Baoziwan-Majiashan Area of Jiyuan Oilfield Analysis of Reservoir Characteristics and Main Control Factors in Long 4 5 Section

Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10−3 µm2. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir.

Controlling factors and models of shale oil enrichment in Lower Permian Fengcheng Formation,Mahu Sag,Junggar Basin,NW China

Based on the combination of core observation,experimental analysis and testingand geological analysis,the main controlling factors of shale oil enrichment in the Lower Permian Fengcheng Formation in the Mahu Sag of the Junggar Basin are clarified,and a shale oil enrichment model is established.The results show that the enrichment of shale oil in the Fengcheng Formation in the Mahu Sag is controlled by the organic abundance,organic type,reservoir capacity and the amount of migration hydrocarbon in shale.The abundance of organic matter provides the material basis for shale oil enrichment,and the shales containing typesⅠandⅡorganic matters have good oil content.The reservoir capacity controls shale oil enrichment.Macropores are the main space for shale oil enrichment in the Fengcheng Formation,and pore size and fracture scale directly control the degree of shale oil enrichment.The migration of hydrocarbons in shale affects shale oil enrichment.The shale that has expelled hydrocarbons has poor oil content,while the shale that has received hydrocarbons migrated from other strata has good oil content.Lithofacies reflect the hydrocarbon generation and storage capacity comprehensively.The laminated felsic shale,laminated lime-dolomitic shale and thick-layered felsic shale have good oil content,and they are favorable lithofacies for shale oil enrichment.Under the control of these factors,relative migration of hydrocarbons occurred within the Fengcheng shale,which leads to the the difference in the enrichment process of shale oil.Accordingly,the enrichment mode of shale oil in Fengcheng Formation is established as"in-situ enrichment"and"migration enrichment".By superimposing favorable lithofacies and main controlling factors of enrichment,the sweet spot of shale oil in the Fengcheng Formation can be selected which has great significance for the exploration and development of shale oil.

Crude oil cracking in deep reservoirs:A review of the controlling factors and estimation methods

The natural cracking of crude oils in deep reservoirs has gained great interest due to continuously increasing depth of petroleum exploration and exploitation.Complex oil compositions and surroundings as well as complicated geological evolutions make oil cracking in nature much more complex than industrial pyrolysis.So far,numerous studies,focused on this topic,have made considerable progress although there still exist some drawbacks.However,a comprehensive review on crude oil cracking is yet to be conducted.This article systematically reviews the controlling factors of oil cracking from six aspects,namely,oil compositions,temperature and time,pressure,water,minerals and solid organic matter.We compare previous experimental and modelling results and present new field cases.In the following,we evaluate the prevailing estimation methods for the extent of oil cracking,and elucidate other factors that may interfere with the application of these estimation methods.This review will be helpful for further investigations of crude oil cracking and provides a guide for estimation of the cracking extent of crude oils.

Distribution Characteristics and Controlling Factors of Heavy Metals in Surface Sediments from the Bay-Island-Estuary System(BIES):A Case Study in Coastal Waters of Fujian Province,China

Based on the contents of six heavy metal elements in surface sediments from coastal areas of Fujian Province,the distribution characteristics and controlling factors of six heavy metals in a bay-island-estuary system(BIES)were studied.This paper focuses on the influence of the hydrodynamic environment,and systematically discusses how grain size compositions,chemical environment,tidal current,ocean circulation and human activities influence the distribution and transportation of the heavy metals.The results indicated that the distribution and migration of Cu,Pb,Zn and Cr elements were mainly controlled by natural factors such as regional geological background,grain size compositions,and tidal residual currents.In contrast,As and Hg was mainly affected by human factors such as agriculture and industrial manufacturing.In the BIES,where the chemical environment exerted limited influence,the accumulation and migration of heavy metals are mainly influenced by human activities and enhanced by estuary processes as well as the complex sedimentary dynamic environment caused by many bays and islands.

