Aiming at the problems that the simulation accuracy which is reduced due to the simplification of the model,a three-dimensional simulation method based on solid modeling is being proposed.By analyzing the motion relat...Aiming at the problems that the simulation accuracy which is reduced due to the simplification of the model,a three-dimensional simulation method based on solid modeling is being proposed.By analyzing the motion relationship and positional relationship between the caries knife and the workpiece,the coordinate system of the caries machining was established.With the MATLAB software,the cutting edge model and the blade sweeping surface model of the boring cutter are sequentially established.Boolean operation is performed on the blade swept surface formed by the tooth cutter teeth with time t and the workpiece tooth geometry as well as the undeformed three-dimensional chip geometry model and the instantaneous cogging geometry model are obtained at different times.Through the compare between gear end face simulation tooth profile and the theoretical inner arc tooth profile,we verified the accuracy and rationality of the proposed method.展开更多
A central Pacific(CP)El Niño event occurred in 2018/19.Previous studies have shown that different mechanisms are responsible for different subtypes of CP El Niño events(CP-I El Niño and CP-II El Niñ...A central Pacific(CP)El Niño event occurred in 2018/19.Previous studies have shown that different mechanisms are responsible for different subtypes of CP El Niño events(CP-I El Niño and CP-II El Niño).By comparing the evolutions of surface winds,ocean temperatures,and heat budgets of the CP-I El Niño,CP-II El Niño,and 2018/19 El Niño,it is illustrated that the subtropical westerly anomalies in the North Pacific,which led to anomalous convergence of Ekman flow and surface warming in the central equatorial Pacific,played an important role in the 2018/19 El Niño event as well as in the CP-II El Niño.Although the off-equatorial forcing played a vital role,it is found that the equatorial forcing acted as a driving(damping)term in boreal spring(summer)of the 2018/19 El Niño.The 2018/19 El Niño provides a timely and vivid example that helps illustrate the proposed mechanism of the CP El Niño,which could be leveraged to improve El Niño predictability.展开更多
Objective: There are no comprehensive studies on survival outcomes and optimal treatment protocols for cervical esophageal cancer(CEC), due to its rare clinical prevalence. Our objective was to determine the relations...Objective: There are no comprehensive studies on survival outcomes and optimal treatment protocols for cervical esophageal cancer(CEC), due to its rare clinical prevalence. Our objective was to determine the relationship between pathological characteristics, treatment protocols, and survival outcomes in Chinese CEC patients.Methods: A total of 500 Chinese CEC patients were selected from our 500,000 esophageal and gastric cardia carcinoma database(1973–2018). There were two main groups: patients treated with surgery, and patients receiving non-surgical treatments(radiotherapy, radiochemotherapy, and chemotherapy). The Chi-square test and Kaplan–Meier method were used to compare the continuous variables and survival.Results: Among the 500 CEC patients, 278(55.6%) were male, and the median age was 60.9 ± 9.4 years. A total of 496 patients(99.2%) were diagnosed with squamous cell carcinoma. In 171(34.2%) patients who received surgery, 22(12.9%) had undergone laryngectomy. In 322(64.4%) patients who received non-surgical treatments, 245(76.1%) received radiotherapy. Stratified survival analysis showed that only T stage was related with survival outcomes for CEC patients in the surgical group, and the outcomes between laryngectomy and non-laryngectomy patients were similar. It was noteworthy that the 5-year survival rate was similar in CEC patients among the different groups treated with surgery, radiotherapy, chemotherapy, or radiochemotherapy(P = 0.244). Conclusions: The CEC patients had similar survival outcomes after curative esophagectomy and radiotherapy, including those with or without total laryngectomy. These findings suggest that radiotherapy could be the initial choice for treatment of Chinese CEC patients.展开更多
Carbonate reservoirs in Western China show tremendous exploration and development potential.These have become the key area for oil and gas reserves addition and sustainable resource development for China.Compared to c...Carbonate reservoirs in Western China show tremendous exploration and development potential.These have become the key area for oil and gas reserves addition and sustainable resource development for China.Compared to conventional carbonate reservoirs,prediction of this kind of reservoir predominated by secondary storage is much more difficultand presents significant challenges.展开更多
Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable p...Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable production and highly enhancing the printing/dyeing color fastness.By only adding trace amounts of salt into the suspensions,here we experimentally achieve the facile and highly efficient control of the coffee ring effect of suspended matter on substrates of graphene,natural graphite,and polyethylene terephthalate surfaces.Notably,friction force measurements show that ion-controlled uniform patterns also greatly enhance color fastness.Molecular dynamics simulations reveal that,due to strong hydrated cation-π interactions between hydrated cations and aromatic rings in the substrate surface,the suspended matters are adsorbed on the surfaces mediated by cations so that the suspended matters are uniformly distributed.These findings will open new avenues for fabricating functional patterns on graphene substrates and will benefit practical applications including printing,coating,and dyeing.展开更多
