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Particulate lead (Pb) is a primary air pollutant that affects society because of its health impacts. This study investigates the source sectors of Pb associated with ambient fine particulate matter (PM

This study utilized unplugged computational thinking learning material named Robot City as the instructional material. The board game corresponds to structural programming, including sequential structure, conditional structure, repetitive structure, and the modeling concept of calling a procedure in programming languages. According to the different task assignment methods, the aim of playing the board game is to help instruct the seventh-grade students in computational thinking, and to explore its impact on students’ learning achievements of computational thinking and the behavioral patterns of computational participation. The results revealed that the learning achievements of the students who worked together to solve the clear-ended task objectives were significantly higher than those of the students who cooperated within their groups to solve the open-ended competitive tasks. When the target task is not gained in advance, the students had to compete with other groups and vie for their target task, resulting in students’ logical thinking constantly changing and being interrupted. From the behavioral pattern analysis, it was found that the students continued to discuss the problems during the game. The pattern of collaborative analysis was iterative itself, indicating that the board game can deepen students’ interaction and enhance their higher level thinking. The results also showed that collaborative creation was observed (RO) by others, proving that the game can increase students’ desire to learn, and thus improve their learning achievement.

Science and technology are driving people?s life changes, including education and the environment. Many scholars have attempted to import technology into the classroom to help students learn in different subjects. However, students often need assistance with unfamiliar learning approaches and learning environments. This study proposed a non-immersive virtual reality (VR) guidance system combined with a two-tier strategy to help students learn geology knowledge. Two groups of students used different learning approaches: the experimental group students were guided by the two-tier test VR guidance system, and the control group students learned with the conventional VR guidance system. According to the experimental result, the two-tier test VR guidance system not only improved the students? learning achievement in natural science, but also enhanced their learning motivation. In addition, according to the sequential results, we found that VR learning materials or environmental resources can help students answer questions and solve problems more effectively.

The chemical composition of fine particulate matters (PM2.5), the size distribution and number concentration of aerosol particles (NCN) and the number concentration of cloud condensation nuclei (NCCN) were measured at the northern tip of Taiwan Island during a campaign from April 2017 to March 2018. The parameters of aerosol hygroscopicity (i.e. activation ratio, activation diameter and kappa) were retrieved from the measurements. Significant variations were found in the hygroscopicity of aerosols, which were suggested be subject to various pollution sources, including aged air pollutants originating in the eastern/northern China and transported on the Asian continental outflows, fresh particles emitted from local sources and distributed by land-sea breeze circulations as well as produced by new particle formation (NPF) processes. Cluster analysis was applied to the backward trajectories of air masses to investigate their respective source regions. The results showed that the aerosols associated with Asian continental outflows were characterized with higher kappa values, whereas higher NCCN and NCN with lower kappa values were found for aerosols in local air masses. The distinct features in hygroscopicity were consistent with the characteristics in the chemical composition of PM2.5. Moreover, this study revealed that the nucleation mode particles from NPF could have participated in the enhancement of CCN activity, most likely by coagulating with sub-CCN particles, although the freshly produced particles were not favored for CCN activation due to their smaller sizes. Thus, the results of this study suggested that the NPF coupling with coagulation processes can significantly increase the NCCN in atmosphere.

Targeting thymidylate kinase (TMPK) that catalyzes the phosphotransfer reaction for formation of dTDP from dTMP is a new strategy for anticancer treatment. This study is to understand the inhibitory mechanism of a previously identified human TMPK (hTMPK) inhibitor YMU1 (1a) by molecular docking, isothermal titration calorimetry, and photoaffinity labeling. The molecular dynamics simulation suggests that 1a prefers binding at the catalytic site of hTMPK, whereas the hTMPK inhibitors that bear pyridino[d]isothiazolone or benzo[d]isothiazolone core structure in lieu of the dimethylpyridine-fused isothiazolone moiety in 1a can have access to both the ATP-binding and catalytic sites. The binding sites of hTMPK inhibitors were validated by photoaffinity labeling and mass spectrometric studies. Taking together, 1a and its analogues stabilize the conformation of ligand-induced degradation (LID) region of hTMPK and block the catalytic site or ATP-binding site, thus attenuating the ATP binding-induced closed conformation that is required for phosphorylation of dTMP.

Template-free, one step formation of Cu(In, Ga)Se 2 (CIGS) nanotip arrays (NTRs) to enhance device efficiency were discussed. Through Ar + ion milling process, the CIGS NTRs could be formed directly on the CIGS layer. The angles and lengths of CIGS NTRs could be precisely controlled by incident angle of Ar + beam and milling time, respectively. Mechanisms were proposed to be a self-masking effect by Cu segregation formed at early stage confirmed by Transmission Electron Microscopy, Grazing Incidence X-ray Diffraction, Energy Dispersive Spectroscopy, and Auger Electron Spectroscopy. Measurements of devices on various KCN washing time and thickness of CdS buffer layer were reported to achieve the highest efficiency of CIGS NTRs devices. This approach provides one-step fast process without templates, easy integration with in-line sputtering process, and no post-selenizatoin process for the formation of CIGS nanostructure, which can stimulate great attention not only in academic investigations but also in industrial side for practical applications.

