This paper considers the uniform parallel machine scheduling problem with unequal release dates and delivery times to minimize the maximum completion time.For this NP-hard problem,the largest sum of release date,proce...This paper considers the uniform parallel machine scheduling problem with unequal release dates and delivery times to minimize the maximum completion time.For this NP-hard problem,the largest sum of release date,processing time and delivery time first rule is designed to determine a certain machine for each job,and the largest difference between delivery time and release date first rule is designed to sequence the jobs scheduled on the same machine,and then a novel algorithm for the scheduling problem is built.To evaluate the performance of the proposed algorithm,a lower bound for the problem is proposed.The accuracy of the proposed algorithm is tested based on the data with problem size varying from 200 jobs to 600 jobs.The computational results indicate that the average relative error between the proposed algorithm and the lower bound is only 0.667%,therefore the solutions obtained by the proposed algorithm are very accurate.展开更多
The steady flow field of a canard missile on different angles of attack and Mach numbers were studied. Based on analysis, a method was proposed to reduce the calculation for the rolling characteristics of the canard m...The steady flow field of a canard missile on different angles of attack and Mach numbers were studied. Based on analysis, a method was proposed to reduce the calculation for the rolling characteristics of the canard missile with free-spinning tails, and was tested to obtain the relations between rolling moment coefficient, Mach number, and angle of attack. All the computed rolling moment coefficients obtained from the proposed method greatly agreed with the experimental results of FD-06 wind tunnel in CAAA, which proved that the method can not only reduce the calculation cost but also keep precision in calculating the rolling characteristics of canard missiles.展开更多
There is a pressing need for developing in vivo or ex vivo assays to screen the glucocorticoid（GC） signaling disruption of chemicals. Thus, we aimed to establish an ex vivo assay for screening GC signaling disruptio...There is a pressing need for developing in vivo or ex vivo assays to screen the glucocorticoid（GC） signaling disruption of chemicals. Thus, we aimed to establish an ex vivo assay for screening GC signaling disruption based on the GC-response gene transcription in Xenopus laevis tails cultured ex vivo. Firstly, we investigated effects of corticosterone（CORT, a main GC in frogs） on GC-response gene expression, and determined the six genes as molecular endpoints for assaying the GC signaling disruption. CORT in the range of 1.56–400 nmol/L was found to up-regulate transcription of the six GC-response genes, exhibiting comparable or higher sensitivity than previously reported assays. To validate this ex vivo assay, then, we examined effects of dexamethasone（a known GC signaling agonist） on GC-response gene expression. Dexamethasone displayed an agonistic action in a concentration-dependent manner, further demonstrating the efficiency of the established assay. Finally, we applied the ex vivo assay to evaluate the GC signaling disruption of bisphenol A（BPA）. In accordance with previous reports, we found a concentration-dependent agonistic activity of BPA,showing that the established assay is effective for detecting the GC signaling disrupting activity of environmental chemicals. Correspondingly, the GC signaling agonistic actions of CORT and BPA in ex vivo tails accorded with the observations in vivo, indicating that the ex vivo assay is able to detect the actions of chemicals in vivo. Overall, we established an ex vivo assay that can effectively screen GC signaling disruption of environmental chemicals.展开更多
The rare earth elements (REE) include the group of 15 lanthanides, scandium and yttrium and have diverse applications in technological and nuclear areas. The existence of REE in massive solid mining wastes generated i...The rare earth elements (REE) include the group of 15 lanthanides, scandium and yttrium and have diverse applications in technological and nuclear areas. The existence of REE in massive solid mining wastes generated in leaching processes of copper minerals in the Atacama region of Chile generates the possibility of creating added value to the treatment of this type of waste and supporting the development of a circular economy, generating a useful by-product in different industries. In order to know the behavior of these elements present in the solid carrier waste, a leaching process was carried out by using two agents separately, corresponding to hydrochloric and nitric acid. The technical feasibility to recover REE from carrier tail was demonstrated, the best