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Objective: Neuroinflammation caused by traumatic brain injury (TBI) can lead to neurological deficits. Acupuncture can inhibit neuroinflammation and promote nerve repair; however, the specific mechanism is still unclear. The purpose of this study was to explore whether acupuncture could modulate the M1 and M2 phenotypic polarization of microglia in a rat model of TBI via the toll-like receptor 4 (TLR4)/intracellular toll-interleukin-1 receptor (TIR) domain-containing adaptor inducing interferon-β (TRIF)/myeloid differentiation factor 88 (MyD88) pathway.Methods: A total of 90 adult male Sprague-Dawley (SD) rats, SPF grade, were randomly divided into a normal group, model group and acupuncture group. Each group was further divided into three subgroups (first, third, and fifth day groups) according to the treatment time (n= 10 rats/subgroup). We used the modified neurological severity score (mNSS) method to quantify neurological deficits before and after modeling. We used Nissl staining to observe the pathological changes in brain tissue, flow cytometry to detect the proportion of M1 and M2 polarized microglia in the injured area on the first, third and fifth day, and co-immunoprecipitation (Co-IP) to examine TLR4/TRIF/MyD88 expression in microglia on the first, third and fifth day, as well as expression of the amount of binding of TLR4 with TRIF and MyD88.Results: Compared to the model group, mNSS in the acupuncture group gradually decreased and pathological morphology improved. The proportion of CD11b/CD86 positive cells was decreased, while that of CD11b/CD206 was increased in the acupuncture group. Expression of IP TLR4, IP TRIF and IP MyD88 also decreased in the acupuncture group.Conclusion: The results of this study demonstrate that one of the mechanisms through which acupuncture mitigates neuroinflammation and promotes nerve repair in TBI rats may be inhibition of M1 phenotypic polarization and promotion of M2 phenotypic polarization through inhibition of the TLR4/TRIF/MyD88 signaling pathway.

This study investigated the effects of grape seed extract (GSE) on fresh and cooked meat color and premature browning (PMB) in ground meat patties (85% beef and 15% pork back fat) packaged under high-oxygen modified atmospheres (HiOx-MAP). The GSE was added to patties at concentrations of 0, 0.10, 0.25, 0.50 and 0.75 g kg−1. This study evaluated the surface color, pH, lipid oxidation, and total viable counts (TVC) of raw patties, and the internal color and pH of patties cooked to a temperature of 66 or 71°C over 10-day storage at 4°C. Compared with the control (0 g kg−1GSE), GSE improved the color stability (P<0.05) and significantly inhibited the lipid and myoglobin oxidation of raw patties from day 5 to 10, but GSE had no effect (P>0.05) on TVC. Patties containing 0.50 and 0.75 g kg−1GSE cooked to 66°C exhibited greater (P<0.05) interior redness than the control and reduced the PMB of cooked patties in the late storage stage. These results suggested that 0.50 and 0.75 g kg−1GSE can improve fresh meat color and minimize PMB of HiOx-MAP patties.

Solution-phase hydrogen reduction (SpHR) was introduced into V2O3preparation to overcome disadvantages of traditional reduction roasting, which include a long process, high energy consumption, and generation of pollution. The research mainly focuses on ϕ–pH diagrams and kinetics of SpHR. Thermodynamic analysis of ϕ–pH diagrams for the V–H2O system demonstrates that V2O3preparation via SpHR requires a high temperature, a high vanadium concentration, and sufficient hydrogen in acidic solution. Kinetic analyses show that the activation energy of V2O3preparation via SpHR is 38.0679 kJ/mol, indicating that the reduction is controlled by a combination of interfacial chemical reaction and internal diffusion. Effects of H2partial pressure (slope K=0.05246) on the reaction rate is not as significant as the vanadium concentration (K=1.58872). V2O3crystals with a purity of 99.59% and a vanadium precipitation rate of 99.83% were obtained under the following conditions: pH=5–6, c(V2O5)=0.5 mol/L, p(H2)=4 MPa, m(PdCl2)=10 mg, T=250 °C, and t=2.5 h.

Through literature review and logical analysis, this paper analyses the pacing strategy and speed features of world-class elite sprint cross-country skiers in multiple-round events, as well as the speed and technical features in single-round events, and discusses the key factors affecting the athletic performance of sprint cross-country skiers. The study holds that the physiological function system, neuromuscular system and body morphological characteristics are important factors that affect and determine the athletic performance of sprint cross-country skiers; among them, aerobic metabolic capacity, anaerobic metabolic capacity, work efficiency, lactic acid metabolism and recovery from fatigue are the key indicators affecting athletes' strategy for high-speed equilibrium pacing in multi-round events; upper limb explosive power, upper limb strength and endurance, muscle type, and neural coordination are the key indicators that affect athletes' choice of higher-grade sliding techniques, high sliding frequency and long sliding performance. At the same time, height, weight and lean weight, especially upper limb strength endurance, are the key indicators affecting the speed and endurance of athletes. Combined with the analysis of the models for annual and periodical training sessions for world-class elite sprint cross-country skiers, the study offers relevant suggestions on China's high-level sprint cross-country skiing training: 1) develop the aerobic metabolic capacity, and value low- and medium-intensity aerobic endurance training; strengthen anaerobic endurance training, especially the high-intensity training based on the intensity of glycolysis anaerobic energy supply, and improve the level of anaerobic endurance based on aerobic metabolism; (3) stress the training for gliding efficiency and motion economy, and strengthen specialized training for main sliding technical movements, technical efficiency and motion economy on specific terrains; 4) strengthen scientific training monitoring, prevent injury and fatigue, and actively prevent and control major public health crises to ensure uninterrupted high-level crosscountry skiing training. [ABSTRACT FROM AUTHOR]

