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Heat pipe cooled reactor has the advantages of simple structure, passive heat transfer and high reliability, owning to the design of solid reactor core and heat transfer using high-temperature heat pipe. In order to study the transient and safety characteristic of space heat pipe cooled reactor with thermoelectric conversion, the detailed mathematical and physical models were established for the most key system of the reactor including the reactor, high temperature heat pipe, thermoelectric conversion system. The reactor model was developed by coupling point-kinetic model, reactivity feedback model and power distribution model based on OpenFOAM, in which three different interface heat transfer models were developed to couple different regions in solid reactor. The reactor model overcome modeling difficulty of some typical accident scenarios such as heat pipe failure accident, the actual distribution and variation of temperature can be accurately obtained. The two-dimensional transient heat pipe model was present which was suitable for transient simulation of high-temperature heat pipe after startup. The transient working condition of a sodium heat pipe was simulated, the result fits quite well with the thermal resistance network model and two-dimensional model. For the thermoelectric generator, the one-dimensional transient model was established, in which the effect of Peltier heat, Fourier's heat conduction, Joule heat and Thomson heat was considered, the dynamic behaviors of thermoelectric generator under different thermal conditions can be simulated. In order to testify the thermoelectric generator model, a BiTe-based thermoelectric module was built and verified with the experiment data under two different working conditions. The output electric power deviation compared with experiment data is 2.47% and 2.75% under two working conditions. The transient system analysis program for thermoelectric space heat pipe cooled reactor was developed and fully verified with the experimental data of the KRUSTY prototype reactor. The detailed KRUSTY reactor model was established in the program, the accident conditions of the KRUSTY were calculated including reactivity control, thermoelectric conversion module failure, loading following and active heat removal accident. The results show that the simulation results of program are in good agreement with test data, the max deviation of surface fuel temperature is less than 4.1 K under these accident conditions and the accuracy of the model is proved. The program will provide effective analysis and research tool for the transient characteristic study of space heat pipe cooled reactor with thermoelectric conversion.

Food grinding is an abnormal behavior in rodents and its influencing factors are unknown. Our study investigated the potential relationships between gut microbiota and food grinding in Brandt's voles (Lasiopodomys brandtii (Radde, 1861)) by comparing the differences between groups with different degrees of food grinding. The strong food-grinding group showed more relative food ground, higher ratio of ground food to food consumption, and lower percentage of time spent in the central area. The structure of fecal microbiota community differed between the strong and weak food-grinding groups. Strong and weak food-grinding voles showed higher abundances of Alistipes and Aerococcus and Atopostipes, Paenalcaligenes, Un--s-Clostridiaceae bacterium GMl, and Streptococcus, respectively. Strong correlations between the food ground to consumption ratio and abundances of fecal microbiota were found in Streptococcus and Paenalcaligenes. Fecal acetate and isobutyrate contents were higher in strong food-grinding voles and positively correlated with relative ground food and food ground to consumption ratio. Our study suggests that gut microbiota and short-chain fatty acids may contribute to the regulation of food-grinding behavior. Key words: food grinding, Brandt's voles (Lasiopodomys brandtii), short-chain fatty acids, gut microbiota, Introduction Food grinding, also known as food wasting, is a phenomenon that occurs in laboratory rodents through which food is ground into small fragments that are then left uneaten and [...]

Objective: The application of olive leaf, a by-product of olive oil production, in food industry was studied. Methods: Taking the yield of olive leaf polyphenols as the evaluation index, on the basis of single factor experiment, the effects of water bath temperature, extraction time and solid-liquid ratio on the yield of polyphenols were analyzed by Box-Behnken response surface method, the effects of olive leaf polyphenols on the oxidative stability of camellia seed oil were studied with peroxide value and acid value as indexes. Results: The optimum extraction conditions of polyphenols from olive leaves by water bath were as follows: ethanol volume fraction 50%, extraction time 1.0 h, solid-liquid ratio 1∶40 （g/mL）, water bath temperature 72 ℃, and the yield of polyphenols from olive leaves was 5.86%. Olive leaf polyphenols had a good antioxidant effect on camellia seed oil, which was better than butyl hydroxyanisole （BHA）, and had a synergistic effect with tert butyl hydroquinone （TBHQ） and BHA. Conclusion: The polyphenols extracted from olive leaves under the optimized conditions have a good antioxidant effect on camellia seed oil.

