Study of the influence of the resonance changer on the longitudinal vibration of marine propulsion shafting system

For investigating the characteristics of the resonance changer and its influence on the longitudinal vibration of marine propulsion shafting system, by the transfer matrix method, the model of the shafting system, including the resonance changer is established. The influences of the resonance changer with various designing parameters on the force transmissibility through the thrust bearing foundation are evaluated. The results show that, the introduction of the resonance changer eliminates the resonance at original 1st natural frequency and introduces another two resonance peaks, as well as significantly lowering the maximum response compared with the original peak. The right one is attributed to the resonance changer, while the other is due to excitation of the other shafting system components. The 2nd natural frequency moves towards the high frequency direction and the peak value nearly stay invariable. If the designing parameters of the resonance changer are well optimized, the objective of reducing the longitudinal vibration transmission through the shafting system to the hull could be achieved

Pharmacokinetic studies and anticancer activity of curcumin-loaded nanostructured lipid carriers

In order to investigate the potential of nanostructured lipid carriers for efficient and targeted delivery of curcumin, the pharmacokinetic parameters of curcumin-loaded nanostructured lipid carriers (Cur-NLC) were evaluated in rats after a single intraperitoneal dose of Cur-NLC. In addition, the anticancer activity of Cur-NLC against human lung adenocarcinoma A549 cells was verified by a cellular uptake study, and a cytotoxicity and apoptosis assay. Bioavailability of Cur-NLC was better than that of native curcumin (p > 0.01), as seen from the area under the plasma concentration-time curve (AUC), maximum plasma concentration (Cmax), mean residence time (MRT) and total plasma clearance (CLz/F). Cur-NLC has a more obvious lung-targeting property in comparison with native curcumin. Cur-NLC showed higher anticancer activity in vitro against A549 cells than native curcumin (IC50 value of 5.66 vs. 9.81 mg L–1, respectively). Meanwhile, Cur-NLC treated A549 cells showed a higher apoptosis rate compared to that of native curcumin. These results indicate that NLC is a promising system for the delivery of curcumin in the treatment of lung adenocarcinoma

Directional Enhanced Probe for Side-Illumination Tip Enhanced Spectroscopy

We demonstrate a high-performance apertureless near-field probe made of a tapered metal tip with a set of periodic shallow grooves near the apex. The spontaneous emission from a single emitter near the tip is investigated systematically for the side-illumination tip enhanced spectroscopy (TES). In contrast with the bare tapered metal tip in conventional side-illumination TES, the corrugated probe not only enhances strongly local excitation field but also concentrates the emission directivity, which leads to high collection efficiency and signal-to-noise ratio. In particular, we propose an asymmetric TES tip based on two coupling nanorods with different length at the apex to realize unidirectional enhanced emission rate from a single emitter. Interestingly, we find that the radiation pattern is sensitive to the emission wavelength and the emitter positions respective to the apex, which can result in an increase of signal-to-noise ratio by suppressing undesired signal. The proposed asymmetrical corrugated probe opens up a broad range of practical applications, e.g. increasing the detection efficiency of tip enhanced spectroscopy at the single-molecule level

An inventory of invasive alien species in China

Invasive alien species (IAS) are a major global challenge requiring urgent action, and the Strategic Plan for Biodiversity (2011–2020) of the Convention on Biological Diversity (CBD) includes a target on the issue. Meeting the target requires an understanding of invasion patterns. However, national or regional analyses of invasions are limited to developed countries. We identified 488 IAS in China’s terrestrial habitats, inland waters and marine ecosystems based on available literature and field work, including 171 animals, 265 plants, 26 fungi, 3 protists, 11 procaryots, and 12 viruses. Terrestrial plants account for 51.6% of the total number of IAS, and terrestrial invertebrates (104 species) for 21.3%. Of the total numbers, 67.9% of plant IAS and 34.8% of animal IAS were introduced intentionally. All other taxa were introduced unintentionally despite very few animal and plant species that invaded naturally. In terms of habitats, 64.3% of IAS occur on farmlands, 13.9% in forests, 8.4% in marine ecosystems, 7.3% in inland waters, and 6.1% in residential areas. Half of all IAS (51.1%) originate from North and South America, 18.3% from Europe, 17.3% from Asia not including China, 7.2% from Africa, 1.8% from Oceania, and the origin of the remaining 4.3% IAS is unknown. The distribution of IAS can be divided into three zones. Most IAS are distributed in coastal provinces and the Yunnan province; provinces in Middle China have fewer IAS, and most provinces in West China have the least number of IAS. Sites where IAS were first detected are mainly distributed in the coastal region, the Yunnan Province and the Xinjiang Uyghur Autonomous Region. The number of newly emerged IAS has been increasing since 1850. The cumulative number of firstly detected IAS grew exponentially

Exposures to particulate matters and childhood sleep disorders—A large study in three provinces in China

Objectives: Evidence on the link between long-term ambient particulate matter (PM) exposures and childhood sleep disorders were scarce. We examined the associations between long-term exposures to PM2.5 and PM1 (PM with an aerodynamic equivalent diameter <2.5 μm and <1 μm, respectively) with sleep disorders in children. Methods: We performed a population-based cross-sectional survey in 177,263 children aged 6 to 18 years in 14 Chinese cities during 2012–2018. A satellite-based spatiotemporal model was employed to estimate four-year annual average PM2.5 and PM1 exposures at residential and school addresses. Parents or guardians completed a checklist using the Sleep Disturbance Scale for Children. We estimated the associations using generalized linear mixed models with adjustment for characteristics of children, parents, and indoor environments. Results: Long-term PM2.5 and PM1 exposures were positively associated with odds of sleep disorders for almost all domains. For example, increments in PM2.5 and PM1 per 10 μg/m3 were associated with odds ratios of global sleep disorder of 1.24 (95 % confidence interval [CI]: 1.14, 1.35) and 1.31 (95 %CI: 1.18, 1.46), respectively. Similar results were observed for subtypes of sleep disorder. These associations were heterogeneous regionally, with stronger associations among children residing in southeast region than in northeast and northwest regions. Moreover, larger estimates of PM1 were found than that of PM2.5 in southeast region. Conclusion: Long-term PM2.5 and PM1 exposures are independently associated with higher risks of childhood sleep disorders, and these associations vary by geographical region