Objective: To investigate the regulatory mechanism of manual acupuncture (MA) on microglial polarization–mediated neuroinflammation after traumatic brain injury (TBI), focusing on the RhoA/Rho-associated coiled coil-forming protein kinase (ROCK2) pathway.Methods: Sprague Dawley (SD) rats were used to generate a TBI model using Feeney’s freefall epidural impact method. MA was performed on half of the TBI model rats, while the others remained untreated. Acupuncture was administered at GV15, GV16, GV20, GV26, and LI4. At the end of the intervention, rat brain tissue samples were collected, and the microglial M1 polarization status was observed by immunofluorescence labeling of CD86, an M1 microglia-specific protein. RhoA/ROCK2 signaling components were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. An enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of inflammatory factors.Results: Compared with normal rats, the CD86 expression density in the untreated TBI model rats was high and showed an aggregated expression pattern. The genes and proteins of the RhoA/ROCK2 signaling pathway were highly expressed, and inflammatory factors were significantly increased. The CD86 expression density in TBI rats after MA was reduced compared to that in untreated TBI rats and showed a scattered distribution. The expression of RhoA/ROCK2 signaling pathway genes and proteins was also significantly reduced, and inflammatory factors were decreased.Conclusion: These results show that MA may inhibit M1 polarization of microglia by regulating the RhoA/ROCK2 signaling pathway, thereby reducing neuroinflammation in TBI.

To conduct a reliability analysis for mechanical components, it is necessary to consider the combined influence of strength deterioration and dynamic loads. An efficient method based on subset simulation is proposed in this paper to analyze time-variant reliability by considering the strength deterioration of mechanical components in a continuous system. A gamma process is used to describe the deterioration of system strength. A model for time-variant reliability considering strength deterioration is constructed for a continuous system. A representative example and tubular cantilever structure are assessed to demonstrate the efficiency and accuracy of the proposed method. The reliability probability examples were analyzed using a first-order reliability method and benchmark results for the proposed method were derived using direct Monte Carlo simulation (MCS). The results of the proposed method and MCS are consistent, indicating that the proposed method is an effective reliability analysis method for evaluating small failure probabilities in a continuous system subjected to strength deterioration and dynamic loads.

The positioning error of ball screw feed systems is mainly caused by thermal elongation of the screw shaft in machine tools. In this article, an adaptive on-line compensation method of positioning error for the ball screw shaft is established. In order to explore the thermal–solid mechanism of ball screw feed drive systems, the experiments were carried out. An exponential fitting equation is presented to obtain the temperature relationship between the temperature sensitive point and its center of each heat source based on the finite element method of the feed drive system. Consequently, based on time and position exponential distribution functions, a variable separation model of heat transfer is established. Furthermore, based on the heat transfer model of multiple varying and moving heat sources, an adaptive on-line analytical compensation model of positioning error is presented. Finally, the effect of the adaptive on-line analytical compensation model of positioning error is verified through the experiments. And, this model has self-adaptive ability and robustness. Therefore, this adaptive on-line analytical compensation model based on the heat transfer theory can be applied in real-time compensation of positioning error.

The current research of reliability allocation of CNC lathes always treat CNC lathes as independent series systems. However, CNC lathes are complex systems in the actual situation. Failure correlation is rarely considered when reliability allocation is conducted. In this paper, drawbacks of reliability model based on failure independence assumption are illustrated, after which, reliability model of CNC lathes considering failure correlation of subsystems is established based on Copula theory, which is an improvement of traditional reliability model of series systems. As the failure time of CNC lathes often obeys Weibull or exponential distribution, Gumbel Copula is selected to build correlation model. After that, a reliability allocation method considering failure correlation is analyzed based on the model established before. Reliability goal is set first and then failure rates are allocated to subsystems according to the allocation vector through solving the correlation model. Reliability allocation is conducted for t= 1. A real case of a CNC lathe and a numerical case are presented together to illustrate the advantages of the reliability model established considering failure correlation and the corresponding allocation method. It shows that the model accords to facts and real working condition more, and failure rates allocated to all the subsystems are increased to some extent. This research proposes a reliability allocation method which takes failure correlation among subsystems of CNC lathes into consideration, and costs for design and manufacture could be decreased.

