Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a ...Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a lower temperature. The water model experiment of a six-strand tundish of Tianjin Iron ＆ Steel Co. Ltd. was performed, a new ＂U＂ type baffle was obtained, and its parameters were defined by perpendicular analysis. The ＂U＂ baffle can not only improve those imperfections, but also prolong the residence time of nonmetallic inclusions, which is good for their flotation and separation.展开更多
The present study examines the results of the researches related to the gob bulking factor carried out at home and abroad.A mathematical function of a three-dimensional gob bulking factor is described based on a three...The present study examines the results of the researches related to the gob bulking factor carried out at home and abroad.A mathematical function of a three-dimensional gob bulking factor is described based on a three-dimensional gob model.The method of taking value for interstice and permeability ratios is also proposed.The law of air leakage of fully mechanized top coal is researched in this study.The results show that the speed of air flow near the upper and lower crossheadings is higher than that in the central section of the gob at the same distance from the working face.When the amount of air at the working face exceeds a critical amount,the width of the spontaneous combustion zone in the upper and lower crossheadings is also larger than that in the central section.In this situation,the key is preventing the coal left in the upper and lower crossheadings from self-igniting.Reducing the amount of air at the working face can decrease the width of the spontaneous combustion zone,especially the width near the upper and lower crossheadings.This also moves the spontaneous combustion zone in the direction of the working face.It can prevent the coal in the gob from self-igniting by making the coal left in the crossheadings to be inert and by effectively controlling the amount of air at the working face.展开更多
Grain weight and grain number are two important traits directly determining grain yield in rice. To date,a lot of genes related to grain weight and grain number have been identified; however, the regulatory mechanism ...Grain weight and grain number are two important traits directly determining grain yield in rice. To date,a lot of genes related to grain weight and grain number have been identified; however, the regulatory mechanism underlying these genes remains largely unknown. In this study, we studied the biological function of OsSPL18 during grain and panicle development in rice. Knockout (KO) mutants of OsSPL18exhibited reduced grain width and thickness, panicle length and grain number, but increased tiller number. Cytological analysis showed that OsSPL18 regulates the development of spikelet hulls by affecting cell proliferation. qRT-PCR and GUS staining analyses showed that OsSPL18 was highly expressed in developing young panicles and young spikelet hulls, in agreement with its function in regulating grain and panicle development. Transcriptional activation experiments indicated that OsSPL18is a functional transcription factor with activation domains in both the N-terminus and C-terminus, and both activation domains are indispensable for its biological functions. Quantitative expression analysis showed that DEP1, a major grain number regulator, was significantly down-regulated in OsSPL18 KO lines.Both yeast one-hybrid and dual-luciferase (LUC) assays showed that OsSPL18 could bind to the DEP1promoter, suggesting that OsSPL18 regulates panicle development by positively regulating the expression of DEP1. Sequence analysis showed that OsSPL18 contains the OsmiR156k complementary sequence in the third exon; 5?RLM-RACE experiments indicated that OsSPL18 could be cleaved by OsmiR156k. Taken together, our results uncovered a new OsmiR156k-OsSPL18-DEP1 pathway regulating grain number in rice.展开更多
In order to investigate the oxidation kinetics of gas coal at low temperatures, we derived a rate equation of oxygen consumption during low-temperature oxidation of gas coal and deduced an E-c equation, expressing the...In order to investigate the oxidation kinetics of gas coal at low temperatures, we derived a rate equation of oxygen consumption during low-temperature oxidation of gas coal and deduced an E-c equation, expressing the relation between active energy E and oxygen concentration c. The reaction order n and active energy E were calculated with this equation based on experiments of static oxygen consumption tests. In addition, we proved the rationality of the E-c equation using a kinetic compensation effect and obtained the isokinetic temperature Tc. The results show that： 1） the gas coal oxidizes easily with increasing temperature and the oxidation tends to be spontaneous at higher temperatures; 2） the oxygen concentration c affects oxygen consumption very much at lower temperatures but has only a small effect at higher temperatures; 3） the isokinetic temperature Tc was 127 ℃ which has been experimentally validated as the key turning point during low-temperature spontaneous combustion of gas coal.展开更多
This present study focused on investigating the content and relative enrichment multiple of rare earth elements（REEs） in different terrain of weathered ore body, and the value of light rare earth elements/middle and...This present study focused on investigating the content and relative enrichment multiple of rare earth elements（REEs） in different terrain of weathered ore body, and the value of light rare earth elements/middle and heavy rare earth elements（LREEs/HREEs）, in order to understand the mobilization and redistribution of HREEs, Furthermore, the abrasion pH was investigated as well, The results show that the average contents of HREEs in the knap, ridge and col are 37.26, 61.71, and 271.3 μg/g, respectively. The value of LREEs/HREEs is decreased from 16.78 to 7.914 between knap and col and the relative enrichment multiple of HREEs is as follows： CCol-HREEs 〉 CRidge-HREEs 〉 0. It is indicated the HREEs is concentrated in the col and the enrichment degree of HREEs is stronger than the ridge and the knap. Rare earth elements fractionation is exhibited in the different terrain of weathered ore body. Based on this study, the finding that HREEs concentrate in the lower terrain of weathered crust elution-deposited rare earth ores, such as in the col, would become a marker or indicator to search for middle and heavy rare earth enriched zone.展开更多
