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In order to ensure the reliability and credibility of the data in wireless sensor networks (WSNs), this paper proposes a trust evaluation model and data fusion mechanism based on trust. First of all, it gives the model structure. Then, the calculation rules of trust are given. In the trust evaluation model, comprehensive trust consists of three parts: behavior trust, data trust, and historical trust. Data trust can be calculated by processing the sensor data. Based on the behavior of nodes in sensing and forwarding, the behavior trust is obtained. The initial value of historical trust is set to the maximum and updated with comprehensive trust. Comprehensive trust can be obtained by weighted calculation, and then the model is used to construct the trust list and guide the process of data fusion. Using the trust model, simulation results indicate that energy consumption can be reduced by an average of 15%. The detection rate of abnormal nodes is at least 10% higher than that of the lightweight and dependable trust system (LDTS) model. Therefore, this model has good performance in ensuring the reliability and credibility of the data. Moreover, the energy consumption of transmitting was greatly reduced.

A novel disordered laser crystal Nd:Ca(3)La(2)(BO(3))(4) is characterized including its crystal growth, structure, thermal properties, inhomogeneously broadened spectra, and laser performance, which result that this crystal should be a promising gain material for the high-power ultrashort pulsed neodymium laser. The complete set of anisotropic thermal properties were systematically studied for the first time. It has been found that thermal contraction happens in the c direction and all the thermal conductivities increase with temperature, indicating a glass-like behavior. Polarized absorption and fluorescence spectra of Nd:Ca(3)La(2)(BO(3))(4) crystal were measured at 298.15 K and 77.3 K, respectively. The results show that both the absorption and the emission spectra of Nd(3+) have been inhomogeneously broadened, and thus it is very promising to be used in laser systems to produce femtosecond pulses. CW laser operations at 1.06 μm along the three crystallographic directions has been demonstrated for the first time. A maximum power of 1.08 W with an optical conversion efficiency of 10.6% and slope efficiency of 12.4% was achieved in the a-cut sample.

In the process of using the cloud platform, how to ensure the safety of users is a matter we must concern. The user authentication can provide a certain degree of security, but when the user information was leaked, this method will not be effective. Therefore, this article proposes a trust evaluation model based on user behavior data. In this model, the user's historical behavior will be used to construct a set of trusted behavior of the cloud users. On this basis, the direct trust of the user's behavior can be obtained. Then, the recommendation trust can be calculated by the interaction between the users and other cloud users. Given the current historical trust, the comprehensive trust can be obtained using the weighted average method. Among them, the initial value of historical trust is set to a constant and then updated by the comprehensive trust. In order to control the user's abnormal behavior more effectively, the suspicious threshold value and the abnormal threshold value were defined, which are used to punish the historical trust. Through the simulation of the virtual digital library cloud platform, the method can effectively evaluate the cloud users.

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Homocysteine is an amino acid related to metabolism in human vivo, which is closely related to cardiovascular disease, senile dementia, bone fracture, et al. Currently, the usual medical test methods for homocysteine include high performance liquid chromatography (HPLC), fluorescence polarization immunoassay (FPIA) and enzyme-linked immunosorbent assay (ELISA), which are time-consuming or expensive. In this paper, we first analyze the vibration and rotation of homocysteine molecules by using density functional theory, and then we ensure that the theoretical absorption peaks are located in the range of the terahertz spectrum. Then, based on the terahertz time-domain spectroscopy system, we measured the absorption spectrum of homocysteine under different concentrations. It is found that as the detection of the concentration, the terahertz results present higher accuracy than that of the laser Raman spectrum, which can be used as the reference for the evaluation of pathological stage. These results are of great significance for the exact and quick diagnosis of homocysteine-related diseases in clinical medicine.

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