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Neonatal hypoxia/ischemia (H/I), injures white matter, results in neuronal loss, disturbs myelin formation, and neural network development. Neuroinflammation and oxidative stress have been reported in neonatal hypoxic brain injuries. We investigated whether Paeoniflorin treatment reduced H/I-induced inflammation and oxidative stress and improved white matter integrity in a neonatal rodent model. Seven-day old Sprague-Dawley pups were exposed to H/I. Paeoniflorin (6.25, 12.5, or 25 mg/kg body weight) was administered every day via oral gavage from postpartum day 3 (P3) to P14, and an hour before induction of H/I. Pups were sacrificed 24 h (P8) and 72 h (P10) following H/I. Paeoniflorin reduced the apoptosis of neurons and attenuated cerebral infarct volume. Elevated expression of cleaved caspase-3 and Bad were regulated. Paeoniflorin decreased oxidative stress by lowering levels of malondialdehyde and reactive oxygen species generation and while, and it enhanced glutathione content. Microglial activation and the TLR4/NF-κB signaling were significantly down-regulated. The degree of inflammatory mediators (interleukin 1β and tumor necrosis factor-α) were reduced. Paeoniflorin markedly prevented white matter injury via improving expression of myelin binding protein and increasing O1-positive olidgodendrocyte and O4-positive oligodendrocyte counts. The present investigation demonstrates the potent protective efficiency of paeoniflorin supplementation against H/I-induced brain injury by effectually preventing neuronal loss, microglial activation, and white matter injury via reducing oxidative stress and inflammatory pathways.

Background There are growing number of researches have shown that mesoderm posterior basic helix-loop helix (BHLH) transcription factor 1 (MESP1) plays a crucial role in the development of tumors. However, its expression pattern and function in non-small cell lung cancer (NSCLC) are still unknown. Methods MESP1 expression and biological process were investigated in NSCLC based on bioinformatics analysis. The mRNA or protein expression levels of MESP1 were measured by quantitative real-time PCR (qRT-PCR) and western blot (WB) assay in NSCLC cells and clinical tissue samples. Then, we used small interfering RNA (siRNA) interference to knocking down expression of gene in NSCLC cells. Cell proliferation was performed using cell counting kit-8 (CCK-8), colony forming assay and real-time cell analyzer (RTCA); transwell chambers and RTCA were used to analysis cell migration and invasion. Besides, analyses of the cell cycle progression and apoptosis were measured via BD JAZZ flow cytometric analysis. All the experiments were repeated ≥3 times. And analyses were performed using SPSS software version 21.0 and GraphPad Prism 6.0. P

Background This study aims to screen and identify the biological functions and prognostic value of CXC chemokines in ovarian cancer (OC) through bioinformatics and molecular biology methods, and to provide data support for the selection of biomarkers and prognostic analysis of OC. Methods In this study, GEO, ONCOMINE, GEPIA, cBioPortal, GeneMANIA, Metascape, STRING, TRRUST, and TIMER databases were used to study CXC chemokines. Angiogenesis and T cell killing assay were used to detect the effect of CXCL10 on tumor cell immunity and angiogenesis. Real-time quantitative PCR (qRT-PCR), immunoblotting, and ectopic tumor formation experiments were used to verify the effect of CXCL10 on ovarian cancer tumors. Results We found that CXCL1, CXCL10, CXCL11, CXCL13, and CXCL14 were significantly upregulated in OC samples compared with normal tissues. Our data showed that there was a relationship between the expression of CXC chemokines and the infiltration of six types of immune cells significant correlation. In vitro assay confirmed that overexpression of CXCL10 could enhance the killing effect of T cells and inhibit angiogenesis. Further in vivo assay had shown that CXCL10 could affect the progression of ovarian cancer by increasing the expression of cytotoxic T cells and inhibiting angiogenesis. Conclusion In conclusion, we hope that our data will provide new insights into the development of immunotherapy and the selection of prognostic markers for patients with OC.