Neomycins are a group of aminoglycoside antibiotics with both clinical and agricultural applications.To elucidate the regulatory mechanism of neomycin biosynthesis,we completed draft genome sequencing of a neomycin pr...Neomycins are a group of aminoglycoside antibiotics with both clinical and agricultural applications.To elucidate the regulatory mechanism of neomycin biosynthesis,we completed draft genome sequencing of a neomycin producer Streptomyces fradiae CGMCC 4.7387 from marine sediments,and the neomycin biosynthesis gene cluster was identified.Inactivation of the afsA-g gene encoding a γ-butyrolactone(GBL) synthase in S.fradiae CGMCC 4.7387 resulted in a significant decrease of neomycin production.Quantitative RT-PCR analysis revealed that the transcriptional level of neoR and the aphA-neoGH operon were reduced in the afsA-g::aac(3)Ⅳ mutant.Interestingly,a conserved binding site of AdpA,a key activator in the GBL regulatory cascade,was discovered upstream of neoR,a putative regulatory gene encoding a protein with an ATPase domain and a tetratricopeptide repeat domain.When neoR was inactivated,the neomycin production was reduced about 40%in comparison with the WT strain.Quantitative RT-PCR analysis revealed that the transcriptional levels of genes in the aphA-neoGH operon were reduced clearly in the neoR::aac(3)Ⅳ mutant.Finally,the titers of neomycin were improved considerably by overexpression of qfsA-gand neoR in S.fradiae CGMCC 4.7387.展开更多
An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching appro...An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.展开更多
The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped w...The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.展开更多
After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a h...After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust. Considering these factors, this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent, then configuring five kinds of wetting agents by adopting various doses and types of surfactants, neutral inorganic salts and chemical additives, etc. After purchasing DA-85 and SRJ-1 wetting agent, the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method. Wetting agent A was confirmed to have the best comprehensive effect. The experiments were optimized by measuring and comparatively analyzing contact angles of pure water, SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument （HARKE- SPCA）. By comparative analysis, dust-proof effects of seam, dynamic pressure water infusion and high- pressure spray in the tunneling face at the Daning coal mine using pure water, wetting agent SRJ-1 and A, it was determined that after using wetting agent A, the average dust concentration in the place of the mining machine driver, 10 m and 110 m away from the tunneling front is approximately 300 rag/ m^3, 240 mg/m^3 and 100 mg/m^3, respectively, This practice increased the dust-proof efficiency dramati- cally and achieved a good comprehensive dust-proof effect.展开更多
Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamin...Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamine（PDA） and dopamine（DA） monomer have recently been reported to increase osteoblast proliferation and mineralization in vitro. Although a well-characterized neurotransmitter, DA＇s role in the bone is unknown. We hypothesize that DA can directly act on osteoblasts, and examined whether osteoblasts express DA receptors that respond to exogenous DA. m RNAs and protein cell lysates were obtained from MC3T3-E1 cells during osteogenic differentiation phase. Reverse transcription polymerase chain reaction and western blot analysis were used to examine the expression of DA receptors, D1–D5. Dose-response effect and time course of DA treatment on cell proliferation, mineralization, and osteogenic differentiation were investigated at pre-determined days. Real-time PCR was performed to investigate whether DA affects osteogenic gene expression（ALP, BSP, OC, OSX, RUNX2, and Collagen1a2） with or without receptor antagonists（SCH233390 and GR103691）. Two-way ANOVA was used for statistical analysis. All five DA receptors（D1, D2, D3, D4, and D5） m RNAs and proteins were expressed in MC3T3-E1 cells. DA treatment increased cell proliferation for up to 7 days（P, 0.05）. Osteogenic mineralization was significantly greater in the DA-treated group than control group（P, 0.05）. Finally, expression of all the osteogenic genes was inhibited by DA receptor antagonists for D1, D3, and D5. Our findings suggest that MC3T3-E1 osteoblasts express functional DA receptors that enhance proliferation and mineralization. PDA is not biologically inert and has important implications in orthopedic applications. Furthermore, osteoblast differentiation might be regulated by the nervous system, presumably during bone development, remodeling, or repair.展开更多
A Synthesis Load Model (SLM) including both the power load and the distribution network has been proposed in the references. The identifiability of SLM is analyzed at first, it is concluded that the model parameters a...A Synthesis Load Model (SLM) including both the power load and the distribution network has been proposed in the references. The identifiability of SLM is analyzed at first, it is concluded that the model parameters are identifiable if one of the resistance, reactance and the ratio of them is known. The conclusion is validated through a simulation example. A strategy for parameter identification of SLM is proposed with the combination of the component based approach and the measurement based approach. During parameter identification, only the key parameters playing very important roles in the dynamics of the load and the system are estimated, while the other parameters playing limited role are set as the default values. The proposed strategy is verified by the field measurements.展开更多
