The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST （drill stem test） crude oil and 8 rock samples were investigated using a comprehensive geochemical method to charact...The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST （drill stem test） crude oil and 8 rock samples were investigated using a comprehensive geochemical method to characterize and identify the origin of the Ordovician oils in the Tazhong Uplift, Tarim Basin, northwest China. Detailed oil–oil and oil–source rock correlations show that the majority of the oils have typical biomarker characteristics of the Middle-Upper Ordovician （O2＋3） source rock and the related crude oil. These characteristics include a distinct ＂V-shaped＂ relative abundance of C27, C28 and C29 regular steranes, low abundance of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. Only a few oils display typical biomarker characteristics indicating the Cambrian–Lower Ordovician （∈-O1） genetic affinity, such as linear or anti ＂L＂ shape distribution of C27, C28 and C29 regular sterane, with relatively high concentrations of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. It appears that most of the Ordovician oils in the Tazhong Uplift were derived from the O2＋3 intervals, as suggested by previous studies. However, the compound specific n-alkane stable carbon isotope data indicate that the Ordovician oils are mixtures from both the ∈-O1 and O2＋3 source rocks rather than from the O2＋3 strata alone. It was calculated that the proportion of the∈-O1 genetic affinity oils mixed is about 10.8%-74.1%, with an increasing trend with increasing burial depth. This new oil-mixing model is critical for understanding hydrocarbon generation and accumulation mechanisms in the region, and may have important implications for further hydrocarbon exploration in the Tarim Basin.展开更多
The effect of source size and emission time on the proton-proton(p-p)momentum correlation function(Cpp(q))has been studied systematically.Assuming a spherical Gaussian source with space and time profile according to t...The effect of source size and emission time on the proton-proton(p-p)momentum correlation function(Cpp(q))has been studied systematically.Assuming a spherical Gaussian source with space and time profile according to the function S(r,t)~exp(-r2/2 r02-t/τ)in the correlation function calculation code(CRAB),the results indicate that one Cpp(q)distribution corresponds to a unique combination of source size r0 and emission timeτ.Considering the possible nuclear deformation from a spherical nucleus,an ellipsoidal Gaussian source characterized by the deformation parameter∈=ΔR/R has been simulated.There is almost no difference of Cpp(q)between the results of spherically and ellipsoidally shaped sources with small deformation.These results indicate that a unique source size r0 and emission time could be extracted from the p-p momentum correlation function,which is especially important for identifying the mechanism of twoproton emission from proton-rich nuclei.Furthermore,considering the possible existence of cluster structures within a nucleus,the double Gaussian source is assumed.The results show that the p-p momentum correlation function for a source with or without cluster structures has large systematical differences with the variance of r0 andτ.This may provide a possible method for experimentally observing the cluster structures in proton-rich nuclei.展开更多
This study considers the Upper Cretaceous Qingshankou Formation,Yaojia Formation,and the first member of the Nenjiang Formation in the Western Slope of the northern Songliao Basin.Dark mudstone with high abundances of...This study considers the Upper Cretaceous Qingshankou Formation,Yaojia Formation,and the first member of the Nenjiang Formation in the Western Slope of the northern Songliao Basin.Dark mudstone with high abundances of organic matter of Gulong and Qijia sags are considered to be significant source rocks in the study area.To evaluate their development characteristics,differences and effectiveness,geochemical parameters are analyzed.One-dimensional basin modeling and hydrocarbon evolution are also applied to discuss the effectiveness of source rocks.Through the biomarker characteristics,the source–source,oil–oil,and oil–source correlations are assessed and the sources of crude oils in different rock units are determined.Based on the results,Gulong and Qijia source rocks have different organic matter primarily detrived from mixed sources and plankton,respectively.Gulong source rock has higher thermal evolution degree than Qijia source rock.The biomarker parameters of the source rocks are compared with 31 crude oil samples.The studied crude oils can be divided into two groups.The oil–source correlations show that group I oils from Qing II–III,Yao I,and Yao II–III members were probably derived from Gulong source rock and that only group II oils from Nen I member were derived from Qijia source rock.展开更多
The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the...The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the relaxation time of the system.In this study,we investigated the effect of relaxation time on the SBBC function.We propose a method for calculating the SBBC function with relaxation-time approximation for evolving sources.SBBC functions of D^(0)D^(-0)in relativistic heavy-ion collisions were investigated using a hydrodynamic model.We found that the relaxation time reduces the amplitudes of the SBBC functions.This becomes apparent for long relaxation times and large initial relative deviations of the chaotic and squeezed amplitudes from their equilibrium values in the temporal steps.展开更多
The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） o...The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance （Ro/%）, the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins.展开更多
In the future time the exploration of marine oil and gas will be one of the significant domains in China. In this paper the biomarker assemblage characteristics of oilshow in the Nanlinghu Formation of the Majiashan p...In the future time the exploration of marine oil and gas will be one of the significant domains in China. In this paper the biomarker assemblage characteristics of oilshow in the Nanlinghu Formation of the Majiashan pro- file, which is located in Chaoxian County, south of Anhui Province, are described in the light of gas chromatogra- phy/mass spectrometric (GCMS) analysis on the qualitative and quantitative basis. Based on the investigation of the biomarker assemblage characteristics of possible source rocks developed in the area studied, a conclusion is drawn that the oilshow was generated from the Nanlinghu Formation source rocks (abbreviated as T1n), instead of the Qixia Formation source rocks (abbreviated as P1q). It is pointed out that the T1n is of strong potential for future oil explora- tion, and therefore much attention should be paid to it.展开更多