leaching agent for these elements being a hydrochloric solution, obtaining a maximum recovery efficiency of 64.5%, for an acid concentration: 3M, temperature: 40<span style="white-space:nowrap;">°</span>C and (liquid/solid) ratio: 4. Lanthanum and cerium present the best individual recoveries compared to the other REE, with a maximum efficiency for a hydrochloric solution of 75.7% and 70.0%, respectively. The interaction of operational parameters that most influence the REE recovery corresponds to the temperature and the (liquid/solid) ratio. After 4 hours of leaching, REE recovery efficiencies remain practically constant. Acid consumptions correspond to 11 (kg HCl/ton mining tail) and 29 (kg HNO<sub>3</sub>/ton mining tail). The highest amount recovery ratios of these elements correspond to 0.355 and 0.224 (kg REE/ton mining tail), for hydrochloric and nitric solutions, respectively. These results influence the types of reagents and parameters to be studied in the following stages of the global process.展开更多
Dear Editor,In vitro transcribed(IVT)mRNA is an emerging class of drug for both therapeu-tics and vaccines(Hao et al..2024;Sahin et al.,2014).Enhancing its translation efficiency remains a core challenge for mRNA-base...Dear Editor,In vitro transcribed(IVT)mRNA is an emerging class of drug for both therapeu-tics and vaccines(Hao et al..2024;Sahin et al.,2014).Enhancing its translation efficiency remains a core challenge for mRNA-based applications(Karikó,2019).展开更多
Let F be a distribution function supported on (-∞,∞) with a finite mean μ. In this note we show that if its tail F = 1 - F is dominatedly varying, then for any r > max{μ, 0}, there exist C(r) > 0 and D(r) &g...Let F be a distribution function supported on (-∞,∞) with a finite mean μ. In this note we show that if its tail F = 1 - F is dominatedly varying, then for any r > max{μ, 0}, there exist C(r) > 0 and D(r) > 0 such thatfor all n ≥ 1 and all x≥rn. This inequality sharpens a classical inequality for the subexponential distribution case.展开更多
For the widely orthant dependent （WOD） structure, this paper mainly investigates the precise large deviations for the partial sums of WOD and non-identically distributed random variables with dominatedly varying tai...For the widely orthant dependent （WOD） structure, this paper mainly investigates the precise large deviations for the partial sums of WOD and non-identically distributed random variables with dominatedly varying tails. The obtained results extend some corresponding results.展开更多
This paper shows the structure of the random variables with dominatedly varying tails and that of the associated random variables, and obtains some results on these r.v.s' precise moderate deviations with random c...This paper shows the structure of the random variables with dominatedly varying tails and that of the associated random variables, and obtains some results on these r.v.s' precise moderate deviations with random centralizing constants, which extend the boundary γλ(t)of large deviations to γ(λ(t)^1/s,whereγ>0,1<s<2,λ(t)is the expectation of the random index N(t),t>0.展开更多
Dear Editor,Poly(A)tails are added to the 3’-end of most mRNAs(Colgan and Manley,1997;Yu and Kim,2020).The regulatory roles of poly(A)tails have long been underestimated due to technical difficulties in analyzing hom...Dear Editor,Poly(A)tails are added to the 3’-end of most mRNAs(Colgan and Manley,1997;Yu and Kim,2020).The regulatory roles of poly(A)tails have long been underestimated due to technical difficulties in analyzing homopolymers(Chang et al.,2014;Subtelny et al.,2014).Several methods were recently developed to accurately measure their length(Chang et al.,2014;Legnini et al.,2019;Liu et al.,2019;Liu et al.展开更多
This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated...This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated in combination with free radical content and FTIR analysis,and direct path coefficients as well as determination coefficients were obtained based on these parameters,such as the absorbance at 294 nm(A294),5-hydroxymethylfurfural(5-HMF),thiobarbituric acid-reactive substances(TBARS),and total phenols(TP).The result showed that the browning of seasoned RTE crayfish tails was ascribe to the synergistic effect of Maillard reaction and lipid oxidation by the order of determination coefficient.After the crayfish hepatopancreas were removed,the content of A294,5-HMF,TBARS,and TP declined more than 30%,specifically affecting the direct pathway from lipid oxidation to Maillard reaction and alleviating the browning.However,no significant change of color was observed in the group without thirteen-spices,while TBARS and free radical content increased by at least 16.7%.The removal of hepatopancreas and the control of Maillard reaction were deemed to be a good measure for inhibiting the non-enzymatic browning of RTE crayfish tails.展开更多