In order to accurately describe the complex transmission systems and clarify the effects of internal and external excitation on the vibration characteristics for large complex transmission systems, a dynamics model considering gear meshing error and time-varying meshing stiffness is established at two-stage planetary gears systems. The coupling model is established by matrix set method for two-stage planetary gears and multistage spur gears transmission systems. The random load excitation verified by experiments is the external excitation in the system, and the excitation caused by the time-varying meshing stiffness and meshing error is the internal excitation. The research on the response of the vibration systems shows that the internal excitation caused by gear meshing stiffness and gear meshing error has important influence on the dynamic load behavior of spur gears transmission in complex systems. For the planetary system with heavy external load, the dynamic behavior mainly depends on the external load, and the influence of internal excitation on the dynamic meshing force is less than that of the external excitation for the planetary system. The external excitation mainly affects the low-frequency region of the dynamic meshing force for the system, and the internal excitation affects the high-frequency region of the dynamic force for the system. The frequency influence interval of the internal excitation is much larger than that of the external excitation.

In order to improve beef color and color stability, step-chilling (SC) was applied on excised bovine longissimus lumborummuscle, with chilling starting at 0–4°C for 5 h, then holding the temperature at 12–18°C for 6 h, followed by 0–4°C again until 24 h post-mortem. pH and temperature were measured during rigor on SC loins as well as those subjected to routine chilling (RC, 0–4°C, till 24 h post-mortem). Color L*, a*, b* values, metmyoglobin (MetMb) content, MetMb reducing ability (MRA) and NADH content were determined on samples aged for 1, 7, and 14 d. Sarcoplasmic proteome analysis was only conducted on d 1 samples. The results showed muscles subjected to SC maintained a temperature at around 15°C for 5 to 10 h post-mortem, and exhibited a slow temperature decline, but rapid pH decline. Beef steaks treated with SC had higher L*, a*, b* and chroma values than those of RC samples at 1 and 7 d chilled storage (0–4°C), while showing no significant difference for a*, b* and chroma values at d 14. The SC samples also exhibited a lower relative content of surface MetMb, higher MRA and NADH content, compared with RC beef steaks during storage, indicating the SC-treated beef showed an improved color stability. Eleven differential protein spots/nine proteins were identified by two-dimensional gel electrophoresis and mass spectrometry, and those proteins were mainly involved in redox, chaperone binding, metabolic and peroxidase activity. Oxidoreductases play a role in decreasing the oxidation-induced myoglobin oxidation and benefiting the production of NADH, and finally improving the colour of beef. Of these, pyruvate dehydrogenase E1 component subunit beta showed a positive correlation with color L*, a*, b* values and accounted for more than 60% of the variation in color values; this protein can be considered as a potential beef color biomarker. The present study provided valuable information for studies on the molecular mechanism of color improvement from step-chilling, as well as for identifying markers associated with beef color.

Objective To study the effect of acupuncture on the TLR2/4-NF-?B signalling pathway in the cortex of Sprague-Dawley rats following traumatic brain injury (TBI), and investigate the possible mechanism underlying the effects of acupuncture on scar repair.Methods TBI was established using Feeney's free-falling epidural percussion model. In total, 108 rats were randomly divided into a normal group (n=18), untreated TBI model group (TBI group, n=36) and manual acupuncture-treated TBI group (TBI+MA, n=36). Each group of rats was subdivided into three time groups: 3-day (3d), 7-day (7d) and 14-day (14d). No treatment was given to rats in the normal and TBI groups. The TBI+MA?group received manual acupuncture at GV20, GV26, GV16 through GV15, and bilateral LI4. mRNA expression of TLR2, TLR4, NF-?B and protein in the rat cortices was quantified using real-time fluorescence quantitative polymerase chain reaction (qPCR) and Western blot analyses.Results The modified neurological severity score (mNSS) scores of the TBI+MA?group were improved compared with baseline scores 12?hours after modelling, and improved at 7d and 14d compared with the TBI group (P<0.05), while the score of the TBI group did not improve until 14d compared to baseline. mRNA and protein expression of TLR2, TLR4 and NF-?B in the TBI group were higher than the normal group at 3d (P<0.05), reached a peak at 7d, then began to decrease at 14d. mRNA and protein expression of TLR2, TLR4 and NF-?B were higher in the TBI+MA?group compared with the TBI group at 3d (P<0.05), were significantly down-regulated at 7d (P<0.01), and decreased to normal levels at 14d.Conclusions Acupuncture has a bidirectional regulatory effect on the TLR2/4-NF-?B signalling pathway-related genes TLR2, TLR4 and NF-?B in the TBI rat cortex, promoting their expression in the early stage and inhibiting it in the later stage.

This study investigated the pH/temperature decline of beef carcasses in a typical Chinese abattoir and color development as pH declined during rigor onset. A natural cubic spline model was used to model the pH/temperature decline for those carcasses which passed through pH 6.0. Six of the 97 carcasses that exhibited a high (≥6.10) ultimate pH (pHu) (dark-cutting) in the M. longissimus lumborum(LL) were sampled, along with the same numbers of normal pHu and intermediate pHu carcasses (5.40–5.79; 5.80–6.10, respectively), to examine color development within 24 h postmortem. It was shown that 66.7% of the modeled carcasses were outside the ideal pH/temperature window with a temperature@pH6.0 lower than ideal, suggesting the need for acceleration of the pH decline. The stable and low a*, b*and chroma values of high pHu beef within the first 12 h indicated dark-cutting beef might be detected earlier than expected.