In precision machining of complex curved surface parts with high performance, geometry accuracy is not the only constraint, but the performance should also be met. Performance of this kind of parts is closely related ...In precision machining of complex curved surface parts with high performance, geometry accuracy is not the only constraint, but the performance should also be met. Performance of this kind of parts is closely related to the geometrical and physical parameters, so the final actual size and shape are affected by multiple source constraints, such as geometry, physics, and performance. These parts are rather difficult to be manufactured and new manufacturing method according to performance requirement is urgently needed. Based on performance and manufacturing requirements for complex curved surface parts, a new classification method is proposed, which divided the complex curved surface parts into two categories： surface re-design complex curved surface parts with multi-source constraints（PRCS） and surface unique complex curved surface parts with pure geometric constraints（PUCS）. A correlation model is constructed between the performance and multi-source constraints for PRCS, which reveals the correlation between the performance and multi-source constraints. A re-design method is also developed. Through solving the correlation model of the typical paws performance-associated surface, the mapping relation between the performance-associated surface and the related removal amount is obtained. The explicit correlation model and the method for the corresponding related removal amount of the performance-associated surface are built based on the classification of surface re-design complex curved surface parts with multi-source constraints. Research results have been used in the actual processing of the typical parts such as radome, common bottom components, nozzle, et al., which shows improved efficiency and accuracy of the precision machining for the surface re-design parts with complex curved surface.展开更多
Stable carbon isotopes were used together with molecular markers to constrain genetic relationships between sandstone extracts and potential source rocks in the pre-Tertiary in the Huanghua Depression,North China.Comp...Stable carbon isotopes were used together with molecular markers to constrain genetic relationships between sandstone extracts and potential source rocks in the pre-Tertiary in the Huanghua Depression,North China.Comparison of the extracts from Permo-Carboniferous terrigenous mudstones and Ordovician marine carbonates indicated that their prominent differences are in stable carbon isotopes,molecular markers and thermal maturity.Although the extracts of the Mesozoic and Lower Permian Xiashihezi Formation sandstones have some similar iso-topic characteristics,molecular markers data provide a good correlation between the Upper Jurassic-Lower Cretaceous oils and the Upper Carboniferous Taiyuan Formation mudstones,and between the Lower Permian Xiashihezi Formation oils and the Lower Permian mudstones.The results showed that the Upper Jurassic-Lower Cretaceous sandstone oils were derived chiefly from the Upper Carboniferous Taiyuan Formation terrigenous mudstones and that the Lower Permian Xiashihezi Formation oils were sourced from the Lower Permian Shanxi Formation and Xiashihezi Formation terrigenous mudstones.展开更多
The identification of marine source rocks in the Tarim Basin is debated vigorously. The intention of this paper is to investigate the asphaltenes in heavy oils from the Lunnan and Tahe oilfields and Well TD2 with ruth...The identification of marine source rocks in the Tarim Basin is debated vigorously. The intention of this paper is to investigate the asphaltenes in heavy oils from the Lunnan and Tahe oilfields and Well TD2 with ruthenium-ions-catalyzed oxidation technique (RICO), in order to explore its role in oil-oil and oil-source correlations. The RICO products included n-alkanoic acids, α, ω-di-n-alkanoic acids, branched alkanoic acids, tricyclic terpanoic acids, hopanoic acids, gammacerane carboxylic acid , regular sterane carboxylic acids and 4-methylsterane carboxylic acids. The n-alkyl chains and biomarkers bounded on the asphaltenes were of unsusceptibility to biodegradation. The distribution and absolute concentrations of n-alkanoic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields are different from those of Well TD2. The biomarkers bounded on the asphaltenes, especially steranes, have a distribution trend similar to that of the counterparts in saturates. The sterane carboxylic acids and 4-methylsterane carboxylic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields, dominated by C-{30} sterane and C-{31} 4-methylsterane carboxylic acids, respectively, are significantly different from those of the heavy oils of Well TD2, whose dominating sterane and 4|methylsterane carboxylic acids are C-{28} sterane and C-{29} 4-methylsterane acids, respectively. The RICO products of the asphaltenes further indicate that the Middle-Upper Ordovician may be the main source rocks for heavy oils from the Lunnan and Tahe oilfields.展开更多
Ten series of aromatic hydrocarbon compounds (biphenyl, naphthalene, phenanthrene, anthracene, retene, chrysene, benzoanthracene, dibenzofuran, fluorene, dibenzothiophene) isolated from seven Triassic and Jurassic lac...Ten series of aromatic hydrocarbon compounds (biphenyl, naphthalene, phenanthrene, anthracene, retene, chrysene, benzoanthracene, dibenzofuran, fluorene, dibenzothiophene) isolated from seven Triassic and Jurassic lacustrine mudstone samples and three swamp coal samples, as well as five crude oil samples collected in the Kuche depression of the Tarim Basin, NW China, have been analysed by GC-MS techniques. It is found that the relative abundances of dibenzofuran series are higher in the three swamp coal samples than those in the lacustrine mudstone samples. Based on the similar relative abundances of dibenzofuran series, especially dibenzofuran compound, in the TICs of aromatic hydrocarbons, crude oils from wells SA3 (K), YTK5 (E, K) and QL1 (E) are thought to have been derived predominantly from the coals of the Lower Jurassic Yangxia Formation or Middle Jurassic Kezilenuer Formation, whereas those from wells YM7 (O) and YH1 (E) were derived mainly from Triassic and Jurassic lacustrine mudstones in the Kuche depression. This is the first report about how to distinguish coal-generated oils from lacustrine mudstone-generated oils in the Kuche depression in terms of the dibenzofuran series. The present paper has enlightening and directive significance for further oil-source rock correlations and oil and/or gas exploration in the Kuche depression of the Tarim Basin.展开更多
Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source ...Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.展开更多
Most of the existing algorithms for blind sources separation have a limitation that sources are statistically independent. However, in many practical applications, the source signals are non- negative and mutual stati...Most of the existing algorithms for blind sources separation have a limitation that sources are statistically independent. However, in many practical applications, the source signals are non- negative and mutual statistically dependent signals. When the observations are nonnegative linear combinations of nonnegative sources, the correlation coefficients of the observations are larger than these of source signals. In this letter, a novel Nonnegative Matrix Factorization (NMF) algorithm with least correlated component constraints to blind separation of convolutive mixed sources is proposed. The algorithm relaxes the source independence assumption and has low-complexity algebraic com- putations. Simulation results on blind source separation including real face image data indicate that the sources can be successfully recovered with the algorithm.展开更多
To solve the problem of multiple moving sources passive location, a novel blind source separa- tion （BSS） algorithm based on the muhiset canonical correlation analysis （MCCA） is presented by exploiting the differe...To solve the problem of multiple moving sources passive location, a novel blind source separa- tion （BSS） algorithm based on the muhiset canonical correlation analysis （MCCA） is presented by exploiting the different temporal structure of uncorrelated source signals first, and then on the basis of this algorithm, a novel multiple moving sources passive location method is proposed using time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements. The key technique of this location method is TDOA and FDOA joint estimation, which is based on BSS. By blindly separating mixed signals from multiple moving sources, the multiple sources location problem can be translated to each source location in turn, and the effect of interference and noise can also he removed. The simulation results illustrate that the performance of the MCCA algorithm is very good with relatively light computation burden, and the location algorithm is relatively simple and effective.展开更多
The multiparticle Bose correlations of bosons emitted from dispersed thermaldroplets of quark-gluon plasma are simulated by Monte Carlo.It turns out that ana-lyses of multiparticle Bose correlations can detect the gra...The multiparticle Bose correlations of bosons emitted from dispersed thermaldroplets of quark-gluon plasma are simulated by Monte Carlo.It turns out that ana-lyses of multiparticle Bose correlations can detect the granularity of the emitting source,providing a signal of the existence of a mixed phase of quark-gluon plasma andhadronic gas in ultrarelativistic heavy ion collisions.展开更多
The acidolysis gas in source rocks is the desorbed hydrocarbon gas in non-connected pores and carbonate crystal lattice,while the absorbed gas lies in the connected pores and is absorbed by surface.It is controversial...The acidolysis gas in source rocks is the desorbed hydrocarbon gas in non-connected pores and carbonate crystal lattice,while the absorbed gas lies in the connected pores and is absorbed by surface.It is controversial about whether to use absorbed gas or acidolysis gas in gas source correlation.Using the absorbed gas and acidolysis gas in the first member of the Middle Permian Maokou Fm(hereinafter referred to as Mao 1 member)of Fuling area in the Sichuan Basin,the differences of components and carbon isotopes between absorbed gas and acidolysis gas and their applicable conditions in gas source correlation were discussed.The results show that:(1)there are larger differences of components and isotopes between absorbed gas and acidolysis gas.The absorbed gas has more heavy hydrocarbons and heavier carbon isotope.This difference can be attributed to the easier diffusion of methane and light hydrocarbons in absorbed gas,leading to relatively enriched heavy hydrocarbons and heavier carbon isotope in absorbed gas;(2)acidolysis gas is a mixture of hydrocarbon gas formed during different stages,while absorbed gas is the result of equilibrium between diffusion and supply of hydrocarbon gas,which can result in the differences on carbon isotope sequences between them;(3)the characteristics of natural gas produced after acid fracturing in the Mao 1 member in Fuling area resembles those of acidolysis gas in source rocks,while the characteristics of natural gas produced without acid fracturing are more similar to those of adsorbed gas;(4)the natural gas pool of the Mao 1 member is a carbonate gas pool with self-generation and self-storage.It is concluded that for the gas pool formed after migration,its producing pays have not been processed by acid fracturing,the produced gas should be correlated with the adsorbed gas in source rocks;for the carbonate gas pool with self-generation and self-storage,acid fracturing is usually needed,and the produced gas should be correlated with the acidolysis gas in source rocks.展开更多
We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We...We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a powerful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the flux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources.展开更多
An iterative detection/decoding algorithm of correlated sources for the LDPC-based relay systems is presented. The signal from the source-destination(S-D) link is formulated as a highly correlated counterpart from the...An iterative detection/decoding algorithm of correlated sources for the LDPC-based relay systems is presented. The signal from the source-destination(S-D) link is formulated as a highly correlated counterpart from the relay-destination(R-D) link. A special XOR vector is defined using the correlated hard decision information blocks from two decoders and the extrinsic information exchanged between the two decoders is derived by the log-likelihood ratio(LLR) associated with the XOR vector. Such the decoding scheme is different from the traditional turbo-like detection/decoding algorithm, where the extrinsic information is computed by the side information and the soft decoder outputs. Simulations show that the presented algorithm has a slightly better performance than the traditional turbo-like algorithm(Taking the(255,175) EG-LDPC code as an example, it achieves about 0.1 dB performance gains aroundBLER=10^(-4)). Furthermore, the presented algorithm requires fewer computing operations per iteration and has faster convergence rate. For example, the average iteration of the presented algorithm is 33 at SNR=1.8 dB, which is about twice faster than that of the turbo-like algorithm, when decoding the(961,721) QC-LDPC code. Therefore, the presented decoding algorithm of correlated sources provides an alternative decoding solution for the LDPC-based relay systems.展开更多
