Academic literature on the topic 'Zhenfu (Sect)'

This chapter maps local initiatives of the Buddhist revitalization movement in Malaysia. Focusing on two groups, the Malaysian Buddhist Association and the Youth Buddhist Association of Malaysia, the history and process of Buddhist revitalization that occurred through local efforts are examined. The notion of Zheng Xin (Right Faith) Buddhism originating from the idea of modern Buddhism has been adopted by the two groups. The process has been strengthened through formalizing the refuge taking ceremony and Buddhicizing the Hungry Ghost Festival. A tussle between reformist Buddhists and a sect called Unity Sect (Yi Guan Dao) is examined to understand a case of religious contestation among Chinese religions germinated by Buddhist revitalization.

Abstract This chapter examines the shifting dynamics of trade, empire, and maritime power between 1370 and 1490 as established Eurasian systems collapsed and new configurations emerged. The Ming Dynasty replaced the Yuan in China, secured its frontiers, and expanded its influence through Zheng He’s treasure fleets, which project Chinese authority across the Indian Ocean. Meanwhile, Portugal and Spain, previously relying on Mediterranean intermediaries for Eastern luxuries, developed direct maritime routes to bypass traditional trade networks. The Portuguese systematically advanced along Africa’s coast, culminating in Bartolomeu Dias rounding the Cape of Good Hope in 1488, which set the stage for European engagement with the Indian Ocean. Finally, the chapter highlights how, by 1490, European maritime expansion threatened to disrupt long-standing trade systems, marking the beginning of an era in which European gunboats challenged existing commercial and political structures.

In this chapter we focus on Chinese imaginaries of the Nan Yang, or southern seas, not excluding the Indian Ocean area. Allowing for filtering and embellishment, the Chinese geographic-cartographic tradition is seminal in this respect, as is the tradition of recording dynastic annals. Accordingly, this chapter taps into a long tradition of scholarly interpretation of such maps and texts. A first section explains the China-centered tribute trade system. A second section frames a Chinese India imaginary around the journey undertaken in 399 CE by a famed Chinese monk to India and back. Taking cues from the “California school” on economic differentials between Europe and China, a third section offer an appraisal of Song China economic strength. Through an examination of navigational texts, a fourth section offers a Song-era world imaginary. A fifth section contemplates China’s South Seas priority under the Mongol-Yuan dynasty, while the early Ming-era voyages of the Muslim admiral Zheng He are set down in a sixth section. Finally, the chapter offers an evaluation of Ming China maritime prowess and cartographic accomplishments.

Nan Zheng of the University of Arkansas developed (Adv. Synth. Catal. 2014, 356, 2831) a Ru catalyst for the addition of an amino cyclopropane 1 to an alkyne 2 to give 3. The reaction proceeded with high regiocontrol, but only modest stereocontrol. Alain De Mesmaeker of Syngenta Crop Protection, Switzerland found (Tetrahedron Lett. 2014, 55, 6577) that the β,γ-unsaturated amide 4 worked particularly well as a precursor to the keteniminium that cyclized to give, after hydrolysis, the cyclobuta­none 5. Baeyer–Villiger oxidation of 5 led to 5-deoxystrigol 6. David Tymann and Martin Hiersemann of the Technische Universität Dortmund have been exploring (Org. Lett. 2014, 16, 4062; Synthesis 2014, 46, 3110) the intra­molecular carbonyl ene reaction as a tool for the assembly of highly substituted cyclopentanes, as in the conversion of 7 to 8. On oxidation, 8 was readily carried on to the alkene 9. James L. Leighton of Columbia University conceived (J. Am. Chem. Soc. 2014, 136, 9878) the cascade transformation of 10 to 12. Deprotonation/silylation set the stage for Claisen rearrangement to give 11. The subsequent Cope rearrangement is an equilibrium process, driven by the ring strain of 11. K. C. Nicolaou of Rice University described (Angew. Chem. Int. Ed. 2014, 53, 10970) the total synthesis of the cytotoxic tetramic acid derivative myceliothermo­phin E 15. A key step in the synthesis was the intramolecular Michael addition/ aldol condensation that converted 13 to 14.

