当代韩国政党体制的结构性问题与原因分析

以往,韩国的左派政党和右派政党在对立的同时,还能够推动政治的发展。但是现如今左右政党的竞争和对立加剧,甚至有可能破坏政党政治体制。去年的议会选举结果导致执政党赢得了足够的议席,使其无需与在野党达成协议就可以通过几乎所有法案,表现出独断专行政党的特征。执政党的这种独断专行和对此持反对意见的在野党之间的矛盾深化导致了政治两极化。而且,可以称为选举民主制度弊端的身份政治(identity politics)和粉丝政治现象也日益明显。

Recent progress in production and usage of hydrogen peroxide

Hydrogen peroxide has attracted increasing interest as an environmentally benign and green oxidant that can also be used as a solar fuel in fuel cells.This review focuses on recent progress in production of hydrogen peroxide by solar-light-driven oxidation of water by dioxygen and its usage as a green oxidant and fuel.The photocatalytic production of hydrogen peroxide is made possible by combining the e^(-)and 4e-oxidation of water with the e^(-)reduction of dioxygen using solar energy.The catalytic control of the selectivity of the e^(-)vs.4e-oxidation of water is discussed together with the selectivity of the e^(-)vs.4e-reduction of dioxygen.The combination of the photocatalytic e^(-)oxidation of water and the e^(-)reduction of dioxygen provides the best efficiency because both processes afford hydrogen peroxide.The solar-light-driven hydrogen peroxide production by oxidation of water and by reduction of dioxygen is combined with the catalytic oxidation of substrates with hydrogen peroxides,in which dioxygen is used as the greenest oxidant.

Cycloaddition of CO_2 and propylene oxide by using M(HBTC)(4,4'-bipy)·3DMF(M=Ni,Co,Zn) metal-organic frameworks

Three pillar-layered metal-organic frameworks（MOFs） based on M（HBTC）（4,4＇-bipy）.3DMF（M =Ni, Co, and Zn; HBTC = 1,3,5-benzenetricarboxylic acid, 4,4＇-bipy = 4,4′-bipyridine） were synthesized using a solvothermal method. Zn（HBTC）（4,4＇-bipy）.3DMF was synthesized for the first time using both a solvothermal and microwave method, and subsequently characterized by various physicochemical methods. The structure of M（HBTC）（4,4＇-bipy）.3DMF consisted of honeycomb grid layers of M2＋ ions and BTC units, which were further linked by the 4,4＇-bipy pillars to form a three-dimensional highly porous framework. All the MOFs displayed excellent synergistic catalytic properties with alkyl ammonium halides（TBAX） in the solventless fixation of CO_2 with epoxides to produce cyclic carbonates. The catalytic activities of these MOFs followed the trend Zn Co Ni,which was explained by the acid-base bifunctional properties. The microwave-synthesized Zn（HBTC）（4,4＇-bipy）.3DMF material exhibited physical, chemical, and catalytic properties that were similar to those of the catalyst obtained using a conventional solvothermal synthesis. The scope of various parameters, including recyclability, was studied, and a plausible reaction mechanism was suggested.

Surface elemental distribution effect of Pt-Pb hexagonal nanoplates for electrocatalytic methanol oxidation reaction

Bimetallic Pt-based catalysts have been extensively investigated to enhance the performance of direct methanol fuel cells(DMFCs) because CO, a by-product, reduces the activity of the pure Pt catalysts. Herein, we synthesized Pt-Pb hexagonal nanoplates as a model catalyst for the methanol oxidation reaction(MOR) and further controlled the Pt and Pb distributions on the surface of the nanoplates through acetic acid(HAc) treatment. As a result, we obtained Pt-Pb nanoplates and HAc-treated Pt-Pb nanoplates with homogeneous and heterogeneous distributions of the Pt-Pb alloy surfaces, respectively. We showed that the MOR activity and stability of the Pt-Pb nanoplates improved compared to those of the HAc-treated Pt-Pb nanoplates, mainly due to the enhanced CO tolerance and the modified electronic structure of Pt under the influence of the oxophilic Pb.

Cycloaddition of CO_2 with epoxides by using an amino-acid-based Cu(Ⅱ)–tryptophan MOF catalyst

Metal organic frameworks(MOFs)constructed from natural/biological units(amino acids)are prospective candidates as catalysts in CO2chemistry owing to their natural origin and high abundance of Lewis acid/base sites and functional groups.Herein,we report the catalytic efficiency of an amino‐acid‐based Cu‐containing MOF,denoted as CuTrp(Trp=L‐tryptophan).The CuTrp catalyst was synthesized by direct mixing at room temperature using methanol as a solvent-a synthetic route with notable energy efficiency.The catalyst was characterized using various physicochemical techniques,including XRD,FT‐IR,TGA,XPS,ICP‐OES,FE‐SEM,and BET analysis.The catalytic activity of CuTrp was assessed in the synthesis of cyclic carbonates from epoxides and CO2.The CuTrp operated in synergy with the co‐catalyst tetrabutylammonium bromide under solvent‐free conditions.Several reaction parameters were studied to identify the optimal reaction conditions and a reaction mechanism was proposed based on experimental evidence and previous density functional theory studies.The CuTrp also exhibited satisfactory stability in water and could be reused more than three times without any significant loss of activity.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Modern applications of scanning electrochemical microscopy in the analysis of electrocatalytic surface reactions

