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.

The US-Korea FTA, in its initial days of negotiation saw severe protests by public and political turmoil in Seoul. After crossing several procedural hoops and political hurdles in parliaments of both countries it became effective in 2012, though it was signed in 2007. At that time, it was considered by the US a ‘model agreement’ which could open opportunities for the US exporters in the Korean market. However, only couple of years later, the Trump administration called this FTA a ‘horrible’ deal that has ‘destroyed’ America. Thus, the Trump administration wanted to scrap the FTA. After considering the political implications of such action, the US government decided to re-negotiate the FTA so that the US concerns are addressed. In a short period of negotiation, both sides agreed to the revised terms of the FTA which has become effective from January 1, 2019. This paper analyses outcomes of the revised US-Korea FTA, 2018 from the US perspective and evaluate if all concerns of the US are met.

The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interferometry (VLBI) facilities all over the globe start to implement compatible optics systems. Simultaneous dual/multi-frequency VLBI observations at mm wavelengths with international baselines are thus possible. In this paper, we present the results from the first successful simultaneous 22/43 GHz dualfrequency observation with KaVA(KVN and VERA array), including images and astrometric results. Our analysis shows that the newly implemented simultaneous receiving system has brought a significant extension of the coherence time of the 43 GHz visibility phases along the international baselines. The astrometric results obtained with KaVA are consistent with those obtained with the independent analysis of the KVN data. Our results thus confirm the good performance of the simultaneous receiving systems for the non-KVN stations. Future simultaneous observations with more global stations bring even higher sensitivity and micro-arcsecond level astrometric measurements of the targets.

This study is aimed at analyzing the research trends on the internationalization policy of Chinese higher education. Descriptively, it would respectively research the policy change and political reasons thereof, the change of internationalization policies of Chinese university, and the change of the researches on the topic, and uncover the relation between the policies and researches by retrieving the relevant research journals from the academic sources including CNKI, China’s largest academic article database. In order to collect as many articles as possible concerning the research topic, the keyword search in the database was adopted with words expressing the meaning of the topic. In conclusion, internationalization policy of higher education has become an important issue in higher education in China. With the change of the policies, researches focusing on internationalization policy of higher education have increased a lot and have made a new research area in China. After analyzing the research trends, it could be believed that the researches in this area would continue to increase in the future and scholars from the higher education field should pay attention to it.

Culture teaching is little included in the practice of teaching Chinese to Speakers of Other Languages, which has lasted for a long time. Taking Chinese teaching in Shaanxi Normal University of China (a splendid university famous for Chinese teaching to foreigners) for example, the explanation and description of basic Chinese language uses is the most important objective in the teaching of reading, speaking, listening and writing, whereas culture teaching is very limited. This results in low motivation for students to learn Chinese, who are then unable to adapt into the local community and culture, and therefore cannot increase their Chinese standards. Based on the theory of culture intelligence firstly put forth by Peterson, one would be influenced by culture intelligence if he studies, learns, and works in a non-native language environment, and culture intelligence is closely related to culture teaching. Students with high culture intelligence could perform better than those without. This thesis is aiming at discussing the present situation of China’s Chinese teaching to foreigners and giving suggestions based on Culture Intelligence Theory. Firstly, it will discuss the concept and values of culture intelligence. After that, it will discuss the present condition of domestic Teaching Chinese as a Foreign Language and the lack of culture elements therein from the perspective of teacher, teaching and students. Finally, it will utilize Culture Intelligence Theory to make suggestions in related areas and explore students' Culture Intelligence cultivation standard as well.

Endoplasmic reticulum (ER) stress is well known as a suppressor in osteoblast differentiation and activating transcription factor 3 (ATF3) could be induced by a various extracellular signals including cytokines, hormones, DNA damage. Up to date, although the role of ATF3 have been studied, the function of ATF3 in osteoblast differentiation is still not clear yet. Our study showed that expression level of ATF3 could be incresed by tunicamycin which is ER stress inducer in preosteoblasts. BMPs, which are secreted by osteoblasts, can be important regulators in osteogenic differentiation. The stress-responsive transcription factor ATF3 is a negative regulator of osteoblast differentiation in MC3T3-E1 cells. In this study, we verified that BMP2-stimulated osteoblast differentiation could be inhibited by over-expressed ATF3 through regulating alkaline phosphatase (ALP) expression and activation.