A multifactor reliability allocation method for CNC lathes is proposed in this paper based on the failure mode effects and criticality analysis (FMECA) modified criticality factor and objective information. Firstly, taking into consideration the cost of reducing subsystems’ failure rates, criticality in FMECA analysis is introduced into reliability allocation. By making severity value nonlinear and based on subsystems’ failure rate, mathematical model of the cost of reducing subsystems’ failure rates is established, and then computational formula for modified criticality is obtained. Secondly, according to the objective information in existence, failure frequency ratio, failure stopping time ratio, reliability influence degree and structure complexity are calculated respectively. The four sets of values above and modified criticality are combined together as allocation factors. Ratio matrix of each allocation factor is computed to get comprehensive allocation matrix and allocation vector. Finally, the method is applied to a case of reliability allocation of a certain type of CNC lathes, and practicability of the method is analyzed. According to the allocation results, reliability design can be improved to increase the mean time between failure (MTBF) of subsystems and the overall lathe. The proposed method together with the example serves appropriately to show the feedback effect of failure information on reliability design and role of cost reduction in the allocation process.

ObjectiveTo study the effect of acupuncture on the TLR2/4-NF-κB signalling pathway in the cortex of Sprague-Dawley rats following traumatic brain injury (TBI), and investigate the possible mechanism underlying the effects of acupuncture on scar repair.MethodsTBI was established using Feeney’s free-falling epidural percussion model. In total, 108 rats were randomly divided into a normal group (n=18), untreated TBI model group (TBI group, n=36) and manual acupuncture-treated TBI group (TBI+MA, n=36). Each group of rats was subdivided into three time groups: 3-day (3d), 7-day (7d) and 14-day (14d). No treatment was given to rats in the normal and TBI groups. The TBI+MA group received manual acupuncture at GV20, GV26, GV16 through GV15, and bilateral LI4. mRNA expression of TLR2, TLR4, NF-κB and protein in the rat cortices was quantified using real-time fluorescence quantitative polymerase chain reaction (qPCR) and Western blot analyses.ResultsThe modified neurological severity score (mNSS) scores of the TBI+MA group were improved compared with baseline scores 12 hours after modelling, and improved at 7d and 14d compared with the TBI group (P<0.05), while the score of the TBI group did not improve until 14d compared to baseline. mRNA and protein expression of TLR2, TLR4 and NF-κB in the TBI group were higher than the normal group at 3d (P<0.05), reached a peak at 7d, then began to decrease at 14d. mRNA and protein expression of TLR2, TLR4 and NF-κB were higher in the TBI+MA group compared with the TBI group at 3d (P<0.05), were significantly down-regulated at 7d (P<0.01), and decreased to normal levels at 14d.ConclusionsAcupuncture has a bidirectional regulatory effect on the TLR2/4-NF-κB signalling pathway-related genes TLR2, TLR4 and NF-κB in the TBI rat cortex, promoting their expression in the early stage and inhibiting it in the later stage.

A new process for vanadium recovery from stone coal by roasting–flotation was investigated based on the mineralogy. The process comprised four key steps: decarburization, preferential grinding, desliming and flotation. In the decarburization stage, roasting at 550 °C effectively avoided the negative effect of the carbonaceous materials in raw ore and generation of free CaO from calcite decomposition during roasting. Through preferential grinding, the high acid-consuming minerals were enriched in the middle fractions, while mica was enriched in the fine and coarse fractions. Through flotation, the final concentrate can be obtained with V2O5grade of 1.07% and recovery of 83.30%. Moreover, the vanadium leaching rate of the final concentrate increased 13.53% compared to that of the feed. The results reveal that the decarburization by roasting at 550 °C is feasible and has little negative impact on mica flotation, and vanadium recovery from stone coal is conducive to reducing handling quantity, acid consumption and production cost.

Background:Parkinson’s disease (PD) is characterized by dopaminergic neuron degeneration in the substantia nigra (SN) accompanied by pathology of the dorsal motor nucleus of the vagus (DMV). Gastroparesis is a common non-motor system symptom of PD in patients and in animal models. However, the underlying mechanism of this symptom is not clear. We previously reported on the expression of enhanced tyrosine hydroxylase (TH) and decreased choline acetyltransferase (ChAT) in the DMV of a PD animal model and colocalization of TH and ChAT with the dopamine receptors D1and D2. We hypothesize that these receptors might contribute to the delayed gastric emptying observed in PD.Objective:To investigate the distribution of D1and D2in gastric-projecting DMV neurons and alteration of their distribution in a PD rat model.Methods:Retrograde tracing, double-labeling immunofluorescence techniques and western blotting were used.Results:After injection of the retrograde tracer fluoro-gold (FG) into the gastric wall, FG-labeled gastric-projecting motoneurons were observed in the caudal and rostral parts of the DMV, and neurons with D1-, D2- and ChAT- immunoreactivity (IR) were widely colocalized in the DMV. Many TH-IR fibers were observed around the D1- and D2-IR neurons. Moreover, decreased D1and enhanced D2expression in the DMV was observed in 6-hydroxydopamine (6-OHDA) rats that were treated with a bilateral microinjection of 6-OHDA in the SN.Conclusions:The results indicate that dopamine receptors might affect the activity of gastric-projecting neurons in the DMV, their altered expression may contribute to the gastroparesis observed in PD.