Naringenin is highly potent dietary phenolic compound (Flavonoids) found as a major bioactive in citrus fruits. The low solubility of Naringenin, decreases its availability at the site of action by hindering solubility and transportation across the biological membrane. Naringenin loaded nanoparticles enhance the solubility and drug availability at site of action. Naringenin solid lipid nanoparticles were prepared by emulsification and homogenization method using GMO (glycerylmonooleate) and TPGS (Tocopheryl polyethylene glycol succinate) as co-stabilizer. Physico-chemical characterization confirmed the particles were of nanometer size, smooth and spherical morphology. The FTIR and DSC studies conforms that drug and polymers are compatible. The in-vitro study shows prolong and sustained release of Naringenin upto 90 Hrs. In-vivo studies conforms the prolonged and efficient treatment of Hepatic fibrosis. The liver enzymes and pro inflammatory cytokines in blood got significantly reversed with the rats exposed to Naringenin nanoparticle indicating reduced liver damage and fibrosis. Nanoformulation enhances the bioavailability of Naringenin and liver specific delivery of the same, which up-regulates MMP-2 hepatic proteins resulting in reduced liver fibrosis.

Objective Hypertension is an important risk factor for cardiovascular disease. The purpose of this survey was to determine the prevalence of hypertension subtypes and the risk factors associated with hypertension subtypes among ethnic Dai adults in rural China. Methods A population-based survey was carried out with 2150 rural inhabitants aged 50 years or older. The definition of hypertension was a systolic blood pressure (SBP) ≥140 mmHg and/or a diastolic blood pressure (DBP) ≥90 mmHg, or a current treatment plan with an antihypertensive medication. Hypertension included the following subtypes: systolic–diastolic hypertension (SDH), isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH). All participants were interviewed, had physical examinations performed, and had blood pressure measurements taken. Multivariate logistic regression analysis was applied to analyse the risk factors for hypertension. Results The prevalence of HBP was 43.2% (95% CI: 41.1-45.3). The subtype-specific prevalence of hypertension was 16.5% (95% CI: 14.9-18.0) for SDH, 24.2% (95% CI: 22.4-26.0) for ISH and 2.5% (95% CI: 1.9-3.2) for IDH. Among hypertensive participants, 37.9% were SDH, 56.8% were ISH and 5.8% were IDH. Older age is a risk factor for HBP and ISH. Obesity, smoking, drinking and history of hypertension are risk factors for HBP, SDH, ISH and IDH (OR>1). Of the hypertensive participants, the awareness of hypertension in our study was 25.0% for HBP, 34.7% for SDH, 20.0% for ISH and 9.3% for IDH. The rates of treatment and control were 23.8% and 6.9% for HBP, 26.8% and 7.9% for SDH, 23.1% and 6.3% for ISH and 11.1% and 5.6% for IDH, respectively. Conclusions Among Dai people in rural China, the prevalence of hypertension is high, and the awareness, treatment and control of hypertension is low. ISH is the most frequent kind of high blood pressure in rural elderly people. With the ageing population in China, ISH remains an important public health problem and a challenging issue for practising physicians in rural China. Public health strategies should regularly provide more information about hypertension to both the local physicians and the general population. To reduce cardiovascular events, a combination of drugs and lifestyle changes are strongly recommended.