There is a considerable amount of work that shows the biomagnetism of organic components without ferromagnetic components at the molecular level,but it is of great challenge to cover the giant gap of biomagnetism betw...There is a considerable amount of work that shows the biomagnetism of organic components without ferromagnetic components at the molecular level,but it is of great challenge to cover the giant gap of biomagnetism between their experimental and theoretical results.Here we show that the diamagnetism of aromatic peptides is greatly enhanced for about 11 times by self-assembling,reaching two orders of magnitude higher than the mass susceptibility of pure water.The self-assembly of aromatic rings in the peptide molecules plays the key role in such a strong diamagnetism.展开更多
Paleo-oil reservoir is of great importance to understand hydrocarbon enrichment mechanism and hydrocarbon exploration potential,but is yet poorly investigated in Kuqa Depression.The occurrence of the paleo-oil reservo...Paleo-oil reservoir is of great importance to understand hydrocarbon enrichment mechanism and hydrocarbon exploration potential,but is yet poorly investigated in Kuqa Depression.The occurrence of the paleo-oil reservoir in Dabei area was proved by quantitative grain fluorescence(QGF)and fluid inclusion petrography.Development history of the paleo-oil reservoir was reconstructed through:(1)oil-source correlation;(2)time coupling of source rock maturation,porosity evolution and migration pathways.The impact of paleo-oil reservoir on tight-gas accumulation was consequently discussed.Results suggest that considerable oil was accumulated in the K_(1)bs reservoir with paleo oil-water contact in Dabei 2 Well and Dabei 201 Well at 5800 and 6040 m,respectively.Crude oil was primarily sourced from Triassic source rocks with Jurassic source rocks of secondary importance,which was at oil generation window(0.7%–1.1%Ro)during 9–6 and 7.5–5 Ma,respectively.The occurrence of K_(1)bs tight reservoir(porosity<12%)was about 25 Ma,while faults and associated fractures at Kelasue structural belt were developed approximately from 8 to 3.5 Ma.Therefore,the tight oil accumulation was formed during 8–5 Ma.The paleo-oil reservoir in Dabei 1 gas field was destroyed by the evaporation fractionation in later stage.展开更多
The transaction-level analysis of security price changes by Madhavan,Richardson,and Roomans(1997,hereafter MRR)is a useful framework for financial analysis.The first-order Markov property of trading indicator variable...The transaction-level analysis of security price changes by Madhavan,Richardson,and Roomans(1997,hereafter MRR)is a useful framework for financial analysis.The first-order Markov property of trading indicator variables is a critical assumption in the MRR model,which contradicts the information lag empirically demonstrated in high-frequency trading processes.In this study,a nonparametric test is employed,which shows that the Markov property of the trading indicator variables is rejected on most trading days.Based on the spread decomposed structure,an MA-MRR model was proposed with a moving average structure adopted to absorb the information lag as an extension.The empirical results show that the information lag plays an important role in measuring the adverse selection risk parameter and that the difference in this parameter between the original and the extension is significant.Furthermore,our analysis suggests that the information lag parameter is a useful measure of the average speed at which information is incorporated into prices.展开更多
Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can allevia...Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can alleviate synthetic burdens without the need for resynthesis.Here we describe a photocatalytic oxygenisotopic labeling protocol that can efficiently and selectively install ^(18)O and ^(17)O on carbonyls of ketones and aldehydes via oxygen isotope exchange with oxygen-isotopic waters(H_(2)^(18)O or H_(2)^(17)O)as the sources of oxygen isotopes,in which light and oxygen-enabled sodium alkanesulfinates catalyzed this process.This strategy was extended to the in-situ formed ketones from the photocatalytic aerobic oxidation of alkyl arenes and secondary alcohols.Furthermore,reduction of the oxygen-isotopically labeled aldehydes with NaBH_(4) provided the corresponding oxygen-isotopically labeled primary alcohols.We believe that the oxygen-isotopically labeling method will be widely used in chemistry,biology and medicine fields.展开更多
