43 research outputs found
Fault diagnosis-based SDG transfer for zero-sample fault symptom
The traditional fault diagnosis models cannot achieve good fault diagnosis accuracy when a new unseen fault class appears in the test set, but there is no training sample of this fault in the training set. Therefore, studying the unseen cause-effect problem of fault symptoms is extremely challenging. As various faults often occur in a chemical plant, it is necessary to perform fault causal-effect diagnosis to find the root cause of the fault. However, only some fault causal-effect data are always available to construct a reliable causal-effect diagnosis model. Another worst thing is that measurement noise often contaminates the collected data. The above problems are very common in industrial operations. However, past-developed data-driven approaches rarely include causal-effect relationships between variables, particularly in the zero-shot of causal-effect relationships. This would cause incorrect inference of seen faults and make it impossible to predict unseen faults. This study effectively combines zero-shot learning, conditional variational autoencoders (CVAE), and the signed directed graph (SDG) to solve the above problems. Specifically, the learning approach that determines the cause-effect of all the faults using SDG with physics knowledge to obtain the fault description. SDG is used to determine the attributes of the seen and unseen faults. Instead of the seen fault label space, attributes can easily create an unseen fault space from a seen fault space. After having the corresponding attribute spaces of the failure cause, some failure causes are learned in advance by a CVAE model from the available fault data. The advantage of the CVAE is that process variables are mapped into the latent space for dimension reduction and measurement noise deduction; the latent data can more accurately represent the actual behavior of the process. Then, with the extended space spanned by unseen attributes, the migration capabilities can predict the unseen causes of failure and infer the causes of the unseen failures. Finally, the feasibility of the proposed method is verified by the data collected from chemical reaction processes
Research on the Relationship between Urban Development Intensity and Eco-Environmental Stresses in Bohai Rim Coastal Area, China
To realize sustainable urban development that minimizes environmental impacts, the relationship between urban development intensity and eco-environmental stresses should be clearly revealed. This paper focused on the Bohai Rim coastal area, where cities have experienced significant development in the last decade. An index system was developed to quantify the comprehensive urban development intensity (CDI) and comprehensive eco-environment stresses (CES). Remote sensing imagery and statistical data were used to provide indices for CDI and CES. Spatiotemporal analysis was carried out on the correlation between the two indices. The coupling between the CDI and CES was then investigated to explore the urban development characteristics of each city in the study area, its development level, and the trend of urban development. Results showed that human activities surrounding urban development were partly dependent on the use of ecological resources to a certain degree, and that the degree of dependence increased with year. To promote a sustainable level of urban development, the government should focus on not only the high development intensity, but also the high quality of the eco-environment. Dalian was a good model of how to achieve a balance between the two
Cannabinoid Receptor Subtype 2 (Cb2R) Agonist Gw405833 Reduces Agonist-Induced Ca2+ Oscillations In Mouse Pancreatic Acinar Cells
Emerging evidence demonstrates that the blockade of intracellular Ca 2+ signals may protect pancreatic acinar cells against Ca 2+ overload, intracellular protease activation, and necrosis. The activation of cannabinoid receptor subtype 2 (CB 2 R) prevents acinar cell pathogenesis in animal models of acute pancreatitis. However, whether CB 2 Rs modulate intracellular Ca 2+ signals in pancreatic acinar cells is largely unknown. We evaluated the roles of CB 2 R agonist, GW405833 (GW) in agonist-induced Ca 2+ oscillations in pancreatic acinar cells using multiple experimental approaches with acute dissociated pancreatic acinar cells prepared from wild type, CB 1 R-knockout (KO), and CB 2 R-KO mice. Immunohistochemical labeling revealed that CB 2 R protein was expressed in mouse pancreatic acinar cells. Electrophysiological experiments showed that activation of CB 2 Rs by GW reduced acetylcholine (ACh)-, but not cholecystokinin (CCK)-induced Ca 2+ oscillations in a concentration-dependent manner; this inhibition was prevented by a selective CB 2 R antagonist, AM630, or was absent in CB 2 R-KO but not CB 1 R-KO mice. In addition, GW eliminated L-arginine-induced enhancement of Ca 2+ oscillations, pancreatic amylase, and pulmonary myeloperoxidase. Collectively, we provide novel evidence that activation of CB 2 Rs eliminates ACh-induced Ca 2+ oscillations and L-arginine-induced enhancement of Ca 2+ signaling in mouse pancreatic acinar cells, which suggests a potential cellular mechanism of CB 2 R-mediated protection in acute pancreatitis
