超声速进气道喉部附面层抽吸

为研究超声速进气道喉部之后流场激波附面层干扰,采用FLUENT软件模拟了单楔角进气道在设计工况下流动情况。通过分析,提出进气道喉部抽吸。计算了三种抽吸缝大小下进气道喉部之后流场,计算结果表明,喉部抽吸能使激波稳定于喉部,通过抽吸能改善喉部之后流场状况,提高进气道性能,少量抽气不改变流场结构,加大抽气量,使喉部之后激波串转变成正激波,正激波之后流场不分离,进气道出口性能参数提高显著。

高压离心压气机导叶流场的附面层抽吸控制研究

通过数值模拟研究了某小型涡扇发动机离心压气机的出口导叶流场特点,结合拓扑分析方法讨论了附面层抽吸对叶栅性能的影响。结果表明:原型叶栅由于展弦比较小,流动空间狭窄,各种形式的附面层分离相互掺混,恶化了整个叶栅的流动。通过附面层抽吸可以改变叶栅内的分离结构,明显减小吸力面的分离,使得流场结构趋于简单,从而减小损失、提高叶栅效率。

Li^+ extraction/adsorption properties of Li-Sb-Mn composite oxides in aqueous medium

Series Li-Sb-Mn composite oxides with different Sb/Mn molar ratios were obtained by solid state reaction.Their structure,morphology and Li^＋ extraction/adsorption properties were characterized by X-ray diffractometry （XRD）,scanning electron microscopy （SEM） and atomic absorption spectrophotometry （AAS）,respectively.XRD and SEM analyses reveal that the crystal of the products transfers from spinel to orthorhombic phase with the increase of molar ratio of Sb to Mn from 0.05 to 1.00.The Li^＋ extraction and adsorption experiments for these Li-Sb-Mn composite oxides demonstrate that the composite oxides can all be used as lithium inorganic adsorbents.The acid treated spinel Li-Sb-Mn composite oxide with Sb/Mn molar ratio of 0.05 has a high Li^＋ adsorption capacity of 33.23mg/g in lithium solution.The Sb/Mn molar ratio of these Li-Sb-Mn composite oxides should be a crucial factor in determining their structure and Li^＋ extraction and adsorption properties.

Superluminal Propagation in Er^(3+)-doped Fiber Bragg Grating

The method to pump the FBGT written into an Er^3＋-doped optical fiber is proposed to increase the group velocity of a probing pulse based on the facts that pump-induced process changes the refractive index and dispersion associated with the ^4I15/2-^4I12/2 transition in Er^3＋-doped optical fiber.The system equations are derived.The effects of pump power and doping concentration on the group velocity are discussed.

Droplet generation due to two health care procedures

Preliminary experiments are carried out to characterize the droplets generated in two aerosol-generating health care procedures,i.e.taking nasopharyngeal aspirates（NPA）and nebulizer therapy.Glass slides and water-sensitive paper（WSP）are used to collect large droplets when taking NPA.Droplet stain-marks on glass slides are counted under a microscope,and then a size analysis is performed.During nebulizer therapy dust monitors are used to detect small droplets and droplet nuclei at different positions around the nebulizer and in the room.From the preliminary results it is found that taking NPA can stimulate coughing and generate large droplets.Nebulizers can generate more than tens of millions fine droplets ranging from 0.3 to 20 μm per minute,a large volume of which can escape from the holes on the nebulizer＇s facemask and disperse in the whole room.Droplets coagulate on the inner surface of the mask and the volunteer＇s face,suggesting a great possibility of drug solution contamination by patients＇ secretion during nebulizer therapy.