Aims Better understanding of microbial compositional and physiological acclimation mechanisms is critical for predicting terrestrial ecosystem responses to global change.The aim is to assess variations in soil microbi...Aims Better understanding of microbial compositional and physiological acclimation mechanisms is critical for predicting terrestrial ecosystem responses to global change.The aim is to assess variations in soil microbial communities under future scenarios of changing precipitation and N deposition in a semiarid grassland of northern China.Methods In order to explicitly estimate microbial responses,a field experiment with water and N addition was established in April 2005 and continuously conducted for 4 years.Specifically,soil microbial community composition and microbial C utilization potential were determined by phospholipid fatty acid(PLFA)and community-level physiological profiles,respectively.Important Findings Water addition had no effects on the PLFA concentrations of grampositive(GP)and negative bacteria(GN),total bacteria and fungi.However,N addition caused significant reductions in the PLFA concentrations of GP,GN,total bacteria and fungi and thus decreased total PLFA of microbial communities.Moreover,there were interactive effects of water and N addition on GN/GPand the ratio of fungal to bacterial PLFA(F/B).In addition,synergistic effects were found between water and nitrogen in affecting microbial C utilization potentials,which implies that microbial C utilization potentials tend to be enhanced when both N and water availability are sufficient.Overall,the microbial responses to water and N addition support our hypothesis that water and N addition may be combined together to affect microbial communities in the semiarid grassland.展开更多
No clinically available biomarkers can predict pathological complete response(pCR)for esophageal squamous cell carcinomas(ESCCs)with neoadjuvant chemoradiotherapy(nCRT).Considering that antitumor immunity status is an...No clinically available biomarkers can predict pathological complete response(pCR)for esophageal squamous cell carcinomas(ESCCs)with neoadjuvant chemoradiotherapy(nCRT).Considering that antitumor immunity status is an important determinant for nCRT,we performed an integrative analysis of immune-related gene profiles from pretreatment biopsies and constructed the first individualized immune signature for pCR and outcome prediction of ESCCs through a multicenter analysis.During the discovery phase,14 differentially expressed immune-related genes(DEIGs)with greater than a twofold change between pCRs and less than pCRs(<pCRs)were revealed from 28 pretreatment tumors in a Guangzhou cohort using microarray data.Ten DEIGs were verified by qPCR from 30 cases in a Beijing discovery cohort.Then,a four-gene-based immune signature(SERPINE1,MMP12,PLAUR,and EPS8)was built based on the verified DEIGs from 71 cases in a Beijing training cohort,and achieved a high accuracy with an area under the receiver operating characteristic curve(AUC)of 0.970.The signature was further validated in an internal validation cohort and an integrated external cohort(Zhengzhou and Anyang cohorts)with AUCs of 0.890 and 0.859,respectively.Importantly,a multivariate analysis showed that the signature was the only independent predictor for pCR.In addition,patients with high predictive scores showed significantly longer overall and relapse-free survival across multiple centers(P<0.05).This is the first,validated,and clinically applicable individualized immune signature of pCR and outcome prediction for ESCCs with nCRT.Further prospective validation may facilitate the combination of nCRT and immunotherapy.展开更多
The effects of sediment aluminum(Al),organic carbon(OC),and dissolved oxygen(DO)on phosphorus(P)transformation,at the water-sediment interface of a eutrophic constructed lake,were investigated via a series of simulati...The effects of sediment aluminum(Al),organic carbon(OC),and dissolved oxygen(DO)on phosphorus(P)transformation,at the water-sediment interface of a eutrophic constructed lake,were investigated via a series of simulative experiments.The above three factors had various influences on dissolved P concentration,water pH,water and surface sediment appearance,and P fractions.Additions of Al had the greatest effect on suppressing P release,and the water p H remained alkaline in the water-sediment system under various OC and DO conditions.No dissolution of the added Al was detected.31P-N M R characterization suggested that OC addition did not promote biological P uptake to polyphosphates under oxic conditions.The simulation result on the added phytate indicated the absence of phytate in the original lake sediment.As compared to the reported natural lakes and wetland,the water-sediment system of the constructed lake responded differently to some simulative conditions.Since Al,OC,and DO can be controlled with engineering methods,the results of this study provide insights for the practical site restorations.展开更多
An asymmetric supercapacitor (ASC) was assembled by using an activated carbon as positive electrode and WO3 nanowire as negative electrode, and its electrical performances were tested in voltage windows ranging from...An asymmetric supercapacitor (ASC) was assembled by using an activated carbon as positive electrode and WO3 nanowire as negative electrode, and its electrical performances were tested in voltage windows ranging from 0 to 1.5 V. A high specific capacitance of 51 Fog-1 could be achieved at the current density of 0.25 A·g-1 . Moreover, the ASC displays a good cycling stability with 86% of capacitance retention after 800 cycles, its energy density can be up to 11.9 Wh·kg-1 at the power density of 210 W·kg -1, and remains 7.7 Wh·kg-1 at a power density of 1250 W· kg-1. The excellent electrical performance is perhaps due to the crystal orientation of (001) planes for the WO3 nanowire, which favors the rapid reaction between W(VI) and H+ cations. This aqueous asymmetric WO3//AC supercapacitor is promising for practical applications due to its easy preparation of WO3.展开更多
