Flipping the classoom in teaching Chinese as a foreign language

Through an in-depth analysis of quantitative and qualitative data, this article offers a case study of the advantages and challenges in the application of the flipped learning approach in the instruction of Chinese as a foreign language at the beginning level. Data were collected from two first-year Chinese classes (one in traditional and the other in flipped format) to investigate whether there were statistically significant differences in learning outcomes and students’ levels of satisfaction between the two classes. Final exam and oral test scores showed that students in the flipped class performed better in speaking, since more time was devoted to meaningful interactions in class. As indicated in the results of the end-of-the-semester questionnaire, these students also gave higher average ratings on three aspects of their learning experience: level of required self-directedness, amount of practice in class, and stimulation of interest in the subject

Polymorphisms of CYP1A1 I462V and GSTM1 genotypes and lung cancer susceptibility in Mongolian

Aim: To study the genotype of cytochrome P450 1A1(CYP1A1) I462V and glutathions S-transferase M1( GSTM1) and the relationship of the genetic polymorphism of them with the susceptibility of lung cancer in Mongolia of China. 

Methods: Allele-specific PCR and a multiplex PCR were employed to identify the genotypes of I462V of CYP1A1 and GSTM1 in a case-control study of 210 lung cancer patients with bronchoscopy diagnosis and 210 matched controls free of malignancy.

Results: The frequencies of the variant CYP1A1(Val/Val) genotypes and GSTM1(-) in lung cancer groups were higher than that in control groups (15.24% vs 7.4% and 56.67% vs 40.95% ). The individuals who carried with CYP1A1(Val/Val) or GSTM1(-) genotype had a significantly higher risk of lung cancer, the OR is 2.56 and 1.89 respectively. Stratified histologically the relative risk increased to 2.6 - fold when the patients carried with two valine alleles than the ones carried one valine allele in cases of SCC. GSTM1(-) genotype is the risk factor of SCC (OR=2.39) and AC(OR=2.16). The presence of at least one Val allele of CYP1A1 and GSTM1(-), the risk of lung cancer was increased, the OR was 4.15 for one Val allele and GSTM1(-) and 2.67 for two Val alleles and GSTM1 Considering ages and smoking status, the risk of lung cancer increased when the age less than 50 who carried with CYP1A1 valine (one or two) alleles or the age during the 51 to 65 who carried with GSTM1(-) genotype. The light smokers with CYP1A1 valine alleles and GSTM1(-) have a high risk for lung cancer. No association was found between the light and heavy drinkers with the susceptibility of lung cancer and the genetic polymorphisms of CYP1A1 I462V and GSTM1(-). 

Conclusion: The valine allele of CYP1A1 was the risk factors of lung cancer especially for SCC and GSTM1(-) also was the risk factor of lung cancer and especially for SCC and AC of Mongolian, China. Light smoking has a influence each other with genotype of CYP1A1 I462V and GSTM1(-) and susceptibility of lung cancer. No relationship was found between the susceptibility of lung cancer and drinkers with genetic polymorphisms of CYP1A1 I462V and GSTM1(-). The influence of genotypes on the susceptibility of lung cancer may depend on the ages. There may be a synergetic interaction between CYP1A1 valine allele and GSTM1(-) genotypes on the elevated susceptibility of lung cancer. So do those genotypes with light smokers. Key words polymorphism; genotype; lung cancer; cytochrome P450；glutathione S-transferase Abbreviations: SCC, squamous cell carcinoma; AC, adenocarcinoma; SCLC, small cell lung cancer; LCLC, large cell lung cance

External modulation method for generating accurate linear optical FMCW

Frequency modulation continuous wave (FMCW) lasers are key components in modern optical imaging. However, current intracavity modulation lasers do not exhibit low-frequency jitter rate and high linearity due to the inherent relaxation oscillations. Although this may be compensated in a direct modulation laser diode using an optoelectronic feedback loop, the available sweep speed is moderately small. In this letter, a special external modulation method is developed to improve the performance of FMCW. Since only the first sideband optical field is used during the entire generation process, phase noise is kept to a minimum and is also independent of the sweep speed. We demonstrate that the linearity and jitter rates do not deteriorate appreciably when the sweep speed is changed over three orders of magnitude, even up to the highest sweep speed of 2.5 GHz/ μs

Force measurement on coupled flapping flags in uniform flow

An experimental study on the coupled flapping of two identical flags arranged in parallel, tandem, and staggered positions in uniform flow was conducted in a wind tunnel. The dynamic characteristics of each flag were measured using an in-house designed balance and the flapping modes were analyzed through a high-speed video recording technique and a "Spatio-Temporal Evolution" software. For the side-by-side arrangement, the dependences of the kinematic and dynamic parameters on the flow speed and on the mutual distance were observed. The results indicated that the coupling motion and dynamics of two parallel flags in uniform flow were mainly affected by their mutual position. Significant drag reductions were observed when the flags flapped in the in-phase mode for a relatively small separation. For two flags in tandem arrangement, both the upstream and downstream flags experienced a drag reduction compared to the scenario of a single flag in the same flow. Especially, for relatively large separation the upstream flag had a smaller drag coefficient than that of the downstream one. For very small separation, the drag coefficient of the upstream flag was larger than that of the downstream one. Finally, for two flags arranged in a staggered configuration, an anomalous drag distribution was found. This work provides valuable experimental data and casts insight into the coupling mechanism of multiple flexible structures in an air flow