al alloys during recycling of aluminum automotive parts. High Fe content recycle-friendly aluminum alloy sheets (RASs) are discussed in terms of their applications to car body parts and closures. RASs have advantages, such as they are low cost and light weight, they require less energy to process, and they reduce emissions when used in vehicles. The hemming ability of RASs was investigated through various quenching rates and hot-rolling reduction rates. The hemming factor (HF) values of low Fe content samples (0.1 and 0.3 wt% Fe content) were 2 and 3. The hemming ability of samples with an Fe content of 0.5 wt% was unacceptable for applications to automotive outer closures (i.e., HF values of 4 and 5). The HF values changed from 3 to 5 for even higher Fe content samples (0.8 wt% Fe), depending on the quenching and hot-rolling reduction rates. Lower quenching (air quenching) and lower hot-rolling reduction rates (6-pass hot rolling) both improved the hemming ability of the high Fe content samples. A low-cost and recycle-friendly aluminum alloy automotive sheet from end-of-life vehicles is presented, and its hemming properties are characterized.

Based on the TTP curves of 7050 alloy, and the continuous cooling curves of 7B50 alloy at different positions of Φ70 mm improved Jominy specimen, the hardness distribution along the thickness direction of 7B50 alloy thick plates was analyzed and predicted by means of the isothermal precipitation kinetics and the quench factor analysis method. The results show that when 7050 alloy is isothermal treated at 200°C~400°C, the exponent n in its Johnson-Mehl-Avrami equation is close to 1, which indicates that the nucleation process of new precipitates is stable. In this equation the coefficient k is 7.420E-03 at 350°C, which indicates that the nucleation and growth rates of new precipitates are very fast. The hardness distribution along the axial direction of the improved Jominy specimen of 7B50 alloy is predicted by the quench factor analysis method. When the distance is no more than 65 mm from the spraying surface of the improved Jominy specimen, the deviation between the predicted and measured hardness of 7B50 alloy in T6 temper is less than 5%. The quench factor analysis method is feasible to predict the hardness distribution along the thickness direction of 7B50 alloy thick plates after quenching and aging. When the quench factor analysis method is extended to predict the actual water spray quenching process of 7B50 alloy thick plates, the average cooling rate is 21.6°C/s in the quench sensitive temperature range of this alloy, at 15 mm from the spraying surface of the plate. At the same position, the corresponding quench factor is equal to 6 and the predicted hardness is 187.4 HV which is equivalent 98.5% of the Hmax (the maximum hardness) of 7B50 alloy in T6 temper.

Purpose: To investigate whether there has been a changing trend of strabismus surgery in a provincial eye hospital in the central part of China over the past decade. Methods: This was a retrospective analysis of data on all strabismus surgery performed in Shanxi Province Eye Hospital in China during the past 10 years. Recorded characteristics included patient demographics, type of strabismus, age, and gender. Results: A total of 12,327 patients received strabismus surgery in the eye hospital from 2005 to 2014. The number of surgeries increased steadily from 800 in 2005 to 1,723 in 2014 ( P < .01). Constant exotropia was the most common type among all types of strabismus. Superior oblique muscle palsy was the most common type of paralytic strabismus. Exotropia oblique A- and V-pattern type was the most common type of special strabismus. Conclusions: The amount of strabismus surgery increased during the past decade. The proportion of patients with intermittent exotropia increased over time compared to those with other types of strabismus. [ J Pediatr Ophthalmol Strabismus. 2017;54(2):112–116.]