Esophageal squamous cell carcinoma (ESCC) has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exon...Esophageal squamous cell carcinoma (ESCC) has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exonic mutations and structural alterations. The clinical implications of these genetic alterations were also analyzed. Exome sequencing and verification were performed for nine pairs of ESCC and the matched blood samples, followed by validation with additional sam- ples using Sanger sequencing. Whole-genomc SNP arrays were employed to detect copy number alteration (CNA) and loss of heterozygosity (LOH) in 55 cases, including the nine ESCC samples subjected to exome sequencing. A total of 108 non-synonymous somatic mutations (NSSMs) in 102 genes were verified in nine patients. The chromatin modification process was found to be enriched in our gene ontology (GO) analysis. Tumor genomes with TP53 mutations were signifi- cantly more unstable than those without TP53 mutations. In terms of the landscape of genomic alterations, deletion of 9p21.3 covering CDKN2A/2B (30.9%), amplification of 1 1q13.3 covering CCND1 (30.9%), and TP53 point mutation (50.9%) occurred in two-thirds of the cases. These results suggest that the deregulation of the G1 phase during the cell cycle is a key event in ESCC. Furthermore, six minimal common regions were found to be significantly altered in ESCC samples and three of them, 9p21.3, 7p 11.2, and 3p 12.1, were associated with lymph node metastasis. With the high correlation of TP53 mutation and genomic instability in ESCC, the amplification of CCND1, the deletion of CDKN2A/2B, and the somatic mutation of TP53 appear to play pivotal roles via G1 deregulation and therefore helps to classify this cancer into different genomic subtypes. These findings provide clinical significance that could be useful in future molecular diagnoses and therapeutic targeting.展开更多
The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a numb...The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.展开更多
Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately fe...Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.展开更多
The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of th...The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e^+e^- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.展开更多
基金The National Natural Science Foundation of China (No.52165060,12272189)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region: (NJYT23022)+2 种基金Science and Technology Projects of Inner Mongolia Autonomous Region: (2021GG0432)Central Guiding Local Science and Technology Development Plan (2022ZY0013)Basic research business fee project for universities directly under Inner Mongolia Autonomous Region (GXKY22046).
文摘Aiming at the problems that the simulation accuracy which is reduced due to the simplification of the model,a three-dimensional simulation method based on solid modeling is being proposed.By analyzing the motion relationship and positional relationship between the caries knife and the workpiece,the coordinate system of the caries machining was established.With the MATLAB software,the cutting edge model and the blade sweeping surface model of the boring cutter are sequentially established.Boolean operation is performed on the blade swept surface formed by the tooth cutter teeth with time t and the workpiece tooth geometry as well as the undeformed three-dimensional chip geometry model and the instantaneous cogging geometry model are obtained at different times.Through the compare between gear end face simulation tooth profile and the theoretical inner arc tooth profile,we verified the accuracy and rationality of the proposed method.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41925024 and 41876021)Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB42000000)+2 种基金Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences (ISEE2021ZD01)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0306)Natural Science Foundation of Shandong Province, China (Grant No. ZR2020QD065)
文摘A central Pacific(CP)El Niño event occurred in 2018/19.Previous studies have shown that different mechanisms are responsible for different subtypes of CP El Niño events(CP-I El Niño and CP-II El Niño).By comparing the evolutions of surface winds,ocean temperatures,and heat budgets of the CP-I El Niño,CP-II El Niño,and 2018/19 El Niño,it is illustrated that the subtropical westerly anomalies in the North Pacific,which led to anomalous convergence of Ekman flow and surface warming in the central equatorial Pacific,played an important role in the 2018/19 El Niño event as well as in the CP-II El Niño.Although the off-equatorial forcing played a vital role,it is found that the equatorial forcing acted as a driving(damping)term in boreal spring(summer)of the 2018/19 El Niño.The 2018/19 El Niño provides a timely and vivid example that helps illustrate the proposed mechanism of the CP El Niño,which could be leveraged to improve El Niño predictability.
