36 research outputs found

    Anisotropic linear and nonlinear charge-spin conversion in topological semimetal SrIrO3

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    Over the past decade, utilizing spin currents in the linear response of electric field to manipulate magnetization states via spin-orbit torques (SOTs) is one of the core concepts for realizing a multitude of spintronic devices. Besides the linear regime, recently, nonlinear charge-spin conversion under the square of electric field has been recognized in a wide variety of materials with nontrivial spin textures, opening an emerging field of nonlinear spintronics. Here, we report the investigation of both linear and nonlinear charge-spin conversion in one single topological semimetal SrIrO3(110) thin film that hosts strong spin-orbit coupling and nontrivial spin textures in the momentum space. In the nonlinear regime, the observation of crystalline direction dependent response indicates the presence of anisotropic surface states induced spin-momentum locking near the Fermi level. Such anisotropic spin textures also give rise to spin currents in the linear response regime, which mainly contributes to the fieldlike SOT component. Our work demonstrates the power of combination of linear and nonlinear approaches in understanding and utilizing charge-spin conversion in topological materials.Comment: 18 pages, 5 figure

    The impact of guardian's usage of the Internet on children's cognitive skills

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    Abstract In the digital age, the internet has become an essential source of information gathering and maintains a network of social contact. In this paper, we use microdata from the China Family Panel StudiesĀ to examine the effects of guardian's internet use on teenager's cognitive skills. Using mobile internet users and base station density as instruments, we found that guardian's internet use had a significant impact on teenager's cognitive abilities as measured by math and verbal tests. Heterogeneity analysis shows that the impact is more substantial for guardians in rural areas and lessā€educated guardians. Further exploration of the mechanism shows that internet usage affects cognitive skills through monetary investment, time investment, and parental environment. The result suggests that promoting internet usage for less educated families in rural areas can potentially improve children's academic performance and decrease inequality across regions and generations

    Formation Mechanism of Regional Stigma ā€”ā€” Impact of Major Public Health Emergencies

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    The COVID-19 was taken as an example to study the mechanism of regional stigmatization ā€”ā€” the impact of major public health emergencies. By collecting the data of Sina Weibo, a social media platform, and using the rooted theory method, the negative comments on the major public health emergency related to the epidemic situation of new crown virus pneumonia were coded. The model of the impact of major public health emergencies on regional stigma is constructed, and the theoretical saturation test is carried out. It is found that the topic events of major public health emergencies will produce regional stigma through the attribution of responsibility and negative emotions of Internet users. In order to reduce or eliminate the negative effects of regional stigma, this study suggests that the strategy and suggestion of de-stigmatization should be adopted for different subjects and different levels

    A Smart Grid AMI Intrusion Detection Strategy Based on Extreme Learning Machine

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    The smart grid is vulnerable to network attacks, thus requiring a high detection rate and fast detection speed for intrusion detection systems. With a fast training speed and a strong model generalization ability, the extreme learning machine (ELM) perfectly meets the needs of intrusion detection of the smart grid. In this paper, the ELM is applied to the field of smart grid intrusion detection. Aiming at the problem that the randomness of input weights and hidden layer bias in the ELM cannot guarantee the optimal performance of the ELM intrusion detection model, a genetic algorithm (GA)-ELM algorithm based on a genetic algorithm (GA) is proposed. GA is used to optimize the input weight and hidden layer bias of the ELM. Firstly, the input weight and hidden layer bias of the ELM are mapped to the chromosome vector of a GA, and the test error of the ELM model is set as the fitness function of the GA. Then, the parameters of the ELM intrusion detection model are optimized by genetic operation; the input weight and bias, corresponding to the minimum test error, are selected to improve the performance of the ELM model. Compared with the ELM and online sequential extreme learning machine (OS-ELM), the GA-ELM effectively improves the accuracy, detection rate and precision of intrusion detection and reduces the false positive rate and missing report rate

    Tourist emotion-learning nexus: A case of Sertar, China

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    This paper discusses the nexus between tourists\u27 emotions and learning at a religious site, Sertar, in China. Based on Kolb\u27s learning cycle, this qualitative study proposes a conceptual framework regarding the connections between tourist attraction stimuli, tourist emotions, and tourist learning outcomes. The findings reveal that tourists have experienced mixed and intense emotions and obtained valuable learning outcomes, including changes in attitudes toward life, changes in attitudes toward others, changes in values and beliefs, and cross-cultural awareness. Tourist emotions play a vital role in triggering reflection and further generating transformative learning. Negative emotions could also result in positive learning and future behavior intentions. Practical implications are offered to destination marketers to design experience products and individuals seeking learning and eudaimonia

    From Hyperbranched Polymer to Nanoscale CMP (NCMP): Improved Microscopic Porosity, Enhanced Light Harvesting, and Enabled Solution Processing into White-Emitting Dye@NCMP Films

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    A two-step polymerization combining miniemulsion and solvothermal techniques was applied to synthesize tetraphenylethene-based nanoscale conjugated microporous polymers (TPE-NCMP), which simultaneously possessed a large surface area (1214 m<sup>2</sup>/g) and a high aggregation-induced florescence quantum yield (58%). Immobilization of Nile Red within micropores of TPE-NCMPs constructed a light-harvesting composite with characteristics of intense photons acquisition and efficient energy migration. Homogenous NCMP-based films were fabricated by blending the dye-doped TPE-NCMPs with PVA. The fluorescence emission could be flexibly tuned by varying the dosage of dyes over the whole visible spectrum including a pure white light

    Maternal serum disintegrin and metalloprotease protein-12 in early pregnancy as a potential marker of adverse pregnancy outcomes.

