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Introduction: An ideal bone repair scaffold should have dual functions of osteoinductive ability and in vivo imaging. In this study, the simultaneous substitution of silicon (Si) and gadolinium (Gd) in hydroxyapatite (HA) as potential multifunctional bone graft materials has been successfully developed.Methods: A series of HA nanoparticles (HA NPs) doped with different proportions of Si and Gd were prepared. The chemical structure and phase composition of the materials were analyzed using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The microstructure, magnetic properties, surface potential, and cytotoxicity of the materials were also analyzed. The magnetic resonance imaging (MRI) effect of Gd&Si-HA/poly(lactic-co-glycolic acid) (Gd&Si-HA/PLGA) composite materials was evaluated. Osteogenic-related gene expression, alkaline phosphatase (ALP) level, and mineralization capacity of MC3T3-E1 cultured on Gd&Si-HA/PLGA composite materials were also detected.Results and Discussion: The 1.5Gd&Si-HA@PLGA group showed good ability to promote osteogenic differentiation of cells. The MRI effect of the 1.5Gd&Si-HA@PLGA scaffold was observable. This HA material containing Si and Gd co-doping has a broad application prospect in the field of bone tissue engineering owing to its ability to enhance osteoinductive property and improve MRI effect.

The physical properties and fire extinguishing performance in diesel fire of aqueous film-forming foam (AFFF) and protein foam (PF) were studied, and the fire extinguishing mechanism of different foams were also analyzed. The results show that 6%AFFF and 6%PF have better performance than that of 3%AFFF and 3%PF, respectively, and AFFF possess higher expansion ratio, 25% drainage time and surface tension than PF at the same concentration. The fire extinguishing test show that the extinguishing performance of foam enhanced with the increase of gas-liquid ratio firstly, and decreased subsequently. The best fire extinguishing performance were achieved when gas-liquid ratio of 6%AFFF and 6%PF were 17 and 20, and the extinguishing agent dosage were 229 ml and 260 ml, respectively. Compared with PF, the fire extinguishing time and agent dosage of AFFF are reduced by 10% and 6.15% respectively at gas-liquid ratio of 20. Besides, AFFF can form more dense, stable and high-multiple foam cover layer, endow it with better fire extinguishing performance than PF. However, PF can reduce the temperature around the oil pool more quickly, showing better cooling effect than AFFF.

The evaluation of reservoirs is of great importance in exploration practices, and reservoir distribution is dependent on multiple geological factors. The carbonate platform of the fourth member (Z2dn4) of the Dengying Formation (Z2dn) in the Gaoshiti-Moxi area (GMA) was uplifted above sea level during episode II of the Tongwan movement and underwent prolonged karstification by meteoric freshwater in the terminal Sinian, leading to a strong heterogeneity in reservoirs. Paleogeomorphology reflects hydraulic gradients that can affect the intensities of surface karstification and may be approximated by terrain slope gradients. Karst products (especially solution vugs and caverns) exist prevailingly in the Z2dn4; their development mirrors the extents of internal dissolution. Based on paleogeomorphological reconstruction using the elevation method, the slope angles of single boreholes were calculated through the digital elevation model (DEM). In accordance with single-borewell Fullbore Formation MicroImager (FMI) logging data, four electrofacies (host rock, vug, fracture, and cave) were identified in boreholes possessing FMI data. The identified electrofacies were matched with corresponding conventional logging curves to obtain the training data. A model generalized for other boreholes without FMI data was established with the random forest algorithm and the thicknesses of the four electrofacies in each borehole were determined to characterize the extent of karstification. Slope gradients and electrofacies thicknesses, together with multiple physical parameters of reservoirs in boreholes, were utilized for factor analysis. Four factors were obtained and fused into one comprehensive score based on their ratios of variance proportions. The favorability of reservoirs was described by the comprehensive scores of each borehole. These analyses showed that the most advantageous reservoirs are distributed in the vicinity of the platform margin in the west of the GMA, where they enjoy several benefits. Deposition of porous mound-shoal complexes occurs predominantly in the platform margin where large-scale caves are more developed in the mixing karst zone of seawater and freshwater. Meanwhile, the transmeridional lateral migration of hydrocarbons from the regional hydrocarbon-generating center abutting the west of the GMA contributes to earlier entrapment and accumulation in the mound-shoal complexes in the platform margin.

