This paper examined farmers’ perceptions and preferences for improved varietal traits in the Wenchi and Offinso North Municipalities of Ghana. Data from 306 randomly selected tomato farmers were analyzed using perception indices, Kendall’s Coefficient of concordance and the Poisson regression model. The results show that tomato farmers are willing to adopt an improved variety with long shelf life, good fruit quality and large fruit size. The study further indicates that tomato farmers lack requisite skills in pest and disease management. The number of varietal attributes preferred by farmers was positively influenced by sex of farmer, education, experience in tomato cultivation, household size, access to credit, FBO membership, extension contacts farm size and off-farm income. These factors and attributes need to be carefully considered by breeders and policy makers in the development of an improved tomato variety to enhance its uptake. The major constraints identified in tomato production include limited access to capital followed by low commodity prices coupled with low demand with the least constraint being access to tractors for land preparation. The potential of adoption of improved tomato varieties in Ghana will be augmented through paragenetic measures towards addressing these constraints.

최근 중국을 비롯하여 전세계적으로 모바일 게임의 사용자 수와 시장 규모는 지속적으로 확대되고 있다. 성공적인 모바일 게임 특성은 무엇이며 어떤 요소가 사용자에게 영향을 미치는지를 살펴보기 위해 현재 세계 최대 규모의 게임 시장인 중국 모바일 게임의 대표적 특성을 분석하고 이용자가 게임의 선택과 지속적인 이용에 영향을 미치는 중용한 원인을 찾아봤다. 특히, 게임 방송의 영향력을 감안하여 오피니언 리더로서의 게임 BJ 가 사람들의 게임 선택과 지속적인 이용에 어떠한 영향을 미치는지도 함께 살펴보았다. 기술수용모델(TAM, Technology Acceptance Model)에 기반하여 모바일 게임의 특성과 오피니언 리더에 대한 인식의 외적 변수가 게이머 인식(지각된 유용성, 지각된 용이성, 지각된 오락성)에 미치는 영향을 통해 모바일 게임에 대한 태도와 지속적인 이용 의도를 예측하는 모델을 구축하고, 이를 검증하기 위하여 346 명의 게이머를 대상으로 설문 조사를 실시하였다. 분석 결과, 모바일 특성, 특시 상호작용성과 비용 저렴성, 시공간 편의성이 모바일 게임 이용자의 인식에 큰 영향을 미치는 것으로 나타났으며, 오피니언 리더에 대한 인식이 지각된 오락성에 긍정적인 효과를 보였다. 지각된 오락성과 지각된 유용성은 모바일 게임 태도에 유의한 효과를 보였으며, 게임 태도는 지속적 이용 의도를 유의하게 예측하는 결과를 나타냈다.

Carbonaceous materials are considered as potential adsorbents for organic dyes due to their unique structures which provide high aspect ratios, hydrophobic property, large efficient surface area, and easy surface modification. In this work, graphene nanoribbons (GNRs) were prepared by atomic hydrogen-induced treatment of single-walled carbon nanotube (SWCNTs), which inspire the idea of cutting and unzipping the SWCNTs carpets with the modified in molecules prevent because of the unfolding of the side-walls. The unfolded spaces and uniform vertical arrangement not only enhance the active surface area, but also promote the electrostatic and π–π interactions between dyes and GNRs. The improved adsorption capacity of GNRs beyond original SWCNTs can be determined by the adsorption kinetics and isotherm, which are evaluated through adsorption batch experiments of the typical cationic methylene blue (MB) and anionic orange II (OII) dye, respectively. It is shown that the adsorption kinetics follow a pseudo second-order model while the adsorption isotherm could be determined by Langmuir model. The results reveal that the maximum adsorption capacities of GNRs for MB and OII are 280 and 265 mg/g, respectively. The GNRs present the highly efficient, cost effective, and environmental friendly properties for the commercial applications of wastewater treatment.

Since its accession to the WTO in 2001, China has been involved in 21 cases as complainant, 44 as respondent, and 179 as a third party. However, China-related cases have not overburdened the WTO dispute settlement system. Instead, China has assisted in the development of international trade law through the creative interpretations of different provisions achieved in the WTO dispute settlement proceedings. This article seeks to provide an overview of China’s participation in the WTO dispute settlement mechanism and contribution to the rules over the past decade. In doing so, the article not only highlights the jurisprudential and doctrinal contributions of some of the critical disputes, but also examines the role of various interest groups and stakeholders in shaping China’s dispute settlement activity. Overall, the article provides an overview of China’s WTO dispute settlement activities and its role in assisting the development of international trade law.