The accuracy of the occlusion vertical dimensions of edentulous Han patients from Yunnan province was compared and analyzed on the basis of cone-beam computed tomography (CBCT)-synthesized cephalograms, closest speaking space method, and interocclusal distance.A database correlating the CBCT head lateral images of Han patients from Yunnan province with normal occlusal conditions was first constructed. Then, five edentulous Han patients aged 63-78 years old from Yunnan Province were selected. NNT.View software was used to measure and analyze hard tissue cephalometric radiographs that had been transformed by the CBCT marker. The radiographs were then combined with the normal population database for the assessment of occlusion vertical dimensions. The occlusion vertical dimensions determined on the basis of CBCT-synthesized cephalograms, the closest speaking space method, and the free-way space were analyzed.The closest speaking space method was used as the standard control group, the differences between seven methods and the closest speaking space method were analyzed. The seven methods include free-way space method and six CBCT-synthesized cephalograms methods (N-ANS/ANS-Me, S-Go/N-Me, ANS-Gn/N-ANS, ANS-FH/Me-FH, ANS-Xi-Pm, and CA/LA). The seven methods were highly consistent with the closest speaking space method (intraclass correlation coefficient0.986). The absolute values of the differences between the methods of free-way space, N-ANS/ANS-Me, S-Go/N-Me and the closest speaking space method were lower than those of the other four groups (P0.05), while the differences between ANS-FH/Me-FH and the closest speaking space method was higher than those other groups (P0.05).CBCT-synthesized cephalograms, with the exception of ANS-FH/Me-FH, can provide references for the clinical evaluation of the occlusion vertical dimensions of patients with edentulous jaws.目的 对三维转化头影测量法、发音法及息止牙合间隙法确定的云南省汉族无牙颌患者咬合垂直距离的准确性进行比较和分析。方法 首先建立云南省汉族正常牙合者锥形束CT（CBCT）头颅侧位影像各标志点间相关性数据库，随后选取5名63~78岁云南省汉族无牙颌患者，使用NNT.View软件对由CBCT转化的头颅侧位片的各硬组织标志点进行测量分析，结合正常人群数据库，评估出咬合垂直距离，并对CBCT转化头影测量法、发音法及息止牙合间隙法确定的咬合垂直距离进行分析。结果 本研究以发音法为标准参照组，分析了息止牙合间隙法和6种CBCT转化头影测量法（包括N-ANS/ANS-Me、S-Go/N-Me、ANS-Gn/N-ANS、ANS-FH/Me-FH、ANS-Xi-Pm、CA/LA）与发音法的差值，结果发现：7种测量方法与发音法均有很高的一致性（组内相关系数0.986）；其中息止牙合间隙法、N-ANS/ANS-Me、S-Go/N-Me法差值的绝对值较其他4组更小，而ANS-FH/Me-FH差值的绝对值最大，差异均有统计学意义（P0.05）。结论 三维转化头影测量法除ANS-FH/Me-FH外，其余5种方法均可为临床评估无牙颌患者咬合垂直距离提供参考。.

Enzymes from various natural resources are valuable in management of thrombosis. Blood-sucking arthropods are one of these resources because they have a wide array of anti-hemostasis molecules in their salivary gland. However, it is difficult to purify enough protein samples from the salivary glands for pharmacological studies. In this work, a fibrinogenolytic enzyme (tablysin 2) identified from salivary glands of the horsefly Tabanus yao was expressed in Escherichia coli to further study its biological activities. The primary structure of tablysin 2 showed significant domain similarity to arthropod proteins from the antigen 5 family containing SCP domain, whose biological functions are poorly understood. Tablysin 2 cleaved the Aα and part of Bβ chains of fibrinogen and did not affect γ chain and fibrin. It inhibited platelet aggregation induced by ADP. It did not directly induce hemorrhage or activate plasminogen. The fibrinogenolytic activity of tablysin 2 provides a clue for the functions of antigen 5-related proteins in other haematophagous arthropods. This work demonstrate a method of expression of arthropod salivary proteins which are difficult to obtain from natural resources for further functional studies.