Factors Controlling Organic Matter Enrichment in Alkaline Lacustrine Source Rocks:A Case Study of the Late Paleozoic Fengcheng Formation in the Junggar Basin,NW China

The late Paleozoic Fengcheng Formation shale(LPF shale)in the Junggar Basin,NW China,is the oldest alkaline source rock discovered in the world,providing a unique perspective with which to explore organic matter(OM)enrichment in alkaline lake environments.Combined with the organic carbon isotope profile and paleoenvironmental proxies,this study reveals that the LPF shale was deposited in an arid climate with high salinity and a strong reducing environment,accompanied by frequent volcanic activity.High TOC values are concentrated in two intervals with frequent fluctuations in OM types.A negative excursion due to changes in sedimentary OM source is found in the δ^(13)C_(org) profile.The excursion corresponds to the OM enrichment interval and is accompanied by abnormally high values of Sr/Ba and Sr/Cu.This implies that the extreme arid climate has led to high salinity,resulting in strong reducibility and changes in paleontological assemblages,which in turn controlled the differential enrichment of OM.The Fengcheng Fm.high-quality source rocks are the result of the combined action of climatic events,volcanism,high-salinity water environment and superior hydrocarbon-generating organisms.The results provide new insights into the formation conditions of terrestrial alkaline high-quality source rocks and the factors controlling alkaline OM enrichment.

A comparative study of the main factors controlling geohazards induced by 10 strong earthquakes in Western China since the Wenchuan earthquake in 2008

Determining the main controlling factors of earthquake-triggered geohazards is a prerequisite for studying earthquake geohazards and post-disaster emergency response.By studying these factors,the geomorphic and geological factors controlling the nature,condition,and distribution of earthquake-induced geohazards can be analyzed.Such insights facilitate earthquake disaster prediction and emergency response planning.The authors combined field investigations and spatial data analysis to examine geohazards induced by seismic events,examining ten earthquakes including the Wenchuan,Yushu,Lushan events,to elucidate the main control factors of seismic geohazard.The authors observed that seismic geohazard occurrence is usually affected by many factors,among which active nature of the seismogenic fault,seismic peak ground acceleration(PGA),topographic slope and geomorphic height differences,and distance from the fault zone and river system are the most important.Compared with strike-slip earthquakes,thrust earthquakes induce more high-altitude and high-speed remote landslides,which can cause great harm.Slopes of 0°–40°are prone to secondary seismic geohazards,which are mainly concentrated 0–6 km from the river system.Secondary geohazards are not only related to seismogenic fault but also influenced by the associated faults in the earthquake area.The maximum seismic PGA and secondary seismic geohazard number are positively correlated,and the horizontal and vertical ground motions play leading and promoting roles in secondary geohazard formation,respectively.Through the research,the spatial distribution of seismic geohazards is predicted,providing a basis for the formulation of emergency response plans following disasters.

Behavior and controlling factors of methane adsorption in Jurassic continental shale,northeastern Sichuan Basin

The behavior and controlling factors of natural gas adsorption in the Jurassic continental shale in the northeastern Sichuan Basin are studied based on the organic geochemical features,mineral compositions and pore structure parameters through a series of experiments on samples from the shale.Results show that the total gas content of the shale measured on-site is 0.1-5.3 cm^(3)/g,with an average of 0.7 cm^(3)/g.The methane isothermal adsorption curves show a trend of increasing first and then decreasing,indicating an obvious excessive adsorption.The shale has a maximum adsorption capacity(V^(L))of 0.44-3.59 cm^(3)/g,with an average of 1.64 cm^(3)/g,lower than that of marine shale in the same basin.The organic matter content and pore structure characteristics are identified as the two main factors controlling the adsorption capacity of the shale.Micropores in the shale are the main storage space for gas to be adsorbed.Due to well developed shell laminae and interlayers in the shale,calcite plays a more important role than clay minerals in affecting the adsorption of gas to the rock.The formation temperature and water content also significantly inhibit the gas adsorption to the shale.Compared with marine shale in the basin,the Jurassic continental shale is more heterogeneous and lower in TOC values.Furthermore,with a more widely developed clayey shale lithofacies and shell limy shale lithofacies as well as relatively less developed organic pores and micropores,the continental shale is inferior to marine shale in terms of gas adsorption capacity.