Readout circuits are fundamental components in many application systems that utilize piezoelectric micro-machined ultrasonic transducers (pMUTs). This study models the noise and signal transfer functions of trans-impedance amplifiers (TIAs), charge-sensitive circuits, and voltage-mode readout circuits in detail. A series of simulations and experiments were conducted to elucidate the advantages and disadvantages of these circuit types. Both theoretical and experimental results indicate that the intrinsic capacitance of large pMUTs can significantly degrade the quality of the readout signal. Furthermore, while the TIA-based readout circuit demonstrates clear gain advantages, it is also susceptible to considerable noise interference. This work proposes an improved readout circuit design that effectively mitigates noise interference while preserving the gain advantages of the TIA architecture. The implemented prototype circuit successfully reduces the noise from 73 mVp-p to 13 mVp-p. [ABSTRACT FROM AUTHOR]

This investigation aimed to develop and validate a novel oxidative stress score for prognostic prediction in locally advanced cervical cancer (LACC) patients receiving chemoradiotherapy. A total of 301 LACC patients were enrolled and randomly divided into a training and a validation set. The association between oxidative stress parameters and prognosis was analyzed for oxidative stress score (OSS) establishment. A Cox regression model was conducted for overall survival (OS) and progression-free survival (PFS). A nomogram prediction model was developed using independent prognostic factors from the training set and validated in the validation set. A novel OSS was established with four oxidative stress parameters, including albumin, total bilirubin, blood urea nitrogen, and lactate dehydrogenase. Multivariate regression analysis identified OSS as an independent prognostic factor for OS (p = 0.001) and PFS (p < 0.001). A predictive nomogram based on the OSS was established and validated. The C-indexes of the nomogram in the training set were 0.772 for OS and 0.781 for PFS, while in the validation set the C-indexes were 0.642 for OS and 0.621 for PFS. This study confirmed that preoperative OSS could serve as a useful independent prognostic factor in LACC patients who received CCRT. [ABSTRACT FROM AUTHOR]

The manipulation of spin textures by spin currents is of fundamental and technological interest. A particularly interesting system is the 2D van der Waals ferromagnet Fe3GeTe2, in which Néel-type skyrmions have recently been observed. The origin of these chiral spin textures is of considerable interest. Recently, it was proposed that these derive from defects in the structure that lower the symmetry and allow for a bulk vector Dzyaloshinsky-Moriya interaction. Here, we demonstrate current-induced domain wall motion in Fe3GeTe2 flakes, in which the maximum domain wall velocity is an order of magnitude higher than those reported in previous studies. In heterostructures with Pt or W layers on top of the Fe3GeTe2 flakes, domain walls can be moved via a combination of spin transfer and spin-orbit torques. The competition between these torques leads to a change in the direction of domain wall motion with increasing magnitude of the injected current. In this work, the researchers realize the current-induced motion of Néel type chiral domain walls via spin-transfer-torque in the pristine van der Waals ferromagnet Fe3GeTe2 and via spin-orbit-torques in heterostructures with platinum or tungsten. [ABSTRACT FROM AUTHOR]

Trans-impedance amplifier (TIA) based capacitance–voltage (C–V) readout circuits are widely used in micro-machined gyroscopes' control system. In this work, the noise performance of a TIA and charge sensitive amplifier (CSA) based C–V readout circuit is analyzed in detail. The theoretical derivation and simulation experiments carried out in this paper show that the thermal noise of high value feedback resistors in TIA dominates the output noise of the circuit, while a CSA-based readout circuit can overcome this shortcoming. Then, a CSA-based C–V readout circuit is designed with a 1.8 V transistor on a 180 nm complementary metal-oxide-semiconductor. This C–V-based readout circuit occupies an area of 0.039 mm2, which is smaller than the area of a 0603 package resistor. When 1 V bias voltage (Vb) is added to the capacitors under test, the tested C–V gain of this circuit is as high as 225 dB, and the tested output noise of the circuit is less than 150 n V / H z . Finally, the fabricated chip achieved a resolution of 840 z F / H z at Vb as low as 1 V. This CSA-based C–V readout circuit has more advantages in terms of noise and area over the TIA circuit and is more suitable for integration into the interface integrated circuit for micro-gyroscopes. [ABSTRACT FROM AUTHOR]