High-glucose-induced retinal tissue impairment is the major pathological phenotype of diabetic retinopathy. In an in vitro diabetic apoptosis cell model, we evaluated the function of long noncoding RNA, insulin growth factor 2 antisense (IGF2-AS) in high-glucose-injured human retinal pigment epithelial cells. A human retinal pigment epithelial cell line, ARPE-19 was incubated with high-glucose in vitro to induce apoptosis. SiRNA-mediated IGF2-AS downregulation was conducted in ARPE-19 cells to evaluate its effect on high-glucose induced apoptosis, assessed by a TUNEL assay. qRT-PCR and western blot assays were applied to examine the functional effect of IGF2-AS on IGF2/AKT/Casp-9 expressions in glucose-injured ARPE-19 cells. ART was further knocked down, specifically in IGF2-AS-downregualted ARPE-19 cells, to investigate its functional involvement in IGF2-AS-inhibition-mediated apoptotic protection in glucose-injured ARPE-19 cells. High-glucose induced apoptosis in ARPE-19 cells, and upregulated IGF-2AS in a dose-dependent manner. SiRNA-mediated IGF2-AS downregulation ameliorated apoptosis, upregulated IGF2/AKT and decreased Casp-9, in high-glucose-treated ARPE-19 cells. AKT knockdown was shown to dramatically reverse the preventive effect of IGF2-AS-downregulation on high-glucose-induced apoptosis in ARPE-19 cells. Moreover, it was demonstrated that AKT knockdown directly upregulated Casp-9 in IGF2-AS-downregulated and high-glucose-treated ARPE-19 cells. We demonstrated that inhibiting IGF2-AS, possibly also through activation of AKT signaling pathway, has a protective function in high-glucose-induced apoptosis in human retinal pigment epithelial cells in diabetic retinopathy.

Mg-containing high-Si aluminum alloys are heat-treatable alloys that are widely used in industry. Substantial attention has been paid to increasing the performance of such alloys by adding a small amount of Mn, which is an effective and common alloying element in aluminum alloys. In the present work, the solidification process of Mn-free Al-5Si-0.8Mg alloy and Al-5Si-0.8Mg-(0.45–1.97)Mn alloys are analyzed by the experimental results combined with thermodynamic calculation. The results showed that α-Al, Si, Mg2Si and π (Al8Mg3FeSi6) are predominant phases in the Mn-free Al-5Si-0.8Mg alloy while the π (Al8Mg3FeSi6) phase are transformed to α-Al(FeMn)Si phase with the addition of 0.45% Mn. With increasing Mn addition to 0.72%, the L→α-Al was replaced by L→α-Al(FeMn)Si and a primary α-Al(FeMn)Si phase appeared. Further increasing the Mn to 1.97%, the solidification reactions remained unchanged. However, the size and number of the primary α-Al(FeMn)Si phase gradually increased, while the divorced eutectic phenomenon of quaternary eutectic structure gradually weakened. Meanwhile, the Mg2Si phase in the quaternary eutectic structure gradually transformed from blocky to fine eutectic lamellar, and the quaternary eutectic structure was significantly refined. Primary blocky α-Al(FeMn)Si began to form when the Mn content was higher than 0.75%.

Mg-containing high-silicon aluminum alloy is a heat-treatable aluminum alloy that is now widely used in the aerospace and automotive industries because of its high specific strength, high wear resistance and corrosion resistance, low thermal expansion coefficient, and low cost. More attention has been paid to optimizing the microstructure to increase the performance of this type of aluminum alloy. In the present work, the solidification processes of Mg-free and Mg-containing (0.33–1.32%) Al-8Si alloys were analyzed by the experimental results combined with the thermodynamic calculation. The results showed that α-Al, Si, and Al5FeSi were in the Mg-free Al-8Si alloy ingots, while the Al5FeSi phases in alloys with Mg additions were transformed into π phases (Al8Mg3FeSi6) by the reaction L+Al5FeSi→α-Al+Si+Al8Mg3FeSi6. There was a binary eutectic reaction of L→α-Al+Al5FeSi when the Mg content exceeded 0.51% and the Fe content was higher than 0.17%. With the increase of Mg content, the volume of Mg2Si was gradually increased while the divorced eutectic phenomenon of the quaternary eutectic structure (α-Al+Si+Mg2Si+Al8Mg3FeSi6) was weakened and the eutectic structure was significantly refined.