Spatial-Temporal Distribution, Geological Characteristics and Ore-Formation Controlling Factors of Major Types of Rare Metal Mineral Deposits in China

Rare metals including Lithium(Li),Beryllium(Be),Rubidium(Rb),Cesium(Cs),Zirconium(Zr),Hafnium(Hf),Niobium(Nb),Tantalum(Ta),Tungsten(W)and Tin(Sn)are important critical mineral resources.In China,rare metal mineral deposits are spatially distributed mainly in the Altay and Southern Great Xingán Range regions in the Central Asian orogenic belt;in the Middle Qilian,South Qinling and East Qinling mountains regions in the Qilian-Qinling-Dabie orogenic belt;in the Western Sichuan and Bailongshan-Dahongliutan regions in the Kunlun-Songpan-Garze orogenic belt,and in the Northeastern Jiangxi,Northwestern Jiangxi,and Southern Hunan regions in South China.Major ore-forming epochs include Indosinian(mostly 200-240 Ma,in particular in western China)and the Yanshanian(mostly 120-160 Ma,in particular in South China).In addition,Bayan Obo,Inner Mongolia,northeastern China,with a complex formation history,hosts the largest REE and Nb deposits in China.There are six major rare metal mineral deposit types in China:Highly fractionated granite;Pegmatite;Alkaline granite;Carbonatite and alkaline rock;Volcanic;and Hydrothermal types.Two further types,namely the Leptynite type and Breccia pipe type,have recently been discovered in China,and are represented by the Yushishan Nb-Ta-(Zr-Hf-REE)and the Weilasituo Li-Rb-Sn-W-Zn-Pb deposits.Several most important controlling factors for rare metal mineral deposits are discussed,including geochemical behaviors and sources of the rare metals,highly evolved magmatic fractionation,and structural controls such as the metamorphic core complex setting,with a revised conceptual model for the latter.

Quantitative analysis of geological ore-controlling factors and stereoscopic quantitative prediction of concealed ore bodies

To address the issues for assessing and prospecting the replaceable resource of crisis mines,a geological ore-controlling field model and a mineralization distribution field model were proposed from the viewpoint of field analysis. By dint of solving the field models through transferring the continuous models into the discrete ones,the relationship between the geological ore-controlling effect field and the mineralization distribution field was analyzed,and the quantitative and located parameters were extracted for describing the geological factors controlling mineralization enrichment. The method was applied to the 3-dimensional localization and quantitative prediction for concealed ore bodies in the depths and margins of the Dachang mine in Guangxi,China,and the 3-dimensional distribution models of mineralization indexes and ore-controlling factors such as magmatic rocks,strata,faults,lithology and folds were built. With the methods of statistical analysis and the non-linear programming,the quantitative index set of the geological ore-controlling factors was obtained. In addition,the stereoscopic located and quantitative prediction models were set up by exploring the relationship between the mineralization indexes and the geological ore-controlling factors. So far,some concealed ore bodies with the resource volume of a medium-sized mineral deposit are found in the deep parts of the Dachang Mine by means of the deep prospecting drills following the prediction results,from which the effectiveness of the predication models and results is proved.

