Integrated Diagenesis Study of Tight Gas Sandstone: The Permian Lower Shihezi Formation, Northern Ordos Basin, China

AbstractDiagenesis varies greatly from basin to basin and has been considered as the key control of the reservoir quality of tight sandstones. In this study, we analyzed the petrographic characteristics, diagenesis, and pore types and characteristics of the Permian Lower Shihezi Formation in the Ordos Basin. Results show that most of sandstones are litharenites with minor sublitharenites and feldspathic litharenites. The tight sandstones have ultralow permeabilities (averaging 0.67 mD) and porosities (averaging 8.35%), with pore-throat sizes ranging from 0.035 to 13.29 μm with 94.12% less than 5 μm. Overall, the tight sandstone reservoirs have undergone complex diagenetic alteration. Compaction and clay mineral cements are the two crucial diagenetic factors that controlled the tightness of the reservoirs. The compaction destroyed most of primary porosity, and the effective pores are mainly dissolved micropores, intragranular dissolved micropores, and micropores in clay minerals and mineral grains. The chlorite coating might have helped preserve a certain amount of porosity, but pore-lining chlorites significantly obstructed pore throats and reduced permeability. Results of the study provide insights and direct implications for the future success of exploration and production of the tight gas sandstone in the Ordos Basin and other similar tight sandstone reservoirs

The effect of chemotherapy combined with recombination mutant human tumor necrosis factor on advanced cancer

BACKGROUND: Past studies suggested that tumor necrosis factor (TNF) assisted anti-tumor treatment and intensified the sensitivity of chemotherapy. However its clinical application has been curbed because of its low purity, high dosage, and strong toxicity. This research, through perspective random clinical control experiment, observed the therapeutic effect of the treatment of late malignant tumor through the injection of recombinant mutant human tumor necrosis factor (rmhTNF) combined with general chemotherapy and its adverse reactions. METHODS: 105 patients with advanced malignant tumor were randomly divided into trial group, 69 patients, and control group, 36 patients. Injection of rmhTNF 4 × 10(6)u/m(2 )was given to the trial group, from the 1(st )to 7(th )days, the 11(th )to 17(th )days combined with chemotherapy course. The chemotherapy plan was as follows: CAP for patients with the NSCLC; FAM for patients with gastric cancer; FC for patients with colorectal cancer. One treatment cycle lasted for 21 days and two cycles were scheduled. The control group was given only the same chemotherapy as the trial group. RESULTS: In the trial group there was 1 CR case and 12 PR cases, and the response rate is 13/69 (18.84%); in the control group 1 PR case, the response rate 1/36 (2.78%). The response rate of the trial group was significantly higher than that of the control group (P = 0.022). The response rate for NSCLC in the trial group was 8/17 (47.06%), and 1/6 (16.67%) in the control group. The response rates for gastric cancer and colorectal cancer in the trial groups also were higher than those of the control groups. After the treatment the KPS is 89.00 ± 9.92 in the trial group, and 84.17 ± 8.84 in the control group, with a significant difference between the two groups (P = 0.028). The adverse reactions of rmhTNF injection included: pain in the injection area, chill, hardening and swelling and redness in the injection area, fever, ostealgia and myosalgia, and cold-like symptoms. All these adverse reactions were mild and bearable. CONCLUSIONS: The administration of rmhTNF injection in combination with general chemotherapy is an effective and secure means in treating advanced malignant tumor

Internal Architectural Patterns of Bar Fingers Within Digitate Shallow-Water Delta: Insights from the Shallow Core, GPR and Delft3D Simulation Data of the Ganjiang Delta, China

Digitate shallow-water deltas are commonly found in modern lakes and bays, as well as within cratonic petroliferous basins. They develop one or multiple sinuous finger-like sands (i.e., bar fingers), including high-RSI (sinuosity ratio of distributary channel and bar finger ≥1) and low-RSI (RSI 10°) compared with those in the supplying river. This dip angle exhibits a negative relationship with downstream distance and a positive exponential relationship with lateral migration distance. Silty drapes become dense along the migration direction of the distributary channel. The levee develops multiple horizontal muddy accretion beds. The high-RSI bar finger develops a large number (>3) of accretion beds in mouth bars with high dip angles, and a large number of accretion beds in thick levees, compared with the low-RSI bar finger. The results of this paper provide insights into the prediction and development of cratonic digitate shallow-water delta reservoirs