Scholars who observed the lack of color in rural social life in the Maoist era have also witnessed and marveled at the liberalizing energies released by the recent decade of reforms. Unprecedented movements of goods, capital, and people across the rural landscape have been accompanied by a flourishing of popular rituals. The phenomenon poses interesting questions about culture change. Has Maoist politics ironically preserved the popular culture of peasant communities to the extent that, once the party-state attempted to retreat from society, popular culture regained its former momentum to influence the process of modernization? Or, has peasant culture been so touched by the Maoist programs that what we observe today are new reconstitutions of tradition for coping with contemporary existence defined by the socialist state, rather than cultural remnants that survived the encounter with that state? On the basis of fieldwork carried out in 1986 in Nanxi zhen (a pseudonym), a market town in the heart of the Pearl River Delta known for the intensity of popular ritual activities in the past and the present, I will examine a set of rituals, especially those for funerals and weddings, and the meanings that practitioners attribute to them in order to address the issue of cultural continuity and change in rural China today.

Given the expanding scale of Internet access and ample language learning opportunities associated with the emergence of new digital resources and out-of-class digital environments, SLA researchers started to pay more attention to the language learning experiences of students beyond the classroom level (Lai et al., 2018; Soyoof et al., 2021; Toffoli, 2020). Particular interest is aligned to the perception that while formal education may not satisfy all individual expectations, informal language learning practices might grant students opportunities to engage in cross-cultural communication (Lee & Lee, 2021) and construct their own self-directed authentic learning situations (Lai & Zheng, 2018). Expanding this line of thinking, learning patterns are known to be greatly determined by the members of students’ social milieu who can exhibit a favorable or detrimental impact (Niemiec & Ryan, 2009). Ryan and Deci (2016), for instance, numerously stressed out that the nature of relationships between language teachers and students could have an impact on satisfaction of students’ fundamental psychological needs and as a consequence influence students’ motivation, affecting students’ engagement in learning activities. However, researchers underline that EFL students' exposure to authentic language patterns and direct interaction with other people in their online vicinity should be scrutinized more closely nowadays (Noels et al., 2019). Owing to the complex mechanisms behind these processes and interactions, we aim to apply the sub-theory of Basic Psychological Needs (BPN) to consider the impact of significant others (i.e., language instructors, peers, and target language community members) and the perspective of learning ecology (Barron, 2006) to focus on the apparent differences in contextual factors pertaining to formal and informal language learning environments. Based on these frameworks, the data obtained via the mixed-methods research approach is set to provide valuable conclusions that could shed some light on the determinants of EFL students’ informal language learning activities among prospective EFL teachers of one Central Asian country, Kazakhstan.

Jin Kun Cha of Wayne State University prepared (Org. Lett. 2014, 16, 6208) the allene 1 by SN2′ coupling of a cyclopropanol with a propargylic tosylate. Silver-mediated cyclization converted 1 into 2, that was reduced with diimide to the Dendrobates alka­loid indolizidine 223AB 3. Sanghee Kim of Seoul National University observed (Chem. Eur. J. 2014, 20, 17433) high diastereoselectivity in the Ireland–Claisen rearrangement of 4 to 5. The acid 5 was the key intermediate for the synthesis of the tunicate alkaloid lepadiformine 6. Tohru Fukuyama of Nagoya University also used (Eur. J. Org. Chem. 2014, 4823) an ester enolate Claisen rearrangement to set the relative and absolute configuration of 7. Pd-catalyzed cyclization then led to 8, that was carried on to the excitatory amino acid receptor agonist kainic acid 9. Gephyrotoxin 12 was so named because it incorporates structural elements from two different classes of the Dendrobates alkaloids. Martin D. Smith of the University of Oxford envisioned (Angew. Chem. Int. Ed. 2014, 53, 13826) the cascade cyclization of deprotected 10 to give, after reduction, the ketone 11. Zhen Yang of the Peking University Shenzhen Graduate School showed (Chem. Eur. J. 2014, 20, 12881) that the Rh carbene derived from 13 readily cyclized to an imine. The facial selectivity of the addition of the Grignard reagent 14 to that imine depended on the temperature of the reaction. At room temperature, 15 was formed. At low temperature, the other diastereomer predominated. Ring-closing metathesis was used for the elaboration of 15 to the Stemona alkaloid tuberostemospiroline 16. Kevin A. Reynolds of Portland State University prepared (J. Org. Chem. 2014, 79, 11674) 19 by condensation of the pyrrole 17 with the aldehyde 18. The biosyn­thetic enzyme, that they had overexpressed, oxidized 19 to the antimalarial alkaloid permarineosin A 20.

