33,012 research outputs found
Optimization Design of Deep-Coalbed Methane Deliquification in the Linxing Block, China
No full textThe production of deep-coalbed methane (CBM) wells undergoes four stages sequentially: drainage depressurization, unstable gas production, stable gas production, and gas production decline. Upon entering the stable production stage, the recovery rate of deep CBM wells is constrained by bottom hole flowing pressure (BHFP). Reducing BHFP can further optimize CBM productivity, significantly increasing the production and recovery rate of CBM wells. This paper optimizes the deliquification process for deep CBM in the Linxing Block. By analyzing the production of deep CBM wells, an improved sucker rod pump deliquification process is proposed, and a method considering the flow in the tubing, annulus, and reservoir is established. Using the production data of Well GK-25D in the Linxing CBM field as an example, an optimized design of the improved rod pump deliquification process was undertaken, with design parameters including the depth of the sucker rod pump, the stroke length, and stroke rate. The results show that the improved process significantly lowers the pressure at the coalbed, enhancing CBM well production by 12.24%. The improved sucker rod pump process enriches deliquification technology for deep CBM, offering a new approach for its development and helping to maximize CBM well productivity
†Chuchinolepididae Zhang 1978
No full textFamily †Chuchinolepididae Zhang 1978, spelling in prevailing recent practice †Chuchinolepidae Zhang 1978a: 296 (family) † Chuchinolepis Zhang 1978 [family name also seen as †Chuchinolepididae; author also seen as Chang] †Qujinolepidae Zhang 1978b: 173 (family) † Qujinolepis Zhang 1978 [family name sometimes seen as † Qujinolepididae] †Procondylolepidae Zhang 1984: 82 (family) † Procondylolepis Zhang 1984Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 27, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/555755
An enhanced author name dataset for PubMed/MEDLINE
No full text<p>The incompleteness of author names is a well-known issue in the MEDLINE database. It was since 2002, the full author name has been systematically indexed in MEDLINE. Although many full author names have been added to MEDLINE, we still found a significant number of abbreviated names in papers published after 2002.</p>
<p>Here we built an enhanced author name dataset for MEDLINE, called EAN, achieved by linking the whole PubMed to other large literature databases and conducting a large-scale name comparison and restoration with obtained multi-sources author names. Our evaluation shows that more than 90% of author names in EAN are complete as compared to the ratio of ~60% in MEDLINE.</p>
An enhanced author name dataset for PubMed/MEDLINE
No full text<p>The incompleteness of author names is a well-known issue in the MEDLINE database. It was since 2002, the full author name has been systematically indexed in MEDLINE. Although many full author names have been added to MEDLINE, we still found a significant number of abbreviated names in papers published after 2002.</p>
<p>Here we built an enhanced author name dataset for MEDLINE, called EAN, achieved by linking the whole PubMed to other large literature databases and conducting a large-scale name comparison and restoration with obtained multi-sources author names. Our evaluation shows that more than 90% of author names in EAN are complete as compared to the ratio of ~60% in MEDLINE.</p>
Astragalus wui M. Idrees & Z. Y. Zhang 2021, nom. nov.
No full textAstragalus wui M. Idrees & Z.Y. Zhang, nom. nov. Replaced name:— Astragalus sylvaticus Y.H. Wu (2015: 718), nom. illeg., non A. sylvaticus (Pall.) Willd. (1802: 1300). Type:— CHINA. Xinjiang: Yecheng Country, Sukepiya, in border forest, alt. 3000 m, 15 Aug. 1987, Exped. Qinghai-Tibet Wu Yuhu 1067 (holotype: QTPMB, not seen). Etymology:—The specific epithet honours Prof. Dr. Wu Yuhu (Northwest Institute of Plateau Biology, Chinese Academy of Science, Xining, China), author of the replaced name, who first described this new species.Published as part of Idrees, Muhammad & Zhang, Zhiyong, 2021, Astragalus wui, a new replacement name for A. sylvaticus Y. H. Wu (Galegeae, Papilionoideae, Fabaceae), pp. 210-211 in Phytotaxa 524 (3) on page 210, DOI: 10.11646/phytotaxa.524.3.6, http://zenodo.org/record/564936
Petrological characteristics and the impact of mineral content on reservoir quality in coal-bearing strata of Linxing area, eastern margin of Ordos Basin, China
No full text Tight sandstone gas is on the first position of unconventional natural gas sources, which can be developed under today’s technical conditions. In recent years, tight sandstone gas reservoirs have been found in several wells in the Linxing area, eastern margin of Ordos Basin, China. In this article, a variety of methods, including cast thin sections, X-ray diffraction analysis, scanning electron microscope, and drill core data were used to study the petrological characteristics and their influences on tight sandstone reservoir in coal-bearing strata of the Linxing area. Based on the analysis of thin section, it can be concluded that the sandstone reservoir is essentially constituted of lithic sandstone as well as lithic arkose and feldspathic litharenite. Cement types are complicated, including