Paleoenvironment Implication of Red Paleosols in a Late Cretaceous Continental Succession, Songliao Basin, NE China

The limited knowledge of Late Cretaceous terrestrial environments and their response to tectonic events in mid-latitudes can be addressed through continental basin deposits such as paleosols. Paleosols have been discovered in the Late Cretaceous Yaojia Formation in the southern Songlaio Basin and are recognized by evidence of soil structures controlled by pedogenesis. Sedimentary facies research on red paleosols was conducted on the Late Cretaceous Yaojia Formation in the outcrop of the southern Songliao Basin to interpret the depositional environments and tectonic significance of red paleosols during the greenhouse period. Mudflat, lake margin, and shallow lake depositional environments in a semi-arid climate are interpreted from the outcrops based on sedimentary descriptions and interpretation as well as geochemical and micromorphological analyses of paleosols in outcrops. We reconstructed the paleoenvironmental and paleoclimatic conditions through the paleosols in the mudflats and lake margin. The red paleosols in the mudflats and lake margin deposits formed in a stable landscape influenced by the tectonic uplift of the Songliao Basin, which is considered as new important evidence for tectonic uplift influenced by the collision of the Okhotomorsk Block with East Asia. The tectonic uplift process in East Asia is identified from the evolution of the depositional environments and drainage conditions inferred from different types of paleosols. Thus, the paleosols-bearing red bed deposits in outcrops provide an important contribution of the Late Cretaceous terrestrial paleoclimate and the tectonic setting research

Gravel roundness quantitative analysis for sedimentary microfacies of fan delta deposition, Baikouquan Formation, Mahu Depression, Northwestern China

Gravel roundness is one of the simple but crucial parameters in particle shape, which is related to the transportation and deposition of sediments. Based on the digital images of underground drilling cores, this study attempted to characterize and distinguish sedimentary microfacies by quantitatively test gravel roundness trends in the fan delta deposition of the Early Triassic Baikouquan Formation in Mahu Depression, Juggar Basin of China. By the new proposed de-flat roundness measurement, two major parameters are recorded to manifest the rounding degree, which is de-flat roundness value (Rdn) and the corresponding variance value. In the case study, roundness characteristics of four microfacies in the fan delta deposits are displayed and compared. Results show that braided channels and submerged distributary channels are characterized by better rounding (Rdn 0.379 to 0.603, and 0.366 to 0.591, respectively) and smaller variance, while debris flow and submerged debris flow are characterized by worse rounding (Rdn 0.333 to 0.405 and 0.256 to 0.391, respectively) and larger variance. In vertical of the roundness curves, channels deposits and gravity flow deposits reveal notable distinction in terms of the numeric ranges, fluctuation amplitude, and fluctuate frequency. It is interpreted to represent the different sedimentary processes during particle transport and deposit, as well as new clastics mixed in from other sources. Therefore, roundness could be a useful complementary data to provide quantitative sedimentological evidence and theoretical support for the study of coarse clastic depositional system

Computational investigation of the effect of OH on the hydrogen evolution reaction by Nickel-bis(dithiolene) and Nickel-bis(diselenolene) complexes

In the present study, the reactivity of OH with Ni(X2C2H2)2 and Ni(X2C2H2)2- (where X = S or Se) was investigated From the thermodynamics, it found that the OH radical attacks a backbone C-atom of the Ni(S2C2H2)2 complex. For the Ni(Se2C2H2)2 complex, the OH is predicted to target the ligating chalcogen atom. The significance of this is that with the attack of OH to a backbone C-atom, the thermodynamic cost to lose a proton or hydrogen atom ranges from exergonic to marginally endergonic depending on the oxidation state of the complex. Notably, such a process results in a rearrangement of the complex, likely leading to deactivation of the catalyst. Where OH has attacked a ligating chalcogenide atom, the thermodynamic cost to lose a proton or hydrogen is endergonic regardless of oxidation state of the complex. Where OH attacks a coordinating chalcogenide atom, the thermodynamics for the addition of a proton was considered. At the present level of theory, it was found that for the dithiolene and diselenolene monoanionic complexes, the addition of a proton is marginally endergonic. However, following protonation, the loss of water is significantly exergonic and results in the regeneration of the neutral non-oxidized Ni-complex. Given the greater tendency for OH to attack Se versus S it may be speculated that the use of diselenolene ligands may offer a means to protect the Ni-complex from damaging OH radicals due to the thermodynamic tendency for OH to attack Se atom of the diselenolene complexes not seen in the dithiolene complexes.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Application of Time-Domain Airborne Electromagnetic Method to the Study of Qingchengzi Ore Concentration Area in China