The Sinian Dengying Formation in the Sichuan basin is an important potential reservoir for oil and gas exploration in the periphery of the Sichuan basin. Its reservoirs were well developed. And many kinds of fillings which lead to the decrease of pores can be seen in reservoir pores and caves. In this paper, the pore fillings of the Dengying Formation reservoir in Sichuan basin are the object of study. The types and characteristics of the fillings are studied in detail by means of rock slices analysis, cathode luminescence, trace elements and inclusion temperature measurement. The study shows that the fillings include dolomite fillings and siliceous quartz fillings and bitumen fillings. Among them, dolomite fillings can be divided into botryoidal dolomite fillings, foliated dolomite fillings, finely-medium crystalline dolomite fillings and coarse crystalline dolomite fillings. 50%–80% of the pores are filled by the dolomite fillings with botryoidal structure, and the pores can be partially full filled; 0%–20% of pores are filled by foliated dolomite fillings; 20–80% of the pores are filled by finely-medium dolomite fillings; 20–80% of the pores are filled by coarse crystalline dolomite fillings. 1%–5% of secondary pores are often filled by siliceous quartzs, and the pores can be partially full filled. Bitumen fillings often occur after the above-mentioned fillings, and the residual pores are often semi-filled by bitumens, which makes the original pores and throat smaller and reduces the effective porosity and permeability of the reservoir. So, it is a destructive diagenesis. The pore fillings make the secondary porosity in the reservoir significantly lower, which is not conducive to the formation and preservation of the Dengying Formation reservoir. Keywords: Pore fillings, Reservoir, Dengying formation, Sichuan basin

This study investigated the characteristics and genesis of reservoirs in the 2nd and 4th members of Sinian Dengying Formation in northern Sichuan and its surrounding areas, on the basis of outcrop, drilling cores and thin section observation and geochemical analysis. The reservoirs of 2nd member are distributed in the middle part of the stratum. The reservoir quality is controlled by supergene karst and the distribution of mound-shoal complex. The bedded elongated isolated algal framework solution-cave and the residual “grape-lace” cave, which are partially filled with multi-stage dolosparite, constituted the main reservoir space of the 2nd member. There is no asphalt distribution in the pores. The pore connectivity is poor, and the porosity and permeability of the reservoir is relatively low. The reservoirs of 4th member were distributed in the upper and top part of the stratum. The reservoir quality is controlled by burial dissolution and the distribution of mound-shoal complex. The bedded algal framework solution-pores or caves, intercrystalline pores and intercrystalline dissolved pores constituted the main reservoir space of the 4th member. It's partially filled with asphalt and quartz, without any dolosparite fillings in the pores and caves. The pore connectivity is good. Most of the 4th member reservoirs had medium-low porosity and low permeability, and, locally, medium-high porosity and medium permeability. Affected by the development of mound-shoal complex and heterogeneous dissolution, the platform margin along Ningqiang, Guangyuan, Jiange and Langzhong is the most favorable region for reservoir development. Deep buried Dengying Formation in the guangyuan and langzhong areas should be the most important hydrocarbon target for the future exploration. Key words: Sichuan Basin, northern Sichuan area, Sinian, Dengying Formation, mound-shoal complex, supergene karst, burial dissolution, reservoir

With the extended petroleum exploration of the carbonate reservoir in the Longwangmiao Formation, Lower Cambrian in Sichuan basin, looking for a new favorable exploration area is the primary task in current exploration. This paper focusing on the dolomite reservoir in the Longwangmiao Formation in the Northern Sichuan basin, will evaluate the reservoir conditions, including reservoir lithology, reservoir spaces, physical properties and other basic characteristics. Combined with sedimentary environment study and diagenesis analysis, the genetic mechanism of Longwangmiao reservoir in study area will be discussed. It indicates that the reservoir rocks of Longwangmiao Formation in the study area are composed of dolarenite and crystalline dolomite, and the main reservoir spaces are intergranular dissolved pores, intragranular dissolved pores and intercrystalline dissolved pores. However, most of dissolved pores have been filled with bitumen, which lead to the reservoir properties very poor, both the porosity and permeability are worse than that of central Sichuan basin, so the reservoir in the Longwangmiao Formation in the Northern Sichuan basin is low-porosity and low-permeability reservoir. During the Early Cambrian Longwangmiao period, the study was near the old-land, and the energy of sea water was not enough to deposit many grain shoals, which cause the sediments are small with lots of quartz and muds. Moreover, because lacking of large scale karstification in the late diagenesis, there isn't much dissolved pores and vugs develop in the Longwangmiao Formation. Some Intergranular dissolved pores and intercrystalline dissolved pores formed by the early atmosphere water dissolved exist as some reservoir spaces, but most of them have been filled with bitumen, which was residual when the ancient oil reservoir transformed. Above factors cause the Longwangmiao Formation in the Northern Sichuan basin become not a very favorable reservoir in Sichuan basin. Keywords: Reservoir evaluation, Dolomites, Longwangmiao Formation, Northern Sichuan basin