基金supported by the National Key R&D Program “Precision Medicine” of China (Grant No. 2016YFC0901403)the Major Science and Technology Projects of Henan Province (Grant No. 16110031 1300)+2 种基金the Doctoral Team Foundation of the First Affiliated Hospital of Zhengzhou University (Grant No. 2016-BSTDJJ-03)the National Natural Science Foundation of China (Grant No. 81872032, U1804262)the State Key Laboratory of Esophageal Cancer Prevention and Treatment (Grant No. Z2020-0010)。
文摘Objective: There are no comprehensive studies on survival outcomes and optimal treatment protocols for cervical esophageal cancer(CEC), due to its rare clinical prevalence. Our objective was to determine the relationship between pathological characteristics, treatment protocols, and survival outcomes in Chinese CEC patients.Methods: A total of 500 Chinese CEC patients were selected from our 500,000 esophageal and gastric cardia carcinoma database(1973–2018). There were two main groups: patients treated with surgery, and patients receiving non-surgical treatments(radiotherapy, radiochemotherapy, and chemotherapy). The Chi-square test and Kaplan–Meier method were used to compare the continuous variables and survival.Results: Among the 500 CEC patients, 278(55.6%) were male, and the median age was 60.9 ± 9.4 years. A total of 496 patients(99.2%) were diagnosed with squamous cell carcinoma. In 171(34.2%) patients who received surgery, 22(12.9%) had undergone laryngectomy. In 322(64.4%) patients who received non-surgical treatments, 245(76.1%) received radiotherapy. Stratified survival analysis showed that only T stage was related with survival outcomes for CEC patients in the surgical group, and the outcomes between laryngectomy and non-laryngectomy patients were similar. It was noteworthy that the 5-year survival rate was similar in CEC patients among the different groups treated with surgery, radiotherapy, chemotherapy, or radiochemotherapy(P = 0.244). Conclusions: The CEC patients had similar survival outcomes after curative esophagectomy and radiotherapy, including those with or without total laryngectomy. These findings suggest that radiotherapy could be the initial choice for treatment of Chinese CEC patients.
文摘Carbonate reservoirs in Western China show tremendous exploration and development potential.These have become the key area for oil and gas reserves addition and sustainable resource development for China.Compared to conventional carbonate reservoirs,prediction of this kind of reservoir predominated by secondary storage is much more difficultand presents significant challenges.
基金the National Natural Science Foundation of China under Grant Nos.U1632135,U1832170,11862003,11474299,11574339,U1932123,and 11722548the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Nos.QYZDJ-SSW-SLH053 and QYZDJ-SSW-SLH019)the Key Research Program of the Chinese Academy of Sciences(No.KJZDEW-M03)。
文摘Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable production and highly enhancing the printing/dyeing color fastness.By only adding trace amounts of salt into the suspensions,here we experimentally achieve the facile and highly efficient control of the coffee ring effect of suspended matter on substrates of graphene,natural graphite,and polyethylene terephthalate surfaces.Notably,friction force measurements show that ion-controlled uniform patterns also greatly enhance color fastness.Molecular dynamics simulations reveal that,due to strong hydrated cation-π interactions between hydrated cations and aromatic rings in the substrate surface,the suspended matters are adsorbed on the surfaces mediated by cations so that the suspended matters are uniformly distributed.These findings will open new avenues for fabricating functional patterns on graphene substrates and will benefit practical applications including printing,coating,and dyeing.