Principal agent theory is widely used to model supply chain relationship, in which a supplier is the agent and a manufacturer is the principal. Both the manufacturer and supplier can influence product quality and consequentially share costs of product failures. Rich theoretical results under the principal agent model framework have been accumulated in the last two decades, but empirical evidence on whether the Stackelberg’s leadership game truly imitates practical supply chain relationship remains unfound. We study the domestic automobile industry in the last decade and provides to our best knowledge the first empirical evidence to assess the validity and practicality of principal agent theory and draw the implications of principal agent theory on supply chain relationship costs. Our empirical results suggest that Japanese OEMs behave more like principal agent theory suggests than the US OEMs in general and thus gain significant benefits in terms of marginal effort costs in motivating suppliers’ quality improvement behaviors and reducing overall manufacturer’s quality costs. Specifically, Toyota behaves closest to the optimal solution in the principal agent theory and therefore has the lowest manufacturer effort costs in improving product quality and achieves the overall lowest manufacturer’s quality costs in supply chain. Honda and Nissan are ranked 2nd and 3rd in terms of principal agent behaviors, but their marginal quality improvement effort costs are 33% and 61% higher than Toyota, and their total manufacturer’s quality costs are both around 17% higher compared to industrial leader Toyota by our estimate. US OEMs GM, Ford and Chrysler are believed to behave inconsistent to principal agent theory suggest, and consequently suffer a much higher marginal effort cost in motivating supplier’s quality improvement than Toyota as well as the overall manufacturer’s quality costs. GM and Ford are estimated doubled marginal effort costs than Toyota, and Chrysler is even higher at 1.6 times. GM’s overall manufacturer’s quality cost is 24% higher than Toyota, Ford is around 31% higher and Chrysler is around 48% higher. Our analysis gives a new perspective from principal agent theory to explain why Japanese OEMs especially Toyota has a better supply chain quality costs than US OEMs as literature and consensus suggested. In addition, we contribute in literature by linking the principal agent theory with automotive industrial data and first ever empirically validate the legitimacy of principal agent theory in modeling manufacturer-supplier relationship and quantitatively derive practical conclusions on marginal effort costs and manufacturer’s total supply chain quality cost implications. To guarantee the robustness of the empirical results, various sensitivity analyses are conducted and our main conclusions remain unchanged.

As successive interference cancellation (SIC) technology has become a research hotspot recently, random multiple access protocols based on SIC such as contention resolution diversity slotted ALOHA (CRDSA) and irregular repetition slotted ALOHA (IRSA) are put forward one after the other. Although throughput performance for these protocols has been improved significantly. Yet the throughput will drop dramatically when the load increases gradually. In this paper, in order to get a higher throughput in the case of high load, we propose a slot assign algorithm with threshold based on IRSA to obtain a throughput T which is more than 1.

The conductivity of 7050 alloy after isothermal quenched and isothermal quenched then T6 aged was measured by a simple and efficient method of measuring conductivity, its TTP curves fitted by conductivity data and also the isothermal treated microstructure of this alloy studied by the transmission electron microscopy (TEM). At the same time, the TTP curves fitted respectively by hardness and conductivity data of isothermal quenched then T6 aged samples were compared. The results show that it is feasible to fit TTP curves of 7xxx series high strength aluminum alloy by the method of conductivity measurement which can obtain its TTP curves by measuring transient properties of alloy. The nose temperature of the TTP curves of 7050 alloy fitted by conductivity method is about 330°C and at this temperature the incubation period for decomposition and precipitation of supersaturated solid solution is 1.25 s. By isothermal treating at 330°C for 2 s the precipitates in 7050 alloy form mainly by heterogeneous nucleation. It is indicated that for current TTP curves of aluminum alloy fitted by the method of measuring properties, the precipitates corresponding with the TTP curve which represents properties of alloy variations about 0.5% of the target properties are heterogeneous nucleation precipitation.