Three positive carbon isotope excursions are reported from Middle-Upper Ordovician in Tahe oil-gas field, northern Tarim Basin. Based on conodont biostratigraphy, the Middle Darriwilian Isotope Carbon Excursion（MDICE...Three positive carbon isotope excursions are reported from Middle-Upper Ordovician in Tahe oil-gas field, northern Tarim Basin. Based on conodont biostratigraphy, the Middle Darriwilian Isotope Carbon Excursion（MDICE） and the Guttenberg Carbon Isotope Excursion（GICE） are identified from Darriwilian to Early Katian by the aid of whole-rock carbon isotope data from two well cores. Positive excursion within conodont Pygodus anserinus zone is developed in Early Sandbian, and the fluctuation range is no less than MDICE. Because the range of this excursion in the generalized global carbon isotope curve is short, previous studies paid little attention to it, and named Early Sandbian Isotope Carbon Excursion（ESICE） in this paper. Furthermore, these positive excursions are not directly related to sea level fluctuations and the MDICE and GICE identified in northern Tarim can be globally correlated to that in southern China, North America, South America, and Europe. The Saergan Fm. source rocks of Middle-Upper Ordovician in Kalpin Dawangou outcrop are in accord with the geologic time of MDICE and ESICE, and GICE have strong ties to the source rock of Lianglitag Fm. in basin. Abundant organic carbon burial is an important factor in genesis of positive isotope carbon excursions. Positive oxygen isotope excursion, conodont fauna turnover, decreased conodont total diversity, and the change of sedimentary facies indicated that dramatic changes of paleoceanographic environment of Early-Middle Ordovician in Tarim Basin started from the end of Darriwillian, and an obvious icehouse climate of Late Ordovician occurred in ESICE.展开更多
An oil flow obtained from the Middle Ordovician Fengfeng Formation carbonate reservoir in the well KG-3, Kongxi burial-hill zone in 1993 marked a breakthrough in petroleum exploration of the high-mature Lower Palaeozo...An oil flow obtained from the Middle Ordovician Fengfeng Formation carbonate reservoir in the well KG-3, Kongxi burial-hill zone in 1993 marked a breakthrough in petroleum exploration of the high-mature Lower Palaeozoic strata, North China. Both the Lower member of the Fengfeng Formation and the Second Member of the Upper Majiagou Formation in the Middle Ordovician are supposed to be the main source beds. Oil generation peaks range from 1.0% to 1.6% in Ro, showing a “lag effect” of oil generation in high-mature carbonate source rocks under multicyclic tectonic movement conditions. The Kongxi burial-hill zone adjoins a potential Ordovician source kitchen. The KG-3 Ordovician burial-hill reservoir has undergone two oil filling events, i.e., an early event in the Late Carboniferous-Permian and a more significant late event in the early Eogene.展开更多
Stable carbon isotope ratio （δ13Ccarb） analysis has been widely applied to the study of the inter-conti- nental or global marine carbonate correlation. Large-scale Cambrian-Ordovician carbonate platforms were devel...Stable carbon isotope ratio （δ13Ccarb） analysis has been widely applied to the study of the inter-conti- nental or global marine carbonate correlation. Large-scale Cambrian-Ordovician carbonate platforms were developed in the Tarim Basin. But research on fluctuation character- istics and global correlation of δ13Ccarb is still weak. Based on conodont biostratigraphy and whole-rock δ13Ccarb data in the Tahe oil-gas field of the northern Tarim Basin, the global correlation and genesis of positive carbon isotope excursions in the Darriwilian--Early Katian was exam- ined. Three positive excursions were identified in the Tahe oil-gas field including the middle Darriwilian carbon iso- tope excursion （MDICE）, the Guttenberg carbon isotope excursion （GICE）, and a positive excursion within the Pygodus anserinus conodont zone which is named the Early Sandbian carbon isotope excursion （ESICE） in this paper. Furthermore, these positive excursions had no direct relation with sea level fluctuations. MDICE and GICE could be globally correlated. The Middle-Upper Ordovi- cian Saergan Formation source rocks of the Kalpin outcrops were in accordance with the geological time of MDICE and ESICE. GICE had close relationship with the source rock of the Lianglitag Formation in the basin.Massive organic carbon burial was an important factor controlling the genesis of these positive excursions.展开更多
基金This study is funded by the Natural Science Research Council of China (973 State Key Research and Development Program 2006CB202308)National Natural Science Foundation of China (Grant No.40973031)
文摘The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST （drill stem test） crude oil and 8 rock samples were investigated using a comprehensive geochemical method to characterize and identify the origin of the Ordovician oils in the Tazhong Uplift, Tarim Basin, northwest China. Detailed oil–oil and oil–source rock correlations show that the majority of the oils have typical biomarker characteristics of the Middle-Upper Ordovician （O2＋3） source rock and the related crude oil. These characteristics include a distinct ＂V-shaped＂ relative abundance of C27, C28 and C29 regular steranes, low abundance of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. Only a few oils display typical biomarker characteristics indicating the Cambrian–Lower Ordovician （∈-O1） genetic affinity, such as linear or anti ＂L＂ shape distribution of C27, C28 and C29 regular sterane, with relatively high concentrations of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. It appears that most of the Ordovician oils in the Tazhong Uplift were derived from the O2＋3 intervals, as suggested by previous studies. However, the compound specific n-alkane stable carbon isotope data indicate that the Ordovician oils are mixtures from both the ∈-O1 and O2＋3 source rocks rather than from the O2＋3 strata alone. It was calculated that the proportion of the∈-O1 genetic affinity oils mixed is about 10.8%-74.1%, with an increasing trend with increasing burial depth. This new oil-mixing model is critical for understanding hydrocarbon generation and accumulation mechanisms in the region, and may have important implications for further hydrocarbon exploration in the Tarim Basin.