Background:Parkinson’s disease (PD) is characterized by dopaminergic neuron degeneration in the substantia nigra (SN) accompanied by pathology of the dorsal motor nucleus of the vagus (DMV). Gastroparesis is a common non-motor system symptom of PD in patients and in animal models. However, the underlying mechanism of this symptom is not clear. We previously reported on the expression of enhanced tyrosine hydroxylase (TH) and decreased choline acetyltransferase (ChAT) in the DMV of a PD animal model and colocalization of TH and ChAT with the dopamine receptors D1and D2. We hypothesize that these receptors might contribute to the delayed gastric emptying observed in PD. Objective:To investigate the distribution of D1and D2in gastric-projecting DMV neurons and alteration of their distribution in a PD rat model. Methods:Retrograde tracing, double-labeling immunofluorescence techniques and western blotting were used. Results:After injection of the retrograde tracer fluoro-gold (FG) into the gastric wall, FG-labeled gastric-projecting motoneurons were observed in the caudal and rostral parts of the DMV, and neurons with D1-, D2- and ChAT- immunoreactivity (IR) were widely colocalized in the DMV. Many TH-IR fibers were observed around the D1- and D2-IR neurons. Moreover, decreased D1and enhanced D2expression in the DMV was observed in 6-hydroxydopamine (6-OHDA) rats that were treated with a bilateral microinjection of 6-OHDA in the SN. Conclusions:The results indicate that dopamine receptors might affect the activity of gastric-projecting neurons in the DMV, their altered expression may contribute to the gastroparesis observed in PD.

Differentiation of liver progenitor cells (LPCs) to functional hepatocytes holds great potential to develop new strategies for hepatocyte transplantation and the screening of drug-induced cytotoxicity. However, reports on the efficient and convenient hepatic differentiation of LPCs to hepatocytes are few. The present study aims to investigate the possibility of generating functional hepatocytes from LPCs in an indirect co-culture system.

Objective To observe the effects of acupuncture treatment on the expression of Wnt/ß-catenin signalling pathway-related genes (Wnt3a, ß-catenin and Sox2) in the injured cerebral cortex of rats with traumatic brain injury (TBI).Methods A controlled impact model of TBI was established using Feeney's free-drop method. Seventy-eight Sprague-Dawley rats were randomly divided into the following three groups: a normal group (n=18) that was left untreated; a model group (n=30) that received no treatment after TBI; and an acupuncture group (n=30) that received acupuncture (at LI4, GV20, GV26 and GV16) after TBI. Rats in each group were randomly and equally divided into 3-day, 7-day and 14-day subgroups according to the duration of therapy. Real-time fluorescence quantitative PCR (RT-qPCR) was used to measure mRNA expression of Wnt3a, ß-catenin and Sox2. Western blots were performed to determine the expression levels of WNT3a, ß-Catenin and SOX2.Results Wnt3amRNA was upregulated in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.05). ß-cateninexpression was significantly increased in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.01). In the 3-day and 7-day acupuncture subgroups, Sox2 expression was significantly higher than that in the normal and model groups (p<0.01 each). The levels of WNT3a, ß-catenin and SOX2 were generally consistent with the corresponding mRNA levels.Conclusions Acupuncture exerts a regulatory effect on the Wnt/ß-catenin signalling pathway, which may in turn influence the proliferation and differentiation of endogenous neural stem cells.

The existing fractal contact model fails to solve the problem of online real-time irregular curvilinear contact under mixed lubrication conditions. In this study, a novel arbitrary curve contact model is established, considering the actual operating condition that occurs under mixed lubrication. Furthermore, a new online friction–thermal–load coupling model for an arbitrary curve contact under mixed lubrication conditions is presented, considering the actual operating condition. To investigate the effects of the proposed online friction–thermal–load coupling model, a 30,205 tapered roller bearing with curved contact is examined by reading the real-time key point temperatures using thermocouple. Finally, the effectiveness of the presented model is verified through experiments and comparison.

Linezolid is an effective antibiotic reagent for Gram-positive bacterial infection; its most common side effect is thrombocytopenia. However, the incidence of thrombocytopenia in patients with acute-on-chronic liver failure (ACLF) who underwent linezolid therapy was unclear. The present study was to evaluate the incidence of thrombocytopenia in ACLF and non-ACLF patients treated with linezolid and the risk factors of thrombocytopenia in these patients.