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    The aim of this study was to determine whether the concentration of disintegrin and metalloprotease protein12 (ADAM12) in first trimester maternal serum can be used as a marker for first-trimester complete spontaneous abortions, missed abortions, ectopic pregnancies and hydatidiform moles.The maternal serum concentrations of ADAM12 were measured in the range of 5-9+6 weeks of gestation using an automated AutoDelfia immunoassay platform in 9 cases of complete spontaneous abortion, 27 cases of missed abortions, 56 cases of ectopic pregnancies, 12 cases of hydatidiform moles, and 100 controls. Logistic regression analysis was used to determine significant factors for predicting adverse pregnancy outcomes in early pregnancy. Screening performance was assessed using receiver operating characteristic curves.Two hundred and four women were enrolled in the study. In the control group, the level of ADAM12 increased with gestational age. The median ADAM12 levels in the spontaneous abortion (0.430 MoM), ectopic pregnancy (0.460 MoM) and hydatidiform mole (0.037 MoM) groups were lower than that in the control group, while the median ADAM12 level in the missed abortion group (1.062 MoM) was not significant from the controls (1.002 MoM). Logistic regression analysis demonstrated that the level of ADAM12 in maternal serum facilitated the detection of ectopic pregnancies (OR = 0.909; 95% CI = 0.841 āˆ¼ 0.982) and complete spontaneous abortion (OR = 0.863; 95% CI = 0.787 āˆ¼ 0.946).In complete spontaneous abortion and ectopic pregnancy, ADAM12 maintained at low levels in early pregnancies, and there were significant differences compared to normal pregnancies. ADAM12 is a promising marker for the diagnosis of complete spontaneous abortion and ectopic pregnancy in symptomatic women, and under certain conditions, ADAM12 can diagnose ectopic pregnancy and spontaneous abortion before an ultrasonographic detection of the conditions

    Maternal serum disintegrin and metalloprotease protein-12 in early pregnancy as a potential marker of adverse pregnancy outcomes.

    No full text
    The aim of this study was to determine whether the concentration of disintegrin and metalloprotease protein12 (ADAM12) in first trimester maternal serum can be used as a marker for first-trimester complete spontaneous abortions, missed abortions, ectopic pregnancies and hydatidiform moles.The maternal serum concentrations of ADAM12 were measured in the range of 5-9+6 weeks of gestation using an automated AutoDelfia immunoassay platform in 9 cases of complete spontaneous abortion, 27 cases of missed abortions, 56 cases of ectopic pregnancies, 12 cases of hydatidiform moles, and 100 controls. Logistic regression analysis was used to determine significant factors for predicting adverse pregnancy outcomes in early pregnancy. Screening performance was assessed using receiver operating characteristic curves.Two hundred and four women were enrolled in the study. In the control group, the level of ADAM12 increased with gestational age. The median ADAM12 levels in the spontaneous abortion (0.430 MoM), ectopic pregnancy (0.460 MoM) and hydatidiform mole (0.037 MoM) groups were lower than that in the control group, while the median ADAM12 level in the missed abortion group (1.062 MoM) was not significant from the controls (1.002 MoM). Logistic regression analysis demonstrated that the level of ADAM12 in maternal serum facilitated the detection of ectopic pregnancies (OR = 0.909; 95% CI = 0.841 āˆ¼ 0.982) and complete spontaneous abortion (OR = 0.863; 95% CI = 0.787 āˆ¼ 0.946).In complete spontaneous abortion and ectopic pregnancy, ADAM12 maintained at low levels in early pregnancies, and there were significant differences compared to normal pregnancies. ADAM12 is a promising marker for the diagnosis of complete spontaneous abortion and ectopic pregnancy in symptomatic women, and under certain conditions, ADAM12 can diagnose ectopic pregnancy and spontaneous abortion before an ultrasonographic detection of the conditions

    A targeting method for robot-assisted percutaneous needle placement under fluoroscopy guidance

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    Minimally invasive procedures are rapidly growing in popularity thanks to advancements in medical robots, visual navigation and space registration techniques. This paper presents a precise and efficient targeting method for robot-assisted percutaneous needle placement under C-arm fluoroscopy. In this method, a special end-effector was constructed to perform fluoroscopy calibration and robot to image-space registration simultaneously. In addition, formulations were given to compute the movement of robot targeting and evaluate targeting accuracy using only one X-ray image. With these techniques, radiation exposure and operation time were reduced significantly compared to other commonly used methods. A pre-clinical experiment showed that the maximum angle error was 0.94Ā° and the maximum position error of a target located 80mm below the end-effector was 1.31mm. And evaluation of the system in a robot-assisted pedicle screws placement surgery has justified the accuracy and reliability of proposed method in clinical applications
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