The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and...The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting process.Therefore,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is necessary.In the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild steel.Meanwhile,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and AZ91D.AlFe_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg matrix.It is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction process.By measuring the thickness of different layers,the growth constant was calculated.It increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.展开更多
AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all publ...AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.展开更多
AIM:To compare the clinical factors and tumor characteristics that predict survival in colorectal cancer(CRC)patients with different ethnicities in Xin Jiang area.METHODS:A total of 1421 histopathologically confirmed ...AIM:To compare the clinical factors and tumor characteristics that predict survival in colorectal cancer(CRC)patients with different ethnicities in Xin Jiang area.METHODS:A total of 1421 histopathologically confirmed sporadic CRC patients who were either Han/Chinese or Uyghur were identified and enrolled from a database of both diagnoses and operative procedures from Xin Jiang Tumor Hospital,which is affiliated to Xin Jiang Medical University between 2000 and 2007.Patients with family histories of CRC,hereditary nonpolyposis CRC,familial adenomatous polyposis,inflammatory bowel disease,carcinoid,squamous carcinoma or melanoma were excluded.The two ethnic groups were compared with regard to clinical features,tumor characteristics,disease stage,overall survival rate,diseasefree survival rate and cancer-specific survival rate.The factors predicting long-term survival were assessed via both univariate and multivariate analysis.RESULTS:Among the 1421 patients with CRC enrolled in this study,1210 patients were Han/Chinese(mean age,62.3±4.5 years;range,19-92 years),while 211patients were Uyghur(mean age,52.4±15.6 years;range,17-87 years).There were significant differences in proportions of gender,age,blood type,occupation and histopathological type between the Han/Chinese and Uyghur patients(P<0.05).The median overall,disease-free and cancer-specific survival time were 45,62and 65 mo for the Han/Chinese patients and 42,49 and61 mo for the Uyghur patients(P=0.000,P=0.005,P=0.007).The cumulative 5-year survival of the Uyghur patients was significantly worse than that of the Han patients(P=0.000).A multivariate analysis showed that age,ethnicity,histopathological type,differentiation,T(Infiltration depth),N(Lymph node metastasis),staging,postoperative metastasis and metastatic site(P<0.05)were found to be the prognostic factors.CONCLUSION:The Uyghur CRC patients are associated with significantly younger age,more aggressive histopathologic characteristics and have significantly worse prognosis than the Han/Chinese patients.展开更多
Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.Th...Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.展开更多
AIM:To assess the efficacy of immunotherapy with expanded activated autologous lymphocytes(EAALs) in gastric cancer.METHODS:An observational study was designed to retrospectively analyze the clinical data of 84 gastri...AIM:To assess the efficacy of immunotherapy with expanded activated autologous lymphocytes(EAALs) in gastric cancer.METHODS:An observational study was designed to retrospectively analyze the clinical data of 84 gastric cancer patients,of whom 42 were treated by EAAL immunotherapy plus conventional treatment and another 42 only received conventional treatment(control group).EAALs were obtained by proliferation of peripheral blood mononuclear cells from patients followed by phenotype determination.Clinical data including age,gender,clinical stage,chemotherapeutic regimens,hospitalization,surgical,radiotherapy,and survival data were collected along with EAAL therapy details and side effects.Patients were followed and the relationship between treatment and overall survival(OS) data obtained for the immunotherapy and control groups were compared retrospectively.The safety of EAAL immunotherapy was also evaluated.RESULTS:After in vitro culture and proliferation,the percentages of CD3+,CD3+CD8+,CD8+CD27+,CD8+CD28+,and CD3+CD16+/CD56+cells increased remarkably(P < 0.05),while the percentages of CD3+CD4+,CD4+CD25+,and CD3-CD16+/CD56+(natural killer cells) were overtly decreased(P < 0.05); no significant change was observed in CD4+CD25+CD127- cells(P =0.448).Interestingly,OS in the immunotherapy group was significantly higher than that in the control group,with 27.0 and 13.9 mo obtained for the two groups,respectively(P =0.028,HR =0.573,95%CI:0.347-0.945).These findings indicated a 42.7% decrease in the risk of death.In addition,we found that clinical stage and application of EAAL immunotherapy wereindependent prognostic factors for gastric cancer patients.Indeed,the OS in stage Ⅲc and Ⅳ patients that had received surgery was prolonged after EAAL immunotherapy(P < 0.05).Importantly,in vitro induction and proliferation of EAAL were easy and biologically safe.CONCLUSION:Overall,EAAL adoptive immunotherapy might prolong the OS in gastric cancer patients.展开更多
BACKGROUND: The benefits of the application of basiliximab induction therapy in liver transplantation are not clear. The present meta-analysis was to evaluate the pros and cons of basiliximab use in liver transplantat...BACKGROUND: The benefits of the application of basiliximab induction therapy in liver transplantation are not clear. The present meta-analysis was to evaluate the pros and cons of basiliximab use in liver transplantation. DATA SOURCES: We searched the associated publications in English from July 1998 to December 2015 in the following databases: MEDLINE, Pub Med, Ovid, EMBASE, Web of Science and Cochrane Library.RESULTS: Basiliximab significantly decreased the incidence of de novo diabetes mellitus after liver transplantation(RR=0.56; 95% CI: 0.34-0.91; P=0.02). Subgroup analysis showed that basiliximab in combination with steroids-free immunosuppressant significantly decreased the incidence of biopsy-proven acute rejection(RR=0.62; 95% CI: 0.39-0.97; P=0.04) and new-onset hypertension(RR=0.62; 95% CI: 0.42-0.93; P=0.02).CONCLUSIONS: Basiliximab may be effective in reducing de novo diabetes mellitus. What is more, basiliximab in combination with steroids-free immunosuppressant shows statistical benefit to reduce biopsy-proven acute rejection and de novo hypertension.展开更多