The paper is concerned with the frequency reliability sensitivity and related robust analysis problem for the random continuous vibration structure systems. Reliability analysis based on frequency is necessary for reliability problems of uncertain vibration structure systems. With the criterion that the absolute value of the difference between the natural frequency and forcing frequency, the reliability mode and the safety probability of the random systems are defined, and then The frequency sensitivity analysis method is quested by using the random perturbation technique, the reliability theory and sensitivity approach. Furthermore, the frequency reliability-based robust method of the random dynamic structural system was obtained by the robust and the optimization technology on the basis of frequency reliability and sensitivity design, which helped designers to establish acceptable parameter values and to determine the fluctuations of the parameters for the safe operations. Moreover, a numerical example is provided to demonstrate the effectiveness and accuracy of the proposed method. This study established theory basis for sensitivity and robust evaluation.

Based on the matrix calculus, the generalized second moment technique and the stochastic finite element theory, the effective approach for the transfer reliability of vibration transfer path systems was presented. The transfer reliability of vibration transfer path systems with uncertain path parameters including mass and stiffness was analyzed theoretically and computed numerically, and the correlated mathematical expressions were obtained. Thus, it provides the theoretical foundation for the dynamic design of vibration systems in practical project, so that most uncertain factors can be considered to solve the random problems for vibration transfer path systems.

In order to enhance the quality of iron concentrate from magnetic separation, reverse-flotation technology is often applied in iron ore dressing plant. However, this technology has disadvantages in operating cost, energy consumption and environmental protection (Zhao Chunfu, Wu Jianghua &Wang Hui ,2005). Developing innovative equipment to process magnetite ore more-effectively is a way to get rid of these disadvantages of reverse flotation and improve the quality of iron concentrate. This paper describes the development of Complex Flashing-Field Magnetic Cleaner, a new kind of equipment based on the principle of combination of separation in magnetic field and separation in gravity field (Hao Shuhua & Jiang Wenli,2002). This innovative equipment possesses a tailor-made magnetic system and has the characteristics of a magnetic field which can strengthen the formation of magnetic agglomerations and the dispersion of gangue minerals to improve the quality of separation. The automatic control system developed specifically for this equipment can further increase the accuracy of separation and stabilize the process. Test results showed that this equipment is reliable in operation, economically beneficial and it has large potential of application.

Based on the Sobol’ theory, Hamma and Saltelli indicator system, the path parameters were divided into the different subsets for the vibration transfer path systems with random paths in this paper. The object function was constructed and decomposed, thus the global sensitivity based on variances was formed. The first-order and total sensitivities of various parameter subsets were calculated using Monte-Carlo simulation method combined with Latin hypercube sampling technique. Through the analysis example, the way is feasible to analyze the interaction of paths or path parameters in the vibration transfer path systems with uncertainty.

Background: Parkinson's disease (PD) is a neurodegenerative disorder that is characterized by degeneration of dopaminergic neurons in the substantia nigra (SN). Destruction of the SN can lead to gastric dyskinesis accompanied by decreased expression of choline acetyltransferase (ChAT) and increased expression of tyrosine hydroxylase (TH) in the dorsal vagus complex (DVC), which includes the dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitarius (NTS). However, it is unclear if the SN and DVC are directly connected. Objective: To investigate the neural projection from the SN to the DVC in rats. Methods: Retrograde and anterograde tracing techniques combined with double-labeling immunofluorescence technique were used. Results: Destruction of the SN significantly decreases ChAT immunoreactivity (IR) and increases TH-IR in the DVC. After injection of the retrograde tracer fluoro-gold (FG) into the DVC, FG-labeled neurons were observed in the hypothalamic paraventricular nucleus (PVN), lateral hypothalamus (LH), inferior olive (IO), and locus coeruleus (LC). No FG-positive cells were observed in the SN or striatum. Furthermore, after injection of anterograde tracer biotinylated dextran amine (BDA) into the SN, BDA-positive fibers were observed in the caudate putamen (Cpu), globus pallidus (GP), LC, and LH but not in the DVC. Conclusion: This study is the first to demonstrate that neurons in the SN do not directly innervate the DVC in rats. The DVC might be indirectly innervated by the SN through the hypothalamus and/or the LC. These data provide important morphological insights into the potential mechanism underlying the gastroparesis observed in PD patients.

Organic phosphorus in sediments of lake Gehu in China was investigated and researched via two methods: chemical fractionation and phosphorus-31 nuclear magnetic resonance spectroscopy. Results of chemical fractionation suggested that concentration of each organic phosphorus species in different sediments may varied highly since different condition, but showed a rank trend : residual Po> HCl-Po> Fulvic-Po> Humic-Po>NaHCO3-Po. Labile and moderately labile Po , regarded as potential P , contributed to 33.6% to 64.6% relative to total Po, which can be degraded for phytoplankton. 31P-NMR results suggested that the rank order of P species presented in NaOH-EDTA extractants of sediments: orthophosphate> monoester-P> DNA-P> pyrophosphate-P, and polyphosphate and phosphonate were almost not detected.

A new hybrid adsorbent of calcium-alginate encapsulated BaSO4-CR (CABSC) has been prepared. The adsorption selectivity and mechanism were studied by investigating the adsorption performance of two anionic and two cationic dyes. The adsorption of two cationic dyes (EV and MB) from aqueous solutions was examined using a batch sorption technique. The effects of time, pH, temperature and ionic strength on the adsorption were examined. Besides, this material was applied in the treatment of two practical cationic dye wastewaters. Our study shows that the sorbent could be a potential candidate for utilization in dye wastewater treatment processes.