OBJECTIVE:To evaluate the efficacy and safety of Zhumian Tang formula granules(助眠汤配方颗粒)combined with eszopiclone for treating poor sleep quality.METHODS:This multi-center,dynamic blockrandomized,parallel-group ...OBJECTIVE:To evaluate the efficacy and safety of Zhumian Tang formula granules(助眠汤配方颗粒)combined with eszopiclone for treating poor sleep quality.METHODS:This multi-center,dynamic blockrandomized,parallel-group superiority clinical trial included 130 patients.The combined treatment group received Zhumian Tang formula granules combined with eszopiclone treatment,and the control group received eszopiclone treatment only.The group allocation ratio was 1∶1.The duration of treatment was 2 weeks.Participants were asked to complete questionnaires before treatment,after 1 week of the intervention,after 2 weeks of the intervention,and at the follow-up on week 3.The primary outcomes were the Pittsburgh Sleep Quality Index(PSQI)score and the total effective rate of treatment.The secondary outcome was the rate of adverse effects.RESULTS:Compared with the eszopiclone treatment group,the PSQI score of the combined treatment group was significantly lower after 2 weeks of the intervention(6.98 vs 8.26,P<0.05).However,there was no significant difference in the mean PSQI score after 1 week of the intervention(9.89 vs 9.15,P=0.124).After the follow-up on week 3,the PSQI score of the combined treatment group remained significantly lower than that of the eszopiclone treatment group(6.12 vs 8.31,P<0.001).The total effective rates of treatment of the combined group and the eszopiclone group were 36.92%vs 35.38%(Z=0.033,P=0.855)after 1 week of the intervention,83.08%vs 58.46%(Z=9.519,P<0.05)after 2 weeks of the intervention,and 83.08%vs 61.54%(Z=7.530,P<0.05)and after the follow-up on week 3,respectively.There was no significant difference in the overall rate of adverse reactions between the combined and eszopiclone treatment groups(21.53%vs 31.8%,P=0.318).CONCLUSION:The combination of Zhumian Tang formula granules with eszopiclone was found to be safe and more effective in improving sleep quality than eszopiclone alone.Traditional Chinese medicine can enhance the effectiveness of Western medicine in the treatment of inso展开更多
In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging v...In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging vacuum chamber on pipe.That is to say,the vacuum chamber has the effect of absorbing wave and energy.To further deeply analyze the vacuum chamber suppressing gas explosion,this research designed the L-type pipe of gas explosion,and compared the experimental results of gas explosion with vacuum chamber and without vacuum chamber.Besides,using the gas chromatograph,this study also investigated the gas compositions in the pipe before and after explosion.The results show that:(1)without vacuum chamber,the maximum value of explosion overpressure is 0.22 MPa,with60 ms duration,and after explosion,the concentration of oxygen drops to 12.07%,but the concentration of carbon monoxide increases to 4392.3 10à6,and the concentration of carbon dioxide goes up to7.848%,which can make the persons in danger suffocate and die;(2)with vacuum chamber,explosion overpressure drops to 0.18 MPa,with 20 ms duration or less,and after explosion,the concentration of oxygen still remains 12.07%,but the concentration of methane is 7.83%,however the concentration of carbon monoxide is only 727.24 10à6,and the concentration of carbon dioxide is only 1.219%,at the this moment the concentration ratio of toxic gas drops by more than 83%in comparison to be that without vacuum chamber.Consequently,the vacuum chamber can guarantee that most methane does not take part in chemical reaction,and timely quenches the deflagration reaction of gas and oxygen.Because of the two points mentioned above,it reduces the explosion energy,and lowers that the overpressure of blast wave impacts and damages on the persons and facilities,and also decreases the consumption of oxygen and the production of the toxic gas.Therefore,it is safe to conclude that the vacuum chamber not only absorbs wave and energy,but also prevents and suppresses explosion.展开更多
Dear Editor,The ability to manipulate single-nucleotide variations(SNVs),multiple-nucleotide variations(MNVs),and structural variations(SVs)in rice genomes is crucial for studying gene function and improving agricultu...Dear Editor,The ability to manipulate single-nucleotide variations(SNVs),multiple-nucleotide variations(MNVs),and structural variations(SVs)in rice genomes is crucial for studying gene function and improving agricultural traits.Traditionally,these manipulations were achieved mainly through homology-directed repair,which has limited efficiency in plants.展开更多
To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples...To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples were collected from 91 stations and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed for each sample. The results show that the average concentration of dissolved inorganic nitrogen (DIN) in the Bohai Sea in winter (6.529 μmol L -1) is significantly higher than that in summer (3.717 μmol L -1). The phosphorus concentration in winter (0.660 μmol L -1) is also significantly higher than that in summer (0.329 μmol L -1). Mean silicate concentration in winter (7.858 μmol L -1) is, however, not significantly different from that in summer (7.200 μmol L -1). Nutrients also vary considerably in different areas in Bohai Sea. DIN concentration in the Laizhou Bay (4.444 μmol L -1), for example, is significantly higher than those in the Bohai Bay (2.270 μmol L -1) and Bohai Strait (2.431 μmol L -1), which is caused by the discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients show different vertical distribution patterns. In summer, nutrients in bottom layer are generally richer than those in surface and middle layers. In winter, however, nutrients are not significantly different in different layers. Compared with historic data, DIN contents have increased continually since the early 1980 s. Based on atomic ratios of different nutrients, nitrogen is still the limiting factor for algal growth in the Bohai Sea.展开更多
