Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to thei...Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to their small gyromagnetic ratios.A promising approach to achieving high nuclear spin polarization is transferring the polarization of electrons to nuclear spins.The nitrogen-vacancy(NV)center in diamond has emerged as a highly effective medium for this purpose,and various hyperpolarization protocols have been developed.Among these,the pulsed polarization(PulsePol)method has been extensively studied due to its robustness against static energy shifts of the electron spin.In this work,we present a novel polarization protocol and uncover a family of magic sequences for hyperpolarizing nuclear spins,with PulsePol emerging as a special case of our general approach.Notably,we demonstrate that some of these magic sequences exhibit significantly greater robustness compared to the PulsePol protocol in the presence of finite half𝜋pulse duration of the protocol,Rabi and detuning errors.This enhanced robustness positions our protocol as a more suitable candidate for hyper-polarizing nuclear spins species with large gyromagnetic ratios and also ensures better compatibility with high-efficiency readout techniques at high magnetic fields.Additionally,the generality of our protocol allows for its direct application to other solid-state quantum systems beyond the NV center.展开更多
Based on the analysis of well logs, seismic data, core studies, the Dongying （东营） Formation along the nearshore and adjacent sea areas, Bohai （渤海） Bay basin has been subdivided into three third-order sequences...Based on the analysis of well logs, seismic data, core studies, the Dongying （东营） Formation along the nearshore and adjacent sea areas, Bohai （渤海） Bay basin has been subdivided into three third-order sequences from base to top： namely, sequences SQ1, SQ2 and SQ3. The three sequences have different wireline （SP） log responses, showing triple-section characteristics with SQ1 being characterized by primarily flat baseline with intercalation of relatively low spontaneous potential, SQ2 generally exhibiting weak or moderate amplitude spontaneous potential with finger-shaped peaks, and SQ3 having relatively high spontaneous potential with funnel-shaped log curves. On the basis of the triple-section characteristics, the stratigraphic sequences can be correlated consistently throughout the entire study area. A stratigraphic and sedimentary model for sequences SQ1 to SQ3 of the Dongying Formation in the study area has been proposed. The accommodation space change in the two sides of the asymmetrical basin was examined and the asymmetrical basin has the feature of the asymmetrical accommodation space change. The asymmetrical physiography is a vital factor to influence the accommodation changes in additional to the lake level change, tectonism and sediment supply. This may have important implications to similar basins in other parts of China or elsewhere.展开更多
Sequence stratigraphic evidences have been used in this research to investigate the stratigraphic correlation of cretaceous paleogene succession in Shiraz area, Fars, SW Iran. For this purpose, 4 stratigraphic section...Sequence stratigraphic evidences have been used in this research to investigate the stratigraphic correlation of cretaceous paleogene succession in Shiraz area, Fars, SW Iran. For this purpose, 4 stratigraphic sections have been chosen and provided. According to petrographic study and field evidences, 4 depositional sequences were identified including the Tarbur, Sachun and Jahrum formations in the east and the Gurpi, Pabadeh and Asmari formations in the west of study area. After identifying the boundaries and systems tract facies, it has been found that the mentioned formations have been deposited among the continuous/discontinuous boundaries in an equivalent manner. In this case, the purple shale (between the Gurpi and Pabdeh formations) could be considered equivalent to the upper part of the Sachun formation. From the point of Paleogeography, the plat-form sedimentary environment covered almost the whole area during the Oligo-Miocene age, so that the Asmari formation would have been deposited, which is marked by sharp contact as disconformity on Jahrum formation in the east of the basin and with continuous contact (C.C) on the Pabdeh formation in the west and southwest.展开更多
In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovi...In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovician is studied according to the well drilling,logging,geophysical data,detailed observations of core and the paleontology.The Lianglitage formation belongs to the sequence Ⅳ of Ordovician.The second member of Lianglitage formation is prograde sedimentation in highstand systems tract,and is favorable for developing reef flat.The development scale and thickness of reef flat are controlled by the variation of secondary sea level.The types and characteristics of karst in the highstand systems tract show that the late highstand systems tract is dissolved and cemented by the meteoric fresh water and mixed water.Penecontemporaneous karstification is developed at the top of parasequence and high place of geomorphology.Atmospheric diagenetic lens is formed.The developing regulations and controlling factors of penecontemporaneous karstification can provide new clues to the prediction and exploration of favorable reservoir in this area.展开更多
The study of sequence microbiostratigraphy of Jahrum and Asmari formation in Shiraz, Fars, Zagros, SW of Iran and recognition of relationship between depositional sequence parameters and microbiostratigraphy 3 stratig...The study of sequence microbiostratigraphy of Jahrum and Asmari formation in Shiraz, Fars, Zagros, SW of Iran and recognition of relationship between depositional sequence parameters and microbiostratigraphy 3 stratigraphic sections (Beyza, Sarvestan A, B and Estahban sections) have been selected and studied. Jahrum and Asmari formations in study area with unconformity overlying together have been exposed. Based on Field and laboratory studies such as microfossils, microbiostratigraphy, microfaceis, sedimentary environment models and sequence stratigraphy evi- dences recognized 3 depositional sequences in study area that presented during Paleocene-Oli- gomiocene. Jahrum formation consists of one depositional sequence and Asmari formation consists of two depositional sequences. Microfossils and microbiostratigraphy studies will lead to the identification of 6 biozones in the studied area. In Beyza and Estahban sections biozones 1, 2 and 3 are related to Jahrum formation and suggest Paleocene to Middle Eocene age for this formation and biozone 4 is related to Asmari formation and suggests Oligocene age for this formation. In Sar- vestan section biozones 1, 2 and 3 are related to Jahrum formation and suggest Paleocene to Middle Eocene age for this formation and biozones 4 and 5 are related to Asmari formation and these biozones indicate Oligocene-Miocene (Aquitanian) age for Asmari formation. Sequence microbiostratigraphy studies indicate that biozones of Jahrum formation are formed in DS1 and biozones of Asmari formation are formed in DS2 and DS3. Also, some relationship between depositional sequence parameters and distribution of microfossils and biozones as in the case of in SB1 and LST facies didn’t found any microfossil and we can’t suggest biozonation. In study area upper part of