Schindilactone A 3 is one of a closely related family of polycyclic lactones that have been used in China for the treatment of rheumatic disease. The synthesis of 3 reported (Angew. Chem. Int. Ed. 2011, 50, 7373) by Ye-Feng Tang of Tsinghua University and Jia-Hua Chen and Zhen Yang of Peking University is an elegant tour of metal-mediated bond construction, as exemplified by the cyclization of 1 to 2. The preparation of 1 began with the Diels-Alder reaction of 4 with the butadiene 5. Addition of methyl magnesium chloride converted 6 to the crystalline lactone 7. Angular hydroxylation followed by ring expansion gave the bromo enone 8, which was homologated to the lactone 11. Apparently, the bulky silyloxy group directed the addition of the butenyl Grignard reagent 10 to the top face of the ketone carbonyl. Hydroxylation of the lactone followed by the addition of 12 then gave 1 as a mixture of diastereomers. Only one of the two diastereomers of 1 could undergo ring-closing metathesis to form the second of the three carbocyclic rings of 3. The two lactol diastereomers were in equilibrium with each other by way of the open-chain enone. When MgBr2 was added to encourage equilibration, the metathesis proceeded to completion to give 2. The tertiary alcohol of 2 was esterified with 2-butynoic acid to give 13. Intramolecular Pauson-Khand cyclization, using the optimized protocol developed by the authors, then delivered the enone 13, completing the last carbocyclic ring of 3. The last remarkable metal-mediated reaction in the synthesis was the oxidative carbonylation of 14 to 15. It is not clear if the postcarbonylation event is direct Pd-mediated C–O bond formation or the intramolecular addition of alkoxide to a transient butenolide. To complete the synthesis, 15 was methylated, then deprotonated and kinetically quenched to set the proper relative configuration of the last methyl group. Remarkably, despite the presence in the molecule of three other acidic protons, including the one that had just been removed and kinetically reset, exposure of the acetate 16 to a large excess of base, followed by oxidation, gave clean conversion to schindilactone A 3.

Abstract It has been recognized that high ratios of EGR are effective for in-cylinder NOx reduction, the mechanism of which has been largely attributed to thermal NOx reduction. However, engine operations also approach zones with higher instabilities when excessive EGR is used, usually accompanied with higher cycle-to-cycle variations. Although appropriate controlling strategies are capable to set up consistent EGR operations, any drifts in engine control will affect the originally optimized EGR when sufficient feedback control is not available. In reality, without sufficient EGR feedback control, the applicable EGR ratios need to be recessed from maximum allowable ratios in considering discrepancies of EGR control and influences of operating condition variations. An experimental investigation is provided in this paper to propose a method to evaluate the influences of EGR on such instabilities, in terms of independent effects of CO2 addition, O2 dilution, and N2 balancing, with simulated EGR. Extensive tests were conducted using a synthesized intake mixture testing facility. This paper is also a continuation of a cycle-to-cycle variation analysis on such operations reported previously by the authors (Zheng and Reader 1995). The analyses are aimed at identifying thresholds of stable operation with excessive high ratios of EGR whilst without subjecting to the consecutive cyclic disturbances associated actual EGR itself.

ABSTRACT: Early detection of kicks is imperative for ensuring efficient and safe drilling operations. Employing a data-driven approach for binary classification proves to be an effective method for differentiating between pre-kick and normal operational data. This research delves into the application of machine learning for well kick classification, critically addressing the challenge of model generalization. It proposes innovative solutions, including a novel PCA-based method, to overcome these hurdles. This study thoroughly examines the potential and obstacles in training models to achieve enhanced generalization capabilities. Notably, the Artificial Neural Network (ANN) model, with its remarkable nonlinear fitting abilities, demonstrates superior performance. This not only affirms the effectiveness of machine learning in detecting kicks but also signifies a substantial advancement in resolving issues related to data availability and model generalization in training processes. Consequently, this research represents a significant stride towards the practical and reliable application of machine learning in drilling operations, marking a crucial development in the field. 1. INTRODUCTION Well kick is a phenomenon where unexpected formation gas or fluid flows into the wellbore while drilling. The direct cause of a kick is that the hydraulic pressure provided by the drilling fluid cannot balance the formation pressure at the bottom of the hole. This imbalance may result from abnormal formation pressure, defective drilling fluid, or loss of circulation (Liu et al. 2023). A kick can compromise drilling efficiency by causing Non-productive Time (NPT) and, in severe cases, may lead to a blowout, resulting in substantial economic losses. In addition, the establishment and migration of kicks is a self-accelerating process where the lighter influx will further reduce hydraulic pressure at the bottom of the hole and drive more formation influx. Therefore, detecting, confirming, and treating kicks as early as possible is crucial for ensuring efficient and safe drilling operations. Traditional kick detection methods rely on monitoring data from one or more sensors, such as changes in pit volume, standpipe pressure or flow rate differences (Tarr et al. 2016). These methods offer significant improvements over relying solely on human experience. However, due to the transient nature of drilling and sensor disturbances, they often suffer from high rates of false alarms or slow detection times. Without adding new sensors and thus increasing drilling costs, traditional approaches encounter bottlenecks in further enhancing detection speed and improving kick detection accuracy. Data-driven methods that utilize the supervised machine learning paradigm have been proven to be powerful tools for solving many drilling engineering problems, both in terms of regression and classification (Kamyab et al. 2010, Singh et al. 2020, Olukoga et al. 2021, Wang et al. 2023, Zhang et al. 2024, Jing et al. 2024, Wang et al. 2024, Zheng et al. 2024). Adding binary labels to differentiate between pre-kick and normal operational states in real-time drilling data at each timestep transforms the task of kick detection into a supervised machine learning binary classification problem (Yang et al. 2019, Muojeke et al. 2020, Yin et al. 2020, Wang et al. 2022). At each moment, the multidimensional real-time drilling parameters serve as inputs to the machine learning model, while the target variable to be learned and predicted is the binary class (kick or normal), which represents the current tendency for a kick to occur. Multiple studies have attempted this approach, and the results are promising (Unrau et al. 2017, Alouhali et al. 2018, Obi et al. 2023). These research efforts share a common procedure: aggregating datasets from multiple wells, randomizing them, and then splitting them into training and testing sets. Models are trained on the training set and their accuracy is evaluated on the testing set. However, the generalization ability of models has seldom been studied or discussed. This refers to the accuracy of kick classification predictions for data originating from a new well (one that was not included in the training set) after the model has been trained. Subsequent sections of this paper presented a test specifically designed to analyze this issue. The examples demonstrate that the generalization capabilities of such models are indeed limited. This suggests that the development of a robust kick classification model necessitates training on multidimensional, real-time drilling data sourced from a significant number of wells, typically at the scale of an entire field.