The NS2A protein of dengue virus (DENV) has eight predicted transmembrane segments (pTMS1 to -8) and participates in RNA replication, virion assembly, and host antiviral response. However, the roles of specific amino acid residues within the pTMS regions of NS2A during the viral life cycle are not clear. Here, we explore the function of DENV NS2A by introducing a series of alanine substitutions into the N-terminal half (pTMS1 to -4) of the protein in the context of a DENV infectious clone or subgenomic replicon. Six NS2A mutants (NM5, -7, -9, and -17 to -19) around pTMS1 and -2 displayed a novel phenotype showing a >1,000-fold reduction in virus yield, an absence of plaque formation despite wild-type-like replicon activity, and infectious-virus-like particle yields. HEK-293 cells infected with the six NS2A mutant viruses failed to cause a virus-induced cytopathic effect (CPE) by MitoCapture staining, cell proliferation, and lactate dehydrogenase release assays. Sequencing analyses of pseudorevertant viruses derived from lethal-mutant viruses revealed two consensus reversion mutations, leucine to phenylalanine at codon 181 (L181F) within pTMS7 of NS2A and isoleucine to threonine at codon 114 (I114T) within NS2B. The introduction of an NS2A-L181F mutation into the lethal (NM15, -16, -25, and -33) and CPE-defective (NM7, -9, and -19) mutants substantially rescued virus infectivity and virus-induced CPE, respectively, whereas the NS2B-L114T mutation rescued the NM16, -25, and -33 mutants. In conclusion, the results revealed the essential roles of the N-terminal half of NS2A in RNA replication and virus-induced CPE. Intramolecular interactions between pTMSs of NS2A and intermolecular interactions between the NS2A and NS2B proteins were also implicated. IMPORTANCE The characterization of the N-terminal (current study) and C-terminal halves of DENV NS2A is the most comprehensive mutagenesis study to date to investigate the function of NS2A during the flaviviral life cycle. A novel region responsible for virus-induced cytopathic effect (CPE) within pTMS1 and -2 of DENV NS2A was identified. Revertant genetics studies implied unexpected relationships between various pTMSs of DENV NS2A and NS2B. These results provide comprehensive information regarding the functions of DENV NS2A and the specific amino acids and transmembrane segments responsible for these functions. The positions and properties of the rescuing mutations were also revealed, providing important clues regarding the manner in which intramolecular or intermolecular interactions between the pTMSs of NS2A and NS2B regulate virus replication, assembly/secretion, and virus-induced CPE. These results expand the understanding of flavivirus replication. The knowledge may also facilitate studies of pathogenesis and novel vaccine and antiflaviviral drug development.

Mutual enhancement of dermal absorption of N,N-diethyl-m-toluamide (DEET) and oxybenzone (OBZ) has been reported recently with DEET and OBZ being active ingredients of insect repellent and sunscreen, respectively. To assess the reported enhancing effect directly, we used human urinary metabolites as biomarkers; besides, we also sought to determine the best way for concurrent use of these two products without extra absorption of either. Four dermal application methods were used: DEET only (S1), OBZ only (S2), DEET on top of OBZ (S3), and OBZ on top of DEET (S4). Among the study methods, there was a significant difference (p = 0.013), which was attributed to the difference between S1 and S4, suggesting that applying OBZ over DEET on the skin lead to significantly higher absorption of DEET. Using both products in reverse order, (S3) did not result in extra DEET absorption significantly. As for OBZ permeation, no significant difference was observed among the methods. In summary, the enhancement of DEET absorption is confirmed for OBZ being applied over DEET on the skin; should concurrent use of both be necessary, applying sunscreen (OBZ) first and then insect repellent (DEET) with a 15-min interval is recommended.

Dengue virus (DENV) is a global health problem that affects approximately 3.9 billion people worldwide. Since safety concerns were raised for the only licensed vaccine, Dengvaxia, and since the present treatment is only supportive care, the development of more effective therapeutic anti-DENV agents is urgently needed. In this report, we identified a potential small-molecule inhibitor, BP34610, via cell-based high-throughput screening (HTS) of 12,000 compounds using DENV-2 reporter viruses. BP34610 reduced the virus yields of type 2 DENV-infected cells with a 50% effective concentration (EC50) and selectivity index value of 0.48 ± 0.06 μM and 197, respectively. Without detectable cytotoxicity, the compound inhibited not only all four serotypes of DENV but also Japanese encephalitis virus (JEV). Time-of-addition experiments suggested that BP34610 may act at an early stage of DENV virus infection. Sequencing analyses of several individual clones derived from BP34610-resistant viruses revealed a consensus amino acid substitution (S397P) in the N-terminal stem region of the E protein. Introduction of S397P into the DENV reporter viruses conferred an over 14.8-fold EC90 shift for BP34610. Importantly, the combination of BP34610 with a viral replication inhibitor, ribavirin, displayed synergistic enhancement of anti-DENV-2 activity. Our results identify an effective small-molecule inhibitor, BP34610, which likely targets the DENV E protein. BP34610 could be developed as an anti-flavivirus agent in the future.