Cambrian in Sichuan basin developed thick black shale, varies carbonate and clastic rock, which deposited in different sedimentary environment. Sichuan basin in the upper Yangtze platform contained a record of environment during the Cambrian. Detail facies analyses of Cambrian enable us to discuss the sedimentary environment and palaeogeographic setting. Sedimentation commenced in the Early Cambrian with the deposition of shelf facies (Qiongzhusi Formation and Canglangpu Formation). At this stage, thick shale and clastic rock deposited in Sichuan basin. At the end of the Early Cambrian, a carbonate platform developed in upper Yangtze platform, and Sichuan basin was located in restricted platform (Longwangmiao Formation). In the Middle Cambrian, tidal flat and restricted platform developed in Sichuan basin (Douposi Formation), because of continuous regression. During the Late Cambrian, Sichuan basin was located in carbonate platform again (Xixiangchi Formation). There are three types of sedimentary system in the Cambrian of Sichuan basin: clastic sedimentary system, clastics-carbonate mixed sedimentary system and carbonate sedimentary system. Vertically, the basin shows the evolutionary character of clastic-carbonate sedimentary systems. The three sedimentary systems correspond to three "transgression-regression" cycles of the Cambrian. The transgression in the initial period of the Early Cambrian led to the formation of clastic sedimentary system in the Qiongzhusi Formation of Lower Cambrian. The transgression in the later period of the Early Cambrian led to the formation of clasticcarbonate mixed sedimentary system in the Middle-Lower Cambrian. The transgression in the initial period of the Late Cambrian led to the formation of carbonate sedimentary system in the Xixiangchi Formation of Upper Cambrian. With the end of Late Sinian continental rifting ended, Sichuan basin entered a stable evolutionary stage of the craton basin, while the paleo-land developed in the north and southwest. In Qiongzhusi-Canglangpu period, the basin developed onshore-shelf sedimentary facies from west to east; In Longwangmiao-Xixiangchi period, the basin developed tidal flat-platform-slope sedimentary facies from west to east. [ABSTRACT FROM AUTHOR]

With market competition becoming fiercer, enterprises must update their products by constantly assimilating new big data knowledge and private knowledge to maintain their market shares at different time points in the big data environment. Typically, there is mutual influence between each knowledge transfer if the time interval is not too long. It is necessary to study the problem of continuous knowledge transfer in the big data environment. Based on research on one-time knowledge transfer, a model of continuous knowledge transfer is presented, which can consider the interaction between knowledge transfer and determine the optimal knowledge transfer time at different time points in the big data environment. Simulation experiments were performed by adjusting several parameters. The experimental results verified the model's validity and facilitated conclusions regarding their practical application values. The experimental results can provide more effective decisions for enterprises that must carry out continuous knowledge transfer in the big data environment. [ABSTRACT FROM AUTHOR]

Purpose – With the clarification of three effective methods (share holding, decision participation and promotion of technical grade) to govern R&D teams in software enterprises, the purpose of this paper is to provide an empirical investigation of the application of these methods in Chinese software enterprises. Design/methodology/approach – The research is based on a quantitative approach with 34 items designed in the questionnaire to measure the indicators. All items were rated by respondents on a five-point Likert-type scale. In order to testify the validity of the three methods of R&D team governance, a correlation analysis and a linear regression were made to examine the relationship between these methods of R&D team governance and R&D performance. Findings – The evidence shows that decision participation and promotion of technical grades are the two most effective methods to govern R&D teams in Chinese software enterprises, while share holding is not conducive to R&D performance. The share holding level of R&D staffs is fairly low; even "no share." What is more important is that many software enterprises regard it as a welfare institution but not an incentive method. Therefore, the shareholding mechanism cannot enhance R&D performance. In addition, relevant regulations have not been established completely. There are many deficiencies in the process of intellectual property management of Chinese enterprises. These factors have hindered the effective performance of R&D staff. Practical implications – The research findings emphasize the importance of governance of R&D teams in the Chinese software industry and highlight the critical issues that need to be addressed in order to enhance the performance of R&D staff. Originality/value – The concept of R&D team governance is examined and elaborated within the context of China, which points to the need of developing new direction of R&D team management. [ABSTRACT FROM AUTHOR]