Additional manual thrombus aspiration for ST-segment elevation myocardial infarction during percutaneous coronary intervention： an updated meta- analysis

Background The clinical efficacy and safety of adjunctive thrombus aspiration （TA） in patients with ST-segment elevation myocardial infarction （STEMI） during percutaneous coronary intervention （PCI） remain controversial. Methods Twenty five eligible randomized controlled trials were included to compare the use of thrombus aspiration （TA） with PCI and PCI-only for STEMI. The primary endpoint was all-cause mortality and death. The secondary endpoints were major adverse cardiac events （MACE）, recurrent infarction （RI）, target vessel revascularization （TVR）, stent thrombosis （ST）, perfusion surrogate markers and stroke. Results TIMI flow grade 3 and MBG 2-3 were significantly increased in the TA plus PCI arm compared with the PCI-only arm [relative risk （RR）： 1.05, 95% confidence intervals （CI）： 1.02-1.09, P = 0.004] and （RR： 1.68, 95% CI： 1.40-2.00, P 〈 0.001）, respectively. There were no significant differences in all-cause mortal- ity, MACEs, TVR and ST rates between the two groups. The RI rate was lower in the TA plus PCI arm than that in the PCI-only arm with short-term follow-up duration （RR： 0.60, 95% CI： 0.38-0.96, P = 0.03）, but there was no significant difference in RI incidence over the me- diumor long-term follow-up periods （RR： 1.00, 95% CI： 0.77-1.29, P = 0.98）, and （RR： 0.96, 95% CI： 0.81-1.15, P = 0.69）, respectively. There were statistically significant differences in the rates of crude stroke and stroke over the medium- or long-term follow-up periods and the crude stroke rate in the TA plus PCI （RR： 1.60, 95% CI： 1.08-2.38, P = 0.02） and （RR： 1.43, 95% CI： 1.03-1.98, P = 0.03）, respectively; this was not observed between the two arms during the short-term follow-up period （RR： 1.47, 95% CI： 0.97-2.21, P = 0.07）. Conclusions Routine TA-assisted PCI in STEMI patients can improve myocardial reperfusion and get limited benefits related to the clinical endpoints, which may be associated with stroke risk.

Role of Ekman Transport Versus Ekman Pumping in Driving Summer Upwelling in the South China Sea

Relative roles of Ekman transport and Ekman pumping in driving summer upwelling in the South China Sea （SCS） are examined using QuikSCAT scatterometer wind data. The major upwelling regions in the SCS are the coastal regions east and south- east of Vietnam （UESEV）, east and southeast of Hainan Island （UESEH）, and southeast of Guangdong province （USEG）. It is shown that the Ekman transport due to alongshore winds and Ekman pumping due to offshore wind stress curl play different roles in the three upwelling systems. In UESEV, Ekman pumping and Ekman transport are equally important in generating upwelling. The Ek- man transport increases linearly from 0.49 Sv in May to 1.23 Sv in August, while the Ekman pumping increases from 0.36 to 1.22 Sv during the same period. In UESEH, the mean estimates of Ekman transport and Ekman pumping are 0.14 and 0.07 Sv, respectively, indicating that 33% of the total wind-driven upwelling is due to Ekman pumping. In USEC~ the mean Ekman transport is 0.041 Sv with the peak occurring in July, while Ekman pumping is much smaller （0.003 on average）, indicating that the upwelling in this area is primarily driven by Ekman transport. In the summers of 2003 and 2007 following E1 Nifio-Southern Oscillation （ENSO） events, both Ekman transport and Ekman pumping decrease in UESEV due to the abnormally weak southwest monsoon. During the same events, however, Ekman transport is slightly enhanced and Ekman pumping is weakened in UESEH and USEG.