Particle–bubble interaction during electro-flotation of cassiterite was investigated by determining the recovery of cassiterite and the collision mechanism of cassiterite particle and H2bubble. Flotation tests at different conditions were conducted in a single bubble flotation cell. The recovery of cassiterite was found to be affected by cassiterite particle and bubble size. A matching range, in which the best recovery can be obtained, was found between particle and bubble size. Collision, attachment, and detachment of the particle–bubble were observed and captured by a high-speed camera. Particle–bubble collision and attachment were analyzed with the use of particle–bubble interaction theory to obtain the experimental results. An attachment model was introduced and verified through the photos captured by the high-speed camera. A bridge role was observed between the bubbles and particles. Particle–bubble interaction was found to be affected by bubble size and particle size, which significantly influenced not only the collision and attachment behavior of the particles and bubbles but also the flotation recovery of fine cassiterite particles.

A technology of one-stage roughing and one-stage scavenging vanadium pre-concentration with shaking table was investigated for improving vanadium grade and decreasing acid consumption minerals content based on the quantitative evaluation of minerals by scanning electronic microscopy (QEMSCAN). In order to visually illustrate how the vanadium-bearing minerals were separated from system, a loose-stratification model was established with Bagnold shear loose theory and Kelly stratification hypothesis. Through the model, it was inferred that fine fraction and coarse fraction of vanadium-bearing muscovite particles easily became the concentrate in roughing and scavenging stages, respectively. The type of the dominant effect on the loose-stratification was confirmed. In the roughing stage, gravity sedimentation played a leading role in the loose-stratification process. However, in the scavenging stage, shearing dispersion pressure caused by asymmetric motion of table deck took an important part in the loose-stratification process. Finally, the correction of the loose-stratification model was validated by the practical experiment.

This paper based on the generalized probabilistic perturbation finite element method solves the random response analysis problem of vibration transfer path systems with translational and rotational motions. The effective random response analysis approaches are achieved using Kronecker algebra, matrix calculus, generalized second moment technique of vector-valued functions and matrix-valued functions. For the vibration transfer path system with multi-dimensional paths, the random response is described correctly and expressly in time domain as uncertain factors, which include mass, damping, stiffness and position, are considered. The mathematical expressions of the first order and second order moments for the random vibration response of vibration transfer path are obtained. According to the corresponding numerical example, the results of calculation are consistent with the results of Monte-Carlo simulation, which shows the method is feasible theoretically.

The frequency reliability.method of avoiding resonance is proposed by the mechanical dynamics, stochastic finite element method, the reliability theory in the paper. Furthermore, the frequency reliability sensitivity method is presented based on the frequency reliability research, and the frequency reliability-based robust method is obtained by the robust and the optimization technology on the basis of frequency reliability and sensitivity design, which help designers to establish acceptable parameter values and to determine the fluctuations of the parameters for the safe operations. Moreover a numerical example is provided, the frequency reliability robust numerical results are obtained, which are in agreement with practice and demonstrate the effectiveness and accuracy of the proposed method.

Under continuous cutting conditions, the reliability of alumina-based ceramic cutting tools wear life with abrasion wear was discussed extensively. An ultimate state equation of alumina-based ceramic cutting tools wear life was proposed according to stress-strength interference theory. Based on the premise that the probability distribution of random parameters has been known, the fracture toughness KIC and the hardness H which obey Weibull distribution were transformed into normal distribution by means of the equivalent normal distribution method, and then the reliability of alumina-based ceramic cutting tools wear life was analyzed by saddle point approximation method. The probability density function and cumulative distribution function of the ultimate state equation were accurately and quickly obtained by way of saddle point approximation, as a result, the saddle point approximation method was proved accurate with high computing speed in comparison with the Monte-Carlo method. Therefore, the application of the saddle point approximation method developed the reliability analysis theory of alumina-based ceramic cutting tools wear life.

Multispan rotor system(H858 compressor) is studied in this paper. Based on the rotor dynamic theory, complex rotor system is simplified reasonably, and finite element model is established using finite element software(MSC.Patran&Nastran). The natural frequencies are obtained in the condition of bending vibration, and the functions of frequencies and variables are matched on the basis of the artificial neural network (ANN) technique. With the criterion that the absolute value of the difference between the natural frequency and forcing frequency, the reliability mode and the systems safety probability are defined, then the frequency reliability sensitivity analysis method is presented. And the equations of the related sensitivity with respect to mean values and variances are mathematically expressed. The reliability and sensitivity of rotor system are analyzed, which demonstrate the effectiveness and accuracy of the proposed method.

While dealing with Engineering Drawing based on the secondary development of Inventor, different kinds of label symbols are due to be added based on the lines in the views. For serialized parts, the system sort of the lines will change with the change of 3D models, so we need to add manual sort artificially. Through research, several methods of manual sorting have been summarized: First to traverse lines based on shape, filter out the types of the lines. Then traverse the types, take advantage of extreme value method, method using center of the view as reference system, method using manual sorted line as reference system, and composite method to positioning lines, give them manual sorting. These methods solved the sort consistency of the same lines in different views, ensured the accuracy of labeling.