In 2003, Tang Qihe et al. obtained a simple asymptotic formula for independent identically distributed (i.i.d.) random variables with heavy tails. In this paper, under certain moment conditions, we establish a formula...In 2003, Tang Qihe et al. obtained a simple asymptotic formula for independent identically distributed (i.i.d.) random variables with heavy tails. In this paper, under certain moment conditions, we establish a formula as the same as Tang’s, when random variables are negatively associated (NA).展开更多
Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during...Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.展开更多
As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This ...As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.展开更多
Polypropylene fibers(PPFs) have been widely used in composite materials due to their sound crack resistance and toughness. In cement-based composites, the incorporation of PPFs can significantly improve their dynamic ...Polypropylene fibers(PPFs) have been widely used in composite materials due to their sound crack resistance and toughness. In cement-based composites, the incorporation of PPFs can significantly improve their dynamic mechanical properties. However, cement-iron ore tailings foam composite(CIFC), a sustainable material utilizing iron ore tailings to partially replace cement, has not been investigated under dynamic loading. This study investigates the dynamic compressive behavior of CIFC with 1%–2.5% PPF content and 3–12 mm PPF lengths under various strain rates. The microstructural characteristics were analyzed prior to dynamic testing. X-ray diffraction(XRD) identified crystalline phases including CaCO_(3)Fe_(2)O_(3), SiO, C-S-H gel, and ettringite. Scanning electron microscopy(SEM) observations demonstrated that appropriate PPF_(2) parameters(e.g., C2L9, a CIFC specimen containing 2% PPF with 9 mm length) enhance fiber-matrix bonding and minimize interconnected pores and microcracks, revealing pronounced fiber bridging effects. Split Hopkinson pressure bar(SHPB) tests were then conducted at strain rates of 120–250 s^(-1), showing that the dynamic properties of CIFC were highly dependent on both strain rates and PPF parameters. Compared to other specimens, C2L9 exhibited a more intact failure pattern with superior compressive strength and energy dissipation capacity, despite showing reduced dynamic increase factor(DIF) and normalized energy dissipation(NED) values. These findings provide practical guidance for applying CIFC with varying PPF parameters in impact-resistant structural designs.展开更多
Background:Minimally invasive distal pancreatectomy(MIDP)is increasingly being used,although its oncologic safety for pancreatic ductal adenocarcinoma(PDAC)remains controversial.In Japan,MIDP for PDAC has limited endo...Background:Minimally invasive distal pancreatectomy(MIDP)is increasingly being used,although its oncologic safety for pancreatic ductal adenocarcinoma(PDAC)remains controversial.In Japan,MIDP for PDAC has limited endorsement due to insufficient data.This study aimed to compare the perioperative and long-term outcomes of open distal pancreatectomy(ODP)and MIDP for PDAC.Methods:We retrospectively analyzed patients with resectable pancreatic body and tail cancer treated with ODP or MIDP(laparoscopic or robotic)between January 2007 and July 2022.The surgical procedures(ODP and MIDP)were compared and the patient characteristics,perioperative outcomes,and long-term outcomes were analyzed.We also compared the outcomes of patients with neoadjuvant chemotherapy(NAC)and without NAC.Results:A total of 72 distal pancreatectomies were performed(37 ODPs and 35 MIDPs).In the upfront group,MIDP resulted in significantly less blood loss than ODP(P<0.01),despite similar operative time.There was no statistically significant difference in the 2-year recurrence-free survival(RFS)rates between ODP and MIDP(39.7%vs.57.8%,P=0.60)or in the overall survival(OS)rates(66.7%vs.74.1%,P=0.43).Similarly,in the NAC group,MIDP resulted in significantly less blood loss than ODP(P=0.01);ODP and MIDP had similar 2-year RFS rates(41.7%and 60.0%,P=0.75)and OS rates(50.0%and 70.0%,P=0.36).The interval from surgery to adjuvant chemotherapy initiation did not significantly differ between the ODP and MIDP subgroups in both the upfront group(P=0.13)and the NAC group(P=0.14).The incidence of recurrence was 64.8%for ODP and 42.8%for MIDP(P=0.06).Both procedures showed similar distributions of local and distant recurrence.Conclusions:MIDP caused less blood loss and had similar oncologic safety compared with ODP.MIDP could become a feasible,minimally invasive option with sufficient oncologic safety for pancreatic body and tail cancers.展开更多