基金supported by the National Key R&D Program of China(No.2018YFA0404404)the National Natural Science Foundation of China(Nos.11925502,11935001,11961141003,11421505,11475244,and 11927901)+2 种基金the Shanghai Development Foundation for Science and Technology(No.19ZR1403100)the Strategic Priority Research Program of the CAS(No.XDB34030000)the Key Research Program of Frontier Sciences of the CAS(No.QYZDJ-SSW-SLH002).
文摘The effect of source size and emission time on the proton-proton(p-p)momentum correlation function(Cpp(q))has been studied systematically.Assuming a spherical Gaussian source with space and time profile according to the function S(r,t)~exp(-r2/2 r02-t/τ)in the correlation function calculation code(CRAB),the results indicate that one Cpp(q)distribution corresponds to a unique combination of source size r0 and emission timeτ.Considering the possible nuclear deformation from a spherical nucleus,an ellipsoidal Gaussian source characterized by the deformation parameter∈=ΔR/R has been simulated.There is almost no difference of Cpp(q)between the results of spherically and ellipsoidally shaped sources with small deformation.These results indicate that a unique source size r0 and emission time could be extracted from the p-p momentum correlation function,which is especially important for identifying the mechanism of twoproton emission from proton-rich nuclei.Furthermore,considering the possible existence of cluster structures within a nucleus,the double Gaussian source is assumed.The results show that the p-p momentum correlation function for a source with or without cluster structures has large systematical differences with the variance of r0 andτ.This may provide a possible method for experimentally observing the cluster structures in proton-rich nuclei.
文摘This study considers the Upper Cretaceous Qingshankou Formation,Yaojia Formation,and the first member of the Nenjiang Formation in the Western Slope of the northern Songliao Basin.Dark mudstone with high abundances of organic matter of Gulong and Qijia sags are considered to be significant source rocks in the study area.To evaluate their development characteristics,differences and effectiveness,geochemical parameters are analyzed.One-dimensional basin modeling and hydrocarbon evolution are also applied to discuss the effectiveness of source rocks.Through the biomarker characteristics,the source–source,oil–oil,and oil–source correlations are assessed and the sources of crude oils in different rock units are determined.Based on the results,Gulong and Qijia source rocks have different organic matter primarily detrived from mixed sources and plankton,respectively.Gulong source rock has higher thermal evolution degree than Qijia source rock.The biomarker parameters of the source rocks are compared with 31 crude oil samples.The studied crude oils can be divided into two groups.The oil–source correlations show that group I oils from Qing II–III,Yao I,and Yao II–III members were probably derived from Gulong source rock and that only group II oils from Nen I member were derived from Qijia source rock.
基金supported by the National Natural Science Foundation of China (Nos. 12175031 and 11675034)
文摘The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the relaxation time of the system.In this study,we investigated the effect of relaxation time on the SBBC function.We propose a method for calculating the SBBC function with relaxation-time approximation for evolving sources.SBBC functions of D^(0)D^(-0)in relativistic heavy-ion collisions were investigated using a hydrodynamic model.We found that the relaxation time reduces the amplitudes of the SBBC functions.This becomes apparent for long relaxation times and large initial relative deviations of the chaotic and squeezed amplitudes from their equilibrium values in the temporal steps.
基金supported by the Natural Science Foundation of China(Grant No.40672093)CNPC Innovation Fund(07El001)the ESS-China Hydrocarbon Geosciences Collaboration Project under Natural Resources Canada's International Opportunities Program.
文摘The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance （Ro/%）, the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins.