carbonate minerals, clay minerals, and quartz overgrowth. Illite, kaolinite, chlorite, illite–smectite mixed layer, and chlorite–smectite mixed layer are found in clay minerals. Compared with other clay minerals, illite is in the dominant position. Pores can be divided into residual intergranular pore, intragranular dissolution pore, intergranular dissolution pore, cement dissolution pore, intercrystalline pore, and microcrack in sandstone reservoir of the Linxing area. Quartz has an average content of 68% with the feature of low compositional maturity and plays a major role in increasing porosity due to dissolution and protecting of quartz. Feldspar dissolution plays a role in decreasing porosity because the by-product materials of feldspar dissolution remain in original place, instead of being transported to other areas. Dissolution pores are 2–20 µm and may be filled with kaolinite, illite, or halite. It is worth mentioning that grain-coating chlorite may be of sufficient thickness to protect reservoirs along with the increasing content of chlorite, which is testified by the crossplot between the chlorite and porosity when the absolute content of chlorite is less than 1.5%. </jats:p
Professor Zhang Weihua's Clinical Experience in the Application of Yongquan Acupoint
No full textSummarizing Professor Zhang Weihua's understanding of the bidirectional regulation function of Yongquan Point and his clinical application experience, the author believes that Yongquan is a meeting place of Yin and Yang qi, and both Yin and Yang qi are rooted here, which can be used to balance Yin and Yang, and proposes that Yongquan is the key point of bidirectional regulation, which has the functions of bidirectional regulation, bidirectional lifting, bidirectional replenishing. At the same time, Professor Zhang believes that Yongquan point should be combined with the corresponding stimulation method in the treatment of different diseases, which provides a new idea for the clinical treatment of some difficult diseases
In Memoriam: Prof. Jingdong Zhang
No full textCelebrating the electrochemistry legacy: Prof. Zhang was a member of the Editorial Board of ChemElectroChem as well as a valued author and reviewer. Together with her friends and colleagues Christian Engelbrekt, Xinxin Xiao and Jens Ulstrup (Technical University of Denmark) as well as Bingwei Mao (Xiamen University, China), we hope to commemorate Prof Zhang′s contributions to the electrochemical sciences by this Special ChemElectroChem Collection on the theme of “Electrochemical Materials and Interfaces”
From expectation-3-maximization to bayesian expectation-3-maximization: A latent mixture modeling-based bayesian algorithm for the 4-parameter logistic model
No full textThere is renewed interest in the four-parameter logistic model (4PLM), but the lack of a user-friendly calibration method constitutes a major barrier to its widespread application. In the present study, this researcher reformulated the 4PLM from a latent mixture modeling view and developed the Expectation-Maximization-Maximization-Maximization (EMMM) method. Combining the EMMM with the Bayesian approach, allowed the Bayesian Expectation-Maximization-Maximization-Maximization (BEMMM) algorithm to be proposed. First, the author compared the EMMM with BEMMM to confirm that the BEMMM method reduced the number of implausible estimates in EMMM. Next, when comparing the BEMMM with the Markov Chain Monte Carlo method (Culpepper, 2016) and Bayesian Modal Estimation (Waller & Feuerstahler, 2017), the results from a simulation study and a real-world data calibration indicated that the BEMMM and the MCMC are more accurate than the BME, while the BEMMM is much faster than the MCMC.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-05-01The student, Ci Zhang, accepted the attached license on 2018-04-11 at 15:29.The student, Ci Zhang, submitted this Thesis for approval on 2018-04-11 at 15:36.This Thesis was approved for publication on 2018-04-13 at 11:03.DSpace SAF Submission Ingestion Package generated from Vireo submission #12194 on 2018-08-31 at 17:27:19Made available in DSpace on 2018-09-04T20:47:03Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-04-13Embargo set by: Seth Robbins for item 107382
Lift date: 2020-09-04T20:47:38Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 107382
Lift date: 2020-09-04T20:50:11Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 107382 on 2020-09-05T09:15:09Z
Frank Zhang: Hipster Extraordinaire
No full textAfter the delicate deliberation of the characters of the series Heroes of Olympus by Rick Riordan, it was decided by both writers that Frank Zhang, son of Mars, is the ultimate hipster demigod. The structure of this essay was based on a simple argument, and carefully dissects the full series in order to really convey who Frank Zhang really is. It was additionally concluded by both writers that as complicated and intricate a character as Frank Zhang is, we wanted the audience to be able to not only imagine the illustrations of the character, but to further empathize with the character\u27s emotions. Through the attendance of two separate classes, a review from the professor, and careful editing, the essay comes to a complete conclusion demonstrating our perspective on the author\u27s ultimate purpose
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