库车坳陷东部迪北侏罗系致密砂岩气藏特征

岗位评价又称职位评价,是指在岗位分析的基础上,按照一定的标准,对各个岗位的工作性质、责任要素、复杂因素、任职要素、工作环境等方面进行综合性的评价,确定岗位相对价值的过程[1].岗位评价方案通过对一系列报酬要素的排序或评分,衡量工作的相对价值,明确各个岗位的分类、级别的高低,保证对每个岗位的工作人员进行考核、晋升、奖罚等管理时,具有统一的标准,是现代人力资源管理理论中的重要内容.本文对国内外岗位评价方法及应用现状综述如下.     

Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction

A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO₂. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (n-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO₂ super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date.     

Triassic–Jurassic climate in continental high-latitude Asia was dominated by obliquity-paced variations (Junggar Basin, ürümqi,China)

Empirical constraints on orbital gravitational solutions for the Solar System can be derived from the Earth’s geological record of past climates. Lithologically based paleoclimate data from the thick, coal-bearing, fluvial-lacustrine sequences of the Junggar Basin of Northwestern China (paleolatitude ∼60°) show that climate variability of the warm and glacier-free high latitudes of the latest Triassic–Early Jurassic (∼198–202 Ma) Pangea was strongly paced by obliquity-dominated (∼40 ky) orbital cyclicity, based on an age model using the 405-ky cycle of eccentricity. In contrast, coeval low-latitude continental climate was much more strongly paced by climatic precession, with virtually no hint of obliquity. Although this previously unknown obliquity dominance at high latitude is not necessarily unexpected in a high CO₂ world, these data deviate substantially from published orbital solutions in period and amplitude for eccentricity cycles greater than 405 ky, consistent with chaotic diffusion of the Solar System. In contrast, there are indications that the Earth–Mars orbital resonance was in today’s 2-to-1 ratio of eccentricity to inclination. These empirical data underscore the need for temporally comprehensive, highly reliable data, as well as new gravitational solutions fitting those data.Our understanding of Triassic and Early Jurassic high-latitude climate, biotic evolution, mass extinction, and geochronology is very poor in contrast to that of the contemporaneous tropics (1, 2). This poor resolution impairs an elucidation of the basic patterns of Earth system function during the early Mesozoic, notably the high-latitude climatic response to orbital forcing, as well as the effects of the eruption of the Triassic–Jurassic Central Atlantic Igneous Province (CAMP) (3). The former issue bears on the stability of the Solar System, in which determining variations in orbital eccentricity (via climatic precession) and inclination (via obliquity) figure as crucial (4–6), and the latter bears on the causes, effects, and recovery from the end-Triassic mass extinction (ETE) (e.g., ref. 2). Here, we describe results of a cyclostratigraphic investigation of lithologic variations in the paleo-high latitude, lacustrine, Late Triassic–Early Jurassic Haojiagou and Badaowan formations of the Junggar Basin, China representing, to our knowledge, the first analysis of orbital cyclicity from a high-latitude, early Mesozoic continental sequence, and a step toward development of an empirical basis for evaluating numerical solutions of Solar System chaotic behavior.     

Potential on-shore and off-shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts

Identifying locations for secure sequestration of CO₂ in geological formations is one of our most pressing global scientific problems. Injection into basalt formations provides unique and significant advantages over other potential geological storage options, including large potential storage volumes and permanent fixation of carbon by mineralization. The Central Atlantic Magmatic Province basalt flows along the eastern seaboard of the United States may provide large and secure storage reservoirs both onshore and offshore. Sites in the South Georgia basin, the New York Bight basin, and the Sandy Hook basin offer promising basalt-hosted reservoirs with considerable potential for CO₂ sequestration due to their proximity to major metropolitan centers, and thus to large industrial sources for CO₂. Onshore sites are suggested for cost-effective characterization studies of these reservoirs, although offshore sites may offer larger potential capacity and additional long-term advantages for safe and secure CO₂ sequestration.     

Exceptionally preserved juvenile megalosauroid theropod dinosaur with filamentous integument from the Late Jurassic of Germany

Recent discoveries in Asia have greatly increased our understanding of the evolution of dinosaurs' integumentary structures, revealing a previously unexpected diversity of "protofeathers" and feathers. However, all theropod dinosaurs with preserved feathers reported so far are coelurosaurs. Evidence for filaments or feathers in noncoelurosaurian theropods is circumstantial and debated. Here we report an exceptionally preserved skeleton of a juvenile megalosauroid, Sciurumimus albersdoerferi n. gen., n. sp., from the Late Jurassic of Germany, which preserves a filamentous plumage at the tail base and on parts of the body. These structures are identical to the type 1 feathers that have been reported in some ornithischians, the basal tyrannosaur Dilong, the basal therizinosauroid Beipiaosaurus, and, probably, in the basal coelurosaur Sinosauropteryx. Sciurumimus albersdoerferi represents the phylogenetically most basal theropod that preserves direct evidence for feathers and helps close the gap between feathers reported in coelurosaurian theropods and filaments in ornithischian dinosaurs, further supporting the homology of these structures. The specimen of Sciurumimus is the most complete megalosauroid yet discovered and helps clarify significant anatomical details of this important basal theropod clade, such as the complete absence of the fourth digit of the manus. The dentition of this probably early-posthatchling individual is markedly similar to that of basal coelurosaurian theropods, indicating that coelurosaur occurrences based on isolated teeth should be used with caution.     