Development of reaction-tailored electrocatalysts is becoming increasingly important as energy and environment are among key issues governing our sustainable future.Electrocatalysts are inherently optimized for application towards reactions of interest in renewable energy,such as those involved in water splitting and artificial photosynthesis,owing to its energy efficiency,simple fabrication,and ease of operation.In this view,it is important to secure logical design principles for the synthesis of electrocatalysts for various reactions of interest,and also understand their catalytic mechanisms in the respective reactions for improvements in further iterations.In this review,we introduce several key methods of scanning electrochemical microscopy(SECM)in its applications towards electrocatalysis.A brief history and a handful of seminal works in the SECM field is introduced in advancing the synthetic designs of electrocatalysts and elucidation of the operating mechanism.New developments in nano-sizing of the electrodes in attempts for improved spatial resolution of SECM is also introduced,and the application of nanoelectrodes towards the investigation of formerly inaccessible single catalytic entities is shared.

Acupuncture and moxibustion treating lower urinary tract symptoms due to benign prostatic hyperplasia:a systematic review and network meta-analysis

Objective: Lower urinary tract symptoms(LUTS) caused by benign prostatic hyperplasia(BPH) affect the quality of life of elderly individuals. Acupuncture and moxibustion are used in the clinic in China for improving LUTS symptoms due to BPH. However,there is no evidence to suggest which is the best option. We compared the efficacy of acupuncture and moxibustion to provide evidence for clinical decision-making.Methods: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wan Fang Data, and VIP databases were searched from inception to July 2020 to identify the randomized controlled trials(RCTs) of acupuncture and moxibustion for LUTS due to BPH. Two researchers filtered studies and extracted the information independently. This study conducted a network meta-analysis using the Bayesian random method. The interventions ranking was evaluated using the surface under the cumulative ranking curve(SUCRA).Results: We finally included 40 studies comprising 10 treating therapies and 3,655 patients with LUTS caused by BPH. In terms of the International Prostate Symptom Score, maximum urinary flow rate, and quality of life, electroacupuncture(EA) [MD =-3.6,95% credible interval(CrI)(-5.5,-1.8), very low certainty of evidence;MD = 2.2, 95% CrI(1.1, 3.3), low certainty of evidence;MD =-1.3, 95% CrI(-2.2,-0.43), very low certainty of the evidence] may be consistently the optimal treatment compared with other interventions, with SUCRA values of 84%, 81%, and 89%, respectively.Conclusions: Of all treatments, EA may have the best efficacy with fewer adverse events for LUTS due to BPH. The quality of evidence supporting this result is low to very low certainty of the evidence due to the limitations of primary studies;thus, more highquality RCTs are needed for further evidence.

How Selection of a Target Feature Impacts Corrective Feedback:Finding Answers Through Meta-Analysis of Chinese EFL Learners

Rather than looking at variables like grammatical feature type,proficiency,and L1 as separate,we must start to view them as interrelated and codependent.In this way,educators may finally learn how to maximize the effect of corrective feedback(CF).A meta-analysis of 13 studies was conducted to examine four styles of CF(implicit prompt,implicit reformulation,explicit prompt,and explicit reformulation)along with the following variables:grammatical feature type,L1 similarity(with Mandarin Chinese),and proficiency level.Results suggest that effect size is highly dependent upon the grammatical feature targeted.Explicit feedback appears to have a scaffolding effect for more semantically or syntactically complex grammatical features.Implicit reformulations(recasts)also provide scaffolding,yielding larger effect sizes than implicit prompts when used with L1 dissimilar features that are more semantically or syntactically complex.

Free Energy Level Correction by Monte Carlo Resampling with Weighted Histogram Analysis Method

Free energy calculations may provide vital information for studying various chemical and biological processes.Quantum mechanical methods are required to accurately describe interaction energies,but their computations are often too demanding for conformational sampling.As a remedy,level correction schemes that allow calculating high level free energies based on conformations from lower level simulations have been developed.Here,we present a variation of a Monte Carlo(MC)resampling approach in relation to the weighted histogram analysis method(WHAM).We show that our scheme can generate free energy surfaces that can practically converge to the exact one with sufficient sampling,and that it treats cases with insufficient sampling in a more stable manner than the conventional WHAM-based level correction scheme.It can also provide a guide for checking the uncertainty of the levelcorrected surface and a well-defined criterion for deciding the extent of smoothing on the free energy surface for its visual improvement.We demonstrate these aspects by obtaining the free energy maps associated with the alanine dipeptide and proton transfer network of the KillerRed protein in explicit water,and exemplify that the MC resampled WHAM scheme can be a practical tool for producing free energy surfaces of realistic systems.