An offline two-dimensional system combining a rat cardiac muscle cell membrane chromatography time-of-flight mass spectrometry(CMC-TOF/MS)with a high performance liquid chromatography time-of-flight mass spectrometry(...An offline two-dimensional system combining a rat cardiac muscle cell membrane chromatography time-of-flight mass spectrometry(CMC-TOF/MS)with a high performance liquid chromatography time-of-flight mass spectrometry(HPLC-TOF/MS)was established for investigating the parent components and metabolites in rat urine samples after administration of the roots of Aconitum carmichaeli.On the basis of the analysis of the first dimension,retention components of the urine sample were collected into 30 fractions(one fraction per minute).Then offline analysis of the second dimension was carried out.34 compounds including 24 parent alkaloids and 10 potential metabolites were identified from the dosed rat urine,and then binding affinities of different compounds on cell membranes were compared and influences of some functional groups on activity were estimated with the semi-quantification and curve fitting method.As a result,binding affinities decreased along with the process of deacylation,debenzoylation and demethylation,which may be related to the alleviation of toxicity in the procedure of herb processing or metabolism.Moreover,some minor components in rat urine(Songorine,14-benzoylneoline,Deoxyaconitine,etc.)exerted relatively strong affinity on cell membranes are worth exploring.The results delivered by the system suggest that the CMC can be applied to in vivo study.展开更多
A liquid fueled thorium molten salt reactor(TMSR-LF),one of the Generation IV reactors,was designed by the Shanghai Institute of Applied Physics,Chinese Academy of Sciences.This study uses the‘rt code to calculate th...A liquid fueled thorium molten salt reactor(TMSR-LF),one of the Generation IV reactors,was designed by the Shanghai Institute of Applied Physics,Chinese Academy of Sciences.This study uses the‘rt code to calculate the neutron and gamma dose rate distributions around the reactor.Multiple types of tallies and variance reduction techniques were employed to reduce calculation time and obtain convergent calculation results.Based on the calculation and analysis results,the TMSR-LF1 radiation shield with a 60-cm serpentine concrete layer and a 120-cm ordinary concrete layer is able to meet radiation requirements.The gamma dose rate outside the reactor biological shield was 16.1 mSv h-1;this is higher than the neutron dose rate of 3.71×10^(–2)mSv h^(-1).The maximum thermal neutron flux density outside the reactor biological shield was 1.899103 cm^(-2)s^(-1),which was below the 19105 cm^(-2)s^(-1)limit.展开更多
Phosphorus adsorption tests were carried out using poly-aluminum chloride sludge(PACS),which was collected from a water treatment plant in Nanjing.The amount of phosphorus adsorbed by PACS increased quickly within the...Phosphorus adsorption tests were carried out using poly-aluminum chloride sludge(PACS),which was collected from a water treatment plant in Nanjing.The amount of phosphorus adsorbed by PACS increased quickly within the first hour and reached equilibrium after about 48 h.The adsorption behavior of PACS for phosphorus is consistent with the Langmuir adsorption isotherm equation(R2>0.99)and parallel first-order kinetic equation(R2>0.98).With the increase of the PACS concentration,the adsorption capacity of PACS for phosphorus decreased,and the removal rate increased.The results of batch tests showed that the adsorption capacities of PACS for phosphorus ranged from 1.64 to 1.13 mg/g when the pH value varied from 4 to 10.However,the adsorption capacity of PACS was not evidently influenced by temperature.In comparison with the ion exchange resin,the adsorption capacity of PACS was barely inhibited by competitive ions,such as SO24,NO3,and Cl.The PACS surface after adsorption became smooth,and the vibration peaks of AleO and AleOH shifted.Both HCl and NaOH have a strong desorption effect on PACS after adsorption saturation,and with higher concentrations of HCl and NaOH,the desorption effect was stronger.Results of column adsorption experiments showed that with lower phosphorus and hydraulic loads,the adsorption column took longer to reach saturation.This indicated that PACS could be used as an efficient material for removal of phosphorus from water.This study provides a new treatment method with PACS.展开更多
The precipitation behavior of γ′ phase,under various interrupt cooling tests after 1170℃,solution treatment was examined.The results indicate that the size of secondary γ′ precipitates increases with the decrease...The precipitation behavior of γ′ phase,under various interrupt cooling tests after 1170℃,solution treatment was examined.The results indicate that the size of secondary γ′ precipitates increases with the decrease of interrupt temperature,and the shape changes from spherical to butterfly like.The fine tertiary γ′ can form either during the post cool air quenching at high interrupt-temperatures,or during the specified 5℃ min-1cooling.Air quenching at high temperatures cannot suppress further nucleation of tertiary γ′ phase.展开更多
The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy (PM) Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the prec...The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy (PM) Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries (PPB). Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200°C, but this carbide network is hard to be eliminated completely. The combined MC-M 23 C 6 morphology approves the nucleation and growth mechanism of carbide evolution.展开更多