文摘In the future time the exploration of marine oil and gas will be one of the significant domains in China. In this paper the biomarker assemblage characteristics of oilshow in the Nanlinghu Formation of the Majiashan pro- file, which is located in Chaoxian County, south of Anhui Province, are described in the light of gas chromatogra- phy/mass spectrometric (GCMS) analysis on the qualitative and quantitative basis. Based on the investigation of the biomarker assemblage characteristics of possible source rocks developed in the area studied, a conclusion is drawn that the oilshow was generated from the Nanlinghu Formation source rocks (abbreviated as T1n), instead of the Qixia Formation source rocks (abbreviated as P1q). It is pointed out that the T1n is of strong potential for future oil explora- tion, and therefore much attention should be paid to it.
基金supported by Key Program of National Natural Science Foundation of China(Grant No.50835001)Program for New Century Excellent Talents in University,China(Grant No.NCET-13-0081)
文摘In precision machining of complex curved surface parts with high performance, geometry accuracy is not the only constraint, but the performance should also be met. Performance of this kind of parts is closely related to the geometrical and physical parameters, so the final actual size and shape are affected by multiple source constraints, such as geometry, physics, and performance. These parts are rather difficult to be manufactured and new manufacturing method according to performance requirement is urgently needed. Based on performance and manufacturing requirements for complex curved surface parts, a new classification method is proposed, which divided the complex curved surface parts into two categories： surface re-design complex curved surface parts with multi-source constraints（PRCS） and surface unique complex curved surface parts with pure geometric constraints（PUCS）. A correlation model is constructed between the performance and multi-source constraints for PRCS, which reveals the correlation between the performance and multi-source constraints. A re-design method is also developed. Through solving the correlation model of the typical paws performance-associated surface, the mapping relation between the performance-associated surface and the related removal amount is obtained. The explicit correlation model and the method for the corresponding related removal amount of the performance-associated surface are built based on the classification of surface re-design complex curved surface parts with multi-source constraints. Research results have been used in the actual processing of the typical parts such as radome, common bottom components, nozzle, et al., which shows improved efficiency and accuracy of the precision machining for the surface re-design parts with complex curved surface.
文摘Stable carbon isotopes were used together with molecular markers to constrain genetic relationships between sandstone extracts and potential source rocks in the pre-Tertiary in the Huanghua Depression,North China.Comparison of the extracts from Permo-Carboniferous terrigenous mudstones and Ordovician marine carbonates indicated that their prominent differences are in stable carbon isotopes,molecular markers and thermal maturity.Although the extracts of the Mesozoic and Lower Permian Xiashihezi Formation sandstones have some similar iso-topic characteristics,molecular markers data provide a good correlation between the Upper Jurassic-Lower Cretaceous oils and the Upper Carboniferous Taiyuan Formation mudstones,and between the Lower Permian Xiashihezi Formation oils and the Lower Permian mudstones.The results showed that the Upper Jurassic-Lower Cretaceous sandstone oils were derived chiefly from the Upper Carboniferous Taiyuan Formation terrigenous mudstones and that the Lower Permian Xiashihezi Formation oils were sourced from the Lower Permian Shanxi Formation and Xiashihezi Formation terrigenous mudstones.
文摘The identification of marine source rocks in the Tarim Basin is debated vigorously. The intention of this paper is to investigate the asphaltenes in heavy oils from the Lunnan and Tahe oilfields and Well TD2 with ruthenium-ions-catalyzed oxidation technique (RICO), in order to explore its role in oil-oil and oil-source correlations. The RICO products included n-alkanoic acids, α, ω-di-n-alkanoic acids, branched alkanoic acids, tricyclic terpanoic acids, hopanoic acids, gammacerane carboxylic acid , regular sterane carboxylic acids and 4-methylsterane carboxylic acids. The n-alkyl chains and biomarkers bounded on the asphaltenes were of unsusceptibility to biodegradation. The distribution and absolute concentrations of n-alkanoic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields are different from those of Well TD2. The biomarkers bounded on the asphaltenes, especially steranes, have a distribution trend similar to that of the counterparts in saturates. The sterane carboxylic acids and 4-methylsterane carboxylic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields, dominated by C-{30} sterane and C-{31} 4-methylsterane carboxylic acids, respectively, are significantly different from those of the heavy oils of Well TD2, whose dominating sterane and 4|methylsterane carboxylic acids are C-{28} sterane and C-{29} 4-methylsterane acids, respectively. The RICO products of the asphaltenes further indicate that the Middle-Upper Ordovician may be the main source rocks for heavy oils from the Lunnan and Tahe oilfields.
文摘Ten series of aromatic hydrocarbon compounds (biphenyl, naphthalene, phenanthrene, anthracene, retene, chrysene, benzoanthracene, dibenzofuran, fluorene, dibenzothiophene) isolated from seven Triassic and Jurassic lacustrine mudstone samples and three swamp coal samples, as well as five crude oil samples collected in the Kuche depression of the Tarim Basin, NW China, have been analysed by GC-MS techniques. It is found that the relative abundances of dibenzofuran series are higher in the three swamp coal samples than those in the lacustrine mudstone samples. Based on the similar relative abundances of dibenzofuran series, especially dibenzofuran compound, in the TICs of aromatic hydrocarbons, crude oils from wells SA3 (K), YTK5 (E, K) and QL1 (E) are thought to have been derived predominantly from the coals of the Lower Jurassic Yangxia Formation or Middle Jurassic Kezilenuer Formation, whereas those from wells YM7 (O) and YH1 (E) were derived mainly from Triassic and Jurassic lacustrine mudstones in the Kuche depression. This is the first report about how to distinguish coal-generated oils from lacustrine mudstone-generated oils in the Kuche depression in terms of the dibenzofuran series. The present paper has enlightening and directive significance for further oil-source rock correlations and oil and/or gas exploration in the Kuche depression of the Tarim Basin.