Qingchengzi is an important polymetallic mineral concentration zone in China. However, long-term mining has led to the depletion of proven reserves in the Qingchengzi ore concentration zone. Therefore, it is necessary to carry out prospecting in the periphery of the existing ore bodies. Taking into account the complex surface conditions of the Qingchengzi mining area, we carried out an airborne time-domain electromagnetic survey in this region and obtained a high-precision underground resistivity model which covers the whole area. The quasi-3D inversion result shows a good agreement with the surface geological information. After analyzing the relationship between the underground geological structures and the resistivity model, we constructed a geological model with the distribution of the main strata, the rock masses and the faults. The reconstructed resistivity distribution of the entire region added new knowledge to understand the geology of the Qingchengzi survey area

Petrology, Physical Properties and Geochemical Characteristics of Alkaline Lake Shale—Fengcheng Formation in Mahu Sag, Junggar Basin

There are rare comparative studies on the geological characteristics of shale in different members of Permian Fengcheng Formation in Mahu Sag, Junggar basin, China. In order to compare the mineral composition, physical properties, and geochemical characteristics of shale in three members of Fengcheng Formation in Mahu Sag, a large number of test data such as X-ray diffraction, high-pressure mercury injection, organic carbon, rock pyrolysis, and vitrinite reflectance were collected and analyzed. Results showed that the content of clay minerals in the shale of the third member of Fengcheng Formation (P1f3) is the highest. The content of carbonate minerals is the highest and the content of clay minerals is the lowest in the shale of the second member of Fengcheng Formation (P1f2). The content of felsic minerals is the highest and the content of carbonate minerals is the lowest in the shale of the first member of Fengcheng Formation (P1f1). The physical properties of the shale of P1f3 are the best, and the porosity of the shale of P1f2 is the smallest, but its permeability is relatively large, and the permeability of shale of P1f1 is the lowest. The organic matter abundance of shale of P1f2 is the highest, while that of P1f1 is relatively the lowest. Most of the organic matter types of shale of P1f3 are type I–II, those of P1f2 are mainly type II, and those of P1f1 section are distributed from type I–III. On the whole, the shale of Fengcheng Formation in the peripheral fault zone and slope area of Mahu Sag has reached the low mature to mature stage, and the shale in the central area of the sag has reached the mature stage. More than half of the shale samples of Fengcheng Formation belong to fair to good source rocks, especially the samples of P1f2. A few samples from P1f3 and P1f1 belong to non-source rocks. This study indicates that the shale of Fengcheng Formation in Mahu Sag has good hydrocarbon generation potential, especially the shale of P1f2, and can become the target of shale oil exploration

Slack resources and individual performance of clinicians: the mediating role of job satisfaction and empirical evidence from public hospitals in Beijing, China

Abstract Background Clinicians in Chinese public hospitals face a complex and severe clinical practice environment, and the individual performance of clinicians is key to improving the output of the healthcare industry. This study aims to explore the mechanism of slack resources in improving individual performance of clinicians and the role of job satisfaction in this process, while the study framework is based on the widely applied Job-Demands Resources theory. Methods Based on the study framework composed of slack resources, individual performance, and job satisfaction, hypotheses have been put forward, and questionnaires have been distributed to representative clinicians in tertiary public hospitals. Finally, 318 valid data collected from clinicians have been obtained. To verify the hypotheses, multiple linear regression models have been established to explore the relationship between variables, and the three-stage regression models have been used to verify the presence of mediating role. Results All four hypotheses proposed in this study have been proved to be held. Clinicians' job satisfaction has played a mediating role in the impact of slack resources and its three dimensions on individual performance. Among them, there has been a complete mediating role for staff slack, while time and space dimensions have played a partial mediating role in the impact of slack resources on individual performance. Conclusions In public hospitals in environments where behavior is subject to significant government interference, it is necessary and feasible to retain appropriate slack resources to improve individual performance. From the perspective of resources management in hospitals, it is necessary for public hospitals to implement a strategy of reserving an appropriate portion of time, staff and space in order to have the conditions to improve clinicians' satisfaction. The existence of slack resources in public hospitals can improve the job satisfaction of clinicians, and then improve the individual performance through the process