A practical approach to predict the yield strength and work-hardening exponent (n value) to evaluate the deep-drawing performance of annealed 3104 aluminum sheets is presented in the present work by only measuring and analyzing the grain size of the sheet. The various grain sizes were obtained through the different annealing treatment and then the evolution of the n value under different strains and the yield strength of annealed 3104 aluminum sheet were evaluated. Results showed that the n value and yield strength vary greatly with the grain size. A mathematical model relating grain size d, work-hardening exponent n, target strain ε, and yield strength Rp0.2 was developed in the present work. Within the studied grain size range d (12–29 μm), the n value generally increased with d in a strain-dependent manner, such that n = 0.1875 − 85.03 × exp [ − d / 1.94 ] when the ε was less than 0.5%, but n = 0.3 − 0.15 d − 1 / 2 when the ε was greater than 2%. On the other hand, the n value was found to depend on the target strain ε as n = 0.276 − A 1 × exp [ − e / 1.0435 ] , where A1 varies with d and its value is in the range of 0.132–0.364. In addition, the relationship between Rp0.2 and d followed the Hall-Petch equation ( R p 0.2 = 36.273 + 139.8 × d − 1 / 2 ).

To investigate the influence of ethanol catalyzed oxidation on activity of Pd/C with different ratio of Pd and C. Pd/C catalyst samples with Pd loads of 20, 30, 40 and 50 wt% were obtained by chemical reduction reaction of PdCl2 and NaBH4. The samples morphology and structure were characterized by XRD and SEM. The electrocatalytic oxidation activities of ethanol were examined by cyclic voltammetry in alkaline media. The results show that a face centered cubic (FCC) Pd phase can be identified in the sample powders. The average particle size of the Pd/C powder is about 10 nm. The performance of ethanol oxidation on 40 % Pd/C electro-catalyst is better than that of the other Pd/C samples.

Microstructures of creep-aged 2524 (Al–4.3Cu–1.5Mg) aged at 170 °C with various stresses (0, 173 and 250 MPa) were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy (TEM). The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S (Al 2 CuMg) phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.

The deformability and the microstructures of Al-12.2Si-0.6Mg alloy during hot-rolling were investigated by means of rolling the specimens of wedge bars with length of 180mm and width of 30mm, which had front thickness of 5mm and back thickness of 44mm.The wedge bars were cut from the ingots of the Al-12.2Si-0.6Mg alloy by the semi-continuously direct chill (DC in short) casting. The specimens of wedge bars were hot-rolled following holding between 410°Cand 480°C for different time. The results show that the size, morphology, distribution characters of eutectic Si particles in the Al-12.2Si-0.6Mg alloy can be remarkably modified by semi-continuously DC casting, which consists of coarse ribbon-like Si-particles with less than 5μm in length and 1μm in width and quite a lot eutectic phases of less than 0.4μm in size and space. The results also show that the ingots of the Al-12.2Si-0.6Mg alloy by the semi-continuously DC casting can possess excellent deformability during hot-rolling if the extent of heating is provided over 440°C for 60min and 410°C for 120min, and they cannot emerge cracked edges with the compression ratio of 85% by single-pass rolling. Their hot-plasticity depends on the size and space between eutectic phases in the ingots. Hot-rolling deformation makes ribbon-like Si phases in them crack and spheroidize, and then results in the sizes of coarse Si particles tending to be consistent.