Geological Characteristics and Ore-controlling Factors of the Beiya Gold–Polymetallic Ore Deposit, Northwestern Yunnan Province

Based on comprehensive petrological, geochronological, and geochemical studies, this study analyzed the relationships between the Beiya gold-polymetallic skarn deposit and quartz syenite porphyries, and discussed the source（s） and evolution of magmas. Our results suggest that syenite porphyries（i.e. the Wandongshan, the Dashadi, and the Hongnitang porphyries）, which formed between the Eocene and the early Oligocene epochs, are the sources for the gold-polymetallic ores at the Beiya deposit. Carbonate rocks（T2 b） of the Triassic Beiya Formation in the ore district provide favorable host space for deposit formation. Fold and fault structures collectively play an important role in ore formation. The contact zone between the porphyries and carbonates, the structurally fractured zone of carbonate and clastic rocks, and the zone with well-developed fractures are the ideal locations for ore bodies. Four types of mineralization have been recognized： 1） porphyry-style stockwork gold–iron（copper） ore, 2） skarn-style gold-iron（copper and lead） ore in the near contact zone, 3） strata-bound, lense-type lead–silver–gold ore in the outer contact zone, and 4） distal vein-type gold–lead–silver ore. Supergene processes led to the formation of oxide ore, such as the weathered and accumulated gold–iron ore, the strata-bound fracture oxide ore, and the structure-controlled vein-type ore. Most of these ore deposits are distributed along the axis of the depressed basin, with the hypogene ore controlling the shape and characteristics of the oxide ore. This study provides critical geology understanding for mineral prospecting scenarios.

Assessment of the crucial factors influencing the responses of ammonia and nitrous oxide emissions to controlled release nitrogen fertilizer: A meta-analysis

Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea(CU). However, the crucial factors influencing the responses of NH3and N2O emissions to CRU relative to CU are still unclear. In this study, we evaluated the responses of NH3and N2O emissions to CRU based on collected field data with a meta-analysis. CRU reduced the NH3and N2O emissions by 32.7 and 25.0% compared with CU, respectively. According to subgroup analysis, CRU presented better mitigation of NH3and N2O emissions in soils with pH 6.5–7.5(–47.9 and –23.7%) relative to either pH<6.5(–28.5and –21.4%) or pH>7.5(–29.3 and –17.3%), and in the rice season(–34.8 and –29.1%) relative to the wheat season(–19.8 and –22.8%). The responses of NH3and N2O emissions to CRU increased from rainfed(–30.5 and –17.0%) to irrigated(–32.5 and –22.9%), and then to paddy(–34.8 and –29.1%) systems. In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen(TN);however, soil TN did not significantly affect the response of NH3volatilization. The reduction in NH3emission was greater in sandy-textured soil(–57.7%) relative to loam-textured(–32.9%) and clay-textured(–32.3%) soils, whereas soil texture did not affect N2O emission. Overall, CRU was a good option for reducing the NH3and N2O emissions relative to CU in agricultural production. This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE.

Sedimentary evolution and control factors of the Rizhao Canyons in the Zhongjiannan Basin, western South China Sea

Submarine canyon is an important channel for long-distance sediment transport, and an important part of deepwater sedimentary system. The large-scale Rizhao Canyons have been discovered for the first time in 2015 in the continental slope area of the western South China Sea. Based on the interpretation and analysis of multi-beam bathymetry and two-dimensional multi-channel seismic data, the geology of the canyons has however not been studied yet. In this paper, the morphology and distribution characteristics of the canyon are carefully described,the sedimentary filling structure and its evolution process of the canyon are analyzed, and then its controlling factors are discussed. The results show that Rizhao Canyons group is a large slope restricted canyon group composed of one east-west west main and nine branch canyons extending to the south. The canyon was formed from the late Miocene to the Quaternary. The east-west main canyon is located in the transition zone between the northern terrace and the southern Zhongjiannan Slope, and it is mainly formed by the scouring and erosion of the material source from the west, approximately along the slope direction. Its development and evolution is mainly controlled by sediment supply and topographic conditions, the development of 9 branch canyons is mainly controlled by gravity flow and collapse from the east-west main canyon. This understanding result is a supplement to the study of “source-channel–sink” sedimentary system in the west of the South China Sea, and has important guiding significance for the study of marine geological hazards.