Genome editing,particularly using the CRISPR/Cas system,has revolutionized biological research and crop improvement.Despite the widespread use of CRISPR/Cas9,it faces limitations such as PAM sequence requirements and ...Genome editing,particularly using the CRISPR/Cas system,has revolutionized biological research and crop improvement.Despite the widespread use of CRISPR/Cas9,it faces limitations such as PAM sequence requirements and challenges in delivering its large protein into plant cells.The hypercompact Cas12f,derived from Acidibacillus sulfuroxidans(AsCas12f),stands out due to its small size of only 422 amino acids and its preference for a T-rich motif,presenting advantageous features over SpCas9.However,its editing efficiency is extremely low in plants.Recent studies have generated two AsCas12f variants,AsCas12f-YHAM and AsCas12f-HKRA,demonstrating higher editing efficiencies in mammalian cells,yet their performance in plants remains unexplored.In this study,through a systematic investigation of genome cleavage activity in rice,we unveiled a substantial enhancement in editing efficiency for both AsCas12f variants,particularly for AsCas12f-HKRA,which achieved an editing efficiency of up to 53%.Furthermore,our analysis revealed that AsCas12f predominantly induces deletion in the target DNA,displaying a unique deletion pattern primarily concentrated at positions 12,13,23,and 24,resulting in deletion size mainly of 10 and 11 bp,suggesting significant potential for targeted DNA deletion using AsCas12f.These findings expand the toolbox for efficient genome editing in plants,offering promising prospects for precise genetic modifications in agriculture.展开更多
OBJECTIVE To evaluate the applicability of combined therapyand the prognostic factors in patients with carcinoma of thecervical stump (CCS).METHODS The clinical records of 60 CCS patients whounderwent combined treatme...OBJECTIVE To evaluate the applicability of combined therapyand the prognostic factors in patients with carcinoma of thecervical stump (CCS).METHODS The clinical records of 60 CCS patients whounderwent combined treatment in our hospital during a periodfrom January 2000 to December 2007, were collected andretrospectively analyzed. The prognostic factors were studiedusing univariate analysis. Analytical evaluation of the independentprognostic factors was performed using COX proportionalhazardsregression model.RESULTS The 1-, 3- and 5-year survival rates of the 60 patientswere 95%, 78% and 68%, respectively, with a median survivaltime of 32 months. Univariate survival analysis showed thatthese independent prognostic factors included positive pelviclymph nodes (P = 0.001), lymphovascular tumor embolus (P =0.001), and adjuvant chemotherapy (P = 0.011). In the 60 cases,postoperative local recurrence in the pelvic cavity occurred in1 and distant metastasis in 3. Related complications, such asradiocystitis, recto-vaginal fistula and vesico-vaginal fistula werefound in 6 of the total cases (10%). The serum levels of squamousepithelium antigen detected before and after treatment weresignificantly different (P = 0.000). The incidence of CCS is low;however, the disease is difficult to cure due to the high incidenceof complications and to the frequency of distant metastasis.Therefore, individualized treatment is needed. Complications fromsubtotal hysterectomy (STH) should be treated and controlledaggressively. Careful follow-up as well as close monitoring andobservation for significant symptoms in the postoperative coursewill enhance clinical outcome.CONCLUSION Cancer of the cervical stump has a lowmorbidity and severe complications, and most recurrences aredistant metastases. Because it is difficult to cure, there is a needto design a treatment regimen for each individual patient basedon the factors deemed as high risk. The surgical indications forsubtotal uterine resection should be followed and close follow-upafter surgery 展开更多
Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse...Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.展开更多
In this paper, we consider the empirical likelihood inference for the jump-diffusion model. We construct the confidence intervals based on the empirical likelihood for the infinitesimal moments in the jump-diffusion m...In this paper, we consider the empirical likelihood inference for the jump-diffusion model. We construct the confidence intervals based on the empirical likelihood for the infinitesimal moments in the jump-diffusion models. They are better than the confidence intervals which are based on the asymptotic normality of point estimates.展开更多
文摘Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a lower temperature. The water model experiment of a six-strand tundish of Tianjin Iron ＆ Steel Co. Ltd. was performed, a new ＂U＂ type baffle was obtained, and its parameters were defined by perpendicular analysis. The ＂U＂ baffle can not only improve those imperfections, but also prolong the residence time of nonmetallic inclusions, which is good for their flotation and separation.
基金Financial support for this work was obtained from the National Natural Science Foundation of China(No.51074059)
文摘The present study examines the results of the researches related to the gob bulking factor carried out at home and abroad.A mathematical function of a three-dimensional gob bulking factor is described based on a three-dimensional gob model.The method of taking value for interstice and permeability ratios is also proposed.The law of air leakage of fully mechanized top coal is researched in this study.The results show that the speed of air flow near the upper and lower crossheadings is higher than that in the central section of the gob at the same distance from the working face.When the amount of air at the working face exceeds a critical amount,the width of the spontaneous combustion zone in the upper and lower crossheadings is also larger than that in the central section.In this situation,the key is preventing the coal left in the upper and lower crossheadings from self-igniting.Reducing the amount of air at the working face can decrease the width of the spontaneous combustion zone,especially the width near the upper and lower crossheadings.This also moves the spontaneous combustion zone in the direction of the working face.It can prevent the coal in the gob from self-igniting by making the coal left in the crossheadings to be inert and by effectively controlling the amount of air at the working face.
