In this paper, a compound Poisson risk model with time-dependent claims is studiedunder a multi-layer dividend strategy. A piecewise integro-differential equation for the Gerber- Shiu function is derived and solved. A...
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In this paper, a compound Poisson risk model with time-dependent claims is studiedunder a multi-layer dividend strategy. A piecewise integro-differential equation for the Gerber- Shiu function is derived and solved. Asymptotic formulas of the ruin probability are obtained when the claim size distributions are heavy-tailed.
The continued warming of the Arctic atmosphere and ocean has led to a record retreat of sea ice in the last *** retreat has increased the probability of the opening of the Arctic Passages in the near *** Northwest Pas...
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The continued warming of the Arctic atmosphere and ocean has led to a record retreat of sea ice in the last *** retreat has increased the probability of the opening of the Arctic Passages in the near *** Northwest Passage(NWP)is the most direct shipping route between the Atlantic and Pacific Oceans,producing notable economic *** variations of sea ice and its influencing factors from a high-resolution unstructured-grid finite-volume community ocean model were investigated along the NWP in 1988-2016,and the accessibility of the NWP was assessed under shared socioeconomic pathways(SSP245 and 585)and two vessel classes with the Arctic transportation acces-sibility model in *** ice thickness has decreased with increasing seawater temperature and salinity,especially within the Canadian Arctic Archipelago(CAA)in 1988-2016,which has facilitated the opening of the *** ship navigation is projected to be possible for polar class 6 ships in August-December in 2021-2025,after when it may extends to July under SSP585 in 2026-2030,while open water ships will not be able to pass through the NWP until September in mid-21st *** navigability of the NWP is mainly affected by the ice within the *** the accessibility of the Parry Channel,the west part is worse than that of the eastern part,especially in the Viscount-Melville Sound.
The aim was to investigate transformation behavior and transformation kinetics of an ultra-low carbon bai- nitic steel during continuous cooling. Continuous cooling transformation (CCT) curves of tested steel were m...
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The aim was to investigate transformation behavior and transformation kinetics of an ultra-low carbon bai- nitic steel during continuous cooling. Continuous cooling transformation (CCT) curves of tested steel were measured by thermal dilatometer and metallographic structures at room temperature were observed by optical microscope. Then transformation kinetic equation of austenite to ferrite as well as austenite to bainite was established by analyzing the relationship of lnln]-l/(1--f)] and lnt in the kinetic equation on the basis of processed experimental data. Finally, the measured and calculated kinetic behaviors of the steel during continuous cooling were compared and growth pat- terns of transformed ferrite and bainite were analyzed. Results showed that calculated result was in reasonable agree- ment with the experimental data. It could be concluded that the growth modes of transformed ferrite and bainite were mainly one dimension as the Avrami exponents were between 1 and 2.
During the high nitrogen steel (HNS) melting process, the absorption reaction of nitrogen in the liquid steel by blowing NH3 and N2 was investigated respectively. In order to obtain higher content of nitrogen in ste...
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During the high nitrogen steel (HNS) melting process, the absorption reaction of nitrogen in the liquid steel by blowing NH3 and N2 was investigated respectively. In order to obtain higher content of nitrogen in steel, the liquid steel should be deoxidized and desulfurized because the oxygen and sulfur as surface activity element are not favorable to the absorption of nitrogen in melting process. Based on the metallurgical thermodynamics, the coupling reaction of NH3 with oxygen can improve the generation of activity nitrogen atom in liquid steel. Nitrogen atom is easier to be absorbed than nitrogen molecule. At the same time, blowing ammonia gas can remove the oxygen from liquid steel and decrease the inclusion in the steel. Experiments of HNS melting were carried out in a 10 kg induction furnace, and the results indicated that for liquid steel containing the same content of alloys and blowing the same mole of nitrogen, the absorption effect of nitrogen by blowing NH3 is obviously higher than that of blowing N2. The technical process of melting HNS by blowing NH3 under normal pressure is feasible in industrial production.
We proposed a scheme of fiber Bragg grating (FBG) sensor interrogation system based on all fiber Mach-Zehnder Interferometer (MZI) edge filter and tunable-FBG. The equal power signals from FBG sensor and tunable F...
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We proposed a scheme of fiber Bragg grating (FBG) sensor interrogation system based on all fiber Mach-Zehnder Interferometer (MZI) edge filter and tunable-FBG. The equal power signals from FBG sensor and tunable FBG are coupled into port 1 and port 2 of MZI respectively. The experimental results show that the interrogation precision of the proposed system is 0.02 nm in a range of I nm. Furthermore, the precision can be improved by adjusting the two interference arms of the filter.