As people's income rises dramatically, people's happiness seems not as high as expected. In fact, there are two different arguments about the relationship between income level and happiness. The focus of the debate is whether the correlation between income and probability of happiness is positive or negative. Therefore, we hypothesizes that the relationship between income and probability of happiness presents an inverted U-shaped curve. Then, this paper sets China as an example to explore the effect of income on happiness. The data from the Chinese General Social Survey (CGSS) in 2015 is employed to conduct empirical analyses under the Probit model and the Zero-Inflation-Passion model. The empirical findings indicate that the effect of income on happiness presents an inverted U-shaped curve and significantly in statistic. Meanwhile, spouse’s income, educational level, marriage time and house property have a positive and significant effect on happiness.Conversely, age and local living standards have a negative and significant effect on happiness. Unfortunately, even though registered residence and children have a negative effect on happiness, they do not get through the significant test. In order to ensure the robustness of our empirical results, we test the robustness of the above empirical results by adjusting the sample size. The results of robustness test verify that our empirical results are robust. Moreover, this paper also makes a small contribution to the current literature with a sample from China.

Commercial ultra-high-strength PAN-based carbon fibers (T1000G) were heat-treated at the temperature range of 2300– 2600 °C under a constant stretching of 600 cN. After continuous high-temperature graphitization treatment, microstructures, mechanical properties and thermal stability of the carbon fibers were investigated. The results show that the T1000G carbon fibers present the similar round shape with a smooth surface before and after graphitization, indicating the carbon fibers are fabricated by dry–wet spinning. In comparison, the commercial high-strength and high-modulus PAN-based carbon fibers (M40JB and M55JB) present elliptical shapes with ridges and grooves on the surface, indicating the carbon fibers are fabricated by wet spinning. After graphitization treatment from 2300 to 2600 °C under a constant stretching of 600 cN, the Young’s modulus of the T1000G carbon fibers increases from about 436 to 484 GPa, and their tensile strength decreases from about 5.26 to 4.45 GPa. The increase in Young’s modulus of the graphitized T1000G carbon fibers is attributed to the increase in the crystallite sizes and the preferred orientation of graphite crystallites along the fiber longitudinal direction under a constant stretching condition. In comparison with the M40JB and the M55JB carbon fibers, the graphitized T1000G carbon fibers are easier to be oxidized, which can be contributed to the formation of more micropores and defects during the graphitization process, thus leading to the decrease in the tensile strength.

Boron-doped amorphous carbon (BDAC) thin films with a regular oxygen reduction reaction (ORR) catalytic activity were synthesized in a hot filament chemical vapor deposition device using a mixture of CH4 and H2 as a gas source and B2O3 as a boron source and then oxidized in air at 380–470 °C for 15–75 min. Scanning electron microscope, transmission electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy, and electrochemical tests were used to characterize the physical and electrochemical properties of the BDAC catalysts. It was concluded that the BDAC catalyst oxidized at 450 °C for 45 min showed the best ORR catalytic activity in alkaline medium. The oxygen reduction potential and the transfer electron number n, respectively, are − 0.286 V versus Ag/AgCl and 3.24 from the rotating disk electrode experiments. The treated carbon film has better methanol resistance and stability than the commercial Pt/C catalyst.

The present work introduces a new method for the recycling of waste flocculation sludge to prepare electrode materials for supercapacitor. Hazardous azo dye was removal from textile dying wastewater by a new chitosan-based flocculant, and the generated dye sludge flocs was used as a nitrogen-containing precursor for the fabrication of N-doped carbon materials. The influence of azo dye on specific surface areas, nitrogen content, pore evolution of the resulting products and their electrochemical performance were investigated in detail. The results demonstrated a dual role of azo dye worked as both a nitrogen resource and pore-forming agent. The resulting N-doped carbon nanosheets derived from azo dye flocs demonstrated high electrochemical capacitance and good stability for supercapacitor electrode, which is attributed to the unique nitrogen doping, higher specific surface area and efficient charge transfer ability.