To determine the prevalence and associations of pterygium in a multiethnic adult population in rural China and to examine potential ethnic differences Methods: A total of 6418 adults (2133 ethnic Bai, 2130 ethnic Yi, and 2155 ethnic Han) aged 50 years or older participated in the study. Anterior segment examination was performed without pupil dilation using a slit lamp. Pterygium was defined as a raised fleshy triangular fibrovascular tissue growth of the conjunctiva encroaching onto a clear cornea.Pterygium was least prevalent among adults of Yi ethnicity (29.5%) compared with Bai (39.0%, p0.001) or Han (39.5%, p0.001) ethnicities. Those of Bai ethnicity were most likely to be affected by severe pterygium (7.5%), while Yi were least likely to be affected (3.8%). Multivariate analysis revealed that increasing age (odds ratio, OR, 1.017), female sex (OR 1.53), lower educational level (OR 1.25), higher blood pressure levels (OR 1.002), and greater time spent outdoors per day (OR 1.09) were significantly associated with a higher prevalence of pterygium, while Yi ethnicity (OR 0.65, comparing Yi with Han) and wearing brimmed hats outdoors (OR 0.82) were protective factors.Ethnicity was significantly associated with prevalence of pterygium. Our findings may be applicable to many other countries located within the "pterygium belt" for health resource allocation among different ethnic groups.

Objectives To explore the pathological changes in spinal cord injury with seawater immersion, and provide guidance for the treatment of such injury. Methods The rabbit model of spinal cord injury was reproduced by the modified Allen's method. Ninety-six rabbits were randomly divided into 4 groups: group A (normal control, n=6), in them only the vertebral plate was cut off but the spinal cord was not injured; group B (n=30), vertebral plate was resected and the spinal cord was damaged without sea water immersion; group C (n=30), the vertebral plate was resected and the spinal cord was damaged and treated with normal saline; and group D (n=30), the vertebral plate was resected and the spinal cord was damaged followed by seawater immersion. The immersion time was 60 minutes. In group B, C and D, 6 rabbits were randomly selected from each group at 1, 6, 12, 24 and 48 hours after immersion, and the neurological function of rabbits were evaluated using the Tarlov scale, then the animals were sacrificed, and the histopathological features were studied with light microscopy, the expressions of Bax and Bcl-2 were determined by immunohistochemistry, and the apoptosis of neurons in spinal cord was evaluated by TUNEL method. Results Compared with group A, the Tarlov scores of group B, C and D decreased significantly, but no significant difference was found between the 3 groups at 1h after treatment, while the Tarlov scores were higher at 6h and lower at 12h in group D as compared with those in group B and C (P

The aim of this study was to evaluate the oral health among the elderly in Southwest China and to analyze the correlation between common oral diseases and quality of life (QOL) in the same population, thus providing recommendations to improve their oral health and life quality. Elderly people (>60 years’ old) were randomly recruited into our study, and we performed oral health examinations and diagnoses, using the Community Periodontal Index (CPI) to assess the periodontal condition, and Oral Health Impact Profile-14 (OHIP-14) to score life quality associated with oral health. Then we analyzed correlations between oral health and QOL as well as body mass index (BMI). A total of 687 subjects participated in our study and 212 (30.9%) were diagnosed with gingivitis or subgingival calculus, 291 (42.4%) with moderate chronic periodontitis, 136 (19.8%) with severe chronic periodontitis, 514 (74.8%) with dental caries, and 648 (94.3%) with dentition defects. A total of 653 (95.1%) qualified OHIP-14 scores were collected, with a median score of 13. The scores of the severe and moderate periodontitis were similar to the dentition defects, but higher than the scores for gingivitis and subgingival calculus. Considering the most common side effect, 11% of the subjects with severe chronic periodontitis were reported to be “unsatisfied with eating,” and 48.4% of the participants with dentition defects complained about “troubles with pronunciation.” A logistic regression analysis revealed that underweight (BMI

Based on impulse theories and indentation fracture mechanics, the motion model of the contact between abrasive particle and workpiece in workpiece two-dimension ultrasonic vibration grinding (WTDUVG) was analyzed, and the critical condition of ultrasonic vibration grinding brittle-ductile transition was analyzed theoretically, furthermore the critical cutting depths of a grain under different grinding conditions were obtained by Matlab programs. In this work, the ultrasonic vibration and conventional diamond grinding of Al2O3/ZrO2 nanoceramics were performed in order to investigate the effect of workpiece ultrasonic vibration on the brittle-ductile transition mechanism, the effect of grit size, worktable speed and grinding depth on the critical depth of cut were studied by grinding experiments. the micro-topography of the grinding surface was observed by AFM and SEM. Experiment indicated that only when the grinding depth less than critical grinding depth, ductile regime grinding of ceramics can be realized, the appropriate grinding parameter on surface finish are suggested.