Cancer stem cells(CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability.They have been identified in a variety of tumors,including tumors of the digestive...Cancer stem cells(CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability.They have been identified in a variety of tumors,including tumors of the digestive system.CSCs exhibit some unique characteristics,which are responsible for cancer metastasis and recurrence.Consequently,the development of effective therapeutic strategies against CSCs plays a key role in increasing the efficacy of cancer therapy.Several potential approaches to target CSCs of the digestive system have been explored,including targeting CSC surface markers and signaling pathways,inducing the differentiation of CSCs,altering the tumor microenvironment or niche,and inhibiting ATP-driven efflux transporters.However,conventional therapies may not successfully eradicate CSCs owing to various problems,including poor solubility,stability,rapid clearance,poor cellular uptake,and unacceptable cytotoxicity.Nanomedicine strategies,which include drug,gene,targeted,and combinational delivery,could solve these problems and significantly improve the therapeutic index.This review briefly summarizes the ongoing development of strategies and nanomedicine-based therapies against CSCs of the digestive system.展开更多
The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor(FHR) system, and the ...The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor(FHR) system, and the activity of radionuclides accumulated in the coolant during normal operation was calculated. The release rate(release fraction per unit time) of fission products was calculated with STACY code, which is modelled mainly based on the Fick's law, while the activation of coolant and impurities was calculated with SCALE code. The accumulation of radionuclides in the coolant has been calculated with a simplified model, which is generally a time integration considering the generation and decay of radionuclides. The results show that activation products are the dominant gamma source in the primary coolant system during normal operation of the FHR while fission products become the dominant source after shutdown. In operation condition,health-impacts related nuclides such as ~3H, and ^(14)C originate from the activation of lithium and coolant impurities including carbon, nitrogen, and oxygen. According to the calculated effective cross sections of neutron activation,~6Li and ^(14)N are the dominant ~3H production source and ^(14)C production source, respectively. Considering the high production rate,~3H and ^(14)C should be treated before being released to the environment.展开更多
The fluoride salt-cooled high-temperature reactor(FHR) uses molten FLi Be salt as the coolant, which introduces a corrosive effect on the alloy-N structure material. Fission neutrons activate the corroded alloy-N,alon...The fluoride salt-cooled high-temperature reactor(FHR) uses molten FLi Be salt as the coolant, which introduces a corrosive effect on the alloy-N structure material. Fission neutrons activate the corroded alloy-N,along with alloy-N structures inside the reactor vessel. The activation products of the alloy-N have a big impact on radiation protection during operation, maintenance, and decommissioning of the reactor. We have constructed a SCALE 6.1 model for the core of a typical 10 MW th FHR and analyzed the activity of each constituent of the irradiated alloy-N. The results show that the activity is predominantly due to short-lived^(28) Al,^(60m) Co,^(56) Mn,^(51)Ti, and ^(52) V, as well as long-lived ^(60) Co,^(51)Cr,^(55)Fe,^(59)Fe, and ^(54) Mn.Furthermore, because of their relatively long half-life and high-energy c-rays emissions,^(60) Co and ^(54)Mn are the major contributors to the radiation source terms introduced by alloy-N activation. The yield of ^(60)Co and ^(54)Mn per unit mass of alloy-N under the current core design is 5.58*10~5 and 1.55 * 10~3 Bq MWd^(-1)g^(-1), respectively.The results of this paper, combined with future corrosion studies, may provide a basis for evaluating long-term radiation source terms of the primary loop salt and components.展开更多
Organic cathodes for alkali-metal-ion batteries attract great attentions in recent years,but the ion storage sites are limited to some finite functional groups.This is because an organic cathode must have proper lowes...Organic cathodes for alkali-metal-ion batteries attract great attentions in recent years,but the ion storage sites are limited to some finite functional groups.This is because an organic cathode must have proper lowest unoccupied molecular orbitals(LUMO) to accept electrons at high potential.Herein,a novel type of organophosphate-based cathode has successfully been explored by tuning the LUMO energy level of organophosphates through metal ions with an inert electron pair.For the first time,the P=O of phytate(PA),N,N,N’,N’-ethylenediaminetetrakis(methylene phytate)(EDTMP),and diethylenetriaminepentakis(methyl phytate)(DTPMP) is activated by lead/bismuth(with 6s2electron pair) to storage Li/Na/K ions reversibly.Typically,density functional theory calculations indicate that the LUMO energy of Bi-PA is greatly reduced from-0.99(PA) to-4.61 eV,which shows the first discharge capacity of 173,182 and 206mAh·g-1and the reversibly capacity of 102,102 and 101mAh·g-1with the discharge platform of 2.4,2.1 and 2.4 V for Li/Na/K-ion battery cathodes,respectively.Similarly,with proper LUMO energy level,Pb-PA(-4.63 eV),Pb-EDTMP(-3.71 eV),and Pb-DTPMP(-4.45 eV) all exhibit admirable performance.This unique strategy of organic materials to alkali-metal-ion battery cathodes offers a new avenue for future energy storage systems.展开更多