Occurrence Factors and Efficient Green Prevention and Control Technology of Peanut Stem Rot Caused by Sclerotium rolfsii in Southern Mountainous Area of Shandong Province

Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.

Assessment of Diabetes Control Level and Associated Cardiovascular Risk Factors

Introduction: Cardiovascular diseases are the leading cause of mortality in type 2 diabetics patients. Our work aimed to assess the level of control of type 2 diabetes and associated cardiovascular risk factors. Patients and study method: This was an observational cross-sectional study of type 2 diabetics patients. The parameters studied were: sociodemographic data, lifestyle, anthropometric data, levels of control of diabetes by the level of HbA1C, blood pressure measured at the office and cholesterol. Results: 326 type 2 diabetics patients were collected. The sex-ratio was 0.35. The average age of the patients was 58 ± 11 years. A physical inactivity remained present in 79 patients (24.23%), 2 patients (0.61%) continued to smoke. The prevalence of obesity was 21.16% (n = 69) or 25% of women and 10.4% of men (p = 0.01). Abdominal obesity was observed in 151 patients (46.31%), 139 of whom were female and 12 male (p = 0.001). Diabetes was sufficiently controlled in 65.34% of patients (n = 213) while cholesterolemia and hypertension were controlled in 33.44% and 8.33% of patients respectively. Conclusion: Type 2 diabetes was frequently associated with other cardiovascular risk factors. Control of diabetes and these factors was insufficient. Therapeutic education of type 2 diabetics patients needed to be improved.

Spatial and temporal variations and controlling factors of potential evapotranspiration in China:1956-2000

Based on the climatic data of 580 stations in China during 1956 and 2000, potential evapotranspiration are calculated using the Penman-Monteith Method recommended by FAO. The spatial and temporal distributions of the potential evapotranspiration over China and the temporal trends of the regional means for 10 major river basins and whole China are analyzed. Through a partial correlation analysis, the major climate factors which affect the temporal change of the potential evapotranspiration are analyzed. Major results are drawn as follows： 1） The seasonal and annual potential evapotranspiration for China as a whole and for most basins show decline tendencies during the past 45 years; for the Songhua River Basin there appears a slightly increasing trend. 2） Consequently, the annual potential evapotranspirations averaged over 1980-2000 are lower than those for the first water resources assessment （1956-1979） in most parts of China. Exceptions are found in some areas of Shandong Peninsula, western and middle basins of the rivers in Southwest China, Ningxia Hui Autonomous Region as well as the source regions of the Yangtze and Yellow rivers, which may have brought about disadvantages to the exploration and utilization of water resources. 3） Generally, sunshine duration, wind speed and relative humidity have greater impact on the potential evapotranspiration than temperature. Decline tendencies of sunshine duration and/or wind speed in the same period appear to be the major causes for the negative trend of the potential evapotranspiration in most areas.

Air-sea carbon fluxes and their controlling factors in the Prydz Bay in the Antarctic

The Prydz Bay in the Antarctic is an important area in the Southern Ocean due to its unique geographic feature. It plays an important role in the carbon cycle in the Southern Ocean. To investigate the distributions of carbon dioxide in the atmosphere and surface seawater and its air-sea exchange rates in this region, the Chinese National Antarctic Research Expedition （CHINARE） had set up several sections in the Prydz Bay. Here we present the results from the CHINARE-XVI cruises were presented onboard R/V Xue/ong from November 1999 to April 2000 and the main driving forces were discussed controlling the distributions of partial pressure of carbon dioxide. According to the partial pressure of carbon dioxide distributions, the Prydz Bay can be divided into the inside and outside regions. The partial pressure of carbon dioxide was low in the inside region but higher in the outside region during the measurement period. This distribution had a good negative correlation with the concentrations of ehlorophyll-a in general, suggesting that the partial pressure of carbon dioxide was substantially affected by biological production. The results also indicate that the biological produetion is most likely the main driving force in the marginal ice zone in the Southern Ocean in summer. However, in the Antarctic divergence sector of the Prydz Bay （about 64°S）, the hydrological processes become the controlling factor as the sea surface partial pressure of carbon dioxide is much higher than the atmospheric one due to the upwelling of the high DIC CDW, and this made the outside of Prydz Bay a source of carbon dioxide. On the basis of the calculations, the CO2 flux in January （austral summer） was -3.23 mmol/（m^2 · d） in the inner part of Prydz Bay, i.e. , a sink of atmospheric CO2, and was 0.62 mmol/（m^2 · d） in the outside part of the bay, a weak source of atmospheric CO2. The average air-sea flux of CO2 in the Prydz Bay was 2.50 mmol/（m^2 · d）.