Hydraulic engine mounts (HEMs) are important vehicle components to isolate the vehicle structure from engine vibration. A parameter optimization methodology for an HEM based on a genetic neural network (NN) model is proposed in this study. Samples of HEMs with different structures and rubber materials are manufactured and their dynamic characteristics are tested on an MTS 831 elastomer test system. Then the test results are used as samples to train the NN model which defines the non-linear global mapping relationship between the HEM's structural parameters and its dynamic characteristics. The fitness values of the population in the genetic algorithm are calculated by the trained NN model, and the optimal solution was acquired with the mutation of population. Finally, experiments are made to validate the reliability of the optimal solution. The proposed optimization method can specify the structures and materials of HEMs to meet the design requirements automatically.

A new ultrasonic aided lapping technology was developed by combining lapping technology and ultrasonic machining technology. The appended special tangential ultrasonic vibration changes the material removal rate (MRR) characteristics. In order to clarify the influence of ultrasonic vibration, in this paper, the MRR models in ultrasonic aided single-point scratch were deduced based on indentation fracture theory. Through contrast scratching and lapping experiments, the MRR characteristics in ultrasonic aided lapping of engineering ceramics were presented. Research result shows that the MMR in ultrasonic aided lapping is larger than that in conventional lapping under the same conditions; with the increase of ultrasonic generator power and lapping pressure, the MMR in lapping increases correspondingly.

Aimed at the precision machining characteristics of nano ZTA engineering ceramics external cylindrical components, ultrasonic aided lapping experiments were carried out adopting inhouse developed ultrasonic external cylindrical lapping device with solid abrasive material. To obtain minimum surface roughness with constraint of the material removal rate, response surface methodology (RSM) was adopted to analyze the experimental data, and suitable experiment design was chosen to fit the response surface in this research. Second-order surface response models of surface roughness and material removal rate were developed respectively, and the influence laws of lapping parameters on surface roughness and material removal rate were clarified according to the built models. Finally, parameters optimization of the ultrasonic external cylindrical lapping process for nano ZTA engineering ceramics was realized using surface response methodology.

Ultrasonic aided high speed lapping with solid abrasive material was put forward aimed at the precision finishing of nano ZTA engineering ceramic. Through theoretical analysis and contrast lapping experiments, the influences of ultrasonic assistance on the surface machining quality were clarified. Research results show that the maximum undeformed chip thickness in ultrasonic aided lapping is smaller than that in conventional lapping under the same conditions; ultrasonic assistance is beneficial to enlarging the range of ductile lapping regime and improving the surface quality of nano ZTA ceramic; with the application of ultrasonic vibration, smaller surface roughness and more regular surface profile can be obtained.

Based on the single abrasive particle motion locus of elliptical spiral in two-dimensional ultrasonic vibration grinding (WTDUVG), the theoretical model representing the material removal rate are deduced and verified, and the reason of high efficiency material removal by applying two-dimensional ultrasonic vibration is analyzed. Finally, experimental researches on material removal rate of ceramics were carried out using coarse grit diamond wheel both with and without workpiece two-dimensional ultrasonic vibration assistance grinding. Experimental results indicated that (1) Material removal rate (MRR) in vibration grinding process is about 1.5 times as large as that of in conventional grinding, the experimental results are in good agreement with the calculated ones. (2)The material removal rate increases along with increases of the grinding depth and workpiece velocity both in with and without vibration grinding. (3)The vibration grinding surface had no spur and build-up edge and its surface roughness was smaller than CG significantly. Surface quality of WTDUVG is superior to that of conventional grinding, it is easy for ultrasonic vibration grinding that material removal mechanism is ductile regime grinding.