The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the...The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the stability of underground mining engineering,this paper simulates the generation of different degrees of initial defects inside the CTB by adding different contents of air-entraining agent(AEA),investigates the acoustic emission RA/AF eigenvalues of CTB with different contents of AEA under uniaxial compression,and adopts various denoising algorithms(e.g.,moving average smoothing,median filtering,and outlier detection)to improve the accuracy of the data.The variance and autocorrelation coefficients of RA/AF parameters were analyzed in conjunction with the critical slowing down(CSD)theory.The results show that the acoustic emission RA/AF values can be used to characterize the progressive damage evolution of CTB.The denoising algorithm processed the AE signals to reduce the effects of extraneous noise and anomalous spikes.Changes in the variance curves provide clear precursor information,while abrupt changes in the autocorrelation coefficient can be used as an auxiliary localization warning signal.The phenomenon of dramatic increase in the variance and autocorrelation coefficient curves during the compression-tightening stage,which is influenced by the initial defects,can lead to false warnings.As the initial defects of the CTB increase,its instability precursor time and instability time are prolonged,the peak stress decreases,and the time difference between the CTB and the instability damage is smaller.The results provide a new method for real-time monitoring and early warning of CTB instability damage.展开更多
This paper studies the moderate deviations of real-valued extended negatively dependent(END)random variables with consistently varying tails.The moderate deviations of partial sums are first given.The results are then...This paper studies the moderate deviations of real-valued extended negatively dependent(END)random variables with consistently varying tails.The moderate deviations of partial sums are first given.The results are then used to establish the necessary and sufficient conditions for the moderate deviations of random sums under certain circumstances.展开更多
In this paper, we obtain results on precise large deviations for non-random and random sums of negatively associated nonnegative random variables with common dominatedly varying tail distribution function. We discover...In this paper, we obtain results on precise large deviations for non-random and random sums of negatively associated nonnegative random variables with common dominatedly varying tail distribution function. We discover that, under certain conditions, three precise large-deviation prob- abilities with different centering numbers are equivalent to each other. Furthermore, we investigate precise large deviations for sums of negatively associated nonnegative random variables with certain negatively dependent occurrences. The obtained results extend and improve the corresponding results of Ng, Tang, Yan and Yang （J. Appl. Prob., 41, 93-107, 2004）.展开更多
基金supported by the National Natural Science Foundation of China (7087103290924021+2 种基金70971035)the National High Technology Research and Development Program of China (863 Program) (2008AA042901)Anhui Provincial Natural Science Foundation (11040606Q27)
文摘This paper considers the uniform parallel machine scheduling problem with unequal release dates and delivery times to minimize the maximum completion time.For this NP-hard problem,the largest sum of release date,processing time and delivery time first rule is designed to determine a certain machine for each job,and the largest difference between delivery time and release date first rule is designed to sequence the jobs scheduled on the same machine,and then a novel algorithm for the scheduling problem is built.To evaluate the performance of the proposed algorithm,a lower bound for the problem is proposed.The accuracy of the proposed algorithm is tested based on the data with problem size varying from 200 jobs to 600 jobs.The computational results indicate that the average relative error between the proposed algorithm and the lower bound is only 0.667%,therefore the solutions obtained by the proposed algorithm are very accurate.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.HEUCFG201815)
文摘The steady flow field of a canard missile on different angles of attack and Mach numbers were studied. Based on analysis, a method was proposed to reduce the calculation for the rolling characteristics of the canard missile with free-spinning tails, and was tested to obtain the relations between rolling moment coefficient, Mach number, and angle of attack. All the computed rolling moment coefficients obtained from the proposed method greatly agreed with the experimental results of FD-06 wind tunnel in CAAA, which proved that the method can not only reduce the calculation cost but also keep precision in calculating the rolling characteristics of canard missiles.