Based on the Thermo-Calc thermodynamic software,the type of equilibrium precipitated carbides and their contents in high Mo Nb-microalloyed H13steel(NMH13steel)were calculated.The composition,morphology,and distributi...Based on the Thermo-Calc thermodynamic software,the type of equilibrium precipitated carbides and their contents in high Mo Nb-microalloyed H13steel(NMH13steel)were calculated.The composition,morphology,and distribution of carbides after spheroidal annealing of two forged experimental steels were comparatively examined by means of optical microscopy(OM),scanning electron microscopy(SEM),electron dispersive spectroscopy(EDS)and transmission electron microscopy(TEM).VC,M23C6 and M6C are identified in H13 steel after spheroidizing annealing,while(V,Nb)C,M23C6,M2C and M6C are observed in NMH13 steel.Moreover,it is found that the addition of Nb significantly enhances the stability of MC phase and the high Mo content accelerates the precipitation of small rod-shape M2C phase in NMH13 steel.The amount of the fine carbides in NMH13 steel obviously increased with M2C and M6C precipitated from the ferrite phase,which is in accordance with the results of thermodynamic calculations.展开更多
The hot deformation behavior of powder metallurgical(PM) TiAl alloys was investigated on Gleeble-3500 thermomechanical simulator, at a temperature range of 1050–1200 °C with an interval of 50 °C and a strai...The hot deformation behavior of powder metallurgical(PM) TiAl alloys was investigated on Gleeble-3500 thermomechanical simulator, at a temperature range of 1050–1200 °C with an interval of 50 °C and a strain rate range of 0.001–1.000 s^(-1). The results show that the flow stress of PM TiAl alloy is sensitive to deformation temperature and strain rate, the peak stress decreases with the increase in deformation temperature and decrease in strain rate, and dynamic recrystallization occurs during the hot compression. The deformation active energy was calculated and the flow stress model during high-temperature deformation was established based on the Arrhenius equations and Zener–Hollomon parameter. The deformed microstructure consists of refined homogeneous γ and ɑ_2/γ grains.展开更多
The hot compressive deformation behavior of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders was systematically investigated and the processing map was obtained in the temperat...The hot compressive deformation behavior of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders was systematically investigated and the processing map was obtained in the temperature range of 1323-1473 Kand strain rate range of 0.001-0.5s^(-1).The calculated activation energy in the above variational ranges of temperature and strain rate possesses a low activation energy value of approximately 365.6kJ/mol based on the constitutive relationship models developed with the Arrhenius-type constitutive model respectively considering the strain rate and deformation temperature.The hot working flow behavior during the deformation process was analyzed combined with the microstructural evolution.Meanwhile,the processing maps during the deformation process were established based on the dynamic material model and Prasad instability criterion under different deformation conditions.Finally,the optimal hot processing window of this alloy corresponding to the wide temperature range of 1353-1453 Kand the low strain rate of 0.001-0.1s^(-1) was obtained.展开更多
We propose a built-in fault-tolerant geometric operation to realize fast remote entanglement between superconducting qubits anchored to a 15 m K plate and Rydberg-atom qubits trapped near a 1 K plate via thermal coupl...We propose a built-in fault-tolerant geometric operation to realize fast remote entanglement between superconducting qubits anchored to a 15 m K plate and Rydberg-atom qubits trapped near a 1 K plate via thermal coupled cavities. We show that this operation is robust against the detrimental effects of the thermal mode states and fluctuations in the control parameters. The operation can generate a high-fidelity entanglement between superconducting and atomic qubits under realistic experimental parameters, comparable to the results of the existing methods using auxiliary cooling systems. The scheme proposed here will promote the development of quantum network and distributed superconducting quantum computation.展开更多
We investigate the mean-field energy spectrum and dynamics in a Bose–Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping,and show that the interplay of nonreciprocity an...We investigate the mean-field energy spectrum and dynamics in a Bose–Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping,and show that the interplay of nonreciprocity and nonlinearity leads to exotic properties.Under the two-mode and mean-field approximations,the nonreciprocal generalization of the nonlinear Schrödinger equation and Bloch equations of motion for this system are obtained.We analyze the PT phase diagram and the dynamical stability of fixed points.The reentrance of PT-symmetric phase and the reformation of stable fixed points with increasing the nonreciprocity parameter are found.Besides,we uncover a linear selftrapping effect induced by the nonreciprocity.In the nonlinear case,the self-trapping oscillation is enhanced by the nonreciprocity and then collapses in the PT-broken phase,and can finally be recovered in the reentrant PT-symmetric phase.展开更多
基金supported by the Natural Science Foundation of Chongqing,China(Grant Nos.cstc2020jcyj-msxm X0544,CSTB2022NSCQ-MSX0352,CSTB2022NSCQ-MSX0891,cstc2020jcyj-msxm X0184)Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202001416)National Natural Science Foundation of China(Grant Nos.11847077,52001028)。
文摘The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting process.Therefore,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is necessary.In the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild steel.Meanwhile,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and AZ91D.AlFe_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg matrix.It is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction process.By measuring the thickness of different layers,the growth constant was calculated.It increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.
