RANKL-RANK signaling regulates osteoblast differentiation and bone formation

In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that

Exercise promotes osteogenic differentiation by activating the long non-coding RNA H19/microRNA-149 axis

BACKGROUND Regular physical activity during childhood and adolescence is beneficial to bone development,as evidenced by the ability to increase bone density and peak bone mass by promoting bone formation.AIM To investigate the effects of exercise on bone formation in growing mice and to investigate the underlying mechanisms.METHODS 20 growing mice were randomly divided into two groups:Con group(control group,n=10)and Ex group(treadmill exercise group,n=10).Hematoxylin-eosin staining,immunohistochemistry,and micro-CT scanning were used to assess the bone formation-related indexes of the mouse femur.Bioinformatics analysis was used to find potential miRNAs targets of long non-coding RNA H19(lncRNA H19).RT-qPCR and Western Blot were used to confirm potential miRNA target genes of lncRNA H19 and the role of lncRNA H19 in promoting osteogenic differentiation.RESULTS Compared with the Con group,the expression of bone morphogenetic protein 2 was also significantly increased.The micro-CT results showed that 8 wk moderate-intensity treadmill exercise significantly increased bone mineral density,bone volume fraction,and the number of trabeculae,and decreased trabecular segregation in the femur of mice.Inhibition of lncRNA H19 significantly upregulated the expression of miR-149 and suppressed the expression of markers of osteogenic differentiation.In addition,knockdown of lncRNA H19 significantly downregulated the expression of autophagy markers,which is consistent with the results of autophagy-related protein changes detected in mouse femurs by immunofluorescence.CONCLUSION Appropriate treadmill exercise can effectively stimulate bone formation and promote the increase of bone density and bone volume in growing mice,thus enhancing the peak bone mass of mice.The lncRNA H19/miR-149 axis plays an important regulatory role in osteogenic differentiation.

Control of paleogeographic pattern on sedimentary differentiation of evaporite-carbonate symbiotic system:A case study of the sixth sub-member of Ordovician Majiagou Formation M5 Member in central-eastern Ordos Basin,NW China

The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth member of Ordovician Majiagou Formation(M56)in the central-eastern Ordos Basin as an example.(1)Seven sub-geomorphic units(Taolimiao west low,Taolimiao underwater high,Taolimiao east low,Hengshan high,East salt low,North slope and Southwest slope)developed in the study area.(2)The“three lows”from west to east developed dolomitic restricted lagoon,evaporite evaporative lagoon and salt evaporative lagoon sedimentary facies respectively,the"two highs"developed high-energy grain beach and microbial mound,and the north and south slopes developed dolomitic flats around land.(3)The paleogeographic pattern caused natural differentiation of replenishment seawater from the northwest Qilian sea,leading to the eccentric sedimentary differentiation of dolomite,evaporite and salt rock symbiotic system from west to east,which is different from the classic“bull's eye”and“tear drop”distribution patterns.(4)As the Middle Qilian block subducted and collided into the North China Plate,the far-end compression stress transferred,giving rise to the alternate highland and lowland in near north to south direction during the sedimentary period of M56 sub-member.(5)Taolimiao underwater high and Hengshan high developed favorable zones of microbial mounds and grain shoals in south to north strike in M56 sub-member,making them favorable exploration areas with great exploration potential in the future.

GROWTH DIFFERENTIATION FACTOR-5 STIMULATES THE GROWTH AND ANABOLIC METABOLISM OF ARTICULAR CHONDROCYTES

Objective To observe the effect of growth differentiation factor-5 (GDF-5) on the growth and anabolic metabolism of articular chondrocytes. Methods The articular chondrocytes isolated from rats were treated with various concentrations of rmGDF-5, and the growth of chondrocytes measured by MTT assay, the cellular cartilage matrices formation detected sulfated glycosaminoglycan by Alcian blue staining and type Ⅱcollagen by RT-PCR. Results After 7 days culture, MTT assay showed that GDF-5 enhanced the growth of chondrocytes in a dose-dependent manner, RT-PCR showed that GDF-5 clearly induced the synthesis of type Ⅱ collagen because of the col2a1 mRNA band more and more strong in a dose-dependent. Chondrocytes were cultured with GDF-5 for 14 days, the intensity of Alcian blue staining was greatly enhanced, especially, at a high concentration of 1000ng/mL, and GDF-5 enhanced the accumulation of the Alcian blue-stainable material in a concentration-dependent manner and in a does-dependent manner. Conclusion GDF-5 enhanced the growth of mature articular chondrocytes, and stimulated the cellular cartilage matrices formation in mono-layer culture.

