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  • Author: Zhi Zhang x
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Transient effects of tendon disconnection on the survivability of a TLP in moderate-strength hurricane condition

Abstract

The primary objective of this paper is to investigate the dynamic stability and survivability of a four-column classic TLP(tension-leg platform) under less-than-extreme storm conditions where one or more tendons have been lost due to damage or disconnect. The transient responses of the platform and tendon tensions at the moment of disconnection are in time domain. Compared to the common industry practice of checking the system without a failed tendon on the beginning, the maximum tension on the neighboring tendon can be significantly increased at the moment of disconnection due to the snap-like transient effects, which can lead to unexpected failure of the total system. It is also found that the transient effects can be reduced with the presence of TTRs (top-tensioned risers) with pneumatic tensioners. It is also seen that TLP cannot survive in the 100-yr hurricane condition after losing one tendon

Open access
A Method for Monitoring the Underground Mining Position Based on the Blasting Source Location

Abstract

Some small and medium-sized coal mines are mining beyond their mining boundary driven by profit. The illegal activities cause many mine disasters but effective supervision is very hard to achieve, especially for underground coal mining. Nowadays, artificial blasting operation is widely used in tunneling or mining in small and medium-sized coal mines. A method for monitoring the underground mining position by monitoring the blasting source position is firstly introduced in this paper. The blasting vibration waves are picked up by the detectors and dealt by the signal acquisition sub-station, and then sent to the principal computer. The blasting source is located by the principal computer and displayed in the mine’s electronic map. The blasting source position is located in 10 seconds after the first P wave reaching the detector, whose error is registered within 20 meters by field-proven method. Auto-monitoring of the underground mining position in real-time is solved better and management level is improved using this method.

Open access
Site preference and electronic structure of Mn2RhZ (Z = Al, Ga, In, Si, Ge, Sn, Sb): a theoretical study

Abstract

The electronic structure and magnetism of Mn2RhZ (Z = Al, Ga, In, Si, Ge, Sn, Sb) Heusler alloys have been studied by using first-principles calculations. Three half-metallic ferromagnets, namely, Mn2RhAl, Mn2RhGe and Mn2RhSb have been considered. The calculated equilibrium lattice constant increases with increasing atomic number of Z atoms lying in same column of periodic table. The calculated total magnetic moments Mtot are 2 µB/f.u. for Mn2RhAl and Mn2RhGa, 3 µB/f.u. for Mn2RhSi, Mn2RhGe and Mn2RhSn, and 4 µB/f.u. for Mn2RhSb, which agrees with the Slater-Pauling curve quite well. In all these compounds, except for Mn2RhSb, the moments of Mn (A) and Mn (B) are antiparallel to each other. The total magnetic moments of the three considered half-metals assume integral values in a wide range of equilibrium lattice parameters.

Open access
Camera Calibration by Hybrid Hopfield Network and Self- Adaptive Genetic Algorithm

A new approach based on hybrid Hopfield neural network and self-adaptive genetic algorithm for camera calibration is proposed. First, a Hopfield network based on dynamics is structured according to the normal equation obtained from experiment data. The network has 11 neurons, its weights are elements of the symmetrical matrix of the normal equation and keep invariable, whose input vector is corresponding to the right term of normal equation, and its output signals are corresponding to the fitting coefficients of the camera’s projection matrix. At the same time an innovative genetic algorithm is presented to get the global optimization solution, where the cross-over probability and mutation probability are tuned self-adaptively according to the evolution speed factor in longitudinal direction and the aggregation degree factor in lateral direction, respectively. When the system comes to global equilibrium state, the camera’s projection matrix is estimated from the output vector of the Hopfield network, so the camera calibration is completed. Finally, the precision analysis is carried out, which demonstrates that, as opposed to the existing methods, such as Faugeras’s, the proposed approach has high precision, and provides a new scheme for machine vision system and precision manufacture.

