Predator dummies are usually used to explore the impact of predator features on the anti-predator behavior of birds.Previous studies have shown that the morphology and behavior of aerial predators can signal different...Predator dummies are usually used to explore the impact of predator features on the anti-predator behavior of birds.Previous studies have shown that the morphology and behavior of aerial predators can signal different threat levels to birds.However,whether subtle changes in ground predator dummies cause changes in the nest defense behavior of parent birds is unclear.In this study,we aimed to investigate whether Japanese Tits(Parus minor)exhibit different nest defense behaviors in response to experimentally manipulated variations in the appearance,posture,and size of virtual snake proxies(common nest predators).During the incubation period,we observed the nest defense behaviors of the parent tits against taxidermized Siberian Ratsnakes(Elaphe schrenckii)with varied characteristics and rubber-made model snakes.The tits exhibited more intense responses to taxidermized large(body length about 120 cm)coiled ratsnakes than to large coiled model snakes.They exhibited weaker responses to taxidermized small(body length about 20 cm)coiled ratsnakes than to taxidermized small sinusoidal ratsnakes.In addition,they exhibited more intense responses to taxidermized large coiled ratsnakes than to taxidermized small coiled ratsnakes,and more intense responses to taxidermized small sinusoidal ratsnakes than to large model snakes.However,there was no difference in the response of tits to taxidermized small sinusoidal ratsnakes and taxidermized large coiled ratsnakes,or to taxidermized small coiled ratsnakes and model snakes.Thus,the presence of scales,a sinusoidal posture,and a large body size of snake dummies can induce more intense behavioral responses in Japanese Tits.We suggested that Japanese Tits can discriminate subtle differences in ground predator dummies of nests and exhibit different nest defense behaviors.展开更多
In this work, anthropometric data measured from three-year-old Nigerian child were compared with United States anthropometric database collected by Snyder, 1977 which formed the basis of US anthropometry used today. F...In this work, anthropometric data measured from three-year-old Nigerian child were compared with United States anthropometric database collected by Snyder, 1977 which formed the basis of US anthropometry used today. Further comparison was also carried out with the dimensions of crash dummies: Hybrid III three-year-old (HIII 3YO) and Q3s dummies in order to determine the validity of using such crash dummies for safety evaluation of cars and child restraint systems (CRS) used for Nigerian children. Anthropometric survey was performed on 30 Nigerian children aged 2.5 to 3.5 years old. Twenty three standard measurements were taken from each child including the weight, height and circumferences etc. Various percentiles mean and standard deviation values were obtained and compared with international database. As observed, the dimensions of three-year-old Nigerian child appeared to be about 25% lower than US data reported by Snyder. Significant difference was also found between the dimensions of three-year-old Nigerian child and crash dummies. This study provides the external dimensions of 3-year-old Nigerian child that could be used for crash dummy and CRS design.展开更多
In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficul...In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficulties in dummy gate forma-tion and shadowing effects of I/I.This article systematically investigates the impact of different implantation conditions on the performance of VCTs with and without dummy gates through TCAD simulation.It reveals the significant role of the lightly doped regions(LDRs)naturally formed due to ion implantation in source/drain of VCTs.Furthermore,it was found that VCT with-out dummy gates can achieve an approximately 27%increase in on-state current(Ion)under the same implantation conditions,and can greatly simplify the process flow and reduce costs.Finally,N-type and P-type VCTs were successfully fabricated using this implantation method.展开更多