基金supported by the National Natural Science Foundation of China (No. 21377153)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB14040102)
文摘There is a pressing need for developing in vivo or ex vivo assays to screen the glucocorticoid（GC） signaling disruption of chemicals. Thus, we aimed to establish an ex vivo assay for screening GC signaling disruption based on the GC-response gene transcription in Xenopus laevis tails cultured ex vivo. Firstly, we investigated effects of corticosterone（CORT, a main GC in frogs） on GC-response gene expression, and determined the six genes as molecular endpoints for assaying the GC signaling disruption. CORT in the range of 1.56–400 nmol/L was found to up-regulate transcription of the six GC-response genes, exhibiting comparable or higher sensitivity than previously reported assays. To validate this ex vivo assay, then, we examined effects of dexamethasone（a known GC signaling agonist） on GC-response gene expression. Dexamethasone displayed an agonistic action in a concentration-dependent manner, further demonstrating the efficiency of the established assay. Finally, we applied the ex vivo assay to evaluate the GC signaling disruption of bisphenol A（BPA）. In accordance with previous reports, we found a concentration-dependent agonistic activity of BPA,showing that the established assay is effective for detecting the GC signaling disrupting activity of environmental chemicals. Correspondingly, the GC signaling agonistic actions of CORT and BPA in ex vivo tails accorded with the observations in vivo, indicating that the ex vivo assay is able to detect the actions of chemicals in vivo. Overall, we established an ex vivo assay that can effectively screen GC signaling disruption of environmental chemicals.
文摘The rare earth elements (REE) include the group of 15 lanthanides, scandium and yttrium and have diverse applications in technological and nuclear areas. The existence of REE in massive solid mining wastes generated in leaching processes of copper minerals in the Atacama region of Chile generates the possibility of creating added value to the treatment of this type of waste and supporting the development of a circular economy, generating a useful by-product in different industries. In order to know the behavior of these elements present in the solid carrier waste, a leaching process was carried out by using two agents separately, corresponding to hydrochloric and nitric acid. The technical feasibility to recover REE from carrier tail was demonstrated, the best leaching agent for these elements being a hydrochloric solution, obtaining a maximum recovery efficiency of 64.5%, for an acid concentration: 3M, temperature: 40<span style="white-space:nowrap;">°</span>C and (liquid/solid) ratio: 4. Lanthanum and cerium present the best individual recoveries compared to the other REE, with a maximum efficiency for a hydrochloric solution of 75.7% and 70.0%, respectively. The interaction of operational parameters that most influence the REE recovery corresponds to the temperature and the (liquid/solid) ratio. After 4 hours of leaching, REE recovery efficiencies remain practically constant. Acid consumptions correspond to 11 (kg HCl/ton mining tail) and 29 (kg HNO<sub>3</sub>/ton mining tail). The highest amount recovery ratios of these elements correspond to 0.355 and 0.224 (kg REE/ton mining tail), for hydrochloric and nitric solutions, respectively. These results influence the types of reagents and parameters to be studied in the following stages of the global process.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24020203)the National Key Research and Development Program of China(2018YFA0107001,2024YFA1802403)+3 种基金the National Natural Science Foundation of China(31970588,32470860,32201060,32371357,32170606)Natural Science Foundation of Heilongjiang province(YQ2023C023)the Fundamental Research Funds for the Central Universities(2572023CT09,2572025JT05)CAS Project for Young Scientists in Basic Research(YSBR-012).
文摘Dear Editor,In vitro transcribed(IVT)mRNA is an emerging class of drug for both therapeu-tics and vaccines(Hao et al..2024;Sahin et al.,2014).Enhancing its translation efficiency remains a core challenge for mRNA-based applications(Karikó,2019).
基金Yan's work was supported by the Ministry of Science and Technology of China (973 Project on Mathematics) the Knowledge Innovation Program of the Chinese Academy of Sciences.
文摘Let F be a distribution function supported on (-∞,∞) with a finite mean μ. In this note we show that if its tail F = 1 - F is dominatedly varying, then for any r > max{μ, 0}, there exist C(r) > 0 and D(r) > 0 such thatfor all n ≥ 1 and all x≥rn. This inequality sharpens a classical inequality for the subexponential distribution case.
文摘For the widely orthant dependent （WOD） structure, this paper mainly investigates the precise large deviations for the partial sums of WOD and non-identically distributed random variables with dominatedly varying tails. The obtained results extend some corresponding results.
基金This research is supported by National Science Foundation of China (No. 10271087).
文摘This paper shows the structure of the random variables with dominatedly varying tails and that of the associated random variables, and obtains some results on these r.v.s' precise moderate deviations with random centralizing constants, which extend the boundary γλ(t)of large deviations to γ(λ(t)^1/s,whereγ>0,1<s<2,λ(t)is the expectation of the random index N(t),t>0.