基金Supported by the National Natural Science Foundation of China(Grant Nos.U1632135,11974366,U1932123,51763019 and U1832125)the Key Research Program of Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SLH053)the Fundamental Research Funds for the Central Universities.
文摘There is a considerable amount of work that shows the biomagnetism of organic components without ferromagnetic components at the molecular level,but it is of great challenge to cover the giant gap of biomagnetism between their experimental and theoretical results.Here we show that the diamagnetism of aromatic peptides is greatly enhanced for about 11 times by self-assembling,reaching two orders of magnitude higher than the mass susceptibility of pure water.The self-assembly of aromatic rings in the peptide molecules plays the key role in such a strong diamagnetism.
基金supported by the China National Science and Technology Major Project(No.2016ZX05047-001-006).
文摘Paleo-oil reservoir is of great importance to understand hydrocarbon enrichment mechanism and hydrocarbon exploration potential,but is yet poorly investigated in Kuqa Depression.The occurrence of the paleo-oil reservoir in Dabei area was proved by quantitative grain fluorescence(QGF)and fluid inclusion petrography.Development history of the paleo-oil reservoir was reconstructed through:(1)oil-source correlation;(2)time coupling of source rock maturation,porosity evolution and migration pathways.The impact of paleo-oil reservoir on tight-gas accumulation was consequently discussed.Results suggest that considerable oil was accumulated in the K_(1)bs reservoir with paleo oil-water contact in Dabei 2 Well and Dabei 201 Well at 5800 and 6040 m,respectively.Crude oil was primarily sourced from Triassic source rocks with Jurassic source rocks of secondary importance,which was at oil generation window(0.7%–1.1%Ro)during 9–6 and 7.5–5 Ma,respectively.The occurrence of K_(1)bs tight reservoir(porosity<12%)was about 25 Ma,while faults and associated fractures at Kelasue structural belt were developed approximately from 8 to 3.5 Ma.Therefore,the tight oil accumulation was formed during 8–5 Ma.The paleo-oil reservoir in Dabei 1 gas field was destroyed by the evaporation fractionation in later stage.
基金supported by the National Natural Science Foundation of China(Grant number:71771008)Science and Technology Support Plan of Guizhou(Grant No.2023-221)the Funds for the First-class Discipline Construction(XK 1802-5).
文摘The transaction-level analysis of security price changes by Madhavan,Richardson,and Roomans(1997,hereafter MRR)is a useful framework for financial analysis.The first-order Markov property of trading indicator variables is a critical assumption in the MRR model,which contradicts the information lag empirically demonstrated in high-frequency trading processes.In this study,a nonparametric test is employed,which shows that the Markov property of the trading indicator variables is rejected on most trading days.Based on the spread decomposed structure,an MA-MRR model was proposed with a moving average structure adopted to absorb the information lag as an extension.The empirical results show that the information lag plays an important role in measuring the adverse selection risk parameter and that the difference in this parameter between the original and the extension is significant.Furthermore,our analysis suggests that the information lag parameter is a useful measure of the average speed at which information is incorporated into prices.
基金supported by Natural Science Foundation of Beijing Municipality(No.2222011)National Natural Science Foundation of China(No.22077074)China Postdoctoral Science Foundation(No.2021M701869).
文摘Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can alleviate synthetic burdens without the need for resynthesis.Here we describe a photocatalytic oxygenisotopic labeling protocol that can efficiently and selectively install ^(18)O and ^(17)O on carbonyls of ketones and aldehydes via oxygen isotope exchange with oxygen-isotopic waters(H_(2)^(18)O or H_(2)^(17)O)as the sources of oxygen isotopes,in which light and oxygen-enabled sodium alkanesulfinates catalyzed this process.This strategy was extended to the in-situ formed ketones from the photocatalytic aerobic oxidation of alkyl arenes and secondary alcohols.Furthermore,reduction of the oxygen-isotopically labeled aldehydes with NaBH_(4) provided the corresponding oxygen-isotopically labeled primary alcohols.We believe that the oxygen-isotopically labeling method will be widely used in chemistry,biology and medicine fields.
基金National Natural Science Foundation of China(30970497)Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-JC401).