The effect of cold deformation on the yield strength and precipitate behavior of Al-1.3Mg-1.2Si-0.5Cu-0.7Mn alloy sheet subjected to T4P temper for automotive body panels before and after paint-bake treatment were investigated by tensile test and differential scanning calorimetry (DSC) analysis. The results show that the T4P alloy sheet has significant work-hardening response (WHR), and the yield strength increment exceeds 190MPa as the tensile deformation strain approaches 15%. The unstrained T4P alloy sheet has obvious paint-baking response (PBR), and the yield strength increment is up to 80MPa, while the PBR of the cold stretched T4P alloy sheets decrease with increasing level of tensile deformation, and the minimal PBR is only 17.8MPa. The prior tensile deformation accelerates the precipitation of β″ and β′ phase from the T4P alloy matrix during paint-bake cycle but weakens the age-hardening response (AHR) and PBR of T4P alloy sheet. Moreover, it is evident that the T4P alloy sheet simulation paint-bake treated at 170°C for 30min can not fully exert the aging potential of the alloy sheet.

The texture, microstructure, plastic strain ratio r value, elongation, strain hardening index n, the value of cupping test IE, and the correlation between r value and the other formability indices of two automotive aluminum alloys sheet 6016 and 6181, and commercial pure aluminum sheet were investigated. The results showed that the recrystallization textures of three aluminum alloys sheet are similar to each other, which mainly contain cube component. However, the r and n value, elongation, and IE of three aluminum alloys sheet are different from each other evidently, and there is no correlation between texture and r value, and the other formability indices except the n value. The large quantity of second-phase particles in the aluminum alloy matrix has very important effect on both the r value and the formability of aluminum alloy sheet.

Methadone is a racemic compound composed of the R-form and S-form enantiomers. The drug is usually used in maintenance therapy for the heroin-addicted patients. In our previous study, we found that the cytochrome P-450 (CYP) isozyme 2B6 preferentially metabolizes the S-methadone enantiomer. We thus tested whether CYP2B6 gene polymorphisms had any influence on the concentration or clearance of methadone. Ten single nucleotide polymorphisms within this gene region were evaluated in 366 patients undergoing methadone maintenance for at least 3 months. The plasma steady-state levels of racemic methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine were then measured in these individuals. The rs10403955 (T allele in intron 1), rs3745274 (G allele in exon 4), rs2279345 (T allele in intron 5), and rs707265 (A allele in exon 9) CYP2B6 allele types were found to be significantly associated with a higher clearance, a lower plasma concentration, and a lower concentration-to-dosage (C/D) ratio of (S)-methadone (P < 0.0017). Two haplotype blocks of a trinucleotide haplotype (rs8100458-rs10500282-rs10403955 in intron 1) and a hexanucleotide haplotype (rs2279342-rs3745274-rs2279343-rs2279345-rs1038376-rs707265 from intron 2 to exon 9) were constructed within CYP2B6. The major combinations of T-T-T and A-G-A-T-A-A of these particular haplotypes showed significant associations with the plasma concentrations of S-methadone and its C/D ratio (P < 0.0001, respectively). We conclude that genetic polymorphisms in the CYP2B6 gene may therefore be indicators of the clearance, plasma concentration and C/D ratio of S-methadone.

The cold-rolled sheets of the Al-Mg-Si Alloy were annealed for recrystallization in the box furnace and the bath furnace respectively, then the microstructures were observed and the recrystallization textures were investigated with the orientation distribution functions (ODFs). The results show that after recrystallization annealing at slow heating rate the coarse a-Al grains and the strong recrystallization texture composed of Cube+nd25 components and the {011} components were formed in the sheets of the Al-Mg-Si alloy, and after recrystallization annealing at rapid heating rate the fine a-Al grains and the weak or almost random recrystallization textures were formed.

