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Abstract Atomic force microscope generally works by manipulating the absolute magnitude of the van der Waals force between tip and specimen. This force is, however, less sensitive to atom species than to tip-sample separations, making compositional identification difficult, even under multi-modal strategies or other atomic force microscopy variations. Here, we report the phenomenon of a light-modulated tip-sample van der Waals force whose magnitude is found to be material specific, which can be employed to discriminate heterogeneous compositions of materials. We thus establish a near-field microscopic method, named light-modulated van der Waals force microscopy. Experiments discriminating heterogeneous crystalline phases or compositions in typical materials demonstrate a high compositional resolving capability, represented by a 20 dB signal-to-noise ratio on a MoTe2 film under the excitation of a 633 nm laser of 1.2 mW, alongside a sub-10 nm lateral spatial resolution, smaller than the tip size of 20 nm. The simplicity of the light modulation mechanism, minute excitation light power, broadband excitation wavelength, and diversity of the applicable materials imply broad applications of this method on material characterization, particularly on two-dimensional materials that are promising candidates for next-generation chips.

How to improve students' problem-solving skills and creativity and adapt them to the new situation of the twenty-first century is a rather important educational objective at present, and is expected to be for a long time to come. Project-based learning (PBL) is considered to be an approach that can develop students' higher-order thinking skills, while peer assessment is a strategy that helps students to interact and reflect. To improve the quality of peer assessment in PBL and to further promote learning by using the feedback of peer assessment, this study proposes an online progressive peer assessment (OPPA)-based PBL approach using constructivism as the theoretical framework for instructional design. The aim of the proposed approach is to organise progressive peer-assessment activities for students as they complete the project, thereby promoting high-quality peer evaluations and continuous reflective improvement of the project. To test the effect of the OPPA-based PBL approach, a quasi-experiment was carried out in an educational game development course with 49 university students from two classes. Students in the experimental group used the OPPA-based PBL approach to develop their game projects, while students in the control group used the conventional PBL approach to develop their game projects. The findings show that the OPPA-based PBL approach significantly improved students' learning achievement, self-efficacy, collective efficacy, problem-solving, and creativity awareness, while also reducing their anxiety levels compared to the conventional PBL approach. The results of this study provide a reference for improving project-based learning, and further demonstrate the importance and validity of constructivist learning theory.

Abstract Strong light-matter interactions in two-dimensional transition metal dichalcogenides (TMDCs) with robust spin-valley degrees of freedom open up the prospect of valleytronic devices. A thorough understanding on the dynamics of the valley polarizations in the strong coupling regime is urgently required. Here, multiple polarized TMDCs-SPPs hybrid systems were constructed by combining monolayer WS2 flakes to linear, circular, and spiral Ag gratings, resulting in linear and circular polarized modulation on the coherent hybrid states, respectively. Particularly, valley polaritons can be tailored asymmetrically by chiral strong coupling regime. Furthermore, the dynamics of the polarized polaritons were directly analyzed by transient absorption (TA) measurement. Both of the linear and circular polarization difference in the TA spectra can be retained for a remarkable long time, leading to a polarized PL even at room temperature. More importantly, in the chiral strong coupled WS2-spiral Ag grating devices, the mechanism of the asymmetrical valley-polarized PL (p σ+ = 14.9% and p σ- = 10.8%) is proved by the opposite valley polarization dynamics in the circularly polarized TA spectra. The multiple polarization modulation in monolayer TMDCs-SPPs strong coupling devices could provide a viable route toward multiple polarization polaritonic devices.

Zhejiang Gongshang University is on the crucial turning from teaching-oriented university to the teaching-study-oriented university. How to deal properly with the relation between teaching and study researches is a pressing problem. This article offers several suggestions to deepen the teaching innovation based on the experiences of those famous home and domestic top universities, especially, Zhejiang University's education model called KAQ (Knowledge Ability and Quality).

Biology involves the understanding of life concepts and the exploration of life processes. Due to the complexity of life, the learning content of biology is often microscopic, abstract, and complex. In traditional teaching, The non-visualization of abstract concepts, rote memorization of knowledge and low classroom participation tend to make students feel dull and eventually lead to inefficient and low confidence in learning. Augmented reality (AR) superimposes 3D dynamic virtual information into the real world and visualizes abstract concepts to deepen students' understanding of concepts. In addition, AR supports virtual-real interaction and instant feedback, which helps to stimulate learning interest and reinforce the learning effect. Therefore, the application of AR can solve the problems of traditional biology teaching. This study used a quasi-experimental approach to explore the potential of AR in teaching biology. A total of 81 third grade students were recruited for the study. The experimental group (40 students) was taught with AR, while the control group (41 students) was taught with traditional instruction. The study found that AR instruction significantly increased students' flow experiences and motivation to learn and reduced their cognitive load. However, there were no significant differences in self-efficacy and academic performance between the two groups. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of health education based on integrative therapy of Chinese and Western medicine for type 2 diabetes mellitus (T2DM) from the aspects of knowledge, attitude and practice (KAP), health-related quality of life (HRQoL), body mass index (BMI) and glucose control. Methods: Patients were individually randomized into intervention group (receiving integrative education, n=120) and control group (receiving usual education, n=120). The primary outcome was the changes in glycosylated hemoglobin A1c (HbA1c) levels after 3, 6, 9 and 12 months from baseline. Hierarchical linear models (HLMs) were used to assess within-group changes in outcomes over time and between-group differences in patterns of change. Secondary outcomes were KAP scores, HRQoL scores and BMI after 6 and 12 months, paired-sample t test was used to assess within-group changes in outcomes in 6 and 12 months, independent-sample t test was used to assess between-group differences in patterns of change. Results: HbA1c decreased statistically from baseline to 3 months, from 3 to 6 months, from 6 to 9 months and from 9 to 12 months in the intervention group (all P<0.01); and decreased significantly from baseline to 3 months, and from 3 to 6 months in the control group P<0.01). There was a significant between-group difference from baseline to 3 months ( P=0.044), from 6 to 9 months ( P<0.01) and from 9 to 12 months ( P<0.01). Significant improvements in the intervention group along with significant between-group differences were found in KAP and HRQoL scores respectively (all P<0.05). The number in the intervention group of normal weight increased from 56 at baseline to 81 (6 months), 94 (12 months), the number in the control group were 63 (baseline), 69 (6 months), 70 (12 months), the χ of hierarchical analysis of BMI were 6.93 ( P=0.075), 10.31 ( P=0.016), 15.53 ( P<0.01), respectively. Conclusion: Health education based on integrative therapy of Chinese and Western medicine is beneficial to the control of T2DM and should be recommended for T2DM. [ABSTRACT FROM AUTHOR]