Thixotropy, which is an important rheological behavior of waxy crudes, is very important to the hydraulic characteristics and safety of the restart process of crude oil pipelines. Thixotropic behaviors of four waxy crudes were studied experimentally under three kinds of loading conditions, which were constant shear rate, stepwise increase of shear rate and cyclic change of shear rate, namely hysteresis loop. Eight thixotropic models were evaluated by least-square regressions based on experimental data. The average absolute deviation was taken as the measurement of fitness of a model. It is concluded that the model, which was established on the basis of Houska model and Cheng’s idea that wax crude oil contains both complete and partial reversibility structures, is the most suitable model to describe the thixotropy of wax crude oil

The rheology behavior of waxy crude emulsion is an important basic information on safeguard research of crude oil-water flow. The non-newtonian characteristics of apparent viscosity of three kinds of waxy crude emulsions were studied experimentally around condensation point; three apparent viscosity forecasting models were evaluated by least-square regressions based on experimental data of shear balance and the average absolute deviation was taken as the measurement of fitness of a model to experimental data. It is concluded that the Pal-Rhodes model, whose relative deviation can be as high as 80%, is the worst forecasting model, but it need the least experiment data to obtain model parameters, only water cut was needed. Elgibaly model has the best forecasting results, the average absolute deviation of forecasting results of three waxy crude emulsions under the condition of different temperature, water cut and shear rate were all less than 15%, but compared with the other two models, Elgibaly model needs the most parameters.

Parameter uncertainty of general systems is inherent in most engineering problems. Based on the regularity of oil whip and resonance for rotor system, the reliability problem of rotor system with oil whip and resonance is studied by applying random perturbation technology and reliability theory considering the correlation of the multi-order natural frequency. The reliability mode and the failure probability of rotor systems are defined. The second-order joint failure probability is obtained by using the numerical integration method. The presented method provided the theoretic basis for the reliability design of the rotor system. A numerical example demonstrated that the proposed method is effective.

The purpose of the design of the vibration absorber is to reduce the optimal way vibration of the inverted pendulum system to meet the requirements of the technical mechanical engineering. This research has studied about the theories of the optimal parameters of the vibration absorber TMD form to install the structure inverted pendulum form and has identified the optimal parameters for the vibration absorber in the general case for inverted pendulum structure.

This paper has researched an equation of motion of the inverted pendulum when installation of the reduce system vibration. From the equation of motion of the inverted pendulum system, we can see that it contains a quantity of vibration absorber. This is the basis for our analysis and calculations, to find the parameters of the vibration absorber we need to design an optimum parameters to reduce vibrations. This paper has also researched calculation on the parameters of the vibrations absorber to find the required conditions on the vibrations absorber design to ensure that system to stable working.

In this paper, a four degrees of freedom half body vehicle suspension system is developed .The Radial-Basis Function network algorithm is used to control the suspension system. With the aid of software Matlab/Simulink , the simulation model is achieved. A lot of simulation work is done. Simulation results demonstrate that the proposed active suspension system proves to be effective in vibration reduction of the suspension system.

In this paper, a practical technique for system reliability evaluation of kinematic performance of planar linkages with correlated failure modes is proposed. Taylor series expansion is utilized to derive a general expression of the kinematic performance errors caused by random design variables. A practical limit state function for reliability analysis of the kinematic performance of planar linkages corresponding to different failure models is established. Through the reliability theory and the linear programming method the upper and lower bounds of the system reliability of planar mechanisms are provided.

According to components reliability sensitivity theory methods, looking upon the dynamic characteristics of hydrodynamic lubrication sliding bearing as the target for study, doing some reliability sensitivity analysis for the bearing-rotor system instability issues, numerical simulation results are given though analyzing. The outcome of the dynamic performance index is proposed based on the sliding bearing selection method for engineering practice to the selection of the radial journal bearing and provides a theoretical basis for overall design of shafting.

A new way, which is used to analysis the path contribution, is presented for the vibration transfer path systems considering the interact of vibration source, transfer path and receiver. It is that the path contribution is evaluated using the path transfer probability. According to the dynamic characteristics of vibration systems, the new concept of path transfer probability is given. Based on the generalized probabilistic perturbation method and the reliability theory, the computational approach for path transfer probability with uncertain physics and geometry factors in time range are presented. The transfer probability of vibration transfer path systems with translational and rotational motions is analyzed and calculated via a numerical example, which shows that the proposed method is feasible.

Based on reliability design theory, by using the Edgeworth series method, and the sensitivity analysis method, the reliability sensitivity of the cylindrical gear pairs with non-Gaussian random parameters are extensively discussed and a numerical method for reliability sensitivity design is presented. The variation regularities of reliability sensitivity are obtained and the effects of design parameters on reliability of the cylindrical gear pairs are studied. The presented method provides the theoretic basis for reliability design of cylindrical gear pairs.