基金supported by funds from the Rice Molecular Design Breeding (2016YFD0101801)the National Natural Science Foundation of China (91535102 and 31771760)the Open Research Fund of State Key Laboratory of Hybrid Rice (2016KF09)
文摘Grain weight and grain number are two important traits directly determining grain yield in rice. To date,a lot of genes related to grain weight and grain number have been identified; however, the regulatory mechanism underlying these genes remains largely unknown. In this study, we studied the biological function of OsSPL18 during grain and panicle development in rice. Knockout (KO) mutants of OsSPL18exhibited reduced grain width and thickness, panicle length and grain number, but increased tiller number. Cytological analysis showed that OsSPL18 regulates the development of spikelet hulls by affecting cell proliferation. qRT-PCR and GUS staining analyses showed that OsSPL18 was highly expressed in developing young panicles and young spikelet hulls, in agreement with its function in regulating grain and panicle development. Transcriptional activation experiments indicated that OsSPL18is a functional transcription factor with activation domains in both the N-terminus and C-terminus, and both activation domains are indispensable for its biological functions. Quantitative expression analysis showed that DEP1, a major grain number regulator, was significantly down-regulated in OsSPL18 KO lines.Both yeast one-hybrid and dual-luciferase (LUC) assays showed that OsSPL18 could bind to the DEP1promoter, suggesting that OsSPL18 regulates panicle development by positively regulating the expression of DEP1. Sequence analysis showed that OsSPL18 contains the OsmiR156k complementary sequence in the third exon; 5?RLM-RACE experiments indicated that OsSPL18 could be cleaved by OsmiR156k. Taken together, our results uncovered a new OsmiR156k-OsSPL18-DEP1 pathway regulating grain number in rice.
基金financial support provided by the National Key Technology R&D Program during the 11th Five-Year Period (No. 2006BAK03B05)the National Natural Science Foundation of China (Nos.50534090, 50674090 and 50804047)+1 种基金the Research Fund of the State Key Laboratory of Coal Resources and Mine Safety, China University of Mining and Technology (Nos.08KF14 and SKLCRSM09X04)the Scien-tific Research Foundation of China University of Mining & Technology (No.2007A001)
文摘In order to investigate the oxidation kinetics of gas coal at low temperatures, we derived a rate equation of oxygen consumption during low-temperature oxidation of gas coal and deduced an E-c equation, expressing the relation between active energy E and oxygen concentration c. The reaction order n and active energy E were calculated with this equation based on experiments of static oxygen consumption tests. In addition, we proved the rationality of the E-c equation using a kinetic compensation effect and obtained the isokinetic temperature Tc. The results show that： 1） the gas coal oxidizes easily with increasing temperature and the oxidation tends to be spontaneous at higher temperatures; 2） the oxygen concentration c affects oxygen consumption very much at lower temperatures but has only a small effect at higher temperatures; 3） the isokinetic temperature Tc was 127 ℃ which has been experimentally validated as the key turning point during low-temperature spontaneous combustion of gas coal.
基金Project supported by National Natural Science Foundation of China(41472071,51734001)
文摘This present study focused on investigating the content and relative enrichment multiple of rare earth elements（REEs） in different terrain of weathered ore body, and the value of light rare earth elements/middle and heavy rare earth elements（LREEs/HREEs）, in order to understand the mobilization and redistribution of HREEs, Furthermore, the abrasion pH was investigated as well, The results show that the average contents of HREEs in the knap, ridge and col are 37.26, 61.71, and 271.3 μg/g, respectively. The value of LREEs/HREEs is decreased from 16.78 to 7.914 between knap and col and the relative enrichment multiple of HREEs is as follows： CCol-HREEs 〉 CRidge-HREEs 〉 0. It is indicated the HREEs is concentrated in the col and the enrichment degree of HREEs is stronger than the ridge and the knap. Rare earth elements fractionation is exhibited in the different terrain of weathered ore body. Based on this study, the finding that HREEs concentrate in the lower terrain of weathered crust elution-deposited rare earth ores, such as in the col, would become a marker or indicator to search for middle and heavy rare earth enriched zone.
基金funded in part by the Ministry of Science and Technology of China(2015CB150600)the National Natural Science Foundation of China(31370095 and 31522001)
文摘Neomycins are a group of aminoglycoside antibiotics with both clinical and agricultural applications.To elucidate the regulatory mechanism of neomycin biosynthesis,we completed draft genome sequencing of a neomycin producer Streptomyces fradiae CGMCC 4.7387 from marine sediments,and the neomycin biosynthesis gene cluster was identified.Inactivation of the afsA-g gene encoding a γ-butyrolactone(GBL) synthase in S.fradiae CGMCC 4.7387 resulted in a significant decrease of neomycin production.Quantitative RT-PCR analysis revealed that the transcriptional level of neoR and the aphA-neoGH operon were reduced in the afsA-g::aac(3)Ⅳ mutant.Interestingly,a conserved binding site of AdpA,a key activator in the GBL regulatory cascade,was discovered upstream of neoR,a putative regulatory gene encoding a protein with an ATPase domain and a tetratricopeptide repeat domain.When neoR was inactivated,the neomycin production was reduced about 40%in comparison with the WT strain.Quantitative RT-PCR analysis revealed that the transcriptional levels of genes in the aphA-neoGH operon were reduced clearly in the neoR::aac(3)Ⅳ mutant.Finally,the titers of neomycin were improved considerably by overexpression of qfsA-gand neoR in S.fradiae CGMCC 4.7387.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.9215010612021004,and 11934006)the Innovation Project of Optics Valley Laboratory(No.OVL2021ZD001),the Major Program(JD)of Hubei Province(No.203BAA015)the Cross Research Support Program of Huazhong University of Science and Technology(No.2023JCYJ041).