HST of DS1 (Jahrum formation) and some biozones related to Upper Eocene have been eliminated, for example in Estahban, Sarvestan B and Beyza sections all biozones related to Upper Paleocene to Middle Eocene and eliminated biozones of Upper Eocene. In study area SB2 existed in lower boundary of DS1 (between Sachun and Jahrum formation) and between DS2 and DS3 of Asmari formation. Some parts of biozones in study area could correlate with SB2. For example for upper limit of biozones no 4 in Estahban section overlies to SB2 of DS2 in Asmari formation. Paleoecological situation in TST systems tract suitable for reproduction and growth large foraminifera and biozones 1, 2 and 3 are formed in systems tract. MFS and MFZ in all sections are recognized by mixed pelagic and benthonic foraminifera wackestone. More biozones in Jahrum and As- mari formations have been identified in HST system tract. For example in Beyza section biozones 2 and 3 (Jahrum formation) and biozone 4 (Asmari formation) are in HST. In Saevestan B section bi- ozones 3 and 4 (Jahrum formation) and biozones 5 and 6 (Asmari formation) are in this system tract. In Estahban section biozones 3 and 4 (Jahrum formation) and biozones 4 and 5 (Asmari formation) have been in HST. Also, tests of most identified large foraminifera in HST such as Alveolona sp, Alveolina aragonensis, Austrotrilina sp, Austrotrilina asmaricus and Archias sp are made of porcelaneous calcite and foraminiferal tests in TST systems tract, such as Nummulites sp. Nummulites intermedius, Nummulites fichtelli and Operculina sp are made of hyaline calcite.展开更多
Dalan Formation is one of the most important gas reservoirs of south and southwest Iran which it belongs to Dehram Group and its age is Middle to Late Permian. The Dalan formation is interpreted as reflecting a major ...Dalan Formation is one of the most important gas reservoirs of south and southwest Iran which it belongs to Dehram Group and its age is Middle to Late Permian. The Dalan formation is interpreted as reflecting a major tectono-eustatic event related to the onset of rapid thermal subsidence of the early Neo-Tethys passive margin in Arabia and Iran, and the drowning of its rift shoulders. The Dalan formation consists mainly of medium to thick-bedded oolitic to micritic shallow-marine carbonate, with intercalations of evaporates. This formation overlies the Faraghan formation and extends up into the Lower Triassic kangan formation. The current paper is focused on the facies, sedimentary environment and sequence Stratigraphy study of the Middle to Upper Permian Dalan formation in the West Assaluyeh gas field the subsurface section of well ASL-A. Based on microfacies analysis and significant founa and flora, nineteen major facies in five facies associations including Tidal flat (A), Lagoon (B), Shoal (C), Open marine (D) and Mid ramp (E) were recognized in the Dalan formation. Facies analysis and those comparisons with modern and ancient environments indicated that the Dalan formation was deposited inner to mid parts of a homoclinal ramp. The sequence stratigraphy studies on the Dalan formation in this gas field led to assessment of seven main sedimentary sequences of the third-order in the Assaluyeh field, well ASL-A. The boundary between the third-order sequences with the Faraghan formation and between the Nar and Upper Dalan members are Subaerial Unconformity (SU) and the boundaries between the third-order sequences with each other and also with the Kangan formation are Correlative Conformity (CC). The main diagenetic processes in this formation are dolomitization, dissolution, anhydritization, cementation and compaction which played a significant role in improving reservoir quality. The shoal ooid grainstone facies with intergranular and oomoldic porosity comprise the main reservoir facies of the Dalan formation.展开更多
In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment mo...In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment model was based on the profile HMM (Hidden Markov Model), and the model training was implemented through the SAHMM (Self Adapting Hidden Markov Model) software developed by the authors.展开更多
Wavelet transformation is a widely used method in high-frequency sequence stratigraphic analysis.However, the application is problematic since different wavelets always return the same sequence analysis results. To ad...Wavelet transformation is a widely used method in high-frequency sequence stratigraphic analysis.However, the application is problematic since different wavelets always return the same sequence analysis results. To address this issue, we applied five commonly used wavelets to theoretical sequence models to document some application criteria. Five gradual scale-change sequence models were simplified from the glutenite succession deposition by gravity flows to form the fining-upwards cycle sequences(FUCS) and coarsening-upwards cycle sequences(CUCS). After conducting theoretical sequence model tests, the optimal wavelet(sym4) was selected and successfully used with actual data to identify the sequence boundaries. We also proposed a new method to optimize the scale of continuous wavelet transformation(CWT) for sequence boundary determination. We found that the balloon-like marks in scalograms of db4, sym4, and coif4 wavelet determine, respectively, the fourth-order sequence boundary, the thick succession sequence boundaries in FUCS, and the thick succession sequence in FUCS and CUCS. Comparing the sequence identification results shows that the asymmetric wavelets had an advantage in high-frequency sequence boundary determination and sedimentary cycle discrimination through the amplitude trend of the coefficient, in which the sym4 wavelet is the most effective. In conclusion, the asymmetry of wavelets is the first selection principle, of which asymmetric wavelets are more sensitive to sediment deposition by flood flows. The match of the wavelet between the sequence is the second selection principle, in which the correlation of time-frequency impacts the accuracy of sequence surface localization. However, the waveform of the wavelet is a visual and abstract parameter for sequence boundary detection. The appropriate wavelet for lacustrine sequence analysis is the asymmetric wavelet with a weak number of side lobes. The depositional flows, depositional process,and autogenic are three sedimentary factors that influence the sequence analysis results.展开更多
To study petrography, microfacies, sedimentary environments and sequence stratigraphy of Asmari formation in central Fars, 4 stratigraphic sections have benn chosen and studied (Estahban, Shams-Abad, Sarvestan and Akb...To study petrography, microfacies, sedimentary environments and sequence stratigraphy of Asmari formation in central Fars, 4 stratigraphic sections have benn chosen and studied (Estahban, Shams-Abad, Sarvestan and Akbar-Abad Sections). Field and laboratories study recognized 16?carbonate microfacies and 2 clastic-carbanate facies. Study of microfacies, relative sea level?change and sequence stratigraphy evidences show these microfacies are deposited in carbonate ramp sedimentary environment in 5 facies belt zones: Open marine (A), Restricted (B), Shoal (C), Lagoon (D) and Tidal flat (E) during Oligomiocene. Petrography, microfacies analysis and sedimentary environment of Asmari formation shows this formation in study area consist of 3 depositional sequences. Lower sequence boundary of DS1 with Jahrum formation is erosional (disconformity) SB1. Lower and upper sequence boundary of DS2 is SB2. The upper sequence boundary of DS3 is SB1 and ended under the Razak clastic formation. In central Fars only lower part of Asmari is deposited and upper part of this formation have been eroded and disappeared.展开更多
Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic po...Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic position among them, as well as several other species accessed from the Genbank. Total DNA extracted from the muscular tissue had been obtained through tail cut sampling using the innuPREP DNA micro kit, and amplified using a pair of universal primer, L14841 and H15149. The size of the cyt b gene sequence amplified was 307 bp long. Sequence aligned using CLUSTAL-X program and diversity analysis were done using version 5.2.2. MEGA5 program. Genetic distance had been calculated by Tamura 3 parameter method and phylogenetic tree had been built using Neighbor-Joining and Maximum Likelihood methods. Genetic distance based on cyt b gene nucleotide was found from 0 to 0.240 with an average of 0.080. The phylogenetic tree constructed by Neighbor Joining and Maximum Likelihood methods indicated that T. tarsier, T. sangirensis and T. tumpara were closely related with Tarsius tarsier-complex, and distantly related with Cephalopachus bancanus and Carlito syrichta. The genetic distance and the phylogenetic tree had been constructed on the base of partial cyt b gene sequence of T. tarsier, T. sangirensis, T. tumpara and 5 other tarsier species and their accession. Those results are consistent with taxonomy based on morphology and vocal acoustic form.展开更多
Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented.These stars are located in the association Cepheus OB3,in t...Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented.These stars are located in the association Cepheus OB3,in the field of the young star V733 Cephei.Photometric observations,especially concerning the long-term variability of the stars,are missing in the literature.We present the first longterm V(RI)c monitoring for them,that cover 13 years.Results from our study indicate that all of the investigated stars manifest strong photometric variability.The presented paper is a part of our program for the photometric study of pre-main-sequence stars located in active star-forming regions.展开更多
The Fushan Depression is one of the petroliferous depressions in the Beibuwan Basin,South China Sea.Previous studies have preliminarily explored the origin and source of crude oils in some areas of this depression.Nev...The Fushan Depression is one of the petroliferous depressions in the Beibuwan Basin,South China Sea.Previous studies have preliminarily explored the origin and source of crude oils in some areas of this depression.Nevertheless,no systematic investigations on the classification and origin of oils and hy-drocarbon migration processes have been made for the entire petroleum system in this depression,which has significantly hindered the hydrocarbon exploration in the region.A total of 32 mudstone and 58 oil samples from the Fushan Depression were analyzed to definite the detailed oil-source correlation within the sequence and sedimentary framework.The organic matter of third member of Paleogene Liushagang Formation(Els(3))source rocks,both deltaic and lacustrine mudstone,are algal-dominated with high abundance of C_(23)tricyclic terpane and C_(30)4-methylsteranes.The deltaic source rocks occur-ring in the first member(Els_(1))and second member(Els_(2))of the Paleogene Liushagang Formation are characterized by high abundance of C_(19+20)tricyclic terpane and oleanane,reflecting a more terrestrial plants contribution.While lacustrine source rocks of Els_(1)and Els_(2)display the reduced input of terrige-nous organic matter with relatively low abundance of C 19+20 tricyclic terpane and oleanane.Three types of oils were identified by their biomarker compositions in this study.Most of the oils discovered in the Huachang and Bailian Els_(1)reservoir belong to group A and were derived from lacustrine source rocks of Els_(1)and Els_(2).Group B oils are found within the Els_(1)and Els_(2)reservoirs,showing a close relation to the deltaic source rocks of Els_(1)and Els_(2),respectively.Group C oils,occurring in the Els3 reservoirs,have a good affinity with the Els3 source rocks.The spatial distribution and accumulation of different groups of oils are mainly controlled by the sedimentary facies and specific structural conditions.The Els_(2)reservoir in the Yong'an area belonging to Group B oil,are adjacent to the source kitchen and could be considered as the favorable exploration area in the future.展开更多
Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the ...Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.展开更多
To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D sei...To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D seismic and drilling data,and reservoir sections are thoroughly investigated.Guided by the theory of sequence stratigraphy,the progradational sequence stratigraphic framework of the Yanchang Formation is systematically constructed to elucidate new deposition mechanisms in the depressed lacustrine basin,and it has been successfully applied to the exploration and development practices in the Qingcheng Oilfield.Key findings are obtained in three aspects.First,the seismic progradational reflections,marker tuff beds,and condensed sections of flooding surfaces in the Yanchang Formation are consistent and isochronous.Using flooding surface markers as a reference,a progradational sequence stratigraphic architecture is reconstructed for the middle-upper part of Yanchang Formation,and divided into seven clinoform units(CF1-CF7).Second,progradation predominantly occurs in semi-deep to deep lake environments,with the depositional center not always coinciding with the thickest strata.The lacustrine basin underwent an evolution of“oscillatory regression-progradational infilling-multi-phase superimposition”.Third,the case study of Qingcheng Oilfield reveals that the major pay zones consist of“isochronous but heterochronous”gravity-flow sandstone complexes.Guided by the progradational sequence stratigraphic architecture,horizontal well oil-layer penetration rates remain above 82%.The progradational sequence stratigraphic architecture and associated geological insights are more consistent with the sedimentary infilling mechanisms of large-scale continental depressed lacustrine basins and actual drilling results.The research results provide crucial theoretical and technical support for subsequent refined exploration and development of the Yanchang Formation,and are expected to offer a reference for research and production practice in similar continental lacustrine basins.展开更多
Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modula...Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modulatory effect on neural plasticity associated with MSL remains unclarified.This study was therefore designed to compare the role of the left primary motor cortex and the left supplementary motor area proper(SMAp)in modulating MSL across different complexity levels and for both hands,as well as the associated neuroplasticity by applying intermittent theta burst stimulation together with the electroencephalogram and concurrent transcranial magnetic stimulation.Our data demonstrated the role of SMAp stimulation in modulating neural communication to support MSL,which is achieved by facilitating regional activation and orchestrating neural coupling across distributed brain regions,particularly in interhemispheric connections.These findings may have important clinical implications,particularly for motor rehabilitation in populations such as post-stroke patients.展开更多