PatU3 plays a central role in coordinating cell division and differentiation in pattern formation of filamentous cyanobacterium Nostoc sp.PCC 7120

Spatial periodic signal for cell differentiation in some multicellular organisms is generated according to Turing's principle for pattern formation.How a dividing cell responds to the signal of differentiation is addressed with the filamentous cyanobacterium Nostoc sp.PCC 7120,which forms the patterned distribution of heterocysts.We show that differentiation of a dividing cell was delayed until its division was completed and only one daughter cell became heterocyst.A mutant of patU3,which encodes an inhibitor of heterocyst formation,showed no such delay and formed heterocyst pairs from the daughter cells of cell division or dumbbell-shaped heterocysts from the cells undergoing cytokinesis.The patA mutant,which forms heterocysts only at the filament ends,restored intercalary heterocysts by a single nucleotide mutation of patU3,and double mutants of patU3/patA and patU3/hetF had the phenotypes of the patU3 mutant.We provide evidence that HetF,which can degrade PatU3,is recruited to cell divisome through its C-terminal domain.A HetF mutant with its N-terminal peptidase domain but lacking the C-terminal domain could not prevent the formation of heterocyst pairs,suggesting that the divisome recruitment of HetF is needed to sequester HetF for the delay of differentiation in dividing cells.Our study demonstrates that PatU3 plays a key role in celldivision coupled control of differentiation.

Characteristics and control factors of feldspar dissolution in gravity flow sandstone of Chang 7 Member,Triassic Yanchang Formation,Ordos Basin,NW China

To clarify the formation and distribution of feldspar dissolution pores and predict the distribution of high-quality reservoir in gravity flow sandstone of the 7^(th) member of Triassic Yanchang Formation(Chang 7 Member)in the Ordos Basin,thin sections,scanning electron microscopy,energy spectrum analysis,X-ray diffraction whole rock analysis,and dissolution experiments are employed in this study to investigate the characteristics and control factors of feldspar dissolution pores.The results show that:(1)Three types of diagenetic processes are observed in the feldspar of Chang 7 sandstone in the study area:secondary overgrowth of feldspar,replacement by clay and calcite,and dissolution of detrital feldspar.(2)The feldspar dissolution of Chang 7 tight sandstone is caused by organic acid,and is further affected by the type of feldspar,the degree of early feldspar alteration,and the buffering effect of mica debris on organic acid.(3)Feldspars have varying degrees of dissolution.Potassium feldspar is more susceptible to dissolution than plagioclase.Among potassium feldspar,orthoclase is more soluble than microcline,and unaltered feldspar is more soluble than early kaolinized or sericitized feldspar.(4)The dissolution experiment demonstrated that the presence of mica can hinder the dissolution of feldspar.Mica of the same mass has a significantly stronger capacity to consume organic acids than feldspar.(5)Dissolution pores in feldspar of Chang 7 Member are more abundant in areas with low mica content,and they improve the reservoir physical properties,while in areas with high mica content,the number of feldspar dissolution pores decreases significantly.

Integrative analysis of bone-formation associated genes and immune cell infiltration in osteoporosis, and the prediction of active ingredients in targeted traditional Chinese medicine