Open access
Differentially Expressed Proteins between Esophageal Squamous Cell Carcinoma and Adjacent Normal Esophageal Tissue

Differentially Expressed Proteins between Esophageal Squamous Cell Carcinoma and Adjacent Normal Esophageal Tissue

Proteomics was employed to identify the differentially expressed proteins between esophageal squamous cell carcinoma (ESCC) and adjacent normal esophageal tissues. ESCC tissues and adjacent normal tissues were obtained from 10 patients with ESCC and the proteins were extracted and subjected to two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins were identified after image analysis, and matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) was used to confirm these proteins. Immunohistochemistry was then performed to detect the expressions of HSP27 and ANX1 in ESCC tissues and adjacent normal tissues. A total of 6 differentially expressed proteins were identified by peptide mass fingerprinting, among which SCCA1, KRT4 and ANX1 were down-regulated and TIM1, MnSOD and HSP27 up-regulated in the ESCC. Immunohistochemistry showed HSP27 was highly expressed in the ESCC which, however, had a low expression of ANX1. These findings were consistent with those in proteomics. There were differentially expressed proteins between ESCC and adjacent normal tissues. The investigation of differentially expressed proteins between ESCC and normal esophageal tissue may provide evidence for the molecular pathogenesis of ESCC.

Open access
Long-term clinical effects of treatment by daytime ambulatory peritoneal dialysis with an individualized dialysis dose mode are comparable to traditional dialysis methods (hemodialysis or continuous ambulatory peritoneal dialysis) for end-stage renal failure

Abstract

Background: At present, patients with end-stage renal failure (ESRD) face the question of how to achieve adequate dialysis to maintain their survival with the best quality of life as long as possible. Therefore, the choice of suitable dialysis methods and dialysis dose is important.

Objective: To find suitable dialysis methods and an appropriate dialysis dose for patients with ESRD.

Methods: Our research compares the long-term clinical effects between the patients undergoing continuous ambulatory peritoneal dialysis (CAPD), daytime ambulatory peritoneal dialysis (DAPD), and hemodialysis (HD). Thirty-two patients subjected to peritoneal dialysis were selected and divided into group A (n = 16) and group B (n = 16), group A was treated by using the traditional CAPD pattern; group B was treated by using DAPD. Forty-six patients of renal failure at final stage were divided into group A (n = 23) and group B (n = 23), group A was treated by using a HD method, group B was treated by using a DAPD method.

Results: When the same dialysis dose was applied, the patients with long-term DAPD treatment can obtain satisfactory clinical therapeutic efficacy for the period of maintenance dialysis, thoroughness of dialysis, maintenance of nutritional status, blood pressure regulation, reduction in incidence rate of peritoneal infection, maintenance of relatively high activity in daily life and alleviation in depression, comparable to patients treated with traditional CAPD or HD methods.

Conclusion: The long-term clinical effects of DAPD are comparable to CAPD or HD.

Open access
Initial effects of inflammation-related cytokines and signaling pathways on the pathogenesis of post-traumatic osteoarthritis

Abstract

The main pathological change in post-traumatic osteoarthritis (PTOA) is cartilage degeneration, which is closely related to inflammation and oxidative stress. Inflammation can cause degeneration of articular cartilage. Cartilage degeneration can also stimulate the progression of inflammation. It has been found that inflammatory cytokines can participate in the pathological process of cartilage degeneration through multiple signaling pathways, mainly mitogen-activated protein kinase, nuclear transcription factor kappa B, and Wnt–β-catenin signal transduction pathways. This review aimed at exploring the relationship between PTOA and inflammation-related cytokines by introducing the role of proinflammatory cytokines in chondrocyte destruction and extracellular matrix degradation.

Open access
The rtA181 Mutation Produces Similar Clinical and Cellular Characteristics in Patients infected with Hepatitis B Virus Genotypes B and C

Abstract

Objective to investigate the association between HBV genotypes and characteristics of rtA181 mutation.

