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  • Author: Hui Guo x
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Open access

Christoph Wenge, Hui Guo and Christian Roehrig

Abstract

Electric vehicles (EVs) can be utilized as mobile storages in a power system. The use of battery chargers can cause current harmonics in the supplied AC system. In order to analyze the impact of different EVs with regardto their number and their emission of current harmonics, a generic harmonic current model of EV types was built and implemented in the power system simulation tool PSS®NETOMAC. Based on the measurement data for different types of EVs three standardized harmonic EV models were developed and parametrized. Further, the identified harmonic models are used by the computation of load flow in a modeled, German power distribution system. As a benchmark, a case scenario was studied regarding a high market penetration of EVs in the year 2030 for Germany. The impact of the EV charging on the power distribution system was analyzed and evaluated with valid power quality standards.

Open access

Guo-Qiang Li, Hui Zhao and Fa-Hu Chen

Abstract

The luminescence dating of the K-feldspar fraction is an alternative way for samples that cannot yield reasonable equivalent dose (De) from quartz fraction with very weak luminescence signal. For testing the reliability of the infrared stimulated luminescence (IRSL) dating of K-feldspar, luminescence dating was applied to quartz and K-feldspar fractions respectively for several Holocene samples in this study. K-feldspar apparent ages using routine single aliquot regenerative-dose (SAR) protocol, K-feldspar ages using g value correction method and ages from isochron dating method were compared with quartz ages. It is found that the g value correction method cannot give reliable ages due to the large errors induced during measurements. The isochron dating method is effective to the sample with problematically external dose rate. However, isochron dating may introduce a relatively greater error during grain sizes — De curve fitting, therefore this method could obtain low-resolution ages for Holocene samples. Even K-feldspar apparent age from routine SAR protocol is relatively younger by about 10% than the quartz age, it still could establish reasonable chronological framework for Holocene samples.

Open access

Guo Yongqiang, Wu Yumin and Liu Hui

Abstract

Based on the thoughts of cognitive radar, Fractional Fourier Transform (FrFT) is used to generate a rotatable waveform libraries of Frank coded/Barker coded waveform in this paper. Then, the ambiguity function is used to analyze the delay resolution, Doppler resolution, delay side-lobe level, and Doppler side-lobe level of the waveform libraries and orthogonality of them is also analyzed. Furthermore, we proved theoretically that there is a fixed coordinate transformation between the waveforms of library and its origin waveform. Therefore, the Cramér-Rao low bound (CRLB) of motion parameters can be computed easily using the waveforms of the libraries, which facilitate the subsequent waveform scheduled work. Simulation results show that the library waveforms can reduce delay resolution to satisfy the different situations and can bring significant benefits for delay resolution, orthogonality and reuse interval.

Open access

Wei Guo, Jie Zhang, Jing-yun Li, Yue Ma and Sheng-hui Cui

Abstract

Objective A prospective study was conducted in a tertiary care center to identify the risk factors of ventilator associated pneumonia (VAP) through phenotypic and molecular biological methods.

Methods The patients who were mechanically ventilated in the respiratory intensive care unit (RICU) and the neurological internal intensive care unit (NICU) were enrolled in our study, and samples were collected from the lower respiratory tract, oropharynx and stomach. Other samples, including the environmental air, swabs of nurses’ hands, subglottic secretion and ventilator circuit, were also collected. Microorganisms in the collected samples were recovered and identified at species level by biochemical detection. Genetic relationship of dominant species was further characterized by pulsed field gel electrophoresis (PFGE).

Results Out of 48 enrolled patients, 22 cases developed VAP and bacterial cultures were recovered from the lower respiratory tract samples of 14 cases. The average hospitalization time with VAP was significantly longer than that of patients without VAP (P < 0.05). Among the recovered bacteria cultures, multidrug-resistant Pseudomonas aeruginosa and Stenotrophomonas maltophilia were dominant. It was more likely that subglottic secretion and gastric juice samples contained the same isolates as recovered in the lower respiratory tract by PFGE analysis.

Conclusions Mechanical ventilation in RICU and NICU was a high risk factor for VAP development. Special emphasis of VAP prophylaxis should be paid on subglottic secretion and gastric juice reflux.

Open access

Gong Cheng, Zhao-Hui Yi and Jian-Guo Xiong

Abstract

The present paper proposes a morphological lowering analysis for the structure associated with alethic ACQ, a postverbal morpheme capable of denoting the modality of ability and possibility in Chinese as well as many Southeast Asian languages. Built in the framework of distributed morphology, we suggest that ACQ is base-generated in a preverbal node as a modal element and lowers to a postverbal position during its derivation on the PF branch. We compare and contrast the proposed lowering account with the other model of analysis, the raising analysis, and demonstrate that the lowering account is superior both conceptually and empirically.

Open access

Jiajun He, Huimin Zhang, Hui Zhang, Xuan Guo, Mingwei Song, Junhao Zhang and Xiaotao Li

Abstract

The distribution and extent of heavy metal accumulation in the fluvial sediment of the Beijiang River are described. The potential toxicity of this pollution was quantified using a consensus based sediment quality guidelines (SQGs) method and the Hakanson potential ecological risk index. The concentrations of Hg, As, Cu, Zn, Pb, Ni and Cr were high enough to damage the sediment biota on a frequent basis. The potential ecological risk was much higher in the downstream, urbanized reaches of the river than in the upstream reaches which are still rural, but all sections of the river posed at least a moderate level of ecological risk. Estimates of the economic loss associated with these pollutions were appreciable, and were mainly due to Hg and Cu. The Beijiang River basin is heavily polluted, posing environmental risks for the downstream reaches of the Pearl River, and economic loss to the whole watershed.

Open access

Jiabei Li, Yanqi Zhang, Juan Wang, Dehui Qian, Hui Guo, Mingbao Song, Xiaojing Wu, Jun Jin, Junfu Huang and Lan Huang

Abstract

Background

Whether patients with coronary heart disease (CHD) and resistance to aspirin found by in vitro tests are at a greater risk of major adverse cardiovascular events (MACEs) is controversial.

Objective

To identify any association between resistance to aspirin found by in vitro tests and MACEs in patients with unstable angina pectoris (UAP).

Methods

Previously we demonstrated that 38 of 104 patients admitted to hospital with UAP showed resistance to aspirin using whole blood aggregometry (WBA). In the present study, the same cohort was observed during a 6-month follow-up. The primary end points were MACEs, including cardiovascular death, nonfatal myocardial infarction, revascularization, stroke/transient ischemic attack, or worsening UAP that required the patient to be readmitted to hospital.

Results

During the course of 6 months, only 1 patient in the aspirin-sensitive group was lost in follow-up, and MACEs occurred in 24 patients. Patients with resistance to aspirin found by WBA did not apparently have a higher risk of MACEs compared with patients who were aspirin-sensitive (29% vs 20%, P > 0.05). Cox regression analysis showed that resistance to aspirin found by WBA appeared to have no significant correlation with 6-month clinical outcome (HR 1.56, 95% CI 0.70-3.48, P > 0.05).

Conclusion

Aspirin resistance, as defined by WBA, was not associated with an increased risk of MACEs in patients with UAP in a 6-month follow-up. Clarification of the clinical significance of aspirin responsiveness detected by platelet function tests requires further investigation in larger longitudinal studies.