In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product (GDP) and consumption in Chin...In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product (GDP) and consumption in China was investigated by the cointegration analysis method. Using the Engle-Granger (EG) test and considering the possibility of structural changes, the impact of external economic shocks on the long-run equilibrium relationship between economic growth and consumption in China was analyzed. Analysis results show that without considering structural changes, the EG test cannot detect cointegration in the series subjected to structural changes; in considering structural changes, cointegration is successfully detected by specifying the dummy variable. In addition, the error correction models were constructed in different periods. This study verifies the existence of a long-run equilibrium relationship between economic growth and consumption in China, and this relationship has significantly changed in 1989 and 1997, respectively.展开更多
Randomized controlled trial(RCT)is the golden standard for evaluation of clinical evidence.To assess the effect of acupuncture,due to the specificity of acupuncture intervention,the blinding and control methods are th...Randomized controlled trial(RCT)is the golden standard for evaluation of clinical evidence.To assess the effect of acupuncture,due to the specificity of acupuncture intervention,the blinding and control methods are the difficulties in study design.It is not practical to blind investigators,participants and evaluators simultaneously.At present,blinding is generally conducted for the participants and evaluators in clinical trial.We took a comparative study of manual acupuncture and electroacupuncture for menopausal hot flush as an example to explore a new way with the reference of double-dummy design in new drug study.A single-blind and double-dummy clinical trial model of acupuncture was established.Based on individual acupuncture intervention in each group,the placebo intervention was combined to ensure the form consistency of two groups.Such a study design may eliminate non-specific effect of acupuncture,and can be conductive to comparing the specific effect of acupuncture and can provide the references and regimens for study design.展开更多
Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(a...Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.展开更多
Background:Shenyankangfu Tablet(SYKFT)is a Chinese patent medicine that has been used widely to decrease proteinuria and the progression of chronic kidney disease.Objective:This trial compared the efficacy and safety ...Background:Shenyankangfu Tablet(SYKFT)is a Chinese patent medicine that has been used widely to decrease proteinuria and the progression of chronic kidney disease.Objective:This trial compared the efficacy and safety of SYKFT,for the control of proteinuria in primary glomerulonephritis patients,against the standard drug,losartan potassium.Design,setting,participants and intervention:This was a multicenter,double-blind,randomized,controlled clinical trial.Primary glomerulonephritis patients,aged 18-70 years,with blood pressure≤140/90 mmHg,estimated glomerular filtration rate(eGFR)>45 mL/min per 1.73 ㎡,and 24-hour proteinuria level of 0.5-3.0 g,were recruited in 41 hospitals across 19 provinces in China and were randomly divided into five groups:SYKFT,losartan potassium 50 mg or 100 mg,SYKFT plus losartan potassium 50 mg or 100 mg.Main outcome measu res:The primary outcome was change in the 24-hour proteinuria level,after 48 weeks of treatment.Results:A total of 735 participants were enrolled.The percent decline of urine protein quantification in the SYKFT group after 48 weeks was 8.78%±2.56%(P=0.006)more than that in the losartan 50 mg group,which was 0.51%±2.54%(P=1.000)less than that in the losartan 100 mg group.Compared with the losartan potassium 50 mg group,the SYKFT plus losartan potassium 50 mg group had a 13.39%±2.49%(P<0.001)greater reduction in urine protein level.Compared with the losartan potassium 100 mg group,the SYKFT plus losartan potassium 100 mg group had a 9.77%±2.52%(P=0.001)greater reduction in urine protein.With a superiority threshold of 15%,neither was statistically significant.eGFR,serum creatinine and serum albumin from the baseline did not change statistically significant.The average change in TCM syndrome score between the patients who took SYKFT(-3.00[-6.00,-2.00])and who did not take SYKFT(-2.00[-5.00,0])was statistically significant(P=0.003).No obvious adverse reactions were observed in any group.Conclusion:SYKFT decreased the proteinuria and improved the TCM syndrome scores of primary glomerulonephritis patients,with no change in the rate of decrease in the eGFR.SYKFT plus losartan potassium therapy decreased proteinuria more than losartan potassium therapy alone.Trial registration number:NCT02063100 on ClinicalTrials.gov.展开更多