Objective To explore the differential expression and mechanisms of bone formation-related genes in osteoporosis(OP)leveraging bioinformatics and machine learning methodologies;and to predict the active ingredients of targeted traditional Chinese medicine(TCM)herbs.Methods The Gene Expression Omnibus(GEO)and GeneCards databases were employed to conduct a comprehensive screening of genes and disease-associated loci pertinent to the pathogenesis of OP.The R package was utilized as the analytical tool for the identification of differentially expressed genes.Least absolute shrinkage and selection operator(LASSO)logis-tic regression analysis and support vector machine-recursive feature elimination(SVM-RFE)algorithm were employed in defining the genetic signature specific to OP.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses for the selected pivotal genes were conducted.The cell-type identification by estimating rela-tive subsets of RNA transcripts(CIBERSORT)algorithm was leveraged to examine the infiltra-tion patterns of immune cells;with Spearman’s rank correlation analysis utilized to assess the relationship between the expression levels of the genes and the presence of immune cells.Coremine Medical Database was used to screen out potential TCM herbs for the treatment of OP.Comparative Toxicogenomics Database(CTD)was employed for forecasting the TCM ac-tive ingredients targeting the key genes.AutoDock Vina 1.2.2 and GROMACS 2020 softwares were employed to conclude analysis results;facilitating the exploration of binding affinity and conformational dynamics between the TCM active ingredients and their biological targets.Results Ten genes were identified by intersecting the results from the GEO and GeneCards databases.Through the application of LASSO regression and SVM-RFE algorithm;four piv-otal genes were selected:coat protein(CP);kallikrein 3(KLK3);polymeraseγ(POLG);and transient receptor potential vanilloid 4(TRPV4).GO and KEGG pathway enrichment analy-ses revealed that these trait genes were predominantly engaged in the regulation of defense response activation;maintenance of cellular metal ion balance;and the production of chemokine ligand 5.These genes were notably associated with signaling pathways such as ferroptosis;porphyrin metabolism;and base excision repair.Immune infiltration analysis showed that key genes were highly correlated with immune cells.Macrophage M0;M1;M2;and resting dendritic cell were significantly different between groups;and there were signifi-cant differences between different groups(P<0.05).The interaction counts of resveratrol;curcumin;and quercetin with KLK3 were 7;3;and 2;respectively.It shows that the interac-tions of resveratrol;curcumin;and quercetin with KLK3 were substantial.Molecular docking and molecular dynamics simulations further confirmed the robust binding affinity of these bioactive compounds to the target genes.Conclusion Pivotal genes including CP;KLK3;POLG;and TRPV4;exhibited commendable significant prognostic value;and played a crucial role in the diagnostic assessment of OP.Resveratrol;curcumin;and quercetin;natural compounds found in TCM;showed promise in their potential to effectively modulate the bone-forming gene KLK3.This study provides a sci-entific basis for the interpretation of the pathogenesis of OP and the development of clinical drugs.

Arginine promotes myogenic differentiation and myotube formation through the elevation of cytoplasmic calcium concentration

This study aimed to explore the mechanism underlying arginine-promoted myogenesis of myoblasts.C2C12 cells were cultured with a medium containing 0.1,0.4,0.8,or 1.2 mmol/L arginine,respectively.Cell proliferation,viability,differentiation indexes,cytoplasmic Ca^(2+)concentration,and relative mRNA expression levels of myogenic regulatory factors(MRF)and key Ca2+channels were measured in the absence or presence of 2 chemical inhibitors,dantrolene(DAN,10μmol/L)and nisoldipine(NIS,10μmol/L),respectively.Results demonstrated that arginine promoted myogenic differentiation and myotube formation.Compared with the control(0.4 mmol/L arginine),1.2 mmol/L arginine upregulated the relative mRNA expression levels of myogenin(MyoG)and Myomaker at d 2 during myogenic induction(P<0.05).Cytoplasmic Ca^(2+)concentrations were significantly elevated by arginine supplementation at d 2 and 4(P<0.05).Relative mRNA expression levels of Ca^(2+)channels including the type 1 ryanodine recepto r(RyR1)and voltage-gated Ca^(2+)channel(Cav1.1)were upregulated by 1.2 mmol/L arginine during2-d myogenic induction(P<0.01).However,arginine-promoted myogenic potential of myoblasts was remarkably compromised by DAN and NIS,respectively(P<0.05).These findings evidenced that the supplementation of arginine promoted myogenic differentiation and myotube formation through increasing cytoplasmic Ca^(2+)concentration from both extracellular and sarcoplasmic reticulum Ca^(2+).

Heterogeneity and differential hydrocarbon accumulation model of deep reservoirs in foreland thrust belts: A case study of deep Cretaceous Qingshuihe Formation clastic reservoirs in southern Junggar Basin, NW China

Using the data of drilling, logging, core, experiments and production, the heterogeneity and differential hydrocarbon accumulation model of deep reservoirs in Cretaceous Qingshuihe Formation(K1q) in the western section of the foreland thrust belt in southern Junggar Basin are investigated. The target reservoirs are characterized by superimposition of conglomerates, sandy conglomerates and sandstones, with high content of plastic clasts. The reservoir space is mainly composed of intergranular pores. The reservoirs are overall tight, and the sandy conglomerate has the best physical properties. The coupling of short deep burial period with low paleotemperature gradient and formation overpressure led to the relatively weak diagenetic strength of the reservoirs. Specifically, the sandy conglomerates show relatively low carbonate cementation, low compaction rate and high dissolution porosity. The special stress-strain mechanism of the anticline makes the reservoirs at the top of the anticline turning point more reformed by fractures than those at the limbs, and the formation overpressure makes the fractures in open state. Moreover, the sandy conglomerates have the highest oil saturation. Typical anticline reservoirs are developed in deep part of the thrust belt, but characterized by "big trap with small reservoir". Significantly, the sandy conglomerates at the top of anticline turning point have better quality, lower in-situ stress and higher structural position than those at the limbs,with the internal hydrocarbons most enriched, making them high-yield oil/gas layers. The exponential decline of fractures makes hydrocarbon accumulation difficult in the reservoirs at the limbs. Nonetheless, plane hydrocarbon distribution is more extensive at the gentle limb than the steep limb.