Percutaneous aspiration and drainage with adjuvant medical therapy for treatment of hepatic hydatid cysts

AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty-two patients received at least 2 wk of drug therapy before the procedure was carried out to reduce the risk of recurrence from spillage during the procedure.The procedure was performed under local anesthesia with a 19-gauge 20 cm long needle,the cyst was punctured,cystic content(approximately 30 mL) was aspirated by a 12-14 F pigtail catheter and aspirated fluids were sent for analysis.Once the cyst was almost empty,two-thirds of the net amount of material aspirated was replaced by hypertonic saline and left in the cavity for about 30 min,with the catheter left in place for reaspiration of most of the fluid.When the amount of fluid drained was less than 10 mL per 24 h,the drainage catheter was removed.RESULTS:All 32 cysts showed evidence of immediate collapse after completion of the procedure,and before discharge from hospital,ultrasound examination showed fluid reaccumulation in all cysts.Serial follow-up showed a progressive decrease in the size and change in the appearance of cysts.To confirm the sterility of these cystic cavities,seven cysts were reaspirated on average 3 mo after the procedure.Investigations revealed no viable scolices.CONCLUSION:PAIR using hypertonic saline is very effective and safe with proper precautions.

A dipole wind curl pattern induced by Taiwan Island and its effect on upper stratification in the northeastern South China Sea

Using hydrographic data sampled during four successive late summer-early autumn cruises in 2004-2007, vertical stratification along transects in the lee of Taiwan Island was analyzed to investigate upper ocean responses to orographically induced dipole wind stress curl (WSC). Results indicate that mixed-layer depth (MLD) and its relationship with thermocline depth varied under different local wind forcings. Average MLD along the transects from the 2004 to 2007 cruises were 18.5,30.7,39.2 and 24.5m, respectively. The MLD along the transects deepened remarkably and resulted in thermocline ventilation in 2005 and 2006, whereas ventilation did not occur in 2004 and 2007. Estimates indicate that frictional wind speed was the major factor in MLD variations. To a large degree, the combined effects of frictional wind speed and Ekman pumping are responsible for the spatial pattern of MLD during the cruises.

Seasonal variability of the North Equatorial Current transport in the western Pacific Ocean

Seasonal variability of the North Equatorial Current （NEC） transport in the western Pacific Ocean is investigated with ECMWF Ocean Analysis/Reanalysis System 3 （eRA-S3）. The result shows that NEC transport （NT） across different longitudes in the research area shows a similar double-peak structure, with two maxima （in summer and winter）, and two minima （in spring and autumn）. This kind of structure can also be found in NEC geostrophic transport （NGT）, but in a different magnitude and phase. These differences are attributable to Ekman transport induced by the local meridional wind and transport caused by nonzero velocity at the reference level, which is assumed to be zero in the NGT calculation. In the present work, a linear vorticity equation governing a 1.5-layer reduced gravity model is adopted to examine the dynamics of the seasonal variability of NGT. It is found that the annual cycle of NGT is mainly controlled by Ekman pumping induced by local wind, and westward-propagating Rossby waves induced by remote wind. Further research demonstrates that the maximum in winter and minimum in spring are mostly attributed to wind east of the dateline, whilst the maximum in summer and minimum in autumn are largely attributed to that west of the dateline.

Novel sucker rod pumping system based on linear motor technology

Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.

Summer Monsoon Impacts on Chlorophyll-a Concentration in the Middle of the South China Sea:Climatological Mean and Annual Variability

Climatological mean and annual variations of Chlorophyll-a （Chl-a） distribution, sea surface wind （SSW）, and sea surface temperature （SST） from 1998 to 2008 were analyzed in the middle of the South China Sea （SCS）, focusing on the typical region off the east coast of Vietnam （8.5-14°N, 109.5-114°E）. Based on remote sensing data and SCS summer monsoon index （SCSSMI） data, high Chl-a concentrations in the middle of the SCS in the southwest summer monsoon season （June-September） may be related to strong Ekman pumping and strong wind stress. The maximum of the monthly averaged cli- matological Chl-a in the summer appeared in August. According to the annual variation, there was a significant negative correlation （r = -0.42） between the SCSSMI and SST, a strongly positive correlation （r=0.61） between the SCSSMI and Chl-a, and a strongly negative correlation （r = -0.74） between the SST and Chl-a in the typical region off the east coast of Vietnam during 1998-2008. Due to the E1 Nifio event specifically, the phenomena of a low Chl-a concentration, high SST and weak SCSSMI were extremely predominant in the summer of 1998. These relationships imply that the SCSSMI associated with the SST could be used to predict the annual variability of summer Chl-a in the SCS.