On L2 English Learners’Formulaic Language Use and Spoken English Fluency

This study explored the distribution of three types of English formulaic language, which involves four categories in L1 Chinese L2 English learners’ speaking performance. In addition, it investigated the relationship between the English learners’ use of formulaic language and their spoken English fluency. A CCA(canonical correlation analysis) was conducted to examine the correlations between two sets of fluency variables(dependent variables) and linguistic variables of English formulaic language use(independent variables). The fluency variable set consists of:(1)temporal indices such as SR(speech rate), AR(articulation rate), MLR(mean length of run), and PTR(phonation time ratio);(2) linguistic variables of English formulaic language like F2 R(twoword formulaic sequences/run ratio, B3 R(three-word lexical bundles/run ratio), and B4 R(fourword lexical bundles/run ratio). These are calculated according to the frequency of the English formulaic language in the speech samples of the participants(n = 86) across three academic levels.The results indicate that the learners’ spoken English fluency is highly related to their use of English formulaic language. Its limitations and future research directions are also discussed.

Extensive Reading Research in the EFL Classroom of China: A Qualitative Meta-Analysis

Extensive reading has long been applied in the English as a foreign language classroom in China,but the fundamental theories and practical instruction are not satisfactory. The study aims to synthesize and examine extensive reading studies over the past fifty years(1962-2019) from a holistic perspective. By performing a qualitative meta-analysis, a total of 81 articles published in widely accepted journals were carefully coded and analyzed. Three latent problems emerged,including that 1) most extensive reading researchers misunderstand the inherent characteristic of extensive reading(i. e., pleasure reading) and less frequently follow the principles of extensive reading instruction;2) there are methodological weaknesses in empirical research designs, and;3)research scope is limited regarding participants and methodology. Suggestions for extensive reading research and instruction are included.

Hydrochloric acid‐mediated synthesis of ZnFe_(2)O_(4) small particle decorated one‐dimensional Perylene Diimide S‐scheme heterojunction with excellent photocatalytic ability

The recyclable and stable ZnFe_(2)O_(4) small particle decorated one‐dimensional perylene diimide(PDI)S‐scheme heterojunction(1D PDI/ZnFe_(2)O_(4))is prepared by the hydrochloric acid‐mediated(HCl‐mediated)strategy,interestingly,the morphology of the 1D PDI/ZnFe_(2)O_(4) can also be effectively regulated by HCl‐mediated process,the existence of HCl can regulate PDI into a uniform rod structure,while the co‐existence of HCl and PDI can limit ZnFe_(2)O_(4) to become the uniform small particles.More importantly,based on the 1D rod structure of PDI and the small size effect of ZnFe_(2)O_(4),carriers can migrate to the surface more easily,which can improve the photocatalytic activity.Meanwhile,due to the appropriate energy level structure,the S‐scheme heterojunction structure is formed between PDI and ZnFe_(2)O_(4),which eliminates meaningless photo‐generated charge carriers through recombination and introduces strong redox to further enhance the photodegradation effect,thereby,1D PDI/ZnFe_(2)O_(4) exhibits excellent photocatalytic ability,under the visible light irradiation,the degradation rate of tetracycline(TC)with 1D PDI/ZnFe_(2)O_(4)(66.67%)is 9.18 times that with PDI(7.26%)and 9.73 times that with ZnFe_(2)O_(4)(6.85%).This work proposes new ideas for the assembly of magnetic organic‐inorganic S‐scheme heterojunction photocatalysts.

The Influence of L2 on L1 Lexical Competence and Grammatical Properties in Written Expressions

This article reports a study on the impact of L2 Korean on L1 Chinese lexical diversity and grammar in written expressions by Chinese bilinguals proficient in Korean. The statistical analysis showed that the cross-linguistic effects of L2 on L1 were significant although such impact was bidirectional. There were significantly more grammar errors and longer retrieval time committed by the bilingual group which implied negative L2 transfer to L1. Meanwhile, L2 also showed a positive influence on lexical diversity as there was no decline in lexical richness but an increase in lexical variations, and this indicated that L2-induced patterns did not replace or deteriorate L1 but instead added additional options to L1 expressions. This phenomenon can be characterized as the addition of new concepts and linguistic options to the already-existing L1 and conceptual repertoire. Specifically, meta-linguistic competence was enhanced. This research supports the theory of interference on L1 by the use of L2 （negative transfer）, but it could also be enhanced by L2 （positive transfer）.