PIT tests are usually performed when a mass distribution of High Explosive(H.E) projectile fragments is required. This paper shows the underwater detonation effects of 60 mm, M90 H.E. mortar bomb filled with Comp. B o...PIT tests are usually performed when a mass distribution of High Explosive(H.E) projectile fragments is required. This paper shows the underwater detonation effects of 60 mm, M90 H.E. mortar bomb filled with Comp. B on cylindrical concrete structure(concrete pipe closed at one end-similar to a PIT test)which is 2 m high(inner height) with inner diameter of also 2 m. Thickness of both wall and bottom of a pipe is 0.35 m. Detailed characteristics of concrete which is used for manufacturing of a pipe are specified. Mortar bomb is submerged directly in to the water(no free airspace around the bomb) with the nose pointing to the bottom of a pipe. Number and mass of fragments after detonation are presented by table and photographs. Fragments of dummy fuze, through which blasting cap was protruded, are collected and reassembled to form a shape of a fuze after detonation where expanding of fuze material due to a detonation products is visualized. After underwater detonation, detonation of the same mortar bomb is performed in an empty pipe and the effects of this kind of detonation are observed. Distance at which fragments generated from submerged mortar bomb will not reach concrete pipes wall is also determined.展开更多
In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measuremen...In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.展开更多
Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process.In this study,a single-crystal dummy blade cluster with different crystal orientatio...Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process.In this study,a single-crystal dummy blade cluster with different crystal orientations controlled by the seeding method was prepared,and the influence of the position of the circular platform(relative to the sample and furnace body)on stray grain nucleation was investigated.Results show that the microstructure of the circular platforms could be divided into the center,expansion,and stray grain regions.The inside of the circular platform facing the center of the cluster is more prone to stray grain formation than the outside of the circular platform facing the furnace body.With an increase in the distance between the circular platform and the bottom of the dummy blade cluster,the stray grain region expands,whereas the expansion region narrows.The stray grain is slightly aggravated with increase of the misorientation.Finally,the mechanism underlying the influence of platform position on the formation of stray grains in single-crystal dummy blade clusters is discussed based on the temperature evolution during directional solidification.展开更多
基金sponsored by National Natural Science Foundation of China(No.32271560 to H.W.,32001094 to J.Y.)Natural Science Foundation of Jilin Province,China(No.20230101160JC to L.J.)+1 种基金the Open Project of Ministry of Education Key Laboratory for Ecology of Tropical Islands,Hainan Normal University,China(No.HNSF-OP-202301 to J.Y.)the Fundamental Research Funds for the Central Universities(No.2412022ZD019 to J.Y.)。
文摘Predator dummies are usually used to explore the impact of predator features on the anti-predator behavior of birds.Previous studies have shown that the morphology and behavior of aerial predators can signal different threat levels to birds.However,whether subtle changes in ground predator dummies cause changes in the nest defense behavior of parent birds is unclear.In this study,we aimed to investigate whether Japanese Tits(Parus minor)exhibit different nest defense behaviors in response to experimentally manipulated variations in the appearance,posture,and size of virtual snake proxies(common nest predators).During the incubation period,we observed the nest defense behaviors of the parent tits against taxidermized Siberian Ratsnakes(Elaphe schrenckii)with varied characteristics and rubber-made model snakes.The tits exhibited more intense responses to taxidermized large(body length about 120 cm)coiled ratsnakes than to large coiled model snakes.They exhibited weaker responses to taxidermized small(body length about 20 cm)coiled ratsnakes than to taxidermized small sinusoidal ratsnakes.In addition,they exhibited more intense responses to taxidermized large coiled ratsnakes than to taxidermized small coiled ratsnakes,and more intense responses to taxidermized small sinusoidal ratsnakes than to large model snakes.However,there was no difference in the response of tits to taxidermized small sinusoidal ratsnakes and taxidermized large coiled ratsnakes,or to taxidermized small coiled ratsnakes and model snakes.Thus,the presence of scales,a sinusoidal posture,and a large body size of snake dummies can induce more intense behavioral responses in Japanese Tits.We suggested that Japanese Tits can discriminate subtle differences in ground predator dummies of nests and exhibit different nest defense behaviors.
