语言的镜机制与认知语言学

镜神经元最主要的研究成果是提出了人脑认知机制——镜机制,它适用于解释语言认知机制。从镜机制角度阐述语音、语义和语言符号的神经机制,探究镜机制理论与认知语言学语言观的融合,其主要内容包括:镜神经元和镜机制假设;语音、语义和语言符号的镜机制和认知语言学阐述。研究发现镜机制理论和语言能力在认知科学学科内可以融合,为认知语言学角度的语音研究提供了新视角,并初步提出了语音整合观。

歌剧排演在高校声乐教学中的意义

高校歌剧排演对于歌剧学习来说是一种延伸,弥补了以唱段为主的歌剧学习,让学生能够从表演层面将歌剧的戏剧性融入演唱之中。因此,高校排演歌剧对于还处在声乐学习基础阶段的本科生来讲,有着多方面、不同程度的积极作用。通过参加歌剧排演,不仅能迅速提高学生的人物塑造力及合作意识,作为歌剧排演的教师也可以更加直观地观察到每一个学生的优点与不足,因材施教,使得日后的教学更加顺利、高效。

MECHANISM OF MICROBAND FORMATION IN COLD ROLLED INTERSTITIAL-FREE STEEL

The mechanism of the shear band formation in the high cold rolled BCC metal is analyzed. Based on the plastic deformation theory, the shear distribution in the deformed grain is calculated by using the Taylor constraint model and the Bishop ＆ Hill maximum work principle. Results show that when the rolling direction （RD） is parallel to a certain direction of a grain, the large localized shear occurs on one slip plane, thus generating microbands in the grain because of the high localized shear strain. The angle between the RD and the shear band is about 30°. The plate-like structure of the microband is formed because of the dislocation double cross slip. The transmission electron microscope （TEM） observation of the microband in the cold rolled BCC metal confirms the formation mechanism of the microband.

Corrosion behaviors and mechanism of electroless Ni-Cu-P/n-TiN composite coating

In the present investigation, electroless Ni-Cu-P/n-TiN composite coating was prepared using alkaline citrate-based bath. X-ray diffraction （XRD）, scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS）, electrochemical measurements, weight loss tests and Raman spectrometer were used to character the properties of the coating. As the Cu content increased from 7.3 wt% to 24.8 wt%, the corrosion current density of the Ni-Cu-P/n-TiN coating decreased from 10.80 to 4.34 ~tA. And the inclusion of Cu in NiP alloy resulted in refinement and less porosity in microstructure. The addition of TiN resulted in a slight decline in anti-corrosion property of the coating. As the mass loss test showed, Ni-24.8%Cu-P exhibited perfect corrosion resistance. Studies by Raman spectroscopy on coatings proved that Cu（II）3（PO4）（OH）3, Cu（OH）2 and CuO were examined while no compound of nickel was found, and Cu exhibited preferred corrosion in saline solution, providing cathodic protection to Ni alloy.

Preparation of electrolytic copper powders with high current efficiency enhanced by super gravity field and its mechanism

Super gravity field was employed to enhance electrolytic reaction for the preparation of copper powders.The morphology, microstructure and size of copper powders were characterized by scanning electron microscopy,X-ray diffractometry and laser particle analysis.The results indicated that current efficiencies of electrolytic copper powders under super gravity field increased by more than 20% compared with that under normal gravity condition.Cell voltage under super gravity field was also much lower.The size of copper powders decreased with the increase of gravity coefficient(G).The increase of current efficiency can be contributed to the disturbance of electrode/electrolyte interface and enhanced mass transfer of Cu2+ in super gravity field.Meanwhile,the huge gravity acceleration would promote the detachment of copper powders from electrode surface during electrolytic process,which can prevent the growth of copper powders.

Mechanism of high concentration phosphorus wastewater treated by municipal solid waste incineration fly ash

The mechanism of removing phosphate by MSWI(municipal solid waste incineration)fly ash was investigated by SEM(scanning electron microscopy)with EDS(energy dispersion spectrum),XRD(X-ray diffraction),FT-IR(Fourier transform infrared spectroscopy),BET(specific surface area),and BJH(pore size distribution).The results indicate that the removal rate of phosphate(100 mg/L)in 50 mL phosphorus wastewater reaches at 99.9% as the dosage of MSWI fly ash being 0.9000 g under room temperature.The specific surface area of MSWI fly ash is less than 6.1 m2/g and the total pore volume is below 0.021 cm3/g,suggesting that the absorption capacity of calcite is too weak to play an important role in phosphate removal.SEM images show that drastic changes had taken place on its specific surface shape after reaction,and EDS tests indicate that some phosphate precipitates are formed and attached onto MSWI fly ash particles.Chemical precipitation is the main manner of phosphate removal and the main reaction is: 3Ca2++2 PO4 3-+xH2O→Ca3(PO4)2↓·xH2O.Besides,XRD tests show that the composition of MSWI fly ash is complex,but CaSO4 is likely to be the main source of Ca2+.The soluble heavy metals in MSWI fly ash are stabilized by phosphate.