Self-propelled rotary tools are being rediscovered for their applications in machining of ‘difficult-to-machine’ materials or for general improvement in the productivity of machining operations. The vibration characteristic and the occurrence of chatter during high speed cutting will induce the deterioration of precision and machining surface, tool wear and tool life. This paper deals with the identification of the vibration in SPRT cutting system with AR time series model. The experiment and deduction method provide a sound foundation for improving the structure with high antivibration strength, which could reduce the relative vibration between tool and workpiece in the alloweable scope.

To determine the prevalence of myopia and ocular biometry in population-based samples of ethnic Yi and Han people living in an inland rural community in China.A random cluster sampling strategy was used to select ethnic Han and Yi adults aged 50 years or older living in Yunnan. Refractive error was determined by subjective refraction and ocular biometric parameters, including axial length (AL), anterior chamber depth (ACD), vitreous chamber depth (VCD), and lens thickness (LT), which were measured using an Echoscan.Adults of Yi ethnicity had lower prevalence of myopia (10.3% vs. 8.1%; P = 0.02) and high myopia (2.3% vs. 1.6%; P = 0.10) than their counterparts of Han ethnicity. The prevalence of myopia increased with age (P for trend0.05), whereas the mean AL did not differ significantly among age groups in both ethnic groups (both P for trend0.05). In multivariate analysis, time spent outdoors was associated with myopia (P = 0.003) and AL (P0.001) but not high myopia (P = 0.33). No interaction effect was detected between ethnicity and other risk factors on myopia (all P0.05). Adjustment for lens nuclear opacity score reduced the excess prevalence of myopia in Han ethnicity by 37.5%.There was little evidence showing that ethnic disparities existed in the prevalence and risk factors between the major and minor ethnic groups living in the same communities in rural China. The "cohort effect" on myopia observed in many other populations was not seen in this study.

In the field of fault diagnosis for rotating machines, the conventional methods or the neural network based methods are mainly single symptom domain based methods, and the diagnosis accuracy of which is not always satisfactory. To improve the diagnosis accuracy a method that combines the multi-class support vector machines (MSVMs) outputs with the degree of importance of individual MSVMs based on fuzzy integral is presented. This provides a sound basis for integrating the results from MSVMs to get more accurate classification. The experimental results with the recognition problem of a blower machine show the performance of fault diagnosis can be improved.

In the paper, the machining characteristics of two dimensional ultrasonic grinding(TDUG) are analyzed, and based on the analysis of the working locus of abrasive particle under TDUG and mechanical performances of fine-crystalline ZrO2 ceramics, a theoretical model of material removal rateMRRis proposed under TDUG with workpiece adhered to ultrasonic vibration respectively from the orthogonal directions. The model shows that any increase of static load, size of grain, work speed, number of effective dynamic abrasive particle, the amplitude and frequency of tool or any decrease of fracture toughness property and hardness will result in the increase of the MRR, and the theoretical model of the MRR is tested, meanwhile the paper draws the conclusion that the surface quality under TDUG is superior to that under common grinding, which is tested by the means of grinding of fine-crystalline ZrO2 ceramics.

Based on the grain movement model of ultrasonic grinding, models representing the grinding force of single abrasive and the material removal rate (MRR) are deduced and verified. Mechanism of high efficiency material removal in work lateral ultrasonic vibration grinding (WLUVG) was analyzed. The MRR of fine-crystalline ZrO2 ceramics in WLUVG and conventional grinding (CG) with diamond wheel were researched experimentally in this work. The effects on the MRR, the surface roughness and microstructure of the process parameters and the size of abrasive are measured. It has been concluded that: (1) the MRR in ultrasonic grinding process is two times as large as that of in CG. (2) any increase in the amount of energy imparted to the workpiece in terms of the average diameter of grains, grinding depth both in with and without ultrasonic grinding, will result in an increase in the MRR and the surfaces roughness. (3) the ultrasonic grinding surface had no spur and build-up edge and its surface roughness was smaller than CG significantly. Surface quality of vibration grinding is superior to that of CG, it is easy for ultrasonic vibration grinding that material removal mechanism is ductile mode grinding.