Cystic echinococcosis (CE) is a prevalent zoonotic disease caused by Echinococcus granulosus, with a cosmopolitan distribution. The parasite is transmitted cyclically between canines and numerous intermediate herbivor...Cystic echinococcosis (CE) is a prevalent zoonotic disease caused by Echinococcus granulosus, with a cosmopolitan distribution. The parasite is transmitted cyclically between canines and numerous intermediate herbivorous livestock animals. Also, other Taeniid tapeworms could infect domestic dogs and they pose significant veterinary and public health concerns worldwide. This study aimed to develop a sensitive molecular method for detecting Echinococcus spp. DNA in dog fecal samples using next-generation sequencing (NGS). A set of PCR primers targeting conserved regions of Taeniid tapeworms’ 18s rRNA genes was designed and tested for amplifying genomic DNA from various tapeworm species. The PCR system demonstrated high sensitivity, amplifying DNA from all tested tapeworm species, with differences observed in amplified band sizes. The primers were adapted for NGS analysis by adding forward and reverse adapters, enabling the sequencing of amplified DNA fragments. Application of the developed PCR system to dog fecal samples collected from Yatta town, Palestine, revealed the presence of E. granulosus DNA in five out of 50 samples. NGS analysis confirmed the specificity of the amplified DNA fragments, showing 98% - 99% similarity with the 18s rDNA gene of E. granulosus. This study demonstrates the utility of NGS-based molecular methods for accurate and sensitive detection of Echinococcus spp. in dog fecal samples, providing valuable insights for epidemiological surveillance and control programs of echinococcosis in endemic regions.展开更多
Purpose:Generally,the scientific comparison has been done with the help of the overall impact of scholars.Although it is very easy to compare scholars,but how can we assess the scientific impact of scholars who have d...Purpose:Generally,the scientific comparison has been done with the help of the overall impact of scholars.Although it is very easy to compare scholars,but how can we assess the scientific impact of scholars who have different research careers?It is very obvious,the scholars may gain a high impact if they have more research experience or have spent more time(in terms of research career in a year).Then we cannot compare two scholars who have different research careers.Many bibliometrics indicators address the time-span of scholars.In this series,the h-index sequence and EM/EM’-index sequence have been introduced for assessment and comparison of the scientific impact of scholars.The h-index sequence,EM-index sequence,and EM’-index sequence consider the yearly impact of scholars,and comparison is done by the index value along with their component value.The time-series indicators fail to give a comparative analysis between senior and junior scholars if there is a huge difference in both scholars’research careers.Design/methodology/approach:We have proposed the cumulative index calculation method to appraise the scientific impact of scholars till that age and tested it with 89 scholars data.Findings:The proposed mechanism is implemented and tested on 89 scholars’publication data,providing a clear difference between the scientific impact of two scholars.This also helps in predicting future prominent scholars based on their research impact.Research limitations:This study adopts a simplistic approach by assigning equal credit to all authors,regardless of their individual contributions.Further,the potential impact of career breaks on research productivity is not taken into account.These assumptions may limit the generalizability of our findings Practical implications:The proposed method can be used by respected institutions to compare their scholars impact.Funding agencies can also use it for similar purposes.Originality/value:This research adds to the existing literature by introducing a novel methodology for comparing the scientific impact of scholars.The outcomes of this research have notable implications for the development of more precise and unbiased research assessment frameworks,enabling a more equitable evaluation of scholarly contributions.展开更多
Binary sequences constructed by Legendre symbols are widely used in communication and cryptography since they have many good pseudo-random properties.In this paper,we determine the 2-adic complexity of the sum sequenc...Binary sequences constructed by Legendre symbols are widely used in communication and cryptography since they have many good pseudo-random properties.In this paper,we determine the 2-adic complexity of the sum sequence of any k many Legendre sequences and show that the 2-adic complexity of the sum sequences of any k many Legendre sequences reaches the maximum by proving the case of k=2 and 3,which implies that the sum sequences can resist the attack of rational approximation algorithm.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12475012,62461160263 for P.W.,and 62276171 for H.L.)Quantum Science and Technology-National Science and Technology Major Project of China (Project No.2023ZD0300600 for P.W.)+3 种基金Guangdong Provincial Quantum Science Strategic Initiative (Grant Nos.GDZX240-3009 and GDZX2303005 for P.W.)Guangdong Basic and Applied Basic Research Foundation (Grant No.2024-A1515011938 for H.L.)Shenzhen Fundamental ResearchGeneral Project (Grant No.JCYJ20240813141503005 for H.L.)the Talents Introduction Foundation of Beijing Normal University (Grant No.310432106 for P.W.)。
文摘Hyperpolarization of nuclear spins is crucial for advancing nuclear magnetic resonance and quantum information technologies,as nuclear spins typically exhibit extremely low polarization at room temperature due to their small gyromagnetic ratios.A promising approach to achieving high nuclear spin polarization is transferring the polarization of electrons to nuclear spins.The nitrogen-vacancy(NV)center in diamond has emerged as a highly effective medium for this purpose,and various hyperpolarization protocols have been developed.Among these,the pulsed polarization(PulsePol)method has been extensively studied due to its robustness against static energy shifts of the electron spin.In this work,we present a novel polarization protocol and uncover a family of magic sequences for hyperpolarizing nuclear spins,with PulsePol emerging as a special case of our general approach.Notably,we demonstrate that some of these magic sequences exhibit significantly greater robustness compared to the PulsePol protocol in the presence of finite half𝜋pulse duration of the protocol,Rabi and detuning errors.This enhanced robustness positions our protocol as a more suitable candidate for hyper-polarizing nuclear spins species with large gyromagnetic ratios and also ensures better compatibility with high-efficiency readout techniques at high magnetic fields.Additionally,the generality of our protocol allows for its direct application to other solid-state quantum systems beyond the NV center.
