A Novel High Volume Manufacturing Method for Defect-free and High-yield SiN Micro-sieve Membranes

Micro-sieves have been widely used in medical treatment,quarantine,environment,agriculture,pharmacy and food processing.However,the manufacturing and yield improvement have been difficult due to multiple challenges,such as the sieve unit release defect,cracking,and KOH corrosion.In this paper,we report process details and discuss technical difficulties which are usually the root-causes for process failures,and demonstrate a reliable and high yield production of SiNx micro-sieves processed with our novel method,which is also compatible with high volume manufacturing.

The bubble formation characteristics of oil‐paper insulation and its influence on insulation performance

Engineering experience shows that for transformers with long service life and serious moisture exposure,the inter‐turn paper insulation inside the winding will precipitate bubbles under the condition of electric field and conductor heating,which will endanger the equipment insulation.In order to explore the influence factors of bubbles formation in the moist insulating paper of transformers,based on the existing research on the influence of moisture content and gas dissolution in transformer oil,this study further considers the influence of air pressure(AP)and electric field and establishes an experimental platform to change the air pressure and electric field,thereby studying the formation characteristics of bubbles in oil‐paper insulation.The results show that air pressure and electric field can affect the initial temperature,volume,and shape of bubble formation.From 0 to−0.05 MPa for air pressure,the initial temperature of bubble generation decreased by 41℃,its maximum two‐dimensional projected area increased by 418.4%with more severe distortion,and the breakdown voltage decreased.When the AC voltage applied on the needle plate electrode increased from 0 to 10 kV,the initial temperature of bubble formation increased by 29℃,and the maximum two‐dimensional projection area increased by 336.6%.

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D printing.The effects of sintering temperature on microstructure and physical and mechanical properties were investigated.The results show that the average particle size,shrinkage,bulk density,crystallite size,flexural strength,Vickers hardness,and nanoindentation hardness increased with the increase in sintering temperature,whereas the open porosity decreased with increasing sintering temperature.No change was observed in phase composition,chemical bond,atomic ratio,and surface roughness.For the sintered samples,the shrinkage in Z direction is much greater than that in X or Y direction.The optimum sintering temperature in argon atmosphere is 1350℃with a shrinkage of 3.0%,3.2%,and 5.5%in X,Y,and Z directions,respectively,flexural strength of 26.7 MPa,Vickers hardness of 198.5 HV,nanoindentation hardness of 33.1 GPa,bulk density of 2.5 g/cm^3,and open porosity of 33.8%.The optimum sintering temperature was 70℃higher than that sintering in air atmosphere when achieved the similar properties.

Influence of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3 Ceramic via 3D Stereolithography

In this work,aluminum oxide(Al2O3) ceramic samples were fabricated by 3D stereolithography printing.Printing process was followed by debinding and sintering.In addition,the effect of sintering temperature on micro structure and properties was investigated.Flexure strength was observed to increase with increasing sintering temperature due to fewer pores,fewer defects and stronger grain boundary bonding of samples at higher sintering temperatures.Maximum flexure strength of 138.5 MPa was obtained when sintering temperature was 150℃.Furthermore,the shrinkage along length direction decreased with the decreasing sintering temperature until reaching minimum value of 1.02% after sintering at 1200℃.After sintering at 1280℃,flexure strength was 24.0 MPa and the shrinkage along length direction was 2.1%,which meets demands of ceramic core.

Placebo effect in the treatment of non-small cell lung cancer:a meta-analysis

Objective:The majority of non-small cell lung cancer(NSCLC)cases remain undiagnosed until advanced stages of the disease.Accumulating studies have highlighted the utility of palliative care as an effective treatment option,which relieves patients’suffering by activating placebo effect in the body.To evaluate the clinical significance of palliative care,data from NSCLC drug-randomized controlled trials(RCTs)were collected and the effects of placebo treatment examined.Methods:PubMed(MEDLINE),Scopus,Web of Science,and China National Knowledge Infrastructure databases were searched from January 1,1978 to September 1,2020.Placebo-controlled phase II/III pharmaceutical RCTs enrolling patients with solely stage III/IV NSCLC were included.The quality of included studies was assessed using the Jadad method.Single-arm and two-arm meta-analyses of the therapeutic and adverse effects of placebo,that is,the primary and secondary outcome measures,were subsequently performed using either Bayesian or conventional models.Results:Five RCTs including 2245 drug-treated and 1510 placebo-treated patients at NSCLC stage III or IV were included for the study.Low risk of bias was observed for all five included studies using the Cochrane method.Following placebo treatment,controlled disease rate of 24.1%(95%credible interval[CrI],-0.126-0.609)and dropout rate of 2.1%(95%CrI,0.007-0.039)were calculated,with a dose reduction rate of 3.0%(95%CrI,0.017-0.045).Compared with active drug treatment,the placebo treatment group had a risk ratio of 0.81(95%confidence interval,0.68-0.97)and 0.85(95%confidence interval,0.76-0.96)for the achievement of progression-free survival and overall survival,respectively.Conclusion:In NSCLC drug RCTs,placebo treatment is indicated to generally induce low toxicity in patients by dropout and dose reduction rates and adverse events,although the therapeutic responses could not be precisely determined.The results suggest that under specific circumstances,palliative care which can activate placebo effect may have similar effects as active drugs(such as erlotinib,vandetanib,or pemetrexed)in terms of prolonging survival time.