基金the research project is funded by Abdullah Alrushaid Chair for Earth Science Remote Sensing Research at King Saud University,Riyadh,Saudi Arabia.。
文摘Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (No.20060280003)Shanghai Leading Academic Dis-cipline Project (T0102)
文摘Most of the existing algorithms for blind sources separation have a limitation that sources are statistically independent. However, in many practical applications, the source signals are non- negative and mutual statistically dependent signals. When the observations are nonnegative linear combinations of nonnegative sources, the correlation coefficients of the observations are larger than these of source signals. In this letter, a novel Nonnegative Matrix Factorization (NMF) algorithm with least correlated component constraints to blind separation of convolutive mixed sources is proposed. The algorithm relaxes the source independence assumption and has low-complexity algebraic com- putations. Simulation results on blind source separation including real face image data indicate that the sources can be successfully recovered with the algorithm.
基金Supported by the National High Technology Research and Development Program of China(No.2009AAJ116,2009AAJ208,2010AA7010422)the National Science Foundation for Post-Doctoral Scientists of China(No.20080431379,200902671)the Hubei Natural Science Foundation(No.2009CDB031)
文摘To solve the problem of multiple moving sources passive location, a novel blind source separa- tion （BSS） algorithm based on the muhiset canonical correlation analysis （MCCA） is presented by exploiting the different temporal structure of uncorrelated source signals first, and then on the basis of this algorithm, a novel multiple moving sources passive location method is proposed using time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements. The key technique of this location method is TDOA and FDOA joint estimation, which is based on BSS. By blindly separating mixed signals from multiple moving sources, the multiple sources location problem can be translated to each source location in turn, and the effect of interference and noise can also he removed. The simulation results illustrate that the performance of the MCCA algorithm is very good with relatively light computation burden, and the location algorithm is relatively simple and effective.
基金The project supported by National Natural Science Foundation of Chinathe U.S.National Science Foundation.
文摘The multiparticle Bose correlations of bosons emitted from dispersed thermaldroplets of quark-gluon plasma are simulated by Monte Carlo.It turns out that ana-lyses of multiparticle Bose correlations can detect the granularity of the emitting source,providing a signal of the existence of a mixed phase of quark-gluon plasma andhadronic gas in ultrarelativistic heavy ion collisions.
基金supported by the National Major Science and Technology Project“Hydrocarbon generation and expulsion mechanism of marine source strata and evaluation technology”(No.:2017ZX05005-001-003)the Science&Technology Project of Sinopec Exploration Company“Evaluation on hydrocarbon generation potential in Mao 1 Member,Fuling area”(No.:35450003-17-ZC0607-0032).
文摘The acidolysis gas in source rocks is the desorbed hydrocarbon gas in non-connected pores and carbonate crystal lattice,while the absorbed gas lies in the connected pores and is absorbed by surface.It is controversial about whether to use absorbed gas or acidolysis gas in gas source correlation.Using the absorbed gas and acidolysis gas in the first member of the Middle Permian Maokou Fm(hereinafter referred to as Mao 1 member)of Fuling area in the Sichuan Basin,the differences of components and carbon isotopes between absorbed gas and acidolysis gas and their applicable conditions in gas source correlation were discussed.The results show that:(1)there are larger differences of components and isotopes between absorbed gas and acidolysis gas.The absorbed gas has more heavy hydrocarbons and heavier carbon isotope.This difference can be attributed to the easier diffusion of methane and light hydrocarbons in absorbed gas,leading to relatively enriched heavy hydrocarbons and heavier carbon isotope in absorbed gas;(2)acidolysis gas is a mixture of hydrocarbon gas formed during different stages,while absorbed gas is the result of equilibrium between diffusion and supply of hydrocarbon gas,which can result in the differences on carbon isotope sequences between them;(3)the characteristics of natural gas produced after acid fracturing in the Mao 1 member in Fuling area resembles those of acidolysis gas in source rocks,while the characteristics of natural gas produced without acid fracturing are more similar to those of adsorbed gas;(4)the natural gas pool of the Mao 1 member is a carbonate gas pool with self-generation and self-storage.It is concluded that for the gas pool formed after migration,its producing pays have not been processed by acid fracturing,the produced gas should be correlated with the adsorbed gas in source rocks;for the carbonate gas pool with self-generation and self-storage,acid fracturing is usually needed,and the produced gas should be correlated with the acidolysis gas in source rocks.
基金Supported by the National Natural Science Foundation of China.
文摘We apply a Cross-Correlation （CC） method developed previously for detecting gamma-ray point sources to the WMAP first year data by using the Point-Spread Function of WMAP and obtain a full sky CC coefficient map. We find that the CC method is a powerful tool to examine the WMAP foreground residuals which can be further cleaned accord- ingly. Evident foreground signals are found in the WMAP foreground cleaned maps and the Tegmark cleaned map. In this process 101 point sources are detected, and 26 of them are new sources additional to the originally listed WMAP 208 sources. We estimate the flux of these new sources and verify them by another method. As a result, a revised mask file based on the WMAP first year data is produced by including these new sources.