Ignition-proof mechanism of ZM5 magnesium alloy added with rare earth

The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% （mass fraction） rare earth （RE） was investigated. The oxide scales and substrates were characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, energy dispersive spectrometer （EDS） and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength is slightly improved from 168.2 to 174.6 MPa by adding 0.1% RE. A double-layer oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE203 and A1203, which is 2.5-3.5 μm in thickness. It is found that the forming of protective oxidation film on the thermodynamics is attributed to RE elements congregating on the surface of molten Mg alloy.

Fabrication of SPES/Nano-TiO_2 Composite Ultrafiltration Membrane and Its Anti-fouling Mechanism

Membrane fouling is one of the major obstacles for reaching a high flux over a prolonged period of ultrafiltration（UF）process.In this study,a sulfonated-polyethersulfone（SPES）/nano-TiO2 composite UF membrane with good anti-fouling performance was fabricated by phase inversion and self-assembly methods.The TiO2 nanoparticle self-assembly on the SPES membrane surface was confirmed by X-ray photoelectron spectroscopy （XPS）and FT-IR spectrometer.The morphology and hydrophilicity were characterized by scanning electron microscopy（SEM）,atomic force microscopy（AFM）and contact angle goniometer,respectively.The anti-fouling mechanism of composite UF membrane was discussed through the analysis of the micro-structure and component of UF membrane surface.The results showed that the TiO2 content and the micro-structure of the composite UF membrane surface had great influence on the separation and anti-fouling performance.

Influence of aluminium and lead on activation of magnesium as anode

Mg-6%Al, Mg-5%Pb and Mg-6%Al-5%Pb （mass fraction） alloys were prepared by induction melting with the protection of argon atmosphere. Their electrochemical activations in different electrolyte solutions were investigated by galvanostatic test. The microstructures of these alloys and their corroded surfaces were studied by scanning electron microscopy, X-ray diffractometry and emission spectrum analysis. The results show that the activation of magnesium is not prominent when only aluminum or lead exists in the magnesium matrix, but the coexistence of the two elements can increase the activation. The activation mechanism of Mg-Al-Pb alloy is dissolving-reprecipitating and there is a synergistic effect between aluminium and lead： the precipitated lead oxides on the surface of the alloy can facilitate the precipitation of Al（OH）3, which can peel the Mg（OH）2 film in the form of 2Mg（OH）2AI（OH）3 and activate the magnesium matrix.

Removal of press-through-packs impacted in the upper esophagus using an overtube

Foreign bodies in the upper esophagus should be re-moved as soon as possible to avoid serious complica-tions. However, removals of foreign bodies in the upper esophagus are very difficult, especially if they have sharp edges, such as press-through-packs (PTPs). We expe-rienced four cases of the impacted PTPs in the upper esophagus which was successfully extracted endoscopi-cally with the overtube. Because two edges of PTPs were so firmly impacted in the esophageal wall in all cases, the PTPs were not movable in the upper esophagus. However, after insertion of the overtube, PTPs became movable and were successfully extracted and no serious complications occurred after extraction of PTPs. In one case, insertion of the overtube rapidly expanded the up-per esophagus and PTP progressed to the gastric cavity and it could be extracted with the endoscopic protector hood. The endoscopic removal with the overtube was a simple, safe and effective technique for the removal of the impacted PTPs in upper esophagus.

Laparoscopic versus open appendectomy: Which way to go?