ISLET FORMATION AND REGENERATION

Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected.Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin.Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration.Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation.At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme.During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin.During pancreatic regeneration after damage, nestin expression of islet cells increased.Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration.During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.

Strike-Slip Faults and Their Control on Differential Hydrocarbon Enrichment in Carbonate Karst Reservoirs: A Case Study of Yingshan Formation on Northern Slope of Tazhong Uplift, Tarim Basin

Objective Oil and gas are abundant in the Ordovician Yingshan Formation carbonate karst reservoirs on the northern slope of Tazhong uplift in the Tarim Basin, and have extremely complicated oil-gas-water distribution, however. The difference in burial depth of the reservoirs between east and west sides is up to 1000 m. Water-bearing formations exist between oil- and gas-bearing formations vertically and water-producing wells are drilled between oil- and gas-producing wells. Macroscopically, oil and gas occur at low positions, while water occurs at high positiona on the northern slope of Tazhong uplift. The mechanism of differential hydrocarbon enrichment in heterogeneous reservoirs is by far not clarified, which has affected the efficient exploration and development of oil and gas fields in this area.

Discrete Quantum Transitions, Duality: Emergence of Physical Structures and Occurrence of Observed Formations (Hidden Properties of Mathematical Physics Equations)

With the help of skew-symmetric differential forms, the hidden properties of the mathematical physics equations that describe discrete quantum transitions and emergence the physical structures are investigated. It is shown that the mathematical physics equations possess a unique property. They can describe discrete quantum transitions, emergence of physical structures and occurrence observed formations. However, such a property possesses only equations on which no additional conditions, namely, the conditions of integrability, are imposed. The intergrability conditions are realized from the equations themselves. Just under realization of integrability conditions double solutions to the mathematical physics equations, which describe discrete transitions and so on, are obtained. The peculiarity consists in the fact that the integrability conditions do not directly follow from the mathematical physics equations;they are realized under the description of evolutionary process. The hidden properties of differential equations were discovered when studying the integrability of differential equations of mathematical physics that depends on the consistence between the derivatives in differential equations along different directions and on the consistence of equations in the set of equations. The results of this work were obtained with the help of skew-symmetric differential forms that possess a nontraditional mathematical apparatus such as nonidentical relations, degenerate transformations and the transition from nonintegrable manifolds to integrable structures. Such results show that mathematical physics equations can describe quantum processes.

准噶尔盆地玛湖凹陷三叠系百口泉组储层特征及油气成藏规律

通过岩心分析测试、地震厚度预测、包裹体成藏期次分析以及源储配置关系研究,对准噶尔盆地玛湖凹陷三叠系百口泉组储层特征及油气成藏规律进行了刻画。研究结果表明:①玛湖凹陷斜坡区三叠系百口泉组主要发育扇三角洲沉积,岩性普遍较粗,相对优质的储集层主要分布于扇三角洲前缘水下分流河道微相及少量河口砂坝微相中,其成分以长石岩屑砂砾岩为主,其次为岩屑砂砾岩。岩石普遍较致密。岩心孔隙度为3.17%~23.40%,平均为9.04%,渗透率为0.01~934.00mD,平均为0.73mD,属低孔特低渗型储集层。储集空间类型以次生溶孔为主,可见粒间缝和其他微裂缝。②研究区油气主要来源于下二叠统风城组碱湖沉积的泥页岩,最厚处超过400m,为残留海—潟湖相沉积,水体盐度较高,岩性以云质泥岩和泥质岩为主。有机质类型以Ⅰ和Ⅱ1型为主,总有机碳含量(TOC)多大于1.0%,生烃潜量(S1+S2)多大于6.0mg/g,氯仿沥青“A”平均为0.2%,HI平均为322mg/g,有机质演化处于成熟阶段,为中等—好烃源岩。③研究区具有3期成藏特征,晚三叠世之前为第1期油气充注,未能聚集成藏,早侏罗世为第2期油气充注期,对应黄色荧光烃类包裹体;早—中白垩世为第3期油气充注期,对应蓝白色荧光烃类包裹体,后2期油气充注对百口泉组油气成藏起主要贡献作用。④研究区源储配置紧密性是导致玛湖西斜坡和玛湖东斜坡油气差异性聚集的核心要素。