文摘In this work, anthropometric data measured from three-year-old Nigerian child were compared with United States anthropometric database collected by Snyder, 1977 which formed the basis of US anthropometry used today. Further comparison was also carried out with the dimensions of crash dummies: Hybrid III three-year-old (HIII 3YO) and Q3s dummies in order to determine the validity of using such crash dummies for safety evaluation of cars and child restraint systems (CRS) used for Nigerian children. Anthropometric survey was performed on 30 Nigerian children aged 2.5 to 3.5 years old. Twenty three standard measurements were taken from each child including the weight, height and circumferences etc. Various percentiles mean and standard deviation values were obtained and compared with international database. As observed, the dimensions of three-year-old Nigerian child appeared to be about 25% lower than US data reported by Snyder. Significant difference was also found between the dimensions of three-year-old Nigerian child and crash dummies. This study provides the external dimensions of 3-year-old Nigerian child that could be used for crash dummy and CRS design.
文摘In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficulties in dummy gate forma-tion and shadowing effects of I/I.This article systematically investigates the impact of different implantation conditions on the performance of VCTs with and without dummy gates through TCAD simulation.It reveals the significant role of the lightly doped regions(LDRs)naturally formed due to ion implantation in source/drain of VCTs.Furthermore,it was found that VCT with-out dummy gates can achieve an approximately 27%increase in on-state current(Ion)under the same implantation conditions,and can greatly simplify the process flow and reduce costs.Finally,N-type and P-type VCTs were successfully fabricated using this implantation method.
文摘In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product (GDP) and consumption in China was investigated by the cointegration analysis method. Using the Engle-Granger (EG) test and considering the possibility of structural changes, the impact of external economic shocks on the long-run equilibrium relationship between economic growth and consumption in China was analyzed. Analysis results show that without considering structural changes, the EG test cannot detect cointegration in the series subjected to structural changes; in considering structural changes, cointegration is successfully detected by specifying the dummy variable. In addition, the error correction models were constructed in different periods. This study verifies the existence of a long-run equilibrium relationship between economic growth and consumption in China, and this relationship has significantly changed in 1989 and 1997, respectively.
基金Supported by the program of "the 12^(th) Five-year" National Science and Technology Pillar Program:2012BAJ24B01Scientific research project of Hunan Provincial Health Committee:20201633+2 种基金Natural Science Foundation of Hunan Province:2020JJ5437The fourth batch of academic experience inheritance of Hunan old TCM experts:[2020]No.37The seventh batch of academic experience inheritance of national old TCM experts:[2022]No.76
文摘Randomized controlled trial(RCT)is the golden standard for evaluation of clinical evidence.To assess the effect of acupuncture,due to the specificity of acupuncture intervention,the blinding and control methods are the difficulties in study design.It is not practical to blind investigators,participants and evaluators simultaneously.At present,blinding is generally conducted for the participants and evaluators in clinical trial.We took a comparative study of manual acupuncture and electroacupuncture for menopausal hot flush as an example to explore a new way with the reference of double-dummy design in new drug study.A single-blind and double-dummy clinical trial model of acupuncture was established.Based on individual acupuncture intervention in each group,the placebo intervention was combined to ensure the form consistency of two groups.Such a study design may eliminate non-specific effect of acupuncture,and can be conductive to comparing the specific effect of acupuncture and can provide the references and regimens for study design.
文摘Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.