AIM: To compare the outcome of laparoscopic versus open appendectomy. METHODS: Prospectively collected data from 293 consecutive patients with acute appendicitis were studied. These comprised of 165 patients who underwent conventional appendectomy and 128 patients treated laparoscopically. The two groups were compared with respect to operative time, length of hospital stay, postoperative pain, complication rate and cost. RESULTS: There were no statistical differences regarding patient characteristics between the two groups. Conversion to laparotomy was necessary in 2 patients (1.5%). Laparoscopic appendectomy was associated with a shorter hospital stay (2.2 d vs 3.1 d, P = 0.04), and lower incidence of wound infection (5.3% vs 12.8%, P = 0.03). However, in patients with complicated disease, intra-abdominal abscess formation was more common after laparoscopic appendectomy (5.3% vs 2.1%, P = 0.002). The operative time and analgesia requirements were similar in the two groups. The cost of treatment was higher by 370 € in the laparoscopic group. CONCLUSION: Laparoscopic appendectomy is as safe and effi cient as open appendectomy, provided surgical experience and equipment are available.

Gastrointestinal bezoars: A retrospective analysis of 34 cases

AIM: Bezoars (BZ) are the most common foreign bodies of gastrointestinal tract. Clinical manifestations vary depending on the location of BZ from no symptoms to acute abdominal syndrome. When located in small bowel, they frequently cause small bowel obstruction (SBO). We aimed to present our experience by reviewing literature.METHODS: Thirty-four patients with gastrointestinal BZ were presented. The data were collected from hospital records and analyzed retrospectively. Morbidity and mortality rates were statistically analyzed between the subgroups according to SBO and endoscopic or surgical treatment modalities.RESULTS: The 34 patients had phytobezoars (PBZ). Two patients with mental retardation and trichotillomania had trichobezoars (TBZ). More than half of them (55.88%) had previous gastric surgery. Also most of them had small bowel bezoars resulting in obstruction. Surgical and endoscopic morbidity rates were 32.14% and 14.28% respectively.The total morbidity rate of this study was 29.41%. Four patients in surgically treated group died. There was no death in endoscopically treated group. The total and surgical mortality rates were 11.76% and 14.28% respectively. The differences in morbidity and mortality rates between the subgroups were not statistically significant.CONCLUSION: BZ are commonly seen in stomach and small intestine. SBO is the most common complication.When uncomplicated, endoscopic or surgical removal can be applied easily.

Mechanism of diarrhea in microscopic colitis

AIM： To search the pathophysiological mechanism of diarrhea based on daily stool weights, fecal electrolytes, osmotic gap and pH. METHODS： Seventy-six patients were included： 51 with microscopic colitis （MC） [40 with lymphocytic colitis （LC）; 11 with collagenous colitis （CC）], 7 with MC without diarrhea and 18 as a control group （CG）. They collected stool for 3 d. Sodium and potassium concentration were determined by flame photometry and chloride concentration by titration method of Schales. Fecal osmotic gap was calculated from the difference of osmolarity of fecal fluid and double sum of sodium and potassium concentration. RESULTS： Fecal fluid sodium concentration was significantly increased in LC 58.11±5.38 mmol/L （P〈0.01） and CC 54.14±8.42 mmol/L （P〈0.05） than in CG 34.28±2.98 mmol/L. Potassium concentration in LC 74.65±5.29 mmol/L （P〈0.01） and CC 75.53±8.78 mmol/L （P〈0.05） was significantly less compared to CG 92.67±2.99 mmol/L. Chloride concentration in CC 36.07±7.29 mmol/L was significantly higher than in CG 24.11±2.05 mmol/L（P〈0.05）. Forty-four （86.7%） patients had a secretory diarrhea compared to fecal osmotic gap. Seven （13.3%） patients had osmotic diarrhea. CONCLUSION： Diarrhea in MC mostly belongs to thesecretory type. The major pathophysiological mechanism in LC could be explained by a decrease of active sodium absorption. In CC, decreased CI/HCO3 exchange rate and increased chloride secretion are coexistent pathways.

Diagnosis of autoimmune gastritis by high resolution magnification endoscopy

Endoscopic visualisation of gastric atrophy is usually not feasible with conven.tional endoscopy. Magnifying endoscopy is helpful to analyze the subepithelial microvascular architecture as well as the mucosal surface microstructure without tissue biopsy. Using this technique we were able to describe the normal gastric microvasculature pattern and we also identified characteristic patterns in two cases of autoimmune atrophic gastritis.

Actively bleeding Dieulafoy's lesion of the small bowel identified by capsule endoscopy and treated by push enteroscopy

Dieulafoy＇s lesion is an unusual cause of recurrent GI bleeding. This report describes a case of actively bleeding Dieulafoy＇s lesion of the small bowel in which the diagnosis was made by capsule endoscopy, followed by treatment with the use of push enteroscopy. The case illustrates that capsule endoscopy and enteroscopy are highly complementary in patients with small bowel diseases.