基金supported by the National Key Research and Development Program of China(2018YFA0107001,2020YFA0804000)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24020203)+4 种基金the CAS Project for Young Scientists in Basic Research(YSBR-012)the National Natural Science Foundation of China(31970588,32170606)the Natural Science Foundation of Heilongjiang province(YQ2020C003)the China Postdoctoral Science Foundation(2020M670516,2020T130687)the State Key Laboratory of Molecular Developmental Biology。
文摘Dear Editor,Poly(A)tails are added to the 3’-end of most mRNAs(Colgan and Manley,1997;Yu and Kim,2020).The regulatory roles of poly(A)tails have long been underestimated due to technical difficulties in analyzing homopolymers(Chang et al.,2014;Subtelny et al.,2014).Several methods were recently developed to accurately measure their length(Chang et al.,2014;Legnini et al.,2019;Liu et al.,2019;Liu et al.
基金supported by the National Key R&D Program of China(2019YFC1606002).
文摘This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated in combination with free radical content and FTIR analysis,and direct path coefficients as well as determination coefficients were obtained based on these parameters,such as the absorbance at 294 nm(A294),5-hydroxymethylfurfural(5-HMF),thiobarbituric acid-reactive substances(TBARS),and total phenols(TP).The result showed that the browning of seasoned RTE crayfish tails was ascribe to the synergistic effect of Maillard reaction and lipid oxidation by the order of determination coefficient.After the crayfish hepatopancreas were removed,the content of A294,5-HMF,TBARS,and TP declined more than 30%,specifically affecting the direct pathway from lipid oxidation to Maillard reaction and alleviating the browning.However,no significant change of color was observed in the group without thirteen-spices,while TBARS and free radical content increased by at least 16.7%.The removal of hepatopancreas and the control of Maillard reaction were deemed to be a good measure for inhibiting the non-enzymatic browning of RTE crayfish tails.
文摘In 2003, Tang Qihe et al. obtained a simple asymptotic formula for independent identically distributed (i.i.d.) random variables with heavy tails. In this paper, under certain moment conditions, we establish a formula as the same as Tang’s, when random variables are negatively associated (NA).
基金supported by the National Natural Science Foundation of China(No.52374121)the Henan Province Science and Technology Research and Development Joint Fund,China(No.235200810016)the National Key Research and Development Program,China(No.2023YFC2907203).
文摘Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.
基金the University of Ottawa, the China Scholarship Council and the Natural Sciences and Engineering Research Council of Canada (NSERC) for their financial support.
文摘As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.
基金supported by the National Science Foundation for Excellent Young Scholars of China (Grant No.52422809)the National Natural Science Foundation of China (Grant No.52208491)。
文摘Polypropylene fibers(PPFs) have been widely used in composite materials due to their sound crack resistance and toughness. In cement-based composites, the incorporation of PPFs can significantly improve their dynamic mechanical properties. However, cement-iron ore tailings foam composite(CIFC), a sustainable material utilizing iron ore tailings to partially replace cement, has not been investigated under dynamic loading. This study investigates the dynamic compressive behavior of CIFC with 1%–2.5% PPF content and 3–12 mm PPF lengths under various strain rates. The microstructural characteristics were analyzed prior to dynamic testing. X-ray diffraction(XRD) identified crystalline phases including CaCO_(3)Fe_(2)O_(3), SiO, C-S-H gel, and ettringite. Scanning electron microscopy(SEM) observations demonstrated that appropriate PPF_(2) parameters(e.g., C2L9, a CIFC specimen containing 2% PPF with 9 mm length) enhance fiber-matrix bonding and minimize interconnected pores and microcracks, revealing pronounced fiber bridging effects. Split Hopkinson pressure bar(SHPB) tests were then conducted at strain rates of 120–250 s^(-1), showing that the dynamic properties of CIFC were highly dependent on both strain rates and PPF parameters. Compared to other specimens, C2L9 exhibited a more intact failure pattern with superior compressive strength and energy dissipation capacity, despite showing reduced dynamic increase factor(DIF) and normalized energy dissipation(NED) values. These findings provide practical guidance for applying CIFC with varying PPF parameters in impact-resistant structural designs.