Geological Factors Controlling the Accumulation and High Yield of Marine-Facies Shale Gas: Case Study of the Wufeng-Longmaxi Formation in the Dingshan Area of Southeast Sichuan, China

The main geological factors controlling the accumulation and yield of marine-facies shale gas reservoirs are the focus of the current shale gas exploration and development research.In this study,the Wufeng-Longmaxi Formation in the Dingshan area of southeast Sichuan was investigated.Shale cores underwent laboratory testing,which included the evaluation of total organic carbon(TOC),vitrinite reflectance(Ro),whole-rock X-ray diffraction(XRD),pore permeability,and imaging through field emission scanning electron microscopy(FE-SEM).Based on the results of natural gamma ray spectrum logging,conventional logging,imaging logging,and seismic coherence properties,the exploration and development potential of shale gas in the Dingshan area have been discussed comprehensively.The results showed that(1)layer No.4(WF2-LM4)of the Wufeng-Longmaxi Formation has a Th/U ratio<2 and a Th/K ratio of 3.5–12.Graptolites and pyrite are relatively abundant in the shale core,indicating sub-high-energy and low-energy marine-facies anoxic reducing environments.(2)The organic matter is mainly I-type kerogen with a small amount of II1-type kerogen.There is a good correlation among TOC,Ro,gas content,and brittle minerals;the fracturing property(brittleness)is 57.3%.Organic and inorganic pores are moderately developed.A higher pressure coefficient is correlated with the increase in porosity and the decrease in permeability.(3)The DY1 well of the shale gas reservoir was affected by natural defects and important latestage double destructive effects,and it is poorly preserved.The DY2 well is located far from the Qiyueshan Fault.Large faults are absent,and upward fractures in the Longmaxi Formation are poorly developed.The well is affected by low tectonic deformation intensity,and it is well preserved.(4)The Dingshan area is located at the junction of the two sedimentary centers of Jiaoshiba and Changning.The thickness of the high-quality shale interval(WF2-LM4)is relatively small,which may be an important reason for the unstable production of shale gas thus far.Based on the systematic analysis of the geological factors controlling high-yield shale gas enrichment in the Dingshan area,and the comparative analysis with the surrounding typical exploration areas,the geological understanding of marine shale gas enrichment in southern China has been improved.Therefore,this study can provide a useful reference for shale gas exploration and further development.

Differential Hydrocarbon Enrichment and its Main Controlling Factors in Depressions of the Bohai Bay Basin Differential Hydrocarbon Enrichment and its Main Controlling Factors in Depressions of the Bohai Bay Basin