基金the National Natural ScienceFoundation of China (No. 40702024)the Research Instituteof Petroleum Exploration and Development (RIPED),PetroChina
文摘Based on the analysis of well logs, seismic data, core studies, the Dongying （东营） Formation along the nearshore and adjacent sea areas, Bohai （渤海） Bay basin has been subdivided into three third-order sequences from base to top： namely, sequences SQ1, SQ2 and SQ3. The three sequences have different wireline （SP） log responses, showing triple-section characteristics with SQ1 being characterized by primarily flat baseline with intercalation of relatively low spontaneous potential, SQ2 generally exhibiting weak or moderate amplitude spontaneous potential with finger-shaped peaks, and SQ3 having relatively high spontaneous potential with funnel-shaped log curves. On the basis of the triple-section characteristics, the stratigraphic sequences can be correlated consistently throughout the entire study area. A stratigraphic and sedimentary model for sequences SQ1 to SQ3 of the Dongying Formation in the study area has been proposed. The accommodation space change in the two sides of the asymmetrical basin was examined and the asymmetrical basin has the feature of the asymmetrical accommodation space change. The asymmetrical physiography is a vital factor to influence the accommodation changes in additional to the lake level change, tectonism and sediment supply. This may have important implications to similar basins in other parts of China or elsewhere.
文摘Sequence stratigraphic evidences have been used in this research to investigate the stratigraphic correlation of cretaceous paleogene succession in Shiraz area, Fars, SW Iran. For this purpose, 4 stratigraphic sections have been chosen and provided. According to petrographic study and field evidences, 4 depositional sequences were identified including the Tarbur, Sachun and Jahrum formations in the east and the Gurpi, Pabadeh and Asmari formations in the west of study area. After identifying the boundaries and systems tract facies, it has been found that the mentioned formations have been deposited among the continuous/discontinuous boundaries in an equivalent manner. In this case, the purple shale (between the Gurpi and Pabdeh formations) could be considered equivalent to the upper part of the Sachun formation. From the point of Paleogeography, the plat-form sedimentary environment covered almost the whole area during the Oligo-Miocene age, so that the Asmari formation would have been deposited, which is marked by sharp contact as disconformity on Jahrum formation in the east of the basin and with continuous contact (C.C) on the Pabdeh formation in the west and southwest.
基金Project(2008ZX05004-004)supported by the State Key Scientific Research Programs,ChinaProject(SZD0414)supported by the Sichuan Province Key Discipline Construction Project,ChinaProject(KZCX2-YW-Q05-01)supported by the Chinese Academy of Sciences Innovation Engineering Directional Project
文摘In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovician is studied according to the well drilling,logging,geophysical data,detailed observations of core and the paleontology.The Lianglitage formation belongs to the sequence Ⅳ of Ordovician.The second member of Lianglitage formation is prograde sedimentation in highstand systems tract,and is favorable for developing reef flat.The development scale and thickness of reef flat are controlled by the variation of secondary sea level.The types and characteristics of karst in the highstand systems tract show that the late highstand systems tract is dissolved and cemented by the meteoric fresh water and mixed water.Penecontemporaneous karstification is developed at the top of parasequence and high place of geomorphology.Atmospheric diagenetic lens is formed.The developing regulations and controlling factors of penecontemporaneous karstification can provide new clues to the prediction and exploration of favorable reservoir in this area.