Vertebral Pathology in an Ornithopod Dinosaur: A Hemivertebra in Dysalotosaurus lettowvorbecki from the Jurassic of Tanzania

A vertebral fragment of the Late Jurassic ornithopod dinosaur Dysalotosaurus lettowvorbecki from Tanzania is described. It consists of a hemivertebra that is co‐ossified with a complete vertebral centrum. The hemivertebra causes a hyperkyphotic posture of the vertebral column with an angle of approximately 35° between the end plates of the vertebra, that is, a dorsal bending of the vertebral column. Associated with this is a 15° lateral bending, which suggests a scoliosis. Micro‐CT scans reveal thickening of the cortical bone in the hemivertebra and the complete vertebral centrum as compared to a “normal” vertebra. This can be interpreted as a reaction of the bone to the abnormal direction of forces arising from the defective configuration of the vertebral column. No signs of vertebral fracture are present. The arrangement of the Foramina venosa and the trapezoidal outline of the complete centrum that is co‐ossified with the hemivertebra indicate that the hemivertebra in Dysalotosaurus developed early in embryogenesis probably by “hemimetameric segmental shift”, that is, a defect of the fusion of the paired vertebral anlagen. This finding illustrates that hemivertebrae represent a fundamental defect of the vertebrate ontogenetic program. Anat Rec, 291:1149‐1155, 2008. © 2008 Wiley‐Liss, Inc.     

Does the Maximum Body Size of Theropods Increase across the Triassic–Jurassic Boundary? Integrating Ontogeny,Phylogeny, and Body Size

Mass extinctions change global ecosystems, and the end-Triassic mass extinction was hypothesized to have precipitated the rise of dinosaur dominance, with dinosaurs filling resource zones of eliminated large-bodied reptilian lineages. This replacement has been explicitly hypothesized for theropod dinosaurs, and the eastern North American theropod footprint record suggests an increase in maximum body size across the Triassic-Jurassic boundary. Without taking ontogenetic stage in account, the maximum size of the rare large Triassic theropods worldwide supports this hypothesis, with the size of the largest individuals corresponding to the largest Triassic theropod tracks. However, both morphological data and histological examination suggest that known large-bodied Triassic theropods are represented by immature individuals still growing rapidly at the time of death, indicating that the maximum body size of Triassic theropods was much larger than that a strict reading of the body fossil record would suggest. The size increase recorded in the sediments of eastern North America is not part of a global trend. Instead of a simple ecological replacement of non-dinosaurian archosaurs by dinosaurs, the rise in theropod dinosaurian ecological dominance was an extended process across the end of the Late Triassic into the Jurassic. Anat Rec, 303:1158–1169, 2020. © 2019 Wiley Periodicals, Inc.     

Developmental patterns and variation among early theropods

Understanding ontogenetic patterns is important in vertebrate paleontology because the assessed skeletal maturity of an individual often has implications for paleobiogeography, species synonymy, paleobiology, and body size evolution of major clades. Further, for many groups the only means of confidently determining ontogenetic status of an organism is through the destructive process of histological sampling. Although the ontogenetic patterns of Late Jurassic and Cretaceous dinosaurs are better understood, knowledge of the ontogeny of the earliest dinosaurs is relatively poor because most species‐level growth series known from these groups are small (usually, maximum of n ~ 5) and incomplete. To investigate the morphological changes that occur during ontogeny in early dinosaurs, I used ontogenetic sequence analysis (OSA) to reconstruct developmental sequences of morphological changes in the postcranial ontogeny of the early theropods Coelophysis bauri and Megapnosaurus rhodesiensis, both of which are known from large sample sizes (n = 174 and 182, respectively). I found a large amount of sequence polymorphism (i.e. intraspecific variation in developmental patterns) in both taxa, and especially in C. bauri, which possesses this variation in every element analyzed. Megapnosaurus rhodesiensis is similar, but it possesses no variation in the sequence of development of ontogenetic characters in the tibia and tarsus. Despite the large amount of variation in development, many characters occur consistently earlier or later in ontogeny and could therefore be important morphological features for assessing the relative maturity of other early theropods. Additionally, there is a phylogenetic signal to the order in which homologous characters appear in ontogeny, with homologous characters appearing earlier or later in developmental sequences of early theropods and the close relatives of dinosaurs, silesaurids. Many of these morphological features are important characters for the reconstruction of archosaurian phylogeny (e.g. trochanteric shelf). Because these features vary in presence or appearance with ontogeny, these characters should be used with caution when undertaking phylogenetic analyses in these groups, since a specimen may possess certain character states owing to ontogenetic stage, not evolutionary relationships.