BACKGROUND: The anti-proliferative gene, PC3 (pheochromocytoma cell 3)/BTG2 (B-cell translocation gene 2), is one of the early growth response genes and belongs to the BTG/Tob protein family. This study aimed to asses...
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BACKGROUND: The anti-proliferative gene, PC3 (pheochromocytoma cell 3)/BTG2 (B-cell translocation gene 2), is one of the early growth response genes and belongs to the BTG/Tob protein family. This study aimed to assess the effects of recombinant human hepatopoietin (HPO) and partial hepatectomy on rapidly induced expression of immediate-early genes and to investigate the expression of PC3/BTG2 mRNA in hepatocellular carcinoma (HCC) at different stages of progression. METHODS: After a rat model of partial hepatectomy was established, we investigated gene expression within I hour after 2/3 partial hepatectomy by representational difference analysis and in a primary cultured hepatocyte system. The expression levels of PC3/BTG2 from liver tissues of the rat model were assessed by RT-PCR and Northern blotting. Meanwhile, the expression of BTG2 mRNA in a tissue microarray of HCC was determined by in situ hybridization. RESULTS: The PC3/BTG2 gene was rapidly induced after 2/3 partial hepatectomy and its expression peaked within 1-2 hours after operation. HPO rapidly induced the expression of the genes c-fos, LRF-1, and PC3 in primary cultured rat hepatocytes, which might be one of the molecular mechanisms by which HPO stimulates hepatocyte proliferation. Positive BTG2 mRNA expression was detected in 71.19% (42/59) of the HCC samples and in 75% (3/4) of the normal liver tissue samples obtained from the region around the HCC tissues. PC3/BTG2 mRNA was located mainly in the cytoplasm of HCC cells and its expression was related to the degree of differentiation. CONCLUSIONS: Recombinant human HPO and partial hepatectomy rapidly induce the expression of the PC3/BTG2 gene. PC3/BTG2 mRNA is highly expressed in HCC cells and its expression is related to the degree of cell differentiation. The abnormal expression of PC3/BTG2 is closely related to the genesis and development of HCC, so PC3/BTG2 may play an important role in these processes. (Hepatobilimy Pancreat Dis Int 2009; 8: 288
A Bayesian Network is a reasoning tool based on probability theory and has many advantages that other reasoning tools do not have. This paper discusses the basic theory of Bayesian networks and studies the problems in...
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A Bayesian Network is a reasoning tool based on probability theory and has many advantages that other reasoning tools do not have. This paper discusses the basic theory of Bayesian networks and studies the problems in constructing Bayesian networks. The paper also constructs a Bayesian diagnosis network of a reciprocating compressor. The example helps us to draw a conclusion that Bayesian diagnosis networks can diagnose reciprocating machinery effectively.
Background Hypertensive intracerebral hemorrhage (HICH) is a severe disease with high morbidity and mortality. Timely removal of the hematoma through surgical procedures may effectively reduce secondary injuries. Ho...
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Background Hypertensive intracerebral hemorrhage (HICH) is a severe disease with high morbidity and mortality. Timely removal of the hematoma through surgical procedures may effectively reduce secondary injuries. However, there has long been a debate over the proper timing of such surgery. In this study, we explored the optimal operation time for HICH patients by observing the pathological changes in perihematomal brain regions during different stages of onset. Methods Twenty-five specimens of brain tissue, obtained from perihematomal region of HICH patients in different phases, were subjected to haematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) staining and Caspase-3, matrix metalloproteinases-9 (MMP-9) immunohistochemical staining. The changing roles of necrosis and apoptosis and the expression of MMP-9 and Caspase-3 positive cells were all observed using image analysis. Results The obvious expression of TUNEL positive cells was recognized within 6 hours of ICH onset, reaching its peak between 6 hours and 24 hours in the early phase. Results were highly consistent with Caspase-3 and MMP-9 positive cell counts. Necrosis was found 6 hours after ICH onset and aggravated after 12 hours. Conclusions In the early phase, apoptosis was seen as a major modality of injury in the brain tissue of the perihematomal region and was strongly correlated with the expression of MMP-9 and Caspase-3. The results of the present study suggest that an operation performed as soon as possible after ICH onset may be optimal for preserving the nervous system function.
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