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The purpose of this study is to develop luminescence sensors for the detection of nitroaromatic compounds (NACs) and metal ions to protect human health and prevent environmental pollution.

The composition and morphology of Eu-metal-organic frameworks (MOF) (1) were well characterized by powder X-ray diffraction, elemental analyses, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and scanning electron microscopy. The emission spectrum displays that 1 has significant characteristic emission bands of Eu(III) ions. The authors further investigated the fluorescence sensing performances of 1 to NACs and metal ions.

The results show that Eu-MOF (1) exhibits significant fluorescence quenching effect toward p-nitroaniline and Fe³⁺ ions with good stability and recyclability. This means that 1 can be used as a multifunctional sensing material for the detection of p-nitroaniline and Fe³⁺ ions.

The authors have successfully synthesized a fluorescence Eu-based sensing material under hydrothermal conditions. In addition, the fluorescence property and sensing performances for detecting NACs and metal ions were studied. The results suggest that 1 has highly selective fluorescence quenching toward p-nitroaniline and Fe³⁺ ions with not only high sensitivity and selectivity but also excellent stability and recyclability. Furthermore, this study has confirmed that the multifunctional MOF material is very useful in environment pollutants’ detection and monitoring.

To reduce the influence of temperature on MEMS gyroscope, this paper aims to propose a temperature drift compensation method based on variational modal decomposition (VMD), time-frequency peak filter (TFPF), mind evolutionary algorithm (MEA) and BP neural network.

First, VMD decomposes gyro’s temperature drift sequence to obtain multiple intrinsic mode functions (IMF) with different center frequencies and then Sample entropy calculates, according to the complexity of the signals, they are divided into three categories, namely, noise signals, mixed signals and temperature drift signals. Then, TFPF denoises the mixed-signal, the noise signal is directly removed and the denoised sub-sequence is reconstructed, which is used as training data to train the MEA optimized BP to obtain a temperature drift compensation model. Finally, the gyro’s temperature characteristic sequence is processed by the trained model.

The experimental result proved the superiority of this method, the bias stability value of the compensation signal is 1.279 × 10^–3°/h and the angular velocity random walk value is 2.132 × 10^–5°/h/vHz, which is improved compared to the 3.361°/h and 1.673 × 10^–2°/h/vHz of the original output signal of the gyro.

This study proposes a multi-dimensional processing method, which treats different noises separately, effectively protects the low-frequency characteristics and provides a high-precision training set for drift modeling. TFPF can be optimized by SEVMD parallel processing in reducing noise and retaining static characteristics, MEA algorithm can search for better threshold and connection weight of BP network and improve the model’s compensation effect.

The purpose of this paper is to investigate the relationship between corporate governance and earnings opacity in China.

Two corporate governance mechanisms form the basis of the analysis: 1) the board of directors and 2) the external audit function. OLS regression analysis is employed on a large sample from 2000 to 2014 with 20,235 firm-year observations.

Corporate governance is found to be associated with reduced levels of earnings opacity for Chinese listed companies. Furthermore, the association between corporate governance and reduced levels of earnings opacity strengthened after the implementation of various key reforms.

Chinese regulators are advised to proceed with caution as not all Western approaches to corporate governance are transferrable to the Chinese setting.

This study contributes to the literature by analyzing broad latent constructs of corporate governance in addition to individual observable dimensions in order to reveal that various key reforms have been successful in strengthening the link between governance and reporting quality for Chinese listed companies.

The shield tunnels closely constructed near the foundations have an inevitable influence on the structures, even results in the large settlement or uplift of the structures.

The comparison of structural deformation of three different foundations is presented based on the field monitoring data.

Shield tunnelling parameters vary for the different types of foundations. For the long pile foundations, the recommended speed is 3 to 4 cm/min, the grouting pressure is about 0.3 MPa and the grouting rate ranges from 150 to 180.

The study based on the field monitoring data is rarely reported, especially the topic about the structural deformation of different types of the foundations.

This study aims to explore the audit quality supplied by the Big 4, large indigenous Chinese (LIC) and five largest second-tier international network (Tier 2) audit firms in China during the second phase of their audit market development.

Ordinary least squares regression is used on an archival sample of firm-year observations. Endogeneity and self-selection bias are addressed by creating a propensity score matched sample and using two-stage regression with the inverse Mills’ ratio.

Strong evidence is found for higher levels of actual audit quality for the Big 4 relative to both LIC and Tier 2 audit firms. Weak evidence is found regarding the audit quality superiority of Tier 2 relative to LIC audit firms. Furthermore, the actual audit quality differential between the Big 4 relative to the LIC and Tier 2 firms widens after adopting International Financial Reporting Standards, which is contrary to the intention of Chinese regulators.

To the best of the authors’ knowledge, this is the first known empirical study to trisect Big N and non-Big N audit firm proxies into the Big 4, LIC and Tier 2. Currently, only qualitative studies have fully appreciated the unique regulatory roles of these three firm structures in developing China’s audit market, which reflect tensions between reliance on foreign expertise and self-determination. In addition, this study adds to the ongoing global dialogue on Tier 2 as an alternative to the Big 4 and the benefits of international accounting network membership.