文摘AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.
文摘AIM:To compare the clinical factors and tumor characteristics that predict survival in colorectal cancer(CRC)patients with different ethnicities in Xin Jiang area.METHODS:A total of 1421 histopathologically confirmed sporadic CRC patients who were either Han/Chinese or Uyghur were identified and enrolled from a database of both diagnoses and operative procedures from Xin Jiang Tumor Hospital,which is affiliated to Xin Jiang Medical University between 2000 and 2007.Patients with family histories of CRC,hereditary nonpolyposis CRC,familial adenomatous polyposis,inflammatory bowel disease,carcinoid,squamous carcinoma or melanoma were excluded.The two ethnic groups were compared with regard to clinical features,tumor characteristics,disease stage,overall survival rate,diseasefree survival rate and cancer-specific survival rate.The factors predicting long-term survival were assessed via both univariate and multivariate analysis.RESULTS:Among the 1421 patients with CRC enrolled in this study,1210 patients were Han/Chinese(mean age,62.3±4.5 years;range,19-92 years),while 211patients were Uyghur(mean age,52.4±15.6 years;range,17-87 years).There were significant differences in proportions of gender,age,blood type,occupation and histopathological type between the Han/Chinese and Uyghur patients(P<0.05).The median overall,disease-free and cancer-specific survival time were 45,62and 65 mo for the Han/Chinese patients and 42,49 and61 mo for the Uyghur patients(P=0.000,P=0.005,P=0.007).The cumulative 5-year survival of the Uyghur patients was significantly worse than that of the Han patients(P=0.000).A multivariate analysis showed that age,ethnicity,histopathological type,differentiation,T(Infiltration depth),N(Lymph node metastasis),staging,postoperative metastasis and metastatic site(P<0.05)were found to be the prognostic factors.CONCLUSION:The Uyghur CRC patients are associated with significantly younger age,more aggressive histopathologic characteristics and have significantly worse prognosis than the Han/Chinese patients.
文摘Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.
基金Supported by National Science and Technology Infrastructure Program of China,No.2009BAI86B05
文摘AIM:To assess the efficacy of immunotherapy with expanded activated autologous lymphocytes(EAALs) in gastric cancer.METHODS:An observational study was designed to retrospectively analyze the clinical data of 84 gastric cancer patients,of whom 42 were treated by EAAL immunotherapy plus conventional treatment and another 42 only received conventional treatment(control group).EAALs were obtained by proliferation of peripheral blood mononuclear cells from patients followed by phenotype determination.Clinical data including age,gender,clinical stage,chemotherapeutic regimens,hospitalization,surgical,radiotherapy,and survival data were collected along with EAAL therapy details and side effects.Patients were followed and the relationship between treatment and overall survival(OS) data obtained for the immunotherapy and control groups were compared retrospectively.The safety of EAAL immunotherapy was also evaluated.RESULTS:After in vitro culture and proliferation,the percentages of CD3+,CD3+CD8+,CD8+CD27+,CD8+CD28+,and CD3+CD16+/CD56+cells increased remarkably(P < 0.05),while the percentages of CD3+CD4+,CD4+CD25+,and CD3-CD16+/CD56+(natural killer cells) were overtly decreased(P < 0.05); no significant change was observed in CD4+CD25+CD127- cells(P =0.448).Interestingly,OS in the immunotherapy group was significantly higher than that in the control group,with 27.0 and 13.9 mo obtained for the two groups,respectively(P =0.028,HR =0.573,95%CI:0.347-0.945).These findings indicated a 42.7% decrease in the risk of death.In addition,we found that clinical stage and application of EAAL immunotherapy wereindependent prognostic factors for gastric cancer patients.Indeed,the OS in stage Ⅲc and Ⅳ patients that had received surgery was prolonged after EAAL immunotherapy(P < 0.05).Importantly,in vitro induction and proliferation of EAAL were easy and biologically safe.CONCLUSION:Overall,EAAL adoptive immunotherapy might prolong the OS in gastric cancer patients.
基金supported by a grant from the Science and Technology project of Shenyang(F13-212-9-00)
文摘BACKGROUND: The benefits of the application of basiliximab induction therapy in liver transplantation are not clear. The present meta-analysis was to evaluate the pros and cons of basiliximab use in liver transplantation. DATA SOURCES: We searched the associated publications in English from July 1998 to December 2015 in the following databases: MEDLINE, Pub Med, Ovid, EMBASE, Web of Science and Cochrane Library.RESULTS: Basiliximab significantly decreased the incidence of de novo diabetes mellitus after liver transplantation(RR=0.56; 95% CI: 0.34-0.91; P=0.02). Subgroup analysis showed that basiliximab in combination with steroids-free immunosuppressant significantly decreased the incidence of biopsy-proven acute rejection(RR=0.62; 95% CI: 0.39-0.97; P=0.04) and new-onset hypertension(RR=0.62; 95% CI: 0.42-0.93; P=0.02).CONCLUSIONS: Basiliximab may be effective in reducing de novo diabetes mellitus. What is more, basiliximab in combination with steroids-free immunosuppressant shows statistical benefit to reduce biopsy-proven acute rejection and de novo hypertension.