Significant differential hydrocarbon enrichment occurs in depressions in a petroliferous basin.There are multiple depressions in the Bohai Bay Basin, and each depression as a relatively independent unit of hydrocarbon generation, migration and accumulation, contains significantly different hydrocarbon generation conditions and enrichment degree. On the basis of previous documents and a large number of statistical data, this work comparatively analyzed the differential hydrocarbon enrichment and its major controlling factors in depressions of the Bohai Bay Basin. The results show that depressions in the Bohai Bay Basin have various hydrocarbon enrichment degrees, and can be categorized into four types, namely enormously oil-rich, oil-rich, oily and oil-poor depressions. In general, the enormously oil-rich and oil-rich depressions are distributed in the eastern part of the basin along the Tan-Lu and Lan-Liao faults, whereas depressions in the western part of the basin are poor in hydrocarbons. Moreover, the vertical distribution of hydrocarbons is also highly heterogeneous, with Pre-Paleogene strata rich in hydrocarbons in the northern and western depressions, Paleogene strata rich in hydrocarbons in the entire basin, and Neogene strata rich in hydrocarbons in the off-shore areas of the Bohai Bay Basin. From early depressions in onshore areas to the late depressions in offshore areas of the Bohai Bay Basin, the source rocks and source-reservoir-cap rock assemblages gradually become younger and shallower, and the hydrocarbon resource abundance gradually increases. Hydrocarbon supplying condition is the key factor constraining the hydrocarbon enrichment for different depressions,while the main source-reservoir-cap rock assemblage, sufficient hydrocarbons and the transportation capacity of faults control the vertical distribution of hydrocarbons. The main factors controlling hydrocarbon enrichment are different for different layers. The hydrocarbon supplying condition of source rocks is the key controlling factor, whereas the source-reservoir configuration, the main sourcereservoir-cap rock assemblages, and the fault transportation are the main factors of hydrocarbon enrichment in the Paleogene, Paleogene and Neogene, respectively.

Spatial variability of soil bulk density and its controlling factors in an agricultural intensive area of Chengdu Plain,Southwest China

Soil bulk density is a basic but important physic soil property related to soil porosity,soil moisture and hydraulic conductivity,which is crucial to soil quality assessment and land use management.In this study,we evaluated the spatial variability of soil bulk density in the 0–20,20–40,40–60 and 60–100 cm layers as well as its affecting factors in Southwest China’s agricultural intensive area.Results indicated the mean value of surface soil bulk density(0–20 cm)was 1.26 g cm^(–3),significantly lower than that of subsoil(20–100 cm).No statistical difference existed among the subsoil with a mean soil bulk density of 1.54 g cm^(–3).Spatially,soil bulk density played a similar spatial pattern in soil profile,whereas obvious differences were found in details.The nugget effects for soil bulk density in the 0–20 and 20–40 cm layers were 27.22 and27.02%while 12.06 and 3.46%in the 40–60 and 60–100 cm layers,respectively,gradually decreasing in the soil profile,indicating that the spatial variability of soil bulk density above 40 cm was affected by structural and random factors while dominated by structural factors under 40 cm.Soil organic matter was the controlling factor on the spatial variability of soil bulk density in each layer.Land use and elevation were another two dominated factor controlling the spatial variability of soil bulk density in the 0–20 and 40–60 cm layers,respectively.Soil genus was one of the dominated factors controlling the spatial variability of soil bulk below 40 cm.

Clinical Analysis of Diabetic Nephropathy Risk Factors and Correlation with Blood Pressure Control

Objective:To explore the risk factors of diabetic nephropathy and its correlation with blood pressure control.Methods:A retrospective analysis of 80 patients with diabetic nephropathy(diabetic nephropathy group)and another 80 patients with diabetes(diabetic group)who were admitted to the Department of Nephrology and Endocrinology at our hospital from October 2021 to October 2022 was conducted.The general data of the two groups were compared,the influencing factors associated with the two groups were analyzed unilaterally,and unconditional dichotomous logistic regression was performed to analyze the influencing factors in patients with diabetic nephropathy.Results:There were no significant differences in high-density lipoprotein,systolic blood pressure,diastolic blood pressure,and creatinine between the two groups(P>0.05);however,compared with the diabetic group,the DN group had significantly elevated glycated hemoglobin,low-density lipoprotein,24-h urine protein,insulin resistance,and diabetes duration≥10 years(P<0.05).Conclusion:The clinical research on the correlation between the incidence of hypertension and the control of blood pressure in patients with diabetic nephropathy should be strengthened in order to formulate reasonable and feasible treatment plans.