Human and animal exposure to newly discovered sand fly viruses, China

IntroductionThe Hedi virus (HEDV) and Wuxiang virus (WUXV) are newly discovered Bunyaviruses transmitted by sandflies. The geographical distribution of isolation of these two viruses continues to expand and it has been reported that WUXV causes neurological symptoms and even death in suckling mice. However, little is known about the prevalence of the two viruses in mammalian infections.MethodsIn order to understand the infection status of HEDV and WUXV in humans and animals from regions where the viruses have been isolated, this study used Western blotting to detect the positive rates of HEDV and WUXV IgG antibodies in serum samples from febrile patients, dogs, and chickens in the forementioned regions.ResultsThe results showed that of the 29 human serum samples, 17.24% (5/29) tested positive for HEDV, while 68.96% (20/29) were positive for WUXV. In the 31 dog serum samples, 87.10% (27/31) were positive for HEDV and 70.97% (22/31) were positive for WUXV, while in the 36 chicken serum samples, 47.22% (17/36) were positive for HEDV, and 52.78% (19/36) were positive for WUXV.DiscussionThese findings suggest there are widespread infections of HEDV and WUXV in mammals (dogs, chickens) and humans from the regions where these viruses have been isolated. Moreover, the positive rate of HEDV infections was higher in local animals compared to that measured in human specimens. This is the first seroepidemiological study of these two sandfly-transmitted viruses. The findings of the study have practical implications for vector-borne viral infections and related zoonotic infections in China, as well as providing an important reference for studies on the relationship between sandfly-transmitted viruses and zoonotic infections outside of China

Analysis and design of floating production storage and offloading unit against extreme ice actions

To explore the Arctic regions, ice conditions are taken into account. Ice-structure interactions are analyzed for ice region FPSO FPU-ICE of SEVAN Marine, especially for extreme level ice events (ELIE) and accidental level ice events (ALIE). With respects to ISO/CD 19906 standard, ice conditions including physical properties and mechanical properties are reviewed respectively. Different principles behind DNV, IACS, NORSOK and ISO ice region design codes are discussed, with emphasis on ISO/CD 19906. Local and global ice actions from Barents Sea are researched according to ISO 19906. The conical part of the FPSO is simplified as a stiffened plate with deck and stringer. Simple plastic analysis of FPU-ICE substructure is compared with the nonlinear simulation carried out by ABAQUS. Six models chosen from design preference with regards to optimization by weight have been applied in ABAQUS nonlinear finite element analysis. It is performed to investigate the plastic bending capacity and energy dissipated in plastic strain. Arctic region structure design check ELIE and ALIE are carried out respectively. The nonlinearity of structure under ice loading is presented based on the principles of nonlinear finite element analysis. Sensitivity of mesh size in NLFEA is investigated by convergence test. The target to find ultimate strength capacity of the substructures by critical strain level is integrated in ABAQUS in terms of arch length method with both small (ELIE) and large deformations (ALIE). General guidelines for ELIE design events are introduced on the basis of investigation experience

The earth surface reflectance retrieval by exploiting the synergy of TERRA and AQUA MODIS data

The surface reflectance is of important geophysical parameter for many quantitative remote sensing applications. The inference of earth surface spectral reflectance using visible observations is complicated mainly because of scattering and absorption effects due to gases and aerosols. Surface reflectance product from MODIS data has been operationally offered, however, aerosol effect removal is based DDV algorithm which is restrictedly used for lower reflectance ground surface such as dense vegetation. In this paper we attempt a solution to the problem of retrieval of surface reflectance by exploiting the synergy of TERRA and AQUA MODIS data. Preliminary results of retrieval experiments and validation is encouraging and showed promising potential to address surface reflectance retrieval for land even for higher reflective surface. ? 2007 IEEE.EI

Convolution and Long Short-Term Memory Hybrid Deep Neural Networks for Remaining Useful Life Prognostics

Reliable prediction of remaining useful life (RUL) plays an indispensable role in prognostics and health management (PHM) by reason of the increasing safety requirements of industrial equipment. Meanwhile, data-driven methods in RUL prognostics have attracted widespread interest. Deep learning as a promising data-driven method has been developed to predict RUL due to its ability to deal with abundant complex data. In this paper, a novel scheme based on a health indicator (HI) and a hybrid deep neural network (DNN) model is proposed to predict RUL by analyzing equipment degradation. Explicitly, HI obtained by polynomial regression is combined with a convolutional neural network (CNN) and long short-term memory (LSTM) neural network to extract spatial and temporal features for efficacious prognostics. More specifically, valid data selected from the raw sensor data are transformed into a one-dimensional HI at first. Next, both the preselected data and HI are sequentially fed into the CNN layer and LSTM layer in order to extract high-level spatial features and long-term temporal dependency features. Furthermore, a fully connected neural network is employed to achieve a regression model of RUL prognostics. Lastly, validated with the aid of numerical and graphic results by an equipment RUL dataset from the Commercial Modular Aero-Propulsion System Simulation(C-MAPSS), the proposed scheme turns out to be superior to four existing models regarding accuracy and effectiveness