基金supported by NSF of China (No.61362010,61661005)NSF of Guangxi (No.2015GXNSFAA139290,2014GXNSFBA118276,2012GXNSFAA053217)
文摘An iterative detection/decoding algorithm of correlated sources for the LDPC-based relay systems is presented. The signal from the source-destination(S-D) link is formulated as a highly correlated counterpart from the relay-destination(R-D) link. A special XOR vector is defined using the correlated hard decision information blocks from two decoders and the extrinsic information exchanged between the two decoders is derived by the log-likelihood ratio(LLR) associated with the XOR vector. Such the decoding scheme is different from the traditional turbo-like detection/decoding algorithm, where the extrinsic information is computed by the side information and the soft decoder outputs. Simulations show that the presented algorithm has a slightly better performance than the traditional turbo-like algorithm(Taking the(255,175) EG-LDPC code as an example, it achieves about 0.1 dB performance gains aroundBLER=10^(-4)). Furthermore, the presented algorithm requires fewer computing operations per iteration and has faster convergence rate. For example, the average iteration of the presented algorithm is 33 at SNR=1.8 dB, which is about twice faster than that of the turbo-like algorithm, when decoding the(961,721) QC-LDPC code. Therefore, the presented decoding algorithm of correlated sources provides an alternative decoding solution for the LDPC-based relay systems.
基金supported by the National Key Scientific Project of China (No. 2011ZX05005-0042016ZX05005-002)the National Basic Research Program of China (973 Program) (No. 2012CB214806)
文摘Three positive carbon isotope excursions are reported from Middle-Upper Ordovician in Tahe oil-gas field, northern Tarim Basin. Based on conodont biostratigraphy, the Middle Darriwilian Isotope Carbon Excursion（MDICE） and the Guttenberg Carbon Isotope Excursion（GICE） are identified from Darriwilian to Early Katian by the aid of whole-rock carbon isotope data from two well cores. Positive excursion within conodont Pygodus anserinus zone is developed in Early Sandbian, and the fluctuation range is no less than MDICE. Because the range of this excursion in the generalized global carbon isotope curve is short, previous studies paid little attention to it, and named Early Sandbian Isotope Carbon Excursion（ESICE） in this paper. Furthermore, these positive excursions are not directly related to sea level fluctuations and the MDICE and GICE identified in northern Tarim can be globally correlated to that in southern China, North America, South America, and Europe. The Saergan Fm. source rocks of Middle-Upper Ordovician in Kalpin Dawangou outcrop are in accord with the geologic time of MDICE and ESICE, and GICE have strong ties to the source rock of Lianglitag Fm. in basin. Abundant organic carbon burial is an important factor in genesis of positive isotope carbon excursions. Positive oxygen isotope excursion, conodont fauna turnover, decreased conodont total diversity, and the change of sedimentary facies indicated that dramatic changes of paleoceanographic environment of Early-Middle Ordovician in Tarim Basin started from the end of Darriwillian, and an obvious icehouse climate of Late Ordovician occurred in ESICE.
文摘An oil flow obtained from the Middle Ordovician Fengfeng Formation carbonate reservoir in the well KG-3, Kongxi burial-hill zone in 1993 marked a breakthrough in petroleum exploration of the high-mature Lower Palaeozoic strata, North China. Both the Lower member of the Fengfeng Formation and the Second Member of the Upper Majiagou Formation in the Middle Ordovician are supposed to be the main source beds. Oil generation peaks range from 1.0% to 1.6% in Ro, showing a “lag effect” of oil generation in high-mature carbonate source rocks under multicyclic tectonic movement conditions. The Kongxi burial-hill zone adjoins a potential Ordovician source kitchen. The KG-3 Ordovician burial-hill reservoir has undergone two oil filling events, i.e., an early event in the Late Carboniferous-Permian and a more significant late event in the early Eogene.
基金supported by the National Key Scientific Project of China(No.2011ZX05005-0042016ZX05005-002)the National Basic Research Program of China(973 Program)(No.2012CB214806)
文摘Stable carbon isotope ratio （δ13Ccarb） analysis has been widely applied to the study of the inter-conti- nental or global marine carbonate correlation. Large-scale Cambrian-Ordovician carbonate platforms were developed in the Tarim Basin. But research on fluctuation character- istics and global correlation of δ13Ccarb is still weak. Based on conodont biostratigraphy and whole-rock δ13Ccarb data in the Tahe oil-gas field of the northern Tarim Basin, the global correlation and genesis of positive carbon isotope excursions in the Darriwilian--Early Katian was exam- ined. Three positive excursions were identified in the Tahe oil-gas field including the middle Darriwilian carbon iso- tope excursion （MDICE）, the Guttenberg carbon isotope excursion （GICE）, and a positive excursion within the Pygodus anserinus conodont zone which is named the Early Sandbian carbon isotope excursion （ESICE） in this paper. Furthermore, these positive excursions had no direct relation with sea level fluctuations. MDICE and GICE could be globally correlated. The Middle-Upper Ordovi- cian Saergan Formation source rocks of the Kalpin outcrops were in accordance with the geological time of MDICE and ESICE. GICE had close relationship with the source rock of the Lianglitag Formation in the basin.Massive organic carbon burial was an important factor controlling the genesis of these positive excursions.
