Real-time monitoring the electrical property of semiconductor materials and devices under irradiation can minimize the impact of room temperature annealing and obtain data conveniently. In this work, an in-situ radiation test system was constructed based on a 4.5 MV accelerator and used to measure the electrical property of 4H-SiC under 2 MeV protons irradiation. The results show that the resistance of 4H-SiC increases when the ion fluence increases from 6.37×10 13 cm −2 to 8.16×10 15 cm −2, showing the system is a powerful tool to investigate the in-situ change of the resistance under MeV ion irradiation.
Apriori algorithm is a basic algorithm for all association rules,but it is Low-efficient and time-consuming that requires the scanning of the database repeatedly. It is presented in this paper with a highly efficient updating algorithm based on the latest mining result for the maintenance of discovered association rules which requires only two times scanning of the database and improves the efficiency greatly.
In order to help decision-makers to make correct decision in flood control operation and unit running, it is very necessary to build up an integrated data warehouse feature-based water conservancy decision supporting system to meet the requirements for water conservancy informatization at present. In this article, concerning technology, system, structure form of data warehouse feature-based water conservancy decision supporting system is presented and analyzed by the author.
Due to the demand of 5G cellular network, several multicarrier schemes are proposed to support waveform candidates in the next generation communication system. In this paper, several multicarrier schemes are analyzed, including filter bank multicarrier (FBMC) and universal filtered multicarrier(UFMC). In FBMC systems, each subcarrier is shaped by a filter. The bandwidth efficiency of FBMC scheme is higher than that of UFMC scheme. In UFMC systems, several subcarriers are grouped into one resource block. Thus, the length of shaping filter in UFMC systems is much shorter than that in FBMC systems. However, the inter-symbol interference (ISI) is unavoidable in UFMC systems. Therefore, a novel transceiver structure and a filter optimization solution are proposed for UFMC systems in this paper. The scheme is proposed to overcome the problem of ISI and out-of-band emission (OOBE) with lower computational complexity. The proposed UFMC system is compared with both FBMC and conventional UFMC systems. Simulation results demonstrate that the performance of bit error rate (BER) and OOBE of the proposed scheme are better than those of other schemes presented in the existing literature.
Indoor localization technology is affected by the combination of random and systematic errors, which results in the ranging error not obeying a single distribution over a large monitoring area, making it difficult to perform comprehensive modeling. This causes the accuracy problem of indoor positioning technology and becomes the most challenging research hotspot in recent years. To address the aforementioned issue, this article proposes a novel method, which converts a large monitoring area into multiple independent areas with relatively stable errors by setting precorrection points. Then, an area selection model is constructed using Optuna optimized light gradient boosting machine (LightGBM), while the ranging error compensation model is created by integrating multiple deep neural networks (DNNs) according to the error data characteristics within each area. Consequently, a new area selection and ranging error compensation (ASEC) network is constructed to compensate the ranging error of the tag node. Finally, the African vulture optimization algorithm (AVOA) is combined to solve for the location coordinates.As verified by practical experiments, the proposed indoor localization method can significantly reduce the ranging error while maintaining excellent robustness, thus obtaining higher localization accuracy with a localization error of no more than 0.034 m.
OBJECTIVE To prepare coenzyme Q_(10)(CoQ_(10)) liposome and investigate the character.METHODS The CoQ_(10)liposome was prepared by ethanol injection method.The filtrate-HPLC method was used to determine encapsulation efficiency.RESULTS The drug content was 1.93 g·L~(-1),the encapsulation efficiency was 99.2%,the Zeta potential was-31.2 mV,and the diameter was 163 nm.CONCLUSION The CoQ_(10)liposome is stable,with high encapsulation efficiency.
To evaluate the left atrial phasic function of hypertensive patients with or without coexisting diabetes using two-dimensional speckle tracking echocardiography (2DSTE)-based strain and strain rate imaging and volumetric parameters.The study included an isolated hypertension group (HT group) comprising 99 patients, a hypertension and diabetes group (HT + DM group) comprising 65 patients, and 26 age-matched healthy controls. The 2DSTE-based strain and strain rate images were studied, and the following parameters were measured: peak left atrial longitudinal strain (LAS-S ), early diastolic (LAS-E ) and late diastolic (LAS-A ) atrial longitudinal strains, and systolic (LASR-S ), early diastolic (LASR-E ) and late diastolic (LASR-A ) strain rates.The LAS-S and LASR-S were lower in the HT group and the HT + DM group compared with the control group (P < 0.001). The LAS-E and LASR-E were lower in the HT group (14.9 ± 5.5% and -1.1 ± 0.4/sec, respectively) than in the control group (22.1 ± 8.3% and -1.7 ± 0.6/sec, respectively) (P < 0.001), and they were further depressed in the HT + DM group (12.3 ± 6.3% and -1.0 ± 0.4/sec, respectively) (P < 0.05). There were no significant differences in LAS-A or LASR-A among the 3 groups (P > 0.05). Multivariate regression analysis revealed that HT and DM were independently related to LAS-E and LASR-E .Hypertension can lead to abnormal left atrial reservoir and conduit functions, and coexisting diabetes can further impair conduit function. 2DSTE-derived strain and strain rate imaging are sensitive methods for evaluating left atrial phasic function.
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