基金supported by the National Science and Technology Major Projects of China(No.2014ZX09201021)Beijing Municipal Science and Technology Commission Major Projects(No.D181100000118002)。
文摘Background:Shenyankangfu Tablet(SYKFT)is a Chinese patent medicine that has been used widely to decrease proteinuria and the progression of chronic kidney disease.Objective:This trial compared the efficacy and safety of SYKFT,for the control of proteinuria in primary glomerulonephritis patients,against the standard drug,losartan potassium.Design,setting,participants and intervention:This was a multicenter,double-blind,randomized,controlled clinical trial.Primary glomerulonephritis patients,aged 18-70 years,with blood pressure≤140/90 mmHg,estimated glomerular filtration rate(eGFR)>45 mL/min per 1.73 ㎡,and 24-hour proteinuria level of 0.5-3.0 g,were recruited in 41 hospitals across 19 provinces in China and were randomly divided into five groups:SYKFT,losartan potassium 50 mg or 100 mg,SYKFT plus losartan potassium 50 mg or 100 mg.Main outcome measu res:The primary outcome was change in the 24-hour proteinuria level,after 48 weeks of treatment.Results:A total of 735 participants were enrolled.The percent decline of urine protein quantification in the SYKFT group after 48 weeks was 8.78%±2.56%(P=0.006)more than that in the losartan 50 mg group,which was 0.51%±2.54%(P=1.000)less than that in the losartan 100 mg group.Compared with the losartan potassium 50 mg group,the SYKFT plus losartan potassium 50 mg group had a 13.39%±2.49%(P<0.001)greater reduction in urine protein level.Compared with the losartan potassium 100 mg group,the SYKFT plus losartan potassium 100 mg group had a 9.77%±2.52%(P=0.001)greater reduction in urine protein.With a superiority threshold of 15%,neither was statistically significant.eGFR,serum creatinine and serum albumin from the baseline did not change statistically significant.The average change in TCM syndrome score between the patients who took SYKFT(-3.00[-6.00,-2.00])and who did not take SYKFT(-2.00[-5.00,0])was statistically significant(P=0.003).No obvious adverse reactions were observed in any group.Conclusion:SYKFT decreased the proteinuria and improved the TCM syndrome scores of primary glomerulonephritis patients,with no change in the rate of decrease in the eGFR.SYKFT plus losartan potassium therapy decreased proteinuria more than losartan potassium therapy alone.Trial registration number:NCT02063100 on ClinicalTrials.gov.
文摘PIT tests are usually performed when a mass distribution of High Explosive(H.E) projectile fragments is required. This paper shows the underwater detonation effects of 60 mm, M90 H.E. mortar bomb filled with Comp. B on cylindrical concrete structure(concrete pipe closed at one end-similar to a PIT test)which is 2 m high(inner height) with inner diameter of also 2 m. Thickness of both wall and bottom of a pipe is 0.35 m. Detailed characteristics of concrete which is used for manufacturing of a pipe are specified. Mortar bomb is submerged directly in to the water(no free airspace around the bomb) with the nose pointing to the bottom of a pipe. Number and mass of fragments after detonation are presented by table and photographs. Fragments of dummy fuze, through which blasting cap was protruded, are collected and reassembled to form a shape of a fuze after detonation where expanding of fuze material due to a detonation products is visualized. After underwater detonation, detonation of the same mortar bomb is performed in an empty pipe and the effects of this kind of detonation are observed. Distance at which fragments generated from submerged mortar bomb will not reach concrete pipes wall is also determined.
文摘In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.
文摘Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process.In this study,a single-crystal dummy blade cluster with different crystal orientations controlled by the seeding method was prepared,and the influence of the position of the circular platform(relative to the sample and furnace body)on stray grain nucleation was investigated.Results show that the microstructure of the circular platforms could be divided into the center,expansion,and stray grain regions.The inside of the circular platform facing the center of the cluster is more prone to stray grain formation than the outside of the circular platform facing the furnace body.With an increase in the distance between the circular platform and the bottom of the dummy blade cluster,the stray grain region expands,whereas the expansion region narrows.The stray grain is slightly aggravated with increase of the misorientation.Finally,the mechanism underlying the influence of platform position on the formation of stray grains in single-crystal dummy blade clusters is discussed based on the temperature evolution during directional solidification.