文摘The study of sequence microbiostratigraphy of Jahrum and Asmari formation in Shiraz, Fars, Zagros, SW of Iran and recognition of relationship between depositional sequence parameters and microbiostratigraphy 3 stratigraphic sections (Beyza, Sarvestan A, B and Estahban sections) have been selected and studied. Jahrum and Asmari formations in study area with unconformity overlying together have been exposed. Based on Field and laboratory studies such as microfossils, microbiostratigraphy, microfaceis, sedimentary environment models and sequence stratigraphy evi- dences recognized 3 depositional sequences in study area that presented during Paleocene-Oli- gomiocene. Jahrum formation consists of one depositional sequence and Asmari formation consists of two depositional sequences. Microfossils and microbiostratigraphy studies will lead to the identification of 6 biozones in the studied area. In Beyza and Estahban sections biozones 1, 2 and 3 are related to Jahrum formation and suggest Paleocene to Middle Eocene age for this formation and biozone 4 is related to Asmari formation and suggests Oligocene age for this formation. In Sar- vestan section biozones 1, 2 and 3 are related to Jahrum formation and suggest Paleocene to Middle Eocene age for this formation and biozones 4 and 5 are related to Asmari formation and these biozones indicate Oligocene-Miocene (Aquitanian) age for Asmari formation. Sequence microbiostratigraphy studies indicate that biozones of Jahrum formation are formed in DS1 and biozones of Asmari formation are formed in DS2 and DS3. Also, some relationship between depositional sequence parameters and distribution of microfossils and biozones as in the case of in SB1 and LST facies didn’t found any microfossil and we can’t suggest biozonation. In study area upper part of HST of DS1 (Jahrum formation) and some biozones related to Upper Eocene have been eliminated, for example in Estahban, Sarvestan B and Beyza sections all biozones related to Upper Paleocene to Middle Eocene and eliminated biozones of Upper Eocene. In study area SB2 existed in lower boundary of DS1 (between Sachun and Jahrum formation) and between DS2 and DS3 of Asmari formation. Some parts of biozones in study area could correlate with SB2. For example for upper limit of biozones no 4 in Estahban section overlies to SB2 of DS2 in Asmari formation. Paleoecological situation in TST systems tract suitable for reproduction and growth large foraminifera and biozones 1, 2 and 3 are formed in systems tract. MFS and MFZ in all sections are recognized by mixed pelagic and benthonic foraminifera wackestone. More biozones in Jahrum and As- mari formations have been identified in HST system tract. For example in Beyza section biozones 2 and 3 (Jahrum formation) and biozone 4 (Asmari formation) are in HST. In Saevestan B section bi- ozones 3 and 4 (Jahrum formation) and biozones 5 and 6 (Asmari formation) are in this system tract. In Estahban section biozones 3 and 4 (Jahrum formation) and biozones 4 and 5 (Asmari formation) have been in HST. Also, tests of most identified large foraminifera in HST such as Alveolona sp, Alveolina aragonensis, Austrotrilina sp, Austrotrilina asmaricus and Archias sp are made of porcelaneous calcite and foraminiferal tests in TST systems tract, such as Nummulites sp. Nummulites intermedius, Nummulites fichtelli and Operculina sp are made of hyaline calcite.
文摘Dalan Formation is one of the most important gas reservoirs of south and southwest Iran which it belongs to Dehram Group and its age is Middle to Late Permian. The Dalan formation is interpreted as reflecting a major tectono-eustatic event related to the onset of rapid thermal subsidence of the early Neo-Tethys passive margin in Arabia and Iran, and the drowning of its rift shoulders. The Dalan formation consists mainly of medium to thick-bedded oolitic to micritic shallow-marine carbonate, with intercalations of evaporates. This formation overlies the Faraghan formation and extends up into the Lower Triassic kangan formation. The current paper is focused on the facies, sedimentary environment and sequence Stratigraphy study of the Middle to Upper Permian Dalan formation in the West Assaluyeh gas field the subsurface section of well ASL-A. Based on microfacies analysis and significant founa and flora, nineteen major facies in five facies associations including Tidal flat (A), Lagoon (B), Shoal (C), Open marine (D) and Mid ramp (E) were recognized in the Dalan formation. Facies analysis and those comparisons with modern and ancient environments indicated that the Dalan formation was deposited inner to mid parts of a homoclinal ramp. The sequence stratigraphy studies on the Dalan formation in this gas field led to assessment of seven main sedimentary sequences of the third-order in the Assaluyeh field, well ASL-A. The boundary between the third-order sequences with the Faraghan formation and between the Nar and Upper Dalan members are Subaerial Unconformity (SU) and the boundaries between the third-order sequences with each other and also with the Kangan formation are Correlative Conformity (CC). The main diagenetic processes in this formation are dolomitization, dissolution, anhydritization, cementation and compaction which played a significant role in improving reservoir quality. The shoal ooid grainstone facies with intergranular and oomoldic porosity comprise the main reservoir facies of the Dalan formation.
文摘In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment model was based on the profile HMM (Hidden Markov Model), and the model training was implemented through the SAHMM (Self Adapting Hidden Markov Model) software developed by the authors.
文摘Wavelet transformation is a widely used method in high-frequency sequence stratigraphic analysis.However, the application is problematic since different wavelets always return the same sequence analysis results. To address this issue, we applied five commonly used wavelets to theoretical sequence models to document some application criteria. Five gradual scale-change sequence models were simplified from the glutenite succession deposition by gravity flows to form the fining-upwards cycle sequences(FUCS) and coarsening-upwards cycle sequences(CUCS). After conducting theoretical sequence model tests, the optimal wavelet(sym4) was selected and successfully used with actual data to identify the sequence boundaries. We also proposed a new method to optimize the scale of continuous wavelet transformation(CWT) for sequence boundary determination. We found that the balloon-like marks in scalograms of db4, sym4, and coif4 wavelet determine, respectively, the fourth-order sequence boundary, the thick succession sequence boundaries in FUCS, and the thick succession sequence in FUCS and CUCS. Comparing the sequence identification results shows that the asymmetric wavelets had an advantage in high-frequency sequence boundary determination and sedimentary cycle discrimination through the amplitude trend of the coefficient, in which the sym4 wavelet is the most effective. In conclusion, the asymmetry of wavelets is the first selection principle, of which asymmetric wavelets are more sensitive to sediment deposition by flood flows. The match of the wavelet between the sequence is the second selection principle, in which the correlation of time-frequency impacts the accuracy of sequence surface localization. However, the waveform of the wavelet is a visual and abstract parameter for sequence boundary detection. The appropriate wavelet for lacustrine sequence analysis is the asymmetric wavelet with a weak number of side lobes. The depositional flows, depositional process,and autogenic are three sedimentary factors that influence the sequence analysis results.