鄂尔多斯盆地长7段重力流砂岩长石溶蚀特征及控制因素

基于岩心薄片、扫描电镜、能谱分析、X射线衍射全岩分析及溶蚀实验,研究鄂尔多斯盆地三叠系延长组7段(简称长7段)重力流砂岩中长石溶孔发育特征及控制因素,明确长石溶孔的形成与分布,为预测优质储集层分布提供依据。研究表明:(1)研究区长7段砂岩中的长石经历3类成岩作用:长石次生加大、黏土以及方解石的交代、长石碎屑的溶蚀作用。(2)长7段致密砂岩中的长石溶蚀主要源于有机酸溶蚀,此外还受长石类型、长石早期蚀变程度以及砂岩中云母碎屑对有机酸的缓冲作用影响。(3)不同长石的溶蚀程度不同,表现为钾长石较斜长石易溶蚀,钾长石中正长石较微斜长石易溶,未蚀变的长石较早期高岭土或绢云母化的长石易溶蚀。(4)溶蚀实验显示云母的存在会抑制长石溶蚀,相同质量的云母对有机酸的消耗能力明显强于长石。(5)在云母含量低的情况下,长7段砂岩长石溶孔较为发育,储集层物性得以改善,而云母含量较高的地区长石溶孔则明显减少。

中国中西部含油气盆地超深层油气成藏条件与勘探潜力分析

随着油气工业发展,向深层超深层领域进军已成为常规油气勘探开发的主要趋势。通过对中国中西部含油气盆地超深层油气勘探与研究进展的深入分析,明确深层超深层油气成藏的有利条件,指出中西部叠合盆地的海相碳酸盐岩、碎屑岩、基岩及火山岩3大领域是未来超深层油气勘探重点领域,超深层元古界是值得勘探重视的潜在领域,并指出超深层油气地质理论与关键技术的攻关方向。研究表明:(1)克拉通盆地海相碳酸盐岩发育以多套海相烃源岩、白云岩和断控型缝洞体等规模储集层、3类有利成藏组合,是寻找碳酸盐岩大油气田的重点领域;(2)前陆盆地下组合发育以煤系为主的湖相优质烃源岩、(扇)三角洲砂体为主的规模储集层、大型构造圈闭,是寻找碎屑岩大油气田的重点领域;(3)以花岗岩和变质岩为主的基岩储集层不受埋深限制,源岩-基岩接触型成藏组合最有利,紧邻生烃凹陷及大型走滑断裂带的基岩潜山是深层-超深层基岩油气藏勘探的重点领域;(4)中新元古界受超大陆裂解及全球冰期影响,发育受陆内裂陷控制的优质烃源岩,资源潜力较大,未来勘探地位值得重视。

克拉通盆地不同级次构造—岩相古地理编图思路与实践:以鄂尔多斯盆地早古生代为例

构造—沉积分异思想在地球内部构造地质作用与地球表面沉积响应间建立起了有机联系,可划分为不同序次系统,体现了地球系统思维。以该思想为指导编制了鄂尔多斯盆地早古生代构造—岩相古地理图。盆—山系统级次编图主要体现了不同构造—沉积分异作用对古地理面貌的控制,揭示了古地理演化的动力学机制,反映了不同时期地球深部活动在地表系统的响应;隆—坳系统级次编图揭示出海平面波动过程中不同构造单元沉积环境及充填沉积物的差异;凸—凹系统级次编图清晰展现出东部坳陷内古地貌差异引起的沉积环境分异及生、储、盖物质的分布规律与组合关系。不同级次的构造—岩相古地理图更好地解释了古地理面貌“所以然”的原因,更清晰地揭示了油气成藏物质空间分布规律及其控制因素,从而能更有效指导油气勘探实践。