A new method of terahertz (THz) imaging based on the mean absorption is proposed. Terahertz radiation is an electromagnetic radiation in the range between millimeter waves and far infrared. THz pulse imaging emerges as a novel tool in many fields because of its low energy and non-ionizing character, such as material, chemical, biological medicine and food safety. A character of THz imaging technique is it can get large amount of information. How to extract the useful parameter from the large amount of information and reconstruct sample's image is a key technology in THz imaging. Some efforts have been done for advanced visualization methods to extract the information of interest from the raw data. Both time domain and frequency domain visualization methods can be applied to extract information on the physical properties of samples from THz imaging raw data. The process of extracting useful parameter from raw data of the new method based on the mean absorption was given in this article. This method relates to the sample absorption and thickness, it delivers good signal to noise ratio in the images, and the dispersion effects are cancelled. A paper with a "THz" shape hole was taken as the sample to do the experiment. Traditional THz amplitude imaging methods in time domain and frequency domain are used to achieve the sample's image, such as relative reduction of pulse maximum imaging method, relative power loss imaging method, and relative power loss at specific frequency imaging method. The sample's information that reflected by these methods and the characteristics of these methods are discussed. The method base on the mean absorption within a certain frequency is also used to reconstruct sample's image. The experimental results show that this new method can well reflect the true information of the sample. And it can achieve a clearer image than the other traditional THz amplitude imaging methods. All the experimental results and theoretical analyses indicate that the method base on the mean absorption within a certain frequency can reflects sample absorb and thickness information, it can achieve good signal to noise ratio in the images. Because the absorption is mean absorption within in a certain frequency, so the method proposed in this article is especially suitable for samples with simple structure. And this new method can be a useful added tool for the other traditional THz amplitude imaging methods.

A novel sample offline positioning system was developed for hard X-ray micro-focus beamline (BL15U1) at Shanghai Synchrotron Radiation Facility (SSRF). The positioning system is composed of three parts: off-line sample microscope system, on-line sample experiment system, and high-precision positioning sample holder. It makes a potent combination of the on-line X-ray fluorescence imaging and the off-line microscopic examination in three steps: compiling of control program, positioning of sample holder, and conversion of the two coordinates. It's the first time in the domestic synchrotron radiation facilities to achieve sample offline positioning in micron scale. The system helps the researchers find the object of study in micro zone quickly and accurately, when they study the micro characteristics of materials using synchrotron radiation micro X-ray beam. The gold mesh was used as an object of study. By comparing the differences of coordinates of gold mesh nodes between pictures from offline microscope and pictures from X-ray fluorescence mapping, the accuracy of the offline positioning system was verified. The results showed that the average errors of X-axis and Z-axis were 1.3 and 2.5 microm respectively, using the positioning method. It was demonstrated that the sample offline positioning system not only is suitable for these applications with high efficiency, but also supply hard X-ray micro-focus beamline with the technical preparations of sample automatic focusing method.

Adenosine, thymidine, guanosine, cytidine and uridine form the building blocks of ribose nucleic acid (RNA) and deoxyribose nucleic acid (DNA). Nucleosides and their derivants are all have biological activities. Some of them can be used as medicine directly or as materials to synthesize other medicines. It is meaningful to detect the component and content in nucleosides mixtures. In the present paper, components and contents of the mixtures of adenosine, thymidine, guanosine, cytidine and uridine were analyzed. THz absorption spectra of pure nucleosides were set as standard spectra. The mixture's absorption spectra were analyzed by linear regression with non-negative constraint to identify the components and their relative content in the mixtures. The experimental and analyzing results show that it is simple and effective to get the components and their relative percentage in the mixtures by terahertz time domain spectroscopy with a relative error less than 10%. Component which is absent could be excluded exactly by this method, and the error sources were also analyzed. All the experiments and analysis confirms that this method is of no damage or contamination to the sample. This means that it will be a simple, effective and new method in biochemical materials analysis, which extends the application field of THz-TDS.