文摘To study petrography, microfacies, sedimentary environments and sequence stratigraphy of Asmari formation in central Fars, 4 stratigraphic sections have benn chosen and studied (Estahban, Shams-Abad, Sarvestan and Akbar-Abad Sections). Field and laboratories study recognized 16?carbonate microfacies and 2 clastic-carbanate facies. Study of microfacies, relative sea level?change and sequence stratigraphy evidences show these microfacies are deposited in carbonate ramp sedimentary environment in 5 facies belt zones: Open marine (A), Restricted (B), Shoal (C), Lagoon (D) and Tidal flat (E) during Oligomiocene. Petrography, microfacies analysis and sedimentary environment of Asmari formation shows this formation in study area consist of 3 depositional sequences. Lower sequence boundary of DS1 with Jahrum formation is erosional (disconformity) SB1. Lower and upper sequence boundary of DS2 is SB2. The upper sequence boundary of DS3 is SB1 and ended under the Razak clastic formation. In central Fars only lower part of Asmari is deposited and upper part of this formation have been eroded and disappeared.
文摘为有效预测船舶油耗,提出一种基于混合核函数的船舶油耗预测模型。分别构建径向基函数(radial basis function,RBF)和多项式单核函数的支持向量回归(support vector regression,SVR)模型,并利用自适应随机搜索(adaptive random search,ARS)算法对两者进行优化。在此基础上,建立基于混合核函数ARS-SVR的船舶油耗预测模型。以一艘风帆助航的大型原油运输船(very large crude carrier,VLCC)为研究对象,基于实船监测数据开展船舶油耗预测。结果表明,与单一的RBF和多项式单核ARS-SVR相比,采用混合核函数ARS-SVR的模型的预测结果的均方根误差分别降低了19.8%和30.2%。所提出的船舶油耗预测模型可以提升风帆助航船油耗计算的准确率,有助于优化船舶能效和提升管理技术。
文摘Cyt b gene of North Sulawesi Tarsius sp., T. tumpara, T. sangirensis and T. tarsier (T. spectrum) had been partially sequenced. The homologous sequence of three groups had been compared to describe the phylogenetic position among them, as well as several other species accessed from the Genbank. Total DNA extracted from the muscular tissue had been obtained through tail cut sampling using the innuPREP DNA micro kit, and amplified using a pair of universal primer, L14841 and H15149. The size of the cyt b gene sequence amplified was 307 bp long. Sequence aligned using CLUSTAL-X program and diversity analysis were done using version 5.2.2. MEGA5 program. Genetic distance had been calculated by Tamura 3 parameter method and phylogenetic tree had been built using Neighbor-Joining and Maximum Likelihood methods. Genetic distance based on cyt b gene nucleotide was found from 0 to 0.240 with an average of 0.080. The phylogenetic tree constructed by Neighbor Joining and Maximum Likelihood methods indicated that T. tarsier, T. sangirensis and T. tumpara were closely related with Tarsius tarsier-complex, and distantly related with Cephalopachus bancanus and Carlito syrichta. The genetic distance and the phylogenetic tree had been constructed on the base of partial cyt b gene sequence of T. tarsier, T. sangirensis, T. tumpara and 5 other tarsier species and their accession. Those results are consistent with taxonomy based on morphology and vocal acoustic form.
基金partly supported by the National Science Fund of the Ministry of Education and Science of Bulgaria under grant DN 18-10/2017funds of the project RD-08-125/2021 of the University of Shumen。
文摘Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented.These stars are located in the association Cepheus OB3,in the field of the young star V733 Cephei.Photometric observations,especially concerning the long-term variability of the stars,are missing in the literature.We present the first longterm V(RI)c monitoring for them,that cover 13 years.Results from our study indicate that all of the investigated stars manifest strong photometric variability.The presented paper is a part of our program for the photometric study of pre-main-sequence stars located in active star-forming regions.
基金funded by the South Oil Exploration and Development Company of PetroChina(2021-HNYJ-010).
文摘The Fushan Depression is one of the petroliferous depressions in the Beibuwan Basin,South China Sea.Previous studies have preliminarily explored the origin and source of crude oils in some areas of this depression.Nevertheless,no systematic investigations on the classification and origin of oils and hy-drocarbon migration processes have been made for the entire petroleum system in this depression,which has significantly hindered the hydrocarbon exploration in the region.A total of 32 mudstone and 58 oil samples from the Fushan Depression were analyzed to definite the detailed oil-source correlation within the sequence and sedimentary framework.The organic matter of third member of Paleogene Liushagang Formation(Els(3))source rocks,both deltaic and lacustrine mudstone,are algal-dominated with high abundance of C_(23)tricyclic terpane and C_(30)4-methylsteranes.The deltaic source rocks occur-ring in the first member(Els_(1))and second member(Els_(2))of the Paleogene Liushagang Formation are characterized by high abundance of C_(19+20)tricyclic terpane and oleanane,reflecting a more terrestrial plants contribution.While lacustrine source rocks of Els_(1)and Els_(2)display the reduced input of terrige-nous organic matter with relatively low abundance of C 19+20 tricyclic terpane and oleanane.Three types of oils were identified by their biomarker compositions in this study.Most of the oils discovered in the Huachang and Bailian Els_(1)reservoir belong to group A and were derived from lacustrine source rocks of Els_(1)and Els_(2).Group B oils are found within the Els_(1)and Els_(2)reservoirs,showing a close relation to the deltaic source rocks of Els_(1)and Els_(2),respectively.Group C oils,occurring in the Els3 reservoirs,have a good affinity with the Els3 source rocks.The spatial distribution and accumulation of different groups of oils are mainly controlled by the sedimentary facies and specific structural conditions.The Els_(2)reservoir in the Yong'an area belonging to Group B oil,are adjacent to the source kitchen and could be considered as the favorable exploration area in the future.
基金Supported by Leading Talent Program of Autonomous Region(2022TSYCLJ0070)PetroChina Prospective and Basic Technological Project(2021DJ0108)Natural Science Foundation for Outstanding Young People in Shandong Province(ZR2022YQ30).
文摘Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.
基金Supported by the National Science and Technology Major Project(2017ZX05001)CNPC Technology Project(2023YQX20111).