基金supported by the National Natural Science Foundation of China(No.30873196)Project of Modernization of Traditional Chinese Medicine of Shanghai(No.09dZ1975100)
文摘An offline two-dimensional system combining a rat cardiac muscle cell membrane chromatography time-of-flight mass spectrometry(CMC-TOF/MS)with a high performance liquid chromatography time-of-flight mass spectrometry(HPLC-TOF/MS)was established for investigating the parent components and metabolites in rat urine samples after administration of the roots of Aconitum carmichaeli.On the basis of the analysis of the first dimension,retention components of the urine sample were collected into 30 fractions(one fraction per minute).Then offline analysis of the second dimension was carried out.34 compounds including 24 parent alkaloids and 10 potential metabolites were identified from the dosed rat urine,and then binding affinities of different compounds on cell membranes were compared and influences of some functional groups on activity were estimated with the semi-quantification and curve fitting method.As a result,binding affinities decreased along with the process of deacylation,debenzoylation and demethylation,which may be related to the alleviation of toxicity in the procedure of herb processing or metabolism.Moreover,some minor components in rat urine(Songorine,14-benzoylneoline,Deoxyaconitine,etc.)exerted relatively strong affinity on cell membranes are worth exploring.The results delivered by the system suggest that the CMC can be applied to in vivo study.
基金the Chinese Academy of Sciences TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000).
文摘A liquid fueled thorium molten salt reactor(TMSR-LF),one of the Generation IV reactors,was designed by the Shanghai Institute of Applied Physics,Chinese Academy of Sciences.This study uses the‘rt code to calculate the neutron and gamma dose rate distributions around the reactor.Multiple types of tallies and variance reduction techniques were employed to reduce calculation time and obtain convergent calculation results.Based on the calculation and analysis results,the TMSR-LF1 radiation shield with a 60-cm serpentine concrete layer and a 120-cm ordinary concrete layer is able to meet radiation requirements.The gamma dose rate outside the reactor biological shield was 16.1 mSv h-1;this is higher than the neutron dose rate of 3.71×10^(–2)mSv h^(-1).The maximum thermal neutron flux density outside the reactor biological shield was 1.899103 cm^(-2)s^(-1),which was below the 19105 cm^(-2)s^(-1)limit.
基金This work was supported by the Primary Research and Development Plan of Jiangsu Province(Grant No.BE2016703)the Natural Science Youth Fund of Jiangsu Province(Grant No.BK20171017)+1 种基金the National Natural Science Youth Fund of China(Grant No.51707093)the Science and Technology Program of the Ministry of Housing and Urban-Rural Development of China(Grant No.2014-K7-010).
文摘Phosphorus adsorption tests were carried out using poly-aluminum chloride sludge(PACS),which was collected from a water treatment plant in Nanjing.The amount of phosphorus adsorbed by PACS increased quickly within the first hour and reached equilibrium after about 48 h.The adsorption behavior of PACS for phosphorus is consistent with the Langmuir adsorption isotherm equation(R2>0.99)and parallel first-order kinetic equation(R2>0.98).With the increase of the PACS concentration,the adsorption capacity of PACS for phosphorus decreased,and the removal rate increased.The results of batch tests showed that the adsorption capacities of PACS for phosphorus ranged from 1.64 to 1.13 mg/g when the pH value varied from 4 to 10.However,the adsorption capacity of PACS was not evidently influenced by temperature.In comparison with the ion exchange resin,the adsorption capacity of PACS was barely inhibited by competitive ions,such as SO24,NO3,and Cl.The PACS surface after adsorption became smooth,and the vibration peaks of AleO and AleOH shifted.Both HCl and NaOH have a strong desorption effect on PACS after adsorption saturation,and with higher concentrations of HCl and NaOH,the desorption effect was stronger.Results of column adsorption experiments showed that with lower phosphorus and hydraulic loads,the adsorption column took longer to reach saturation.This indicated that PACS could be used as an efficient material for removal of phosphorus from water.This study provides a new treatment method with PACS.
基金supported by the Science and Technology Project of Beijing (No. D09080300510901)National High Technology Research and Development Pro-gram of China (No. 2012AA03A514)
文摘The precipitation behavior of γ′ phase,under various interrupt cooling tests after 1170℃,solution treatment was examined.The results indicate that the size of secondary γ′ precipitates increases with the decrease of interrupt temperature,and the shape changes from spherical to butterfly like.The fine tertiary γ′ can form either during the post cool air quenching at high interrupt-temperatures,or during the specified 5℃ min-1cooling.Air quenching at high temperatures cannot suppress further nucleation of tertiary γ′ phase.