Cumulative exposure to remnant cholesterol and the risk of fragility fractures: a longitudinal cohort study
ObjectiveTo investigate the association between cumulative remnant cholesterol (cumRC) and the risk of new-onset fragility fractures.MethodsThis study included individuals who participated in the 2006, 2008, and 2010 Kailuan health examinations. Baseline characteristics were compared between groups according to cumRC quartiles. The incidence density was calculated, and the log-rank test was used to compare the cumulative incidence. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI), and restricted cubic spline was used to examine the possibly non-linear relation between cumRC and the risk of fragility fractures. Additional analyses were performed with stratification by age (≥ or <65 years).ResultsA total of 43,839 individuals were included in this study. During the median follow-up period of 10.97 years, a total of 489 fragility fractures occurred. Multivariable Cox proportional hazards regression model 3 showed that the Q1 and Q4 groups versus the Q2 group were associated with a higher HR of fragility fracture (HR 1.61, 95% CI: 1.23–2.11; HR 1.38, 95% CI: 1.06–1.81), and restricted cubic spline regression analysis showed a non-linear relationship between cumRC level and the risk of fragility fractures (POverall association < 0.001, PNon-linear association = 0.001). The association was significant in the age group <65 years but not in the age group ≥65 years. The sensitivity analyses were consistent with the main results.ConclusionsBoth too high and too low cumRC levels were associated with a greater risk of fragility fractures, and this association was more significant in young and middle-aged people
Chinese FDI Approach in Africa: Engaging with A Voracious Dragon?
China¿s expanded links to Africa have created a discourse of how to characterize those ties.
This paper makes an attempt to uncover the determinants of China¿s outbound foreign direct
investment (OFDI) activities in Africa and to what extent a standard economic model can
account for the observed patterns of Chinese FDI in general. To address motivating questions, I
utilize newer data from 2003-2012 to conduct a formal econometric analysis, present year-byyear
estimates of main driving factors behind China¿s OFDI flows, and employ a ¿gravity
toolkit¿ robustness check approach to analyze the robustness of different specifications. By
using a gravity approach, I also provide a ground for a comparison of investment behaviors of
China versus other 36 large FDI source economies. The results show that China¿s OFDI
patterns exhibit both a conventional and an idiosyncratic dimension. Gravity model, overall, can
explain a large part of Chinese OFDI behaviors. Considerations such as host country market
size and geographic proximity play main role in terms of driving China¿s foreign investment
decisions. However, China is less sensitive to institutional risks and focuses more on natural
resources in host countries. Compared to other home countries, China also significantly targets
Africa as its FDI destination. These distinctive approaches, combining both market economy
and planned economy characteristics, are shaped by China¿s government¿s role, institutional
environment, and domestic economic imperatives
Relations between depressor effect induced by stimulation of peripheral ends of abdominal vagi and serotonin
Organophosphate ester metabolites in human breast milk determined by online solid phase extraction coupled to high pressure liquid chromatography tandem mass spectrometry
The analysis of metabolites of organophosphate esters (OPEs) in human breast milk is essential to evaluate OPE and OPE metabolite exposure of newborns. In the current study, an analytical method which only needs a small amount of breast milk (100 μl) was developed and validated for six diester metabolites and three hydroxylated metabolites applying salt-induced liquid–liquid extraction (SI-LLE) and dispersive solid phase extraction (d-SPE) for sample preparation and online solid phase extraction coupled to high pressure chromatography tandem mass spectrometry (online-SPE-HPLC-MS/MS) for quantitative measurement. The final method consisted of an extraction with formic acid (FA)/acetonitrile (1:200, v/v) and a cleanup with C18 d-SPE. The final extracts were trapped on a C18 cartridge with application of a wash step of 2 ml 0.1% FA milli-Q/methanol (98:2, v/v). Method detection limits (MDLs) ranging from 21.7 ng/l for BBOEHEP to 500 ng/l for BCIPP and average recoveries ranging from 58% for 5-OH-EHDPHP to 120% for BCIPP were achieved. Thirty-three breast milk samples from the LINC (Linking EDCs in maternal Nutrition to Child health) cohort collected in three distinct areas in The Netherlands were analyzed using the validated method. BCEP, BCIPP, BCIPHPP, BDCIPP, and 5-OH-EHDPHP were not detected in any of the samples, while BBOEP was the most frequently detected metabolite with a concentration range of <MDL to l.47 ng/ml, followed by DPhP and BBOEHEP, detected in ranges of <MDL to 0.09 and <MDL to 0.027 ng/ml. The results indicated that OPEs entering the human body are only to a limited extent excreted via breast milk
Analysis on the Connotation of Green Logistics
Green logistics which based on ecological environmental protection and sustainable development changed the unilaterally influencing relations between development and logistics, life of consumption and logistics, and it represented the future development direction and trend of logistics. Based on existing definitions of green logistics, this paper analyzed the connotation and related concepts of green logistics both in China and abroad and dissected the connotation of green logistics in aspects of objective, function, content, actors, etc. And the insufficiency of existing research results and future development direction were given on the basis of existing research results. In the current society, with the rapid development of economy, modern logistics activity has become increasingly frequent. At the same time, development of these two just affects each other. It is undeniable that development of modern logistics will promote economic development; meanwhile, rapid development of economy can also increase the logistics quantity. Therefore, they just supplement each other. With continuous development of economy, the demand for logistics increases continuously. Under the condition of high demand, many problems occur, such as urban traffic congestion, waste of resources and fuel consumption. Under such situations, the influence of logistics development on social environment is quite severe and it goes against sustainable development of economy in a new period. At present, people's environmental awareness increases gradually, and they begin to explore new logistics systems which can not only satisfy the demand of social development but also restrain the influence of logistics activity on environment. Thereby, "green logistics" emerges as the times require. "Green logistics" not only effectively improves the environment pollution problems of traditional logistics but also accords with the general trend of the current environmental protection. Therefore, it is the direction of future logistics development. As for study on "green logistics", a definition is proposed for green logistics in Logistics Terms (GB/T 18354-2001) published in 2001. However, the extensive logistics professionals lack a comprehensive understanding about green logistics and its characteristics. As a result, they cannot fully understand and even misunderstand green logistics, or some unnecessary faults might be caused. Therefore, it can provide reference for practical work of green logistics to strengthen cognition about green logistics and accurately comprehend the connotation of green logistics
The Preparation of High-Volume Fraction SiC/Al Composites with High Thermal Conductivity by Vacuum Pressure Infiltration
The high-volume fraction SiC/Al composite is the new type of electronic packaging material, which plays an important role in the field of high-power integrated circuits. In this study, SiC/Al composites with high-volume fraction of SiC particles were prepared by vacuum pressure infiltration. The influence of SiC particle size and NH4HCO3 on the pores in the preform was explored, aiming to accurately adjust the volume fraction of SiC to meet the thermal performance requirements in different fields. In addition, the preform was infiltrated with different Al alloys, and the relationship between the porosity and thermal conductivity of SiC/Al was studied. For the SiC preform, the volume fraction of SiC can be adjusted regularly when 12 μm and 100 μm SiC particles are mixed in different proportions, and the volume fraction reaches the maximum when the proportion of coarse particles is about 77%. NH4HCO3 is conducive to the connectivity of pores in the preform, and about 40 vol.% of NH4HCO3 can effectively increase the porosity of the preform. Thermal conductivity is sensitive to the porosity of composites, especially in the range of 2.5–4.5%. A simple application of the Hasselman–Johnson model and a new thermal conductivity model, λd, established in this article, offer a good agreement with the experimental results