Error analysis and distribution of the driving mechanism for large spherical radio telescope active reflector

In order to reduce the cost,3-PRS mechanism is introduced into the application of supporting theactive reflector unit of large radio telescope.The kinematic model of 3-PRS mechanism with rotationaljoint errors is derived to solve the error problem in actual engineering application.Then based on the errormodel,inverse and forward kinematics are analyzed.Because the solutions can not be analytically ex-pressed,a numerical method is applied.Afterwards,the parasitic motion errors are analyzed using searchmethod and empirical formulas of the maximum parasitic motion error are put forward.Finally,the toler-ance is distributed using empirical formulas to avoid interference between adjacent reflector units.Theanalyses provide a theoretical basis for the design and installation of large radio telescope active reflector.

Primary signet-ring cell carcinoma of the colon at early stage: A case report and a review of the literature

A 67-year-old man, who had undergone surgery to resect multiple gastric cancers 4 years ago, visited our hospital for surveillance colonoscopy. Colonoscopy revealed a discolored, 7-mm in diameter, flat-elevated lesion with central depression in the transverse colon near the splenic flexure. Although the findings of endoscopy and barium enema were suggestive of submucosal invasion, the patient chose to undergo endoscopic mucosal resection. Pathological examination of the resected specimen revealed signet-ring cell carcinoma and a positive surgical margin. A second operation was performed, and no residual tumor or metastasis to lymph nodes was found in the resected specimens. Primary colorectal cancers composed of signet-ring cell carcinoma detected and treated at an early stage are extremely rare. We present a case and review the literature.

Influence of a microscopic positive proximal margin in the treatment of gastric adenocarcinoma of the cardia

AIM： To investigate the influence of a positive proximal margin in total gastrectorny patients with gastric adenocarcinorna of the cardia. METHODS： Medical records of 191 patients with total gastrectornies for adenocarcinorna of the cardia between 1995 and 2000 were reviewed. The clinicopathologic features associated with a positive margin were determined, and the predictors for survival were analyzed. RESULTS： The incidence of positive proximal margin was 8.4% （16/191）. The positive margins were associated with advanced diseases. The tumor size and the depth of tumor invasion were independent risk factors for a positive margin. The mean survival in the positive margin group was 33.9 mo as compared.with 62.4 mo in the negative group （P 〈 0.001）. However, the difference in survival lost significance in subgroup analysis according to stage. Multivariate analysis identified that a positive margin was not an independent prognostic factor for survival. CONCLUSION： A positive margin is more of an indication of advanced disease in patients with gastric adenocarcinoma of the cardia rather than an independent prognostic factor for survival.

Conventional colonoscopy and magnified chromoendoscopy for the endoscopic histological prediction of diminutive colorectal polyps: A single operator study

AIM： To accurately differentiate the adenomatous from the non-adenomatous polyps by colonoscopy. METHODS： All lesions detected by colonoscopy were first diagnosed using the conventional view followed by chromoendoscopy with magnification. The diagnosis at each step was recorded consecutively. All polyps were completely removed endoscopically for histological evaluation. The accuracy rate of each type of endoscopic diagnosis was evaluated, using histological findings as gold standard. RESULTS： A total of 240 lesions were identified, of which 158 （65.8%） were non-neoplastic and 82 （34.2%） were adenomatous. The overall diagnostic accuracy of conventional view, and chromoendoscopy with magnification was 76.3% （183/240） and 95.4% （229/240）, respectively （P〈 0.001） CONCLUSION： The combination of colonoscopy and magnified chromoendoscopy is the most reliable nonbiopsy method for distinguishing the non-neoplastic from the neoplastic lesions.

A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors

AIM： Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study. METHODS： Fifteen patients were diagnosed with rectal carcinoid tumor （less than 10 mm） in our hospital from 1993 to 2002. There were 9 males and 6 females, with a mean age 61.5 years （range, 34-77 years）. The patientshad no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups： 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device. RESULTS： All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups. The rate of complete removal of carcinoid tumors using a ligation device （100%, 8/8） was significantly higher than that of conventional endoscopic resection （57.1%, 4/7）. The three patients had tumor involvement of deep margin, for which additional treatment was performed. No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period. CONCLUSION： Endoscopic resection using a ligation device is a useful and safe method for resection of small rectal carcinoid tumors.