This article analyzes the Sino-US Summit in Osaka in 2019 and its influence on trade negotiations between China and the US in the near future. By a look at the reports from China’s side and the US’ side, the article figures out what has been agreed and what are the most controversial issues on table. Having an observation of the new development after the Summit, the article tries to analyze the direction and ways forwards for the Sino-US trade talks, and make predictions based on a certain of factors including challenges faced by the US, the need of China as well as the attitude of the world. It is easy to figure out that agricultural products and the supply of equipment relating to Huawei were the key points at issue in the Sino-US Summit as well as in the future. The exchange and compromises are necessary between China and the US regardless of whether they are happy to admit it or not.

This research combines the liquid carbon precursor infiltration process for carbon/carbon composites with the fabrication procedure for organic, carbon-matrix friction materials in automotive. In the densification process, different liquid carbon precursors and numbers of densification cycle are adopted to investigate the influence on physical and mechanical properties, microstructure and tribological behavior. Experimental results indicate that the infiltration of liquid carbon precursors could improve the physical, mechanical properties and tribological performances of organic friction materials. The open porosity decreases with the number of densification cycle. Both bulk density and hardness increase with the number of densification cycle. The resin-based specimens show higher hardness and lower open porosity than those of the pitch-based specimens after each densification cycle. The tribological measurement of specimens with different carbon precursors shows that the pitch-based specimen shows lower and more stable friction coefficients and exhibits lower weight losses in comparison with other carbon precursors. Morphological observations show that a large area of smooth lubricative film was easily presented on the worn surfaces of the pitch-based specimens, whereas it was seldom observed on the worn surfaces of the preform specimen and resin-based specimens.

A typical Mathematics class is comprised of a heterogeneous group of students in terms of academic ability, learning styles, intelligence quotient, home background and the likes. The inability of the teachers to effectively manage these differences usually leads to poor academic achievement among the learners, especially the weak ones. This study therefore determined the effectiveness of Cooperative Learning Technique on low learning ability students in Mathematics. Quasi-experimental research design was adopted. The sample size purposively selected consisted of 137 students from four schools in Education District II and IV, Lagos State, Nigeria. Two hypotheses were raised and tested at 0.05 level of significance. The collected data were analyzed using t-test. The result of the analysis revealed that cooperative learning strategy enhanced the low ability students’ achievement in Mathematics. Also, cooperative learning strategy enhanced low learning abilities students in understanding mathematics irrespective of their gender. It is therefore, recommended that teachers should adopt the cooperative learning strategy to teach Mathematics. For teachers to be more conversant with the use of cooperative learning strategy, as well as other interactive methods of teaching mathematics, workshops and conferences should be organized for secondary schools on the use of different methods of teaching learners from different ability levels, especially cooperative learning strategy.

본 논문은 나이지리아 보코하람 소요사태를 다루는 과정에서 나이지리아 현 대통령 소령(rtd) 마하무두 부하리(mahamudu buhari)와 직계 전 대통령 굿럭 조나단(jonathan)의 역할을 분석하고자 한다. 나이지리아는 공정한 분쟁 분담이 없는 적이 없었다. 사실, 독립 후 10년 동안 어떤 나이지리아도 분쟁이 없었던 적이 없었다. 몇몇 쿠데타와 총파업 그리고 내전으로 나이지리아 사람들은 의견과 불신의 차이에서 비롯되는 가장 비참한 비극들 중 일부를 경험해야 했다. 나이지리아에서의 갈등이 지금처럼 필요한 관심을 받지 못했다는 얘기가 흥미롭다. 굿럭 조나단 지도부는 2015년 5월 취임한 무함마두 부하리 전 총리와 비교할 때 같은 노력과 협조를 받지 못했다. 본 논문은 두 나이지리아 지도자가 협력하는 것을 돕거나 방해하는 중요한 역할을 한다고 주장한다. 굿럭 조나단은 약하고 우유부단한 지도자로 인식되어 보코하람의 폭동을 효과적으로 다루지 못했다. 무하마두 부하리는 나이지리아 국민과 국제사회가 보코하람 반란을 타개할 큰 희망과 기대를 안고 취임했다.