基于领航-跟随法的多机器人编队控制

编队控制是多机器人系统研究的核心问题之一,具有广泛的研究价值。针对编队问题,通过对轮式差分驱动机器人运动模型进行分析,并设计相应的控制器。在传统的领航-跟随模型上,引入“虚拟机器人”,将跟随者机器人对领航者机器人的轨迹跟踪转换为跟随者对“虚拟领航者”的轨迹跟踪。首先,预设定实际领航者机器人的行进路径,由实际领航者引导运动方向的运动轨迹被视为主轨迹,虚拟机器人通过数据产生参考点从而生成参考轨迹,跟随者机器人通过对参考轨迹的跟踪与“虚拟领航者”构成轨迹误差跟踪系统。然后通过Lyapunov的控制理论验证控制器的理论可行性,最后在MATLAB/Simulink仿真平台进行实验,通过改变控制参数来使机器人形成相应的期望队形,在较短的时间内,跟随机器人对参考轨迹的跟踪误差趋向于0且速度收敛,验证了编队系统的可行性。

论海相页岩气富集机理——以四川盆地五峰组—龙马溪组为例

深入探究页岩气富集机理是保障勘探开发高效推进的基础。本研究通过对四川盆地五峰组—龙马溪组页岩气勘探开发实践的系统分析,梳理总结前人研究成果,从生成机理、运移机理、赋存机理和保存机理四个方面对海相页岩气富集机理进行了深入分析,并讨论了深层和常压页岩气的勘探开发潜力。结果表明:在生成机理方面,埋藏史和热演化史控制了页岩生排烃史、生排烃量和现今含气量;页岩气运移机理涉及运移动力、运移相态、运移方式和运移通道四方面内容,页岩气运移主要是烃源岩内的初次运移,同时讨论了初次运移的影响因素;在赋存机理方面,甲烷—页岩间表现出单/多分子层吸附和微孔充填等多种赋存机制,组分润湿性和孔隙有效性是决定甲烷吸附赋存和解吸运移的关键;在保存机理方面,盖层和物性自封闭是主要的保存机理,构造运动引起的裂缝—流体活动是页岩气保存条件遭到破坏的主要原因,流体活动时间和期次研究是页岩气保存条件和含气量定量评价的重要内容。页岩气富集机理的系统分析和创新认识为页岩气勘探开发评价提供了重要依据,建议加强页岩气演化历史全过程的动态评价。结合深层和常压页岩气勘探实践,分析了深层和常压页岩气的成因机制及主要特征,指出了下一步攻关内容及勘探方向。

基于改进差分进化算法的跨平台武器目标分配方法

现代战争中,跨平台武器单元的协同利用,是合同编队体系的重要内容,作战方式也正由平台级协同向着能力要素级协同转变,这对武器目标分配问题的解决提出了更大挑战。本文将武器单元的最小划分单位细化到能力要素级,以毁伤概率与成本消耗为优化目标,面向多种来袭目标的编队防空场景,提出了跨平台武器目标分配算法。同时,基于混沌映射提出了混沌种群重构(chaotic population reconstruction,CPR)机制,并结合带存档的自适应差分进化(adaptive differential evolution with optional external archive,JADE)算法提出了CPR-JADE算法,利用CPR机制可以帮助算法在解决高维复杂约束问题时跳出局部最优。再将其运用到武器目标分配模型上,实现了对模型的高效求解。最后,通过在多种数据规模下与其他进化优化算法的仿真对比试验分析,验证了所提方法的正确性与有效性。

贵州黑色岩系和煤系地层发育的富硒黄壤中硒的空间分异特征

研究富硒土壤硒的分异特征对贵州富硒农业开发具有重要意义。本文以黔西南二叠纪煤系地层和遵义寒武纪黑色岩系地层中发育的黄壤为研究对象,对土壤的总硒含量、硒的形态分布、有效硒含量及影响因素进行了研究。结果表明,黑色岩系和煤系地层发育黄壤的总硒平均含量分别为0.76 mg/kg和0.99 mg/kg;两种地层发育黄壤中的硒元素(Se)以有机结合态、残渣态和铁锰氧化物结合态为主;有效硒平均含量分别为67.2μg/kg和71.8μg/kg,分别占其总硒的8.57%和6.98%,包括水溶态、可交换态及碳酸盐结合态的有效硒供给水平很低。黑色岩系地层发育的黄壤总体呈酸性(pH均值为5.88),其有效硒含量主要受有机质影响;煤系地层发育的黄壤总体呈中性(pH均值6.84),其有效硒含量主要受pH影响。黑色岩系和煤系地层发育的黄壤,其影响硒有效性的因素有显著差异。因此,在发展富硒农业时需因地制宜。