文摘An ultrafast fiber laser system comprising two coherently combined amplifier channels is reported.Within this system,each channel incorporates a rod-type fiber power amplifier,with individual operations reaching approximately 233 W.The active-locking of these coherently combined channels,followed by compression using gratings,yields an output with a pulse energy of 504μJ and an average power of 403 W.Exceptional stability is maintained,with a 0.3%root mean square(RMS)deviation and a beam quality factor M^(2)<1.2.Notably,precise dispersion management of the front-end seed light effectively compensates for the accumulated high-order dispersion in subsequent amplification stages.This strategic approach results in a significant reduction in the final output pulse duration for the coherently combined laser beam,reducing it from 488 to 260 fs after the gratings compressor,while concurrently enhancing the energy of the primary peak from 65%to 92%.
基金supported by the Cyrus Chun Ying Tang Foundationsthe Major Science and Technology Project of Qinghai Province(Grant No.2019ZJ-A10)+4 种基金the 111 Project for“Observational and Theoretical Research on Dark Matter and Dark Energy”(Grant No.B23042)the National Natural Science Foundation of China(Grant Nos.11833007,12073078,12173088,12192221,12192224,12233008,12273036,and 12273113)the Frontier Scientific Research Program of Deep Space Exploration Laboratory(Grant No.2022-QYKYJH-HXYF-012)the support from the USTC Research Funds of the Double First-Class Initiative(Grant No.YD2030002009)Project for Young Scientists in Basic Research of the Chinese Academy of Sciences(Grant No.YSBR-061),respectively。
文摘The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.
基金partly supported by the National Natural Science Foundation of China (No.51404263)the National Natural Science Foundation of Jiangsu Province (No.BK20130203)+3 种基金the Coal Mine Joint Funds of the National Natural Science Foundation of China (No.51134023)the State Key Laboratory Cultivation Base for Gas Geology and Gas Control (No.WS2013A05)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the independent study for State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology (No.SKLCRSM09X04)
文摘After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust. Considering these factors, this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent, then configuring five kinds of wetting agents by adopting various doses and types of surfactants, neutral inorganic salts and chemical additives, etc. After purchasing DA-85 and SRJ-1 wetting agent, the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method. Wetting agent A was confirmed to have the best comprehensive effect. The experiments were optimized by measuring and comparatively analyzing contact angles of pure water, SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument （HARKE- SPCA）. By comparative analysis, dust-proof effects of seam, dynamic pressure water infusion and high- pressure spray in the tunneling face at the Daning coal mine using pure water, wetting agent SRJ-1 and A, it was determined that after using wetting agent A, the average dust concentration in the place of the mining machine driver, 10 m and 110 m away from the tunneling front is approximately 300 rag/ m^3, 240 mg/m^3 and 100 mg/m^3, respectively, This practice increased the dust-proof efficiency dramati- cally and achieved a good comprehensive dust-proof effect.
基金supported in part by NIH/NIDCR K08DE018695, K12-EY016333/ K08-EY021520 (HCT), and R01DE022816
文摘Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamine（PDA） and dopamine（DA） monomer have recently been reported to increase osteoblast proliferation and mineralization in vitro. Although a well-characterized neurotransmitter, DA＇s role in the bone is unknown. We hypothesize that DA can directly act on osteoblasts, and examined whether osteoblasts express DA receptors that respond to exogenous DA. m RNAs and protein cell lysates were obtained from MC3T3-E1 cells during osteogenic differentiation phase. Reverse transcription polymerase chain reaction and western blot analysis were used to examine the expression of DA receptors, D1–D5. Dose-response effect and time course of DA treatment on cell proliferation, mineralization, and osteogenic differentiation were investigated at pre-determined days. Real-time PCR was performed to investigate whether DA affects osteogenic gene expression（ALP, BSP, OC, OSX, RUNX2, and Collagen1a2） with or without receptor antagonists（SCH233390 and GR103691）. Two-way ANOVA was used for statistical analysis. All five DA receptors（D1, D2, D3, D4, and D5） m RNAs and proteins were expressed in MC3T3-E1 cells. DA treatment increased cell proliferation for up to 7 days（P, 0.05）. Osteogenic mineralization was significantly greater in the DA-treated group than control group（P, 0.05）. Finally, expression of all the osteogenic genes was inhibited by DA receptor antagonists for D1, D3, and D5. Our findings suggest that MC3T3-E1 osteoblasts express functional DA receptors that enhance proliferation and mineralization. PDA is not biologically inert and has important implications in orthopedic applications. Furthermore, osteoblast differentiation might be regulated by the nervous system, presumably during bone development, remodeling, or repair.