文摘Aims Better understanding of microbial compositional and physiological acclimation mechanisms is critical for predicting terrestrial ecosystem responses to global change.The aim is to assess variations in soil microbial communities under future scenarios of changing precipitation and N deposition in a semiarid grassland of northern China.Methods In order to explicitly estimate microbial responses,a field experiment with water and N addition was established in April 2005 and continuously conducted for 4 years.Specifically,soil microbial community composition and microbial C utilization potential were determined by phospholipid fatty acid(PLFA)and community-level physiological profiles,respectively.Important Findings Water addition had no effects on the PLFA concentrations of grampositive(GP)and negative bacteria(GN),total bacteria and fungi.However,N addition caused significant reductions in the PLFA concentrations of GP,GN,total bacteria and fungi and thus decreased total PLFA of microbial communities.Moreover,there were interactive effects of water and N addition on GN/GPand the ratio of fungal to bacterial PLFA(F/B).In addition,synergistic effects were found between water and nitrogen in affecting microbial C utilization potentials,which implies that microbial C utilization potentials tend to be enhanced when both N and water availability are sufficient.Overall,the microbial responses to water and N addition support our hypothesis that water and N addition may be combined together to affect microbial communities in the semiarid grassland.
基金supported by the CAMS Innovation Fund for Medical Sciences(2017-I2M-1-005,2016-I2M-1-001)the National Key R&D Program of China(2016YFC1303201)+2 种基金the National Natural Science Foundation of China(81802299,81502514)the Fundamental Research Funds for the Central Universities(3332018070)the National Key Basic Research Development Plan(2018YFC1312105).
文摘No clinically available biomarkers can predict pathological complete response(pCR)for esophageal squamous cell carcinomas(ESCCs)with neoadjuvant chemoradiotherapy(nCRT).Considering that antitumor immunity status is an important determinant for nCRT,we performed an integrative analysis of immune-related gene profiles from pretreatment biopsies and constructed the first individualized immune signature for pCR and outcome prediction of ESCCs through a multicenter analysis.During the discovery phase,14 differentially expressed immune-related genes(DEIGs)with greater than a twofold change between pCRs and less than pCRs(<pCRs)were revealed from 28 pretreatment tumors in a Guangzhou cohort using microarray data.Ten DEIGs were verified by qPCR from 30 cases in a Beijing discovery cohort.Then,a four-gene-based immune signature(SERPINE1,MMP12,PLAUR,and EPS8)was built based on the verified DEIGs from 71 cases in a Beijing training cohort,and achieved a high accuracy with an area under the receiver operating characteristic curve(AUC)of 0.970.The signature was further validated in an internal validation cohort and an integrated external cohort(Zhengzhou and Anyang cohorts)with AUCs of 0.890 and 0.859,respectively.Importantly,a multivariate analysis showed that the signature was the only independent predictor for pCR.In addition,patients with high predictive scores showed significantly longer overall and relapse-free survival across multiple centers(P<0.05).This is the first,validated,and clinically applicable individualized immune signature of pCR and outcome prediction for ESCCs with nCRT.Further prospective validation may facilitate the combination of nCRT and immunotherapy.
基金This study was supported by the National Key Research Project on Water Environment Pollution Control in China(Nos.2012ZX07301 and 2017ZX07202002).
文摘The effects of sediment aluminum(Al),organic carbon(OC),and dissolved oxygen(DO)on phosphorus(P)transformation,at the water-sediment interface of a eutrophic constructed lake,were investigated via a series of simulative experiments.The above three factors had various influences on dissolved P concentration,water pH,water and surface sediment appearance,and P fractions.Additions of Al had the greatest effect on suppressing P release,and the water p H remained alkaline in the water-sediment system under various OC and DO conditions.No dissolution of the added Al was detected.31P-N M R characterization suggested that OC addition did not promote biological P uptake to polyphosphates under oxic conditions.The simulation result on the added phytate indicated the absence of phytate in the original lake sediment.As compared to the reported natural lakes and wetland,the water-sediment system of the constructed lake responded differently to some simulative conditions.Since Al,OC,and DO can be controlled with engineering methods,the results of this study provide insights for the practical site restorations.
基金Financial support from the Distinguished Young Scientists Program of the National Natural Science Foundation of China (No. 51425301), the Science and Technology Commission of Shanghai Municipality (Nos. 12JC1401200 and 14520721800) and the Hunan Provincial Natural Science Foundation of China (No. 143J2081) is gratefully appreciated.