We study a two-dimensional granular rapid flow with rough sidewalls stuck with the same size discs by molecular dynamics simulation. A transient state of the double-humped density profile in the flowing process has been found, which appears and moves as travelling wave and is the same as the phenomena in the recent experiments [Acta Phys. Sin. 53 (2004) 3389 (in Chinese)]. Our simulation shows that the rough sidewalls play an important role in the converting momentum of boundary discs from the vertical direction to the horizontal one through particle collisions to form this profile and the good elasticity of discs ensures this effect. The appearance of the double-humped profile may be a precursor, which determines if the whole flow will be far repulsed from the boundary and become dilute eventually.

Being a key step in grinding process, dressing of grinding wheel influences the whole grinding results, especially grinding quality. Because of its good dressing effect, a new dressing method assisted by ultrasonic vibration attracted researchers’ attention. In this paper, on the basis of the researches on dressing with single-point diamond dresser, physical model of ultrasonic dressing of grinding wheel were established. According to the physical model and the SEM photos of grinding wheel’s surface topography, the mechanism of ultrasonic dressing was brought to light. Through contrast experiments, based on roughness and micro-feature of the ground surface, the influence of ultrasonic dressing on grinding quality was researched.

On the basis of analyzing the brittleness, ductileity, and the removal mechanisms of the^nano-ZrO2 Ceramics, the critical ductile grinding depth formula of the nano-ceramics was established. Due to superductileity of the nano-ZrO2 ceramics, it couldn’t apply the formula of the common engineering ceramic material according to experimental results. The value of material coefficient ζ has relations with not only the material characteristics but also the processing methods and the processing parameters. It was proved that ζ has great effects on the accuracy of theoretical calculation. Experimental results showed that the critical ductility grinding depth of the nano-ZrO2 ceramics is up to 12 µm in common grinding methods, while in ultrasonic grinding is up to 20µm. The grinding chips with and without ultrasonic vibration assistance were discussed.

Nano ceramics possessed ascendant mechanical property and physical characteristics contrast with engineering ceramics, so it has extensive application prospect in various industries. On the basis of applying the indentation fracture mechanics to analyze the removal mechanics of ceramic material, this paper analyzed the critical ductile grinding depth of the nano ZrO2 ceramics. Adopting ultrasonic composite processing we describe the influence of different processing parameters and grain size of diamond wheel on the grinding forces and surface roughness. Based on the grinding forces and surface roughness the grinding process with and without vibration is analyzed. By means of SEM and AFM the surface character and critical ductile grinding depth of nano ZrO2 ceramics are also discussed. The paper supplied the theoretical and experimental basis for the grinding of the large-sized ultraprecision plate structure of nano ZrO2 ceramics (nm).

Granular flow of steel beads from dilute flow to dense flow on an inclined two-dimensional channel is studied. The initial inflow Q0 is always a dilute flow. A transition from dilute to dense is observed when D≤Dc. In the dense flow the outflow rate (Q) depends only on opening (D), given by [Formula: see text]. For different inflow rate Q0 in the dilute flow case, the relation between the transition critical exit width (Dc) and the channel width (W) is given. And in larger inflow, the critical exit width is approximately in proportion to the square root of inflow rate, [Formula: see text].

Through systematic experimental and theoretical research, this paper reveals the character of ‘local resonance’ in ultrasonic honing system, which has the same essence as the ‘local resonance’ of the ultrasonic machining deep hole system. The experiment and deduction method and the new design method of a ‘local resonance’ tool system have not only important practical usage but also edification for other ultrasonic systems.