We present systematic works in characterization of CIGS nanotip arrays (CIGS NTRs). CIGS NTRs are obtained by a one-step ion-milling process by a direct-sputtering process of CIGS thin films (CIGS TF) without a postselenization process. At the surface of CIGS NTRs, a region extending to 100 nm in depth with a lower copper concentration compared to that of CIGS TF has been discovered. After KCN washing, removal of secondary phases can be achieved and a layer with abundant copper vacancy (V(Cu)) was left. Such compositional changes can be a benefit for a CIGS solar cell by promoting formation of Cd-occupied Cu sites (Cd(Cu)) at the CdS/CIGS interface and creates a type-inversion layer to enhance interface passivation and carrier extraction. The raised V(Cu) concentration and enhanced Cd diffusion in CIGS NTRs have been verified by energy dispersive spectrometry. Strengthened adhesion of Al:ZnO (AZO) thin film on CIGS NTRs capped with CdS has also been observed in SEM images and can explain the suppressed series resistance of the device with CIGS NTRs. Those improvements in electrical characteristics are the main factors for efficiency enhancement rather than antireflection.

In strongly correlated oxides, heterostructures provide a powerful route to manipulate the charge, spin, orbital, and lattice degrees of freedom to create distinctive functionalities. In this work, we have achieved atomically precise interface control in YBa2Cu3O7−x/La0.7Ca0.3MnO3 (YBCO/LCMO) heterostructures and find a hidden effective doping. This mechanism is responsible for higher Tc in the sample with the MnO2-terminated interface than in that with the La0.7Ca0.3O-terminated interface. The MnO2-terminated sample also shows a larger magnetic moment of Mn together with a lower valence state. For more than a decade, the control of Tc in these heterostructures prior to this work has been solely via the variation of YBCO or LCMO thickness. This work hints at an alternative way of exploiting and exploring the interactions between superconductivity and magnetism in this system.

Objective—To evaluate the effects of butorphanol and carprofen, alone and in combination, on the minimal alveolar concentration (MAC) of isoflurane in dogs. Design—Randomized complete-block crossover study. Animals—6 healthy adult dogs. Procedure—Minimal alveolar concentration of isoflurane was determined following administration of carprofen alone, butorphanol alone, carprofen and butorphanol, and neither drug (control). Anesthesia was induced with isoflurane in oxygen, and MAC was determined by use of a tail clamp method. Three hours prior to induction of anesthesia, dogs were fed a small amount of canned food without any drugs (control) or with carprofen (2.2 mg/kg of body weight [1 mg/lb]). Following initial determination of MAC, butorphanol (0.4 mg/kg [0.18 mg/lb], IV) was administered, and MAC was determined again. Heart rate, respiratory rate, indirect arterial blood pressure, endtidal partial pressure of CO2, and saturation of hemoglobin with oxygen were recorded at the time MAC was determined. Results—Mean ± SD MAC of isoflurane following administration of butorphanol alone (1.03 ± 0.22%) or carprofen and butorphanol (0.90 ± 0.21%) were significantly less than the control MAC (1.28 ± 0.14%), but MAC after administration of carprofen alone (1.20 ± 0.13%) was not significantly different from the control value. The effects of carprofen and butorphanol on the MAC of isoflurane were additive. There were not any significant differences among treatments in regard to cardiorespiratory data. Conclusion and Clinical Relevance—Results suggest that administration of butorphanol alone or in combination with carprofen significantly reduces the MAC of isoflurane in dogs; however, the effects of butorphanol and carprofen are additive, not synergistic. (J Am Vet Med Assoc 2000;217:1025–1028)

In this paper, we demonstrated direct formation of large area Cu(In,Ga)Se2 nanotip arrays (CIGS NTRs) by using one step Ar+ milling process without template.

In this paper, we demonstrated direct formation of large area Cu(In,Ga)Se(2) nanotip arrays (CIGS NTRs) by using one step Ar(+) milling process without template. By controlling milling time and incident angles, the length of CIGS NTRs with adjustable tilting orientations can be precisely controlled. Formation criteria of these CIGS NTRs have been discussed in terms of surface curvature, multiple components, and crystal quality, resulting in a highly anisotropic milling effect. The CIGS NTRs have very low reflectance0.1% at incident wavelengths between 300 to 1200 nm. Open circuit voltage and short circuit current of CIGS NTRs solar cell were measured to be ∼390 mV and ∼22.56 mA/cm(2), yielding the filling factor and the efficiency of 59 and 5.2%, respectively. In contrast to CIGS thin film solar cell with efficiency of 3.2%, the nanostructured CIGS NTRs can have efficiency enhancement of ∼160% due to the higher light absorption ability because of the nanostructure. The merits of current approach include the latest way via template-free direct creating process of nanostructured CIGS NTRs with controllable dimensionality and large scale production without postselenization process.

Magnetoelectrics and multiferroics present exciting opportunities for electric-field control of magnetism. However, there are few room-temperature ferromagnetic-ferroelectrics. Among the various types of multiferroics the bismuth ferrite system has received much attention primarily because both the ferroelectric and the antiferromagnetic orders are quite robust at room temperature. Here we demonstrate the emergence of an enhanced spontaneous magnetization in a strain-driven rhombohedral and super-tetragonal mixed phase of BiFeO₃. Using X-ray magnetic circular dichroism-based photoemission electron microscopy coupled with macroscopic magnetic measurements, we find that the spontaneous magnetization of the rhombohedral phase is significantly enhanced above the canted antiferromagnetic moment in the bulk phase, as a consequence of a piezomagnetic coupling to the adjacent tetragonal-like phase and the epitaxial constraint. Reversible electric-field control and manipulation of this magnetic moment at room temperature is also shown.