基金supported by Scientific Funds for Outstanding Young Scientists of China (Grant No. 50725723)
文摘A Synthesis Load Model (SLM) including both the power load and the distribution network has been proposed in the references. The identifiability of SLM is analyzed at first, it is concluded that the model parameters are identifiable if one of the resistance, reactance and the ratio of them is known. The conclusion is validated through a simulation example. A strategy for parameter identification of SLM is proposed with the combination of the component based approach and the measurement based approach. During parameter identification, only the key parameters playing very important roles in the dynamics of the load and the system are estimated, while the other parameters playing limited role are set as the default values. The proposed strategy is verified by the field measurements.
基金Supported by Sichuan Province Central Guided Local Science and Technology Development Special Project:a Study of the Chinese and Western Medicine Clinical Consensus Program for People with Poor Sleep Quality(No.2021ZYD0109)Natural Science Foundation of Sichuan Province:Study on the Efficacy and Mechanism of Acupuncture in Treating Drug-dependent Insomnia from the Liver based on Multi-modal f MRI Technology(No.2022NSFSC0858)。
文摘OBJECTIVE:To evaluate the efficacy and safety of Zhumian Tang formula granules(助眠汤配方颗粒)combined with eszopiclone for treating poor sleep quality.METHODS:This multi-center,dynamic blockrandomized,parallel-group superiority clinical trial included 130 patients.The combined treatment group received Zhumian Tang formula granules combined with eszopiclone treatment,and the control group received eszopiclone treatment only.The group allocation ratio was 1∶1.The duration of treatment was 2 weeks.Participants were asked to complete questionnaires before treatment,after 1 week of the intervention,after 2 weeks of the intervention,and at the follow-up on week 3.The primary outcomes were the Pittsburgh Sleep Quality Index(PSQI)score and the total effective rate of treatment.The secondary outcome was the rate of adverse effects.RESULTS:Compared with the eszopiclone treatment group,the PSQI score of the combined treatment group was significantly lower after 2 weeks of the intervention(6.98 vs 8.26,P<0.05).However,there was no significant difference in the mean PSQI score after 1 week of the intervention(9.89 vs 9.15,P=0.124).After the follow-up on week 3,the PSQI score of the combined treatment group remained significantly lower than that of the eszopiclone treatment group(6.12 vs 8.31,P<0.001).The total effective rates of treatment of the combined group and the eszopiclone group were 36.92%vs 35.38%(Z=0.033,P=0.855)after 1 week of the intervention,83.08%vs 58.46%(Z=9.519,P<0.05)after 2 weeks of the intervention,and 83.08%vs 61.54%(Z=7.530,P<0.05)and after the follow-up on week 3,respectively.There was no significant difference in the overall rate of adverse reactions between the combined and eszopiclone treatment groups(21.53%vs 31.8%,P=0.318).CONCLUSION:The combination of Zhumian Tang formula granules with eszopiclone was found to be safe and more effective in improving sleep quality than eszopiclone alone.Traditional Chinese medicine can enhance the effectiveness of Western medicine in the treatment of inso
基金Financial support from the State Key Laboratory Cultivation Base for Gas Geology and Gas Control of Henan Polytechnic University of China(No.WS2012A04)
文摘In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging vacuum chamber on pipe.That is to say,the vacuum chamber has the effect of absorbing wave and energy.To further deeply analyze the vacuum chamber suppressing gas explosion,this research designed the L-type pipe of gas explosion,and compared the experimental results of gas explosion with vacuum chamber and without vacuum chamber.Besides,using the gas chromatograph,this study also investigated the gas compositions in the pipe before and after explosion.The results show that:(1)without vacuum chamber,the maximum value of explosion overpressure is 0.22 MPa,with60 ms duration,and after explosion,the concentration of oxygen drops to 12.07%,but the concentration of carbon monoxide increases to 4392.3 10à6,and the concentration of carbon dioxide goes up to7.848%,which can make the persons in danger suffocate and die;(2)with vacuum chamber,explosion overpressure drops to 0.18 MPa,with 20 ms duration or less,and after explosion,the concentration of oxygen still remains 12.07%,but the concentration of methane is 7.83%,however the concentration of carbon monoxide is only 727.24 10à6,and the concentration of carbon dioxide is only 1.219%,at the this moment the concentration ratio of toxic gas drops by more than 83%in comparison to be that without vacuum chamber.Consequently,the vacuum chamber can guarantee that most methane does not take part in chemical reaction,and timely quenches the deflagration reaction of gas and oxygen.Because of the two points mentioned above,it reduces the explosion energy,and lowers that the overpressure of blast wave impacts and damages on the persons and facilities,and also decreases the consumption of oxygen and the production of the toxic gas.Therefore,it is safe to conclude that the vacuum chamber not only absorbs wave and energy,but also prevents and suppresses explosion.
基金supported by the STI 2030-Major Projects(2023ZD04074)to Y.Z.the National Natural Science Foundation of China(award nos.32301245 and 32072045)to Z.Z.and X.Z.
文摘Dear Editor,The ability to manipulate single-nucleotide variations(SNVs),multiple-nucleotide variations(MNVs),and structural variations(SVs)in rice genomes is crucial for studying gene function and improving agricultural traits.Traditionally,these manipulations were achieved mainly through homology-directed repair,which has limited efficiency in plants.