ABSTRACT Exploring ways to enhance the liquid-phase seepage ability and increase the flow-back rate of external fluids in the production process is an important way to solve the problem of water blocking in tight reservoirs. Based on the analysis of the characteristics of water phase retention damage caused by foreign fluid invasion during the development of tight sandstone gas reservoirs, a set of ether nano-displacement agent system was optimized. The mechanism of wetting modification is revealed from the perspective of the physical composition of nano-displacement agent, and the mechanism of action between nano-displacement agent and rock and different clay minerals is clarified. Laboratory experiments show that :(1) 0.5 wt% CNDAD1# nano-displacement agent fluid can change the wettability of sandstone to gas-phase wetting, "air-salt water-rock" three-phase static contact angle increased from 38.5° to 126°. (2) SEM and EDX results prove that the nano-displacement agent has good macroscopic static and dynamic adsorption performance on the sandstone surface. This paper provides a reference method for exploring the use of environmentally friendly chemical agents to remove water blocking damage in tight sandstone gas reservoirs. INTRODUCTION Tight sandstone gas reservoirs refer to sandstone gas reservoirs with overburden matrix permeability less than or equal to 0.1 mD. Single wells generally have no natural productivity or natural productivity is lower than the lower limit of industrial gas flow. Industrial natural gas production needs to be obtained through fracturing, horizontal wells, multi-branch wells, etc. (Wei G, Zhang F, Li J, et al., 2016; Jia C, Zheng M and Zhang Y, 2012; Zou N, Zhu R, Wu S, et al., 2012). According to the data, China contains a wealth of tight sandstone gas reservoirs, tight sandstone gas resources account for about 27.5 % of China ‘s natural gas resources, mainly distributed in different basins in China, such as Sichuan, Tarim Basin and other regions, and most of the reserves have not been effectively developed (Wang J, Hu Y, Liu Y, et al., 2019; Fuhai J, Tang D, Xu H, et al., 2012; Bybee K, 2007). Therefore, the development of tight sandstone gas reservoirs will become one of the key sources of future energy security in China, and it is also the focus of unconventional oil and gas development. However, most of the tight sandstone gas reservoirs have low natural productivity of single wells. The combination of horizontal well drilling and fracturing is one of the main ways to realize the commercial exploitation of tight sandstone gas reservoirs. However, during the fracturing process, the fracturing fluid flowback is not timely or the edge and bottom water invades the reservoir during the production process. The reservoir will produce a large amount of external water phase retention or edge and bottom water invasion water, forming a ‘ liquid phase trap ‘ and further tight sandstone gas well productivity (Dutta R, Lee C H, Odumabo S, et al., 2012; You Q, Wang H, Zhang Y, et al., 2018; Zhang L, Zhou F, Mou J Y, et al., 2018).