基金supported by the Science and Technology Planning Foundation of Beijing (No.D09080300510901)the National Natural Science Foundation of China (No.51104007)
文摘The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy (PM) Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries (PPB). Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200°C, but this carbide network is hard to be eliminated completely. The combined MC-M 23 C 6 morphology approves the nucleation and growth mechanism of carbide evolution.
文摘Cancer stem cells(CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability.They have been identified in a variety of tumors,including tumors of the digestive system.CSCs exhibit some unique characteristics,which are responsible for cancer metastasis and recurrence.Consequently,the development of effective therapeutic strategies against CSCs plays a key role in increasing the efficacy of cancer therapy.Several potential approaches to target CSCs of the digestive system have been explored,including targeting CSC surface markers and signaling pathways,inducing the differentiation of CSCs,altering the tumor microenvironment or niche,and inhibiting ATP-driven efflux transporters.However,conventional therapies may not successfully eradicate CSCs owing to various problems,including poor solubility,stability,rapid clearance,poor cellular uptake,and unacceptable cytotoxicity.Nanomedicine strategies,which include drug,gene,targeted,and combinational delivery,could solve these problems and significantly improve the therapeutic index.This review briefly summarizes the ongoing development of strategies and nanomedicine-based therapies against CSCs of the digestive system.
基金supported by the ‘‘Strategic Priority Research Program’’ of the Chinese Academy of Sciences(No.XDA02050100)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(No.Y519011032)
文摘The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor(FHR) system, and the activity of radionuclides accumulated in the coolant during normal operation was calculated. The release rate(release fraction per unit time) of fission products was calculated with STACY code, which is modelled mainly based on the Fick's law, while the activation of coolant and impurities was calculated with SCALE code. The accumulation of radionuclides in the coolant has been calculated with a simplified model, which is generally a time integration considering the generation and decay of radionuclides. The results show that activation products are the dominant gamma source in the primary coolant system during normal operation of the FHR while fission products become the dominant source after shutdown. In operation condition,health-impacts related nuclides such as ~3H, and ^(14)C originate from the activation of lithium and coolant impurities including carbon, nitrogen, and oxygen. According to the calculated effective cross sections of neutron activation,~6Li and ^(14)N are the dominant ~3H production source and ^(14)C production source, respectively. Considering the high production rate,~3H and ^(14)C should be treated before being released to the environment.
基金Supported by the ‘‘Strategic Priority Research Program’’ of the Chinese Academy of Sciences(Grant No.XDA02050100)
文摘The fluoride salt-cooled high-temperature reactor(FHR) uses molten FLi Be salt as the coolant, which introduces a corrosive effect on the alloy-N structure material. Fission neutrons activate the corroded alloy-N,along with alloy-N structures inside the reactor vessel. The activation products of the alloy-N have a big impact on radiation protection during operation, maintenance, and decommissioning of the reactor. We have constructed a SCALE 6.1 model for the core of a typical 10 MW th FHR and analyzed the activity of each constituent of the irradiated alloy-N. The results show that the activity is predominantly due to short-lived^(28) Al,^(60m) Co,^(56) Mn,^(51)Ti, and ^(52) V, as well as long-lived ^(60) Co,^(51)Cr,^(55)Fe,^(59)Fe, and ^(54) Mn.Furthermore, because of their relatively long half-life and high-energy c-rays emissions,^(60) Co and ^(54)Mn are the major contributors to the radiation source terms introduced by alloy-N activation. The yield of ^(60)Co and ^(54)Mn per unit mass of alloy-N under the current core design is 5.58*10~5 and 1.55 * 10~3 Bq MWd^(-1)g^(-1), respectively.The results of this paper, combined with future corrosion studies, may provide a basis for evaluating long-term radiation source terms of the primary loop salt and components.
基金financially supported by the Science and Technology Commission of Shanghai Municipality (No. 22ZR1471300)the National Science Foundation of China (Nos. 21871008,51922103 and 21801247)+1 种基金the Key Research Program of Chinese Academy of Sciences (No.QYZDJ-SSW-JSC013)China Postdoctoral Science Foundation (Nos.2020M671242 and 2021T140688)。
文摘Organic cathodes for alkali-metal-ion batteries attract great attentions in recent years,but the ion storage sites are limited to some finite functional groups.This is because an organic cathode must have proper lowest unoccupied molecular orbitals(LUMO) to accept electrons at high potential.Herein,a novel type of organophosphate-based cathode has successfully been explored by tuning the LUMO energy level of organophosphates through metal ions with an inert electron pair.For the first time,the P=O of phytate(PA),N,N,N’,N’-ethylenediaminetetrakis(methylene phytate)(EDTMP),and diethylenetriaminepentakis(methyl phytate)(DTPMP) is activated by lead/bismuth(with 6s2electron pair) to storage Li/Na/K ions reversibly.Typically,density functional theory calculations indicate that the LUMO energy of Bi-PA is greatly reduced from-0.99(PA) to-4.61 eV,which shows the first discharge capacity of 173,182 and 206mAh·g-1and the reversibly capacity of 102,102 and 101mAh·g-1with the discharge platform of 2.4,2.1 and 2.4 V for Li/Na/K-ion battery cathodes,respectively.Similarly,with proper LUMO energy level,Pb-PA(-4.63 eV),Pb-EDTMP(-3.71 eV),and Pb-DTPMP(-4.45 eV) all exhibit admirable performance.This unique strategy of organic materials to alkali-metal-ion battery cathodes offers a new avenue for future energy storage systems.