Methods Total of 85 chronic hepatitis B (CHB) patients who appeared rtA181 mutation after nucleos(t)ide analogs (NAs) therapy were enrolled in this study. Levels of serum ALT, AST, HBV DNA and HBsAg titers were monitored during therapy. HBV reverse transcriptase genes were amplified and sequenced to identify genotypes and resistance mutations. Virions and HBsAg in HepG2 cell with rtA181 mutation were also compared between genotypes B and C.

Results The majority of sera contained HBV genotypes B (15.7%) and C (84.3%). There were no significant difference of rtA181 mutant patterns between genotypes (P > 0.05). After emergence of rtA181 mutation, serum ALT, AST, HBV DNA levels and HBsAg titers were decreased than that at baseline (P < 0.05), while these characteristics were not different between genotypes B and C (P > 0.05). In cellular experiment, there were no significant differences between genotypes B and C not only in HBV virions but also in HBsAg titres (P > 0.05).

Conclusions No differences of clinical characteristics and cellular results were found in rtA181 mutation of HBV genotypes B and C.

Open access
Inflammatory Cytokine Secretion Status of Bone Marrow Cells and Clinical Significance in Immunerelated Hematocytopenia

Abstract

Objective To observe the expression of inflammatory molecules in bone marrow immune cells of patients with immune-related hematocytopenia (IRH), and to investigate the immune mechanism and clinical significance of the disease.

Methods Total of 36 IRH patients were selected as observation group and 30 healthy people were taken as control group. Serum cytokines levels, activity of immunocytes and expression of HLA-DR were detected. Immune fluorescence was applied to observe the expression state of immunologic molecules and cytokines in IRH patients.

Results Serum cytokines were elevated in various degrees in observation group. Compared with the control group, the cytokines levels were significantly higher (P < 0.05). After treatement with immunosuppressive drugs, the serum levels of cytokines in observation group reduced to a level close to the control group. HLADR were upregulated in activated tissue basophils, eosinophils, dendritic cells (DC) and macrophages of bone marrow in IRH patients, and POX activity in these immunocytes of IRH was higher than that of the control group. Immune molecules were highly expressed in eosinophils, DC and macrophages.

Conclusions It is demonstrated that antibodies or self-reactive lymphocytes were produced in IRH marrow, which would cause lesions of hemocytes, and lead to pathological process finally. Structure of hematopoietic cells mutated and these cells might be acted as target cells of immunocytes in the pathological process. Immunocytes could secrete inflammatory factors and lead to immunologic injury of hemocyte.

Open access
Estimating Root Zone Moisture from Surface Soil Using Limited Data

Abstract

For estimation of root-zone moisture content from EO-1/Hyperion imagery, surface soil moisture was first predicted by hyperspectral reflectance data using partial least square regression (PLSR) analysis. The textures of more than 300 soil samples extracted from a 900 m × 900 m field site located within the Hetao Irrigation District in China were used to parameterize the HYDRUS-1D numerical model. The study area was spatially discretized into 18,000 compartments (30 m × 30 m × 0.02 m), and Monte Carlo simulations were applied to generate 2000 different soil-particle size distributions for each compartment. Soil hydraulic properties for each realization were determined by application of artificial neural network analysis and used to parameterize HYDRUS-1D to simulate averaged soil-moisture contents within the root zone (0-40 cm) and surface (approximately 0-4 cm). Then the link between surface moisture and root zone was established by use of linear regression analysis, resulting in R and RMSE of 0.38 and 0.03, respectively. Kriging and co-kriging with observed surface moisture, and co-kriging with surface moisture obtained from Hyperion imagery were also used to estimate root-zone moisture. Results indicated that PLSR is a powerful tool for soil moisture estimation from hyperspectral data. Furthermore, co-kriging with observed surface moisture had the highest R (0.41) and linear regression model, and HYDRUS Monte Carlo simulations had a lowest RMSE (0.03) among the four methods. In regions that have similar climatic and soil conditions to our study area, a linear regression model with HYDRUS Monte Carlo simulations is a practical method for root-zone moisture estimation before sowing and it can be easily coupled with remote sensing technology.

Open access