Miniaturized and high‐power‐density 3D electronic devices pose new challenges on thermal management. Indeed, prompt heat dissipation in electrically insulating packaging is currently limited by the thermal conductivity achieved by thermal interface materials (TIMs) and by their capability to direct the heat toward heat sinks. Here, high thermal conductivity boron nitride (BN)‐based composites that are able to conduct heat intentionally toward specific areas by locally orienting magnetically functionalized BN microplatelets are created using magnetically assisted slip casting. The obtained thermal conductivity along the direction of alignment is unusually high, up to 12.1 W m−1 K−1, thanks to the high concentration of 62.6 vol% of BN in the composite, the low concentration in polymeric binder, and the high degree of alignment. The BN composites have a low density of 1.3 g cm−3, a high stiffness of 442.3 MPa, and are electrically insulating. Uniquely, the approach is demonstrated with proof‐of‐concept composites having locally graded orientations of BN microplatelets to direct the heat away from two vertically stacked heat sources. Rationally designing the microstructure of TIMs to direct heat strategically provides a promising solution for efficient thermal management in 3D integrated electronics.
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The refractive index of blood is a key biophysical parameter, which can reflect the physiological state. We measured the refractive index of whole blood and other components, such as serum, plasma, and hemoglobin, based on internal reflection by using a homemade apparatus in the spectral range of 400 to 750 nm. In addition to the hemoglobin solution, which has a Soret band about 420 nm and two Q-bands between 500 and 600 nm, the measurements of other samples are the normal dispersion curve. The results are approximated by the Cauchy equation and Sellmeier equation, and the correlation coefficients are more than 0.997.
(1) The objective of this study was to assess the risk perceptions, attitudes, knowledge, and behaviors related to typhoon among rural residents in Zhejiang province of China. A cross-sectional study was conducted among rural residents in Zhejiang province, China. Information was collected from 659 participants using a structured questionnaire. Univariate analysis and multivariable analysis were used to analyze the data. Participants were most concerned about property damage, followed by their health and life. Television, short message service (SMS), relatives and friends were the most common information sources. Most people had not been educated with disaster prevention measures. The complementary log–log (CLL) model showed that understanding typhoon warning signal, preparation time, risk perception of health damage and life threat, and fears of typhoon were independent predictors of adoption of coping behaviors. We found that: 1. Residents’ risk perception of health and life threat caused by typhoon is inadequate; 2. There is a gap between residents’ cognition or knowledge and behavior in rural areas; 3. The government should further make strategies to develop educational activities, in order to eliminate the gap and improve the ability of preparing for typhoon among rural residents.
Orientin and vitexin are flavone
8-C-glycosides
that exhibit many biological characteristics. This study aimed to
establish a two-enzyme-coupled catalytic strategy to enhance the biosynthesis
of orientin and vitexin from apigenin and luteolin, respectively.
The C-glucosyltransferase (TcCGT1) gene from Trollius chinensis was cloned and expressed in Escherichia coli BL21(DE3). The optimal activity
of TcCGT1 was achieved at pH 9.0 and 37 °C. TcCGT1 was relatively
stable over the pH range of 7.0–10.0 at a temperature lower
than 45 °C. The coupled catalytic strategy of TcCGT1 and different
sucrose synthases was adopted to enhance the production of orientin
and vitexin. By optimizing the coupling reaction conditions, orientin
and vitexin production successfully achieved 2324.4 and 5524.1 mg/L
with a yield of 91.4 and 89.3% (mol/mol), respectively. The coupled
catalytic strategy proposed in this study might serve as a promising
candidate for the large-scale production of orientin and vitexin in
the future.
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