文摘An asymmetric supercapacitor (ASC) was assembled by using an activated carbon as positive electrode and WO3 nanowire as negative electrode, and its electrical performances were tested in voltage windows ranging from 0 to 1.5 V. A high specific capacitance of 51 Fog-1 could be achieved at the current density of 0.25 A·g-1 . Moreover, the ASC displays a good cycling stability with 86% of capacitance retention after 800 cycles, its energy density can be up to 11.9 Wh·kg-1 at the power density of 210 W·kg -1, and remains 7.7 Wh·kg-1 at a power density of 1250 W· kg-1. The excellent electrical performance is perhaps due to the crystal orientation of (001) planes for the WO3 nanowire, which favors the rapid reaction between W(VI) and H+ cations. This aqueous asymmetric WO3//AC supercapacitor is promising for practical applications due to its easy preparation of WO3.
基金supported by the National Basic Research Program of China from the National Ministry of Science and Technology(973 Program)to YK(Grant No.2011CB504300)and to HC(Grant No.2012CB910800)the National Natural Science Foundation of China(Grant No.30930102)to YK+3 种基金the National High-tech R&D Program of China(863 ProgramGrant No.2012AA022502)Key Research Program of the Chinese Academy of Sciences of China(Grant No.KJZD-EW-L06-2)to CZthe Open Fund of MOE Key Laboratory of Carcinogenesis and Translational Research(Grant No.2014KAIFANG-4)to JB
文摘Esophageal squamous cell carcinoma (ESCC) has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exonic mutations and structural alterations. The clinical implications of these genetic alterations were also analyzed. Exome sequencing and verification were performed for nine pairs of ESCC and the matched blood samples, followed by validation with additional sam- ples using Sanger sequencing. Whole-genomc SNP arrays were employed to detect copy number alteration (CNA) and loss of heterozygosity (LOH) in 55 cases, including the nine ESCC samples subjected to exome sequencing. A total of 108 non-synonymous somatic mutations (NSSMs) in 102 genes were verified in nine patients. The chromatin modification process was found to be enriched in our gene ontology (GO) analysis. Tumor genomes with TP53 mutations were signifi- cantly more unstable than those without TP53 mutations. In terms of the landscape of genomic alterations, deletion of 9p21.3 covering CDKN2A/2B (30.9%), amplification of 1 1q13.3 covering CCND1 (30.9%), and TP53 point mutation (50.9%) occurred in two-thirds of the cases. These results suggest that the deregulation of the G1 phase during the cell cycle is a key event in ESCC. Furthermore, six minimal common regions were found to be significantly altered in ESCC samples and three of them, 9p21.3, 7p 11.2, and 3p 12.1, were associated with lymph node metastasis. With the high correlation of TP53 mutation and genomic instability in ESCC, the amplification of CCND1, the deletion of CDKN2A/2B, and the somatic mutation of TP53 appear to play pivotal roles via G1 deregulation and therefore helps to classify this cancer into different genomic subtypes. These findings provide clinical significance that could be useful in future molecular diagnoses and therapeutic targeting.
基金The work was supported by the National Science and Technology Major Project of China(No.2016ZX05003-004).
文摘The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.
基金This work was financially support from the National Key R&D Program of China(no.2016YFA0200200)the National Program on Key Basic Research Project(973 program,no.2013CB933804)+1 种基金the National Natural Science Foundation of China(no.21271112)the Tribology Science Fund of State Key Laboratory of Tribology(SKLTKF20B18).
文摘Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.
基金Supported by the National Key Program for S&T Researh and Development(2016YFA0400400)CAS Center for Excellence in Particle Physics+12 种基金Yifang Wang’s Science Studio of the Ten Thousand Talents Projectthe CAS/SAFEA International Partnership Program for Creative Research Teams(H751S018S5)IHEP Innovation Grant(Y4545170Y2)Key Research Program of Frontier Sciences,CAS(XQYZDY-SSW-SLH002)Chinese Academy of Science Special Grant for Large Scientific Project(113111KYSB20170005)the National Natural Science Foundation of China(11675202)the Hundred Talent Programs of Chinese Academy of Science(Y3515540U1)the National 1000 Talents Program of ChinaFermi Research Alliance,LLC(DE-AC02-07CH11359)the NSF(PHY1620074)by the Maryland Center for Fundamental Physics(MCFP)Tsinghua University Initiative Scientific Research Programthe Beijing Municipal Science and Technology Commission project(Z181100004218003)
文摘The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e^+e^- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.