文摘To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D seismic and drilling data,and reservoir sections are thoroughly investigated.Guided by the theory of sequence stratigraphy,the progradational sequence stratigraphic framework of the Yanchang Formation is systematically constructed to elucidate new deposition mechanisms in the depressed lacustrine basin,and it has been successfully applied to the exploration and development practices in the Qingcheng Oilfield.Key findings are obtained in three aspects.First,the seismic progradational reflections,marker tuff beds,and condensed sections of flooding surfaces in the Yanchang Formation are consistent and isochronous.Using flooding surface markers as a reference,a progradational sequence stratigraphic architecture is reconstructed for the middle-upper part of Yanchang Formation,and divided into seven clinoform units(CF1-CF7).Second,progradation predominantly occurs in semi-deep to deep lake environments,with the depositional center not always coinciding with the thickest strata.The lacustrine basin underwent an evolution of“oscillatory regression-progradational infilling-multi-phase superimposition”.Third,the case study of Qingcheng Oilfield reveals that the major pay zones consist of“isochronous but heterochronous”gravity-flow sandstone complexes.Guided by the progradational sequence stratigraphic architecture,horizontal well oil-layer penetration rates remain above 82%.The progradational sequence stratigraphic architecture and associated geological insights are more consistent with the sedimentary infilling mechanisms of large-scale continental depressed lacustrine basins and actual drilling results.The research results provide crucial theoretical and technical support for subsequent refined exploration and development of the Yanchang Formation,and are expected to offer a reference for research and production practice in similar continental lacustrine basins.
基金supported by grants from the Zhejiang Provincial Natural Science Foundation(LGJ22H180001)Zhejiang Medical and Health Science and Technology Project(2021KY249)the National Key R&D Program of China(2017YFC1310000).
文摘Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modulatory effect on neural plasticity associated with MSL remains unclarified.This study was therefore designed to compare the role of the left primary motor cortex and the left supplementary motor area proper(SMAp)in modulating MSL across different complexity levels and for both hands,as well as the associated neuroplasticity by applying intermittent theta burst stimulation together with the electroencephalogram and concurrent transcranial magnetic stimulation.Our data demonstrated the role of SMAp stimulation in modulating neural communication to support MSL,which is achieved by facilitating regional activation and orchestrating neural coupling across distributed brain regions,particularly in interhemispheric connections.These findings may have important clinical implications,particularly for motor rehabilitation in populations such as post-stroke patients.
文摘Cystic echinococcosis (CE) is a prevalent zoonotic disease caused by Echinococcus granulosus, with a cosmopolitan distribution. The parasite is transmitted cyclically between canines and numerous intermediate herbivorous livestock animals. Also, other Taeniid tapeworms could infect domestic dogs and they pose significant veterinary and public health concerns worldwide. This study aimed to develop a sensitive molecular method for detecting Echinococcus spp. DNA in dog fecal samples using next-generation sequencing (NGS). A set of PCR primers targeting conserved regions of Taeniid tapeworms’ 18s rRNA genes was designed and tested for amplifying genomic DNA from various tapeworm species. The PCR system demonstrated high sensitivity, amplifying DNA from all tested tapeworm species, with differences observed in amplified band sizes. The primers were adapted for NGS analysis by adding forward and reverse adapters, enabling the sequencing of amplified DNA fragments. Application of the developed PCR system to dog fecal samples collected from Yatta town, Palestine, revealed the presence of E. granulosus DNA in five out of 50 samples. NGS analysis confirmed the specificity of the amplified DNA fragments, showing 98% - 99% similarity with the 18s rDNA gene of E. granulosus. This study demonstrates the utility of NGS-based molecular methods for accurate and sensitive detection of Echinococcus spp. in dog fecal samples, providing valuable insights for epidemiological surveillance and control programs of echinococcosis in endemic regions.
文摘Purpose:Generally,the scientific comparison has been done with the help of the overall impact of scholars.Although it is very easy to compare scholars,but how can we assess the scientific impact of scholars who have different research careers?It is very obvious,the scholars may gain a high impact if they have more research experience or have spent more time(in terms of research career in a year).Then we cannot compare two scholars who have different research careers.Many bibliometrics indicators address the time-span of scholars.In this series,the h-index sequence and EM/EM’-index sequence have been introduced for assessment and comparison of the scientific impact of scholars.The h-index sequence,EM-index sequence,and EM’-index sequence consider the yearly impact of scholars,and comparison is done by the index value along with their component value.The time-series indicators fail to give a comparative analysis between senior and junior scholars if there is a huge difference in both scholars’research careers.Design/methodology/approach:We have proposed the cumulative index calculation method to appraise the scientific impact of scholars till that age and tested it with 89 scholars data.Findings:The proposed mechanism is implemented and tested on 89 scholars’publication data,providing a clear difference between the scientific impact of two scholars.This also helps in predicting future prominent scholars based on their research impact.Research limitations:This study adopts a simplistic approach by assigning equal credit to all authors,regardless of their individual contributions.Further,the potential impact of career breaks on research productivity is not taken into account.These assumptions may limit the generalizability of our findings Practical implications:The proposed method can be used by respected institutions to compare their scholars impact.Funding agencies can also use it for similar purposes.Originality/value:This research adds to the existing literature by introducing a novel methodology for comparing the scientific impact of scholars.The outcomes of this research have notable implications for the development of more precise and unbiased research assessment frameworks,enabling a more equitable evaluation of scholarly contributions.
文摘Binary sequences constructed by Legendre symbols are widely used in communication and cryptography since they have many good pseudo-random properties.In this paper,we determine the 2-adic complexity of the sum sequence of any k many Legendre sequences and show that the 2-adic complexity of the sum sequences of any k many Legendre sequences reaches the maximum by proving the case of k=2 and 3,which implies that the sum sequences can resist the attack of rational approximation algorithm.