文摘To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples were collected from 91 stations and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed for each sample. The results show that the average concentration of dissolved inorganic nitrogen (DIN) in the Bohai Sea in winter (6.529 μmol L -1) is significantly higher than that in summer (3.717 μmol L -1). The phosphorus concentration in winter (0.660 μmol L -1) is also significantly higher than that in summer (0.329 μmol L -1). Mean silicate concentration in winter (7.858 μmol L -1) is, however, not significantly different from that in summer (7.200 μmol L -1). Nutrients also vary considerably in different areas in Bohai Sea. DIN concentration in the Laizhou Bay (4.444 μmol L -1), for example, is significantly higher than those in the Bohai Bay (2.270 μmol L -1) and Bohai Strait (2.431 μmol L -1), which is caused by the discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients show different vertical distribution patterns. In summer, nutrients in bottom layer are generally richer than those in surface and middle layers. In winter, however, nutrients are not significantly different in different layers. Compared with historic data, DIN contents have increased continually since the early 1980 s. Based on atomic ratios of different nutrients, nitrogen is still the limiting factor for algal growth in the Bohai Sea.
基金supported by the STI 2030—Major Projects(2023ZD04074)Guidance Foundation,the Sanya Institute of Nanjing Agricultural University(NAUSY-ZZ01)+3 种基金the Natural Science Foundation of Jiangsu(BK20210385,BK20212010)the Project of Zhongshan Biological Breeding Laboratory(ZSBBL-KY2023-04)the Jiangsu Province Key Research and Development Program(BE2023369)the Jiangsu“Innovative and Entrepreneurial Talent”program(to J.T.).
文摘Genome editing,particularly using the CRISPR/Cas system,has revolutionized biological research and crop improvement.Despite the widespread use of CRISPR/Cas9,it faces limitations such as PAM sequence requirements and challenges in delivering its large protein into plant cells.The hypercompact Cas12f,derived from Acidibacillus sulfuroxidans(AsCas12f),stands out due to its small size of only 422 amino acids and its preference for a T-rich motif,presenting advantageous features over SpCas9.However,its editing efficiency is extremely low in plants.Recent studies have generated two AsCas12f variants,AsCas12f-YHAM and AsCas12f-HKRA,demonstrating higher editing efficiencies in mammalian cells,yet their performance in plants remains unexplored.In this study,through a systematic investigation of genome cleavage activity in rice,we unveiled a substantial enhancement in editing efficiency for both AsCas12f variants,particularly for AsCas12f-HKRA,which achieved an editing efficiency of up to 53%.Furthermore,our analysis revealed that AsCas12f predominantly induces deletion in the target DNA,displaying a unique deletion pattern primarily concentrated at positions 12,13,23,and 24,resulting in deletion size mainly of 10 and 11 bp,suggesting significant potential for targeted DNA deletion using AsCas12f.These findings expand the toolbox for efficient genome editing in plants,offering promising prospects for precise genetic modifications in agriculture.
文摘OBJECTIVE To evaluate the applicability of combined therapyand the prognostic factors in patients with carcinoma of thecervical stump (CCS).METHODS The clinical records of 60 CCS patients whounderwent combined treatment in our hospital during a periodfrom January 2000 to December 2007, were collected andretrospectively analyzed. The prognostic factors were studiedusing univariate analysis. Analytical evaluation of the independentprognostic factors was performed using COX proportionalhazardsregression model.RESULTS The 1-, 3- and 5-year survival rates of the 60 patientswere 95%, 78% and 68%, respectively, with a median survivaltime of 32 months. Univariate survival analysis showed thatthese independent prognostic factors included positive pelviclymph nodes (P = 0.001), lymphovascular tumor embolus (P =0.001), and adjuvant chemotherapy (P = 0.011). In the 60 cases,postoperative local recurrence in the pelvic cavity occurred in1 and distant metastasis in 3. Related complications, such asradiocystitis, recto-vaginal fistula and vesico-vaginal fistula werefound in 6 of the total cases (10%). The serum levels of squamousepithelium antigen detected before and after treatment weresignificantly different (P = 0.000). The incidence of CCS is low;however, the disease is difficult to cure due to the high incidenceof complications and to the frequency of distant metastasis.Therefore, individualized treatment is needed. Complications fromsubtotal hysterectomy (STH) should be treated and controlledaggressively. Careful follow-up as well as close monitoring andobservation for significant symptoms in the postoperative coursewill enhance clinical outcome.CONCLUSION Cancer of the cervical stump has a lowmorbidity and severe complications, and most recurrences aredistant metastases. Because it is difficult to cure, there is a needto design a treatment regimen for each individual patient basedon the factors deemed as high risk. The surgical indications forsubtotal uterine resection should be followed and close follow-upafter surgery
基金supportedby the National Natural Science Foundation of China(Grant No.11875140),Science and Technology on Plasma Physics Laboratory(Grant No.6142A04200212)Innovation Project of Optics Valley Laboratory(Grant No.OVL2021ZD001),and Innovation Fund of WNLO.
文摘Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.
基金supported by National Natural Science Foundation of China(Grant No. 10771095)Natural Science Foundation of Jiangsu Province of China
文摘In this paper, we consider the empirical likelihood inference for the jump-diffusion model. We construct the confidence intervals based on the empirical likelihood for the infinitesimal moments in the jump-diffusion models. They are better than the confidence intervals which are based on the asymptotic normality of point estimates.