The rolling texture and its distribution along thickness direction in the Al alloy 6111 sheet cold rolled by synchronous Rolling and asynchronous rolling have been investigated with orientation distribution functions. The results show that the texture distribution is asymmetric on both sides of center layer of the sheet after cross shear rolling. The orientation densities of the main texture compounds on the slow roller side are higher, but are lower on the fast rolled side. The asymmetry of the texture distribution increases with improving the velocity ratio of asynchronous rolling.

The number and size of the precipitation of spherical Al3Zr particles, in aluminium alloy containing trace of Zr which subjected to different heat treatments, have been investigated by transmission electron microscopy. The results show that, the number of spherical Al3Zr particles is determined by the pretreatment, and that the size is determined by the homogenization. The number of spherical Al3Zr particles increases with prolonging the time of pretreatment between 0h to 48h and rising the temperature of pretreatment between 200°C to 400°C, and the size of spherical Al3Zr particles turn out to be the same. The size of spherical Al3Zr particles increases with prolonging the time of homogenization between 0h to 48h and rising the temperature of homogenization between 470°C to 500°C.

The precipitates of bending-age-formed ternary Al-4.31Cu-1.51Mg alloy were studied with load of 6.05 kg aged at 190°C. Transmission electron microscopy and electron diffraction has been used to observe the microstructures of the bend-age-formed alloy. The results show that there is no preferential alignment of S phase or GPB zones in the alloys with load compared with that without load. It is interesting to find that the length of S phase is shorter in age-formed sample than that without load. Dislocations generated after loaded can provide enough nucleation sites for the nucleation and growth of S phase.

In order to improve the resistance properties of HfO2 and increase the consistency and uniformity of conductive filaments formed by oxygen vacancies (VO), the first-principles calculation method based on density functional theory is used to study the micro-properties of Al-doped HfO2 resistive materials. The results show that the interval Al (Int-Al) is more suitable for being incorporated into HfO2, and the closer to the relative position of VO the Int-Al, the faster the convergence rate of the resistive material tends to be stable, and the smaller the formation energy. The effects of different Int-Al concentrations on the formation of HfO2 supercells with VO defects show that when the concentration of doped Int-Al is 4.04%, the fractional charge state density map can form relatively good charge channels. The maximum and critical equipotential surface values are highest, which is conducive to improving the consistency and uniformity of the formation of conductive filaments in HfO2 resistive materials. The calculation of energy formation shows that the change is slow when the concentration of Int-Al is lower than 4.04%. When the concentration of Int-Al is higher than 4.04%, the abnormal increase occurs, which indicates that the defect system becomes more and more difficult to form with the increase of the concentration of Int-Al. The introduction of the impurity and the VO defect destroy the original complete crystal structure, which causes the position of the atoms around the impurity to shift, and the valence electron orbit and the energy level of the crystal are changed, and the distribution of the internal charges of the HfO2 defect system is affected. In order to study the effect of the change of the lattice structure on the formation of the VO conductive filament, the VASP software package is used to calculate the relative ratio of the atoms in the lattice structure of the HfO2 defect system as the reference and the relative ratio of the HfO2 defect system after the optimizing the lattice structure. Further study of the change of lattice structure, when the concentration of doped Int-Al is 4.04%, shows that the defect formation energy decreases significantly, which is conducive to the formation of perfect conductive channel. The conductive channel has a certain reference significance for improving the performance of HfO2 based resistive variable memory materials.

Semi-continuously direct chill (DC in short) casting was carried out to modify the size and morphology of eutectic Si particles in eutectic Al-Si alloy. Successively, the size, morphology, distribution characters of eutectic Si particles and the hot plasticity ability of the alloy during heating and hot-rolling were investigated by the observation of optical microstructure characterization and the rolling of wedge bar. The results show that the eutectics in the eutectic Al-Si alloy can be remarkably fined by semi-continuously DC cast. The eutectic Si phase particles will coarsen and spheroidize after holding at 480°C for 2h, which enables eutectic Al-Si alloy to possess excellent hot plasticity free of cracked edge with compression ratio of rolling up to 85% by single pass. Though little difference on the size of spheroidized Si particles during hot rolling can be observed, uniform distribution of the Si particles can be obtained by hot rolling with compression ratio of 85%.