基金Item Sponsored by National High Technology Research and Development Program of China(2013AA031601)
文摘Based on the Thermo-Calc thermodynamic software,the type of equilibrium precipitated carbides and their contents in high Mo Nb-microalloyed H13steel(NMH13steel)were calculated.The composition,morphology,and distribution of carbides after spheroidal annealing of two forged experimental steels were comparatively examined by means of optical microscopy(OM),scanning electron microscopy(SEM),electron dispersive spectroscopy(EDS)and transmission electron microscopy(TEM).VC,M23C6 and M6C are identified in H13 steel after spheroidizing annealing,while(V,Nb)C,M23C6,M2C and M6C are observed in NMH13 steel.Moreover,it is found that the addition of Nb significantly enhances the stability of MC phase and the high Mo content accelerates the precipitation of small rod-shape M2C phase in NMH13 steel.The amount of the fine carbides in NMH13 steel obviously increased with M2C and M6C precipitated from the ferrite phase,which is in accordance with the results of thermodynamic calculations.
基金supported by the National Natural Science Foundation of China (Nos. 51301157 and 51105102)the National High Technology Research and Development Program (No. 2013AA031103)
文摘The hot deformation behavior of powder metallurgical(PM) TiAl alloys was investigated on Gleeble-3500 thermomechanical simulator, at a temperature range of 1050–1200 °C with an interval of 50 °C and a strain rate range of 0.001–1.000 s^(-1). The results show that the flow stress of PM TiAl alloy is sensitive to deformation temperature and strain rate, the peak stress decreases with the increase in deformation temperature and decrease in strain rate, and dynamic recrystallization occurs during the hot compression. The deformation active energy was calculated and the flow stress model during high-temperature deformation was established based on the Arrhenius equations and Zener–Hollomon parameter. The deformed microstructure consists of refined homogeneous γ and ɑ_2/γ grains.
基金the financial supports from the National Natural Science Foundation of China(Grant Nos.51301157 and 51434007)the National High Technology Research and Development Program of China 863 Program(Grant No.2013AA031103)
文摘The hot compressive deformation behavior of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders was systematically investigated and the processing map was obtained in the temperature range of 1323-1473 Kand strain rate range of 0.001-0.5s^(-1).The calculated activation energy in the above variational ranges of temperature and strain rate possesses a low activation energy value of approximately 365.6kJ/mol based on the constitutive relationship models developed with the Arrhenius-type constitutive model respectively considering the strain rate and deformation temperature.The hot working flow behavior during the deformation process was analyzed combined with the microstructural evolution.Meanwhile,the processing maps during the deformation process were established based on the dynamic material model and Prasad instability criterion under different deformation conditions.Finally,the optimal hot processing window of this alloy corresponding to the wide temperature range of 1353-1453 Kand the low strain rate of 0.001-0.1s^(-1) was obtained.
基金supported by the Key-Area Research and Development Program of Guang-Dong Province(Grant No.2019B030330001)the National Natural Science Foundation of China(Grant Nos.1210040830,12074132,12074180,11822403,U20A2074,12047522,and U1801661)。
文摘We propose a built-in fault-tolerant geometric operation to realize fast remote entanglement between superconducting qubits anchored to a 15 m K plate and Rydberg-atom qubits trapped near a 1 K plate via thermal coupled cavities. We show that this operation is robust against the detrimental effects of the thermal mode states and fluctuations in the control parameters. The operation can generate a high-fidelity entanglement between superconducting and atomic qubits under realistic experimental parameters, comparable to the results of the existing methods using auxiliary cooling systems. The scheme proposed here will promote the development of quantum network and distributed superconducting quantum computation.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174126,12104166,U1830111,11947097,and 12047522)the Key-Area Research and Development Program of Guangdong Province(Grant No.2019B030330001)the Science and Technology of Guangzhou(Grant No.2019050001),and the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2020A1515110290 and 2021A1515010315).
文摘We investigate the mean-field energy spectrum and dynamics in a Bose–Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping,and show that the interplay of nonreciprocity and nonlinearity leads to exotic properties.Under the two-mode and mean-field approximations,the nonreciprocal generalization of the nonlinear Schrödinger equation and Bloch equations of motion for this system are obtained.We analyze the PT phase diagram and the dynamical stability of fixed points.The reentrance of PT-symmetric phase and the reformation of stable fixed points with increasing the nonreciprocity parameter are found.Besides,we uncover a linear selftrapping effect induced by the nonreciprocity.In the nonlinear case,the self-trapping oscillation is enhanced by the nonreciprocity and then collapses in the PT-broken phase,and can finally be recovered in the reentrant PT-symmetric phase.