文摘Background:Minimally invasive distal pancreatectomy(MIDP)is increasingly being used,although its oncologic safety for pancreatic ductal adenocarcinoma(PDAC)remains controversial.In Japan,MIDP for PDAC has limited endorsement due to insufficient data.This study aimed to compare the perioperative and long-term outcomes of open distal pancreatectomy(ODP)and MIDP for PDAC.Methods:We retrospectively analyzed patients with resectable pancreatic body and tail cancer treated with ODP or MIDP(laparoscopic or robotic)between January 2007 and July 2022.The surgical procedures(ODP and MIDP)were compared and the patient characteristics,perioperative outcomes,and long-term outcomes were analyzed.We also compared the outcomes of patients with neoadjuvant chemotherapy(NAC)and without NAC.Results:A total of 72 distal pancreatectomies were performed(37 ODPs and 35 MIDPs).In the upfront group,MIDP resulted in significantly less blood loss than ODP(P<0.01),despite similar operative time.There was no statistically significant difference in the 2-year recurrence-free survival(RFS)rates between ODP and MIDP(39.7%vs.57.8%,P=0.60)or in the overall survival(OS)rates(66.7%vs.74.1%,P=0.43).Similarly,in the NAC group,MIDP resulted in significantly less blood loss than ODP(P=0.01);ODP and MIDP had similar 2-year RFS rates(41.7%and 60.0%,P=0.75)and OS rates(50.0%and 70.0%,P=0.36).The interval from surgery to adjuvant chemotherapy initiation did not significantly differ between the ODP and MIDP subgroups in both the upfront group(P=0.13)and the NAC group(P=0.14).The incidence of recurrence was 64.8%for ODP and 42.8%for MIDP(P=0.06).Both procedures showed similar distributions of local and distant recurrence.Conclusions:MIDP caused less blood loss and had similar oncologic safety compared with ODP.MIDP could become a feasible,minimally invasive option with sufficient oncologic safety for pancreatic body and tail cancers.
基金Projects(52374138,51764013)supported by the National Natural Science Foundation of ChinaProject(20204BCJ22005)supported by the Training Plan for Academic and Technical Leaders of Major Disciplines of Jiangxi Province,China+1 种基金Project(2019M652277)supported by the China Postdoctoral Science FoundationProject(20192ACBL21014)supported by the Natural Science Youth Foundation Key Projects of Jiangxi Province,China。
文摘The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the stability of underground mining engineering,this paper simulates the generation of different degrees of initial defects inside the CTB by adding different contents of air-entraining agent(AEA),investigates the acoustic emission RA/AF eigenvalues of CTB with different contents of AEA under uniaxial compression,and adopts various denoising algorithms(e.g.,moving average smoothing,median filtering,and outlier detection)to improve the accuracy of the data.The variance and autocorrelation coefficients of RA/AF parameters were analyzed in conjunction with the critical slowing down(CSD)theory.The results show that the acoustic emission RA/AF values can be used to characterize the progressive damage evolution of CTB.The denoising algorithm processed the AE signals to reduce the effects of extraneous noise and anomalous spikes.Changes in the variance curves provide clear precursor information,while abrupt changes in the autocorrelation coefficient can be used as an auxiliary localization warning signal.The phenomenon of dramatic increase in the variance and autocorrelation coefficient curves during the compression-tightening stage,which is influenced by the initial defects,can lead to false warnings.As the initial defects of the CTB increase,its instability precursor time and instability time are prolonged,the peak stress decreases,and the time difference between the CTB and the instability damage is smaller.The results provide a new method for real-time monitoring and early warning of CTB instability damage.
基金supported by National Natural Science Foundation of China(Grant No.10571139)the Research Foundation of Education Bureau of Hubei Province,China(Grant No.Q200710002)
文摘This paper studies the moderate deviations of real-valued extended negatively dependent(END)random variables with consistently varying tails.The moderate deviations of partial sums are first given.The results are then used to establish the necessary and sufficient conditions for the moderate deviations of random sums under certain circumstances.
基金Research supported by National Science Foundation of China(No.10271087)
文摘In this paper, we obtain results on precise large deviations for non-random and random sums of negatively associated nonnegative random variables with common dominatedly varying tail distribution function. We discover that, under certain conditions, three precise large-deviation prob- abilities with different centering numbers are equivalent to each other. Furthermore, we investigate precise large deviations for sums of negatively associated nonnegative random variables with certain negatively dependent occurrences. The obtained results extend and improve the corresponding results of Ng, Tang, Yan and Yang （J. Appl. Prob., 41, 93-107, 2004）.