The diagnostic evaluation of fine needle aspiration cytology of thyroid and its clinical application

Objective:The aim of the study was to investigate the diagnostic value of fine needle aspiration cytology (FNAC) and its clinical application.Methods:From April 2009 to February 2011,thyroid FNAC were performed in a total of 186 patients with thyroid nodule or mass in our hospital and 78 of those 186 patients subsequently underwent thyroidectomy.The FNAC findings were compared with the results of the corresponding histological diagnosis.Results:The results of thyroid FNAC for 186 patients showed that,(1) 166 cases of benign lesions,the detection rate was 89.24% (166/186),including 96 cases of nodular colloid goiter (51.61%),28 cases of simple colloid goiter (15.05%),38 cases of Hashimoto's thyroiditis (HT) (20.43%) and 4 cases of thyroid adenoma (2.15%);(2) 4 cases of suspicious malignant lesion,the detection rate was 2.15% (4/186);(3) 16 cases of malignant tumor,the detection rate was 8.60% (16/186).Seventy eight patients including malignant (16),suspicious malignant (4),HT (20) and nodular colloid goiters (38) cases diagnosed by FNAC were performed operation with thyroidectomy and the postoperative histopathologic results showed that there were 2 cases HT combined thyroid papillary carcinoma in HT 20 cases by FNAC,15 cases of thyroid papillary carcinoma and 1 case of follicular carcinoma in 16 cases of malignant tumor by FNAC and 4 case of thyroid papillary carcinoma in 4 cases of suspicious malignant by FNAC.Conclusion:Thyroid FNAC is a valuable and reliable method for the diagnosis of the thyroid nodules or mass or even most diffuse thyroid diseases.Diagnosis of HT and thyroid papillary carcinoma can be made by thyroid FNAC.There was larger hint value for nodular colloid goiter and simple colloid goiter according to thyroid FNAC.

Schemes for Producing 1.8 He Ⅱ and the Prediction of the Pumping Speed for the Method of Vacuum-Pumping

Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.

Novel treatment of coronary artery fistulae concealing severe coronary artery lesion： using thrombus aspiration catheter as a delivery guide

In this case report, we present the occlusion of multiple coronary artery fistulaes originating from proximal left anterior descending （LAD） and fight sinus valsavla and empting to the pulmonary artery at the same place. We occluded LAD fistulae by using thrombus aspira- tion catheter as a delivery guide. To the best of our knowlege, this is the first case of occlusion of coronary fistulaes with the help of throm- bus aspiration catheter. Our experience may suggest that thrombus aspiration catheters can be used in treating coronary artery fistulaes with difficult anotomv.

Low-frequency variations in primary production in the Oman upwelling zone associated with monsoon winds

Thirteen-year satellite-derived data are used to investigate the temporal variability of net primary production （NPP） in the Oman upwelling zone and its potential forcing mechanisms. The NPP in the Oman upwelling zone is characterized by an abnormal decrease during E1 Nifio events. Such an NPP decrease may be related to E1 Nifio-driven anomalous summertime weak wind. During the summer following E1 Nifio, the anomalous northeasterly wind forced by southwest Indian Ocean warming weakens the southwest monsoon and warms the Arabian Sea. The abnormal wind weakens the coastal Ekman transport, offshore Ekman pumping and horizontal advection, resulting in reduced upward nutrient supply to the euphotic zone. A slightly declining trend in NPP after 2000 associated with a gradual decrease in surface monsoon winds is discussed.

Successful treatment of intracardiac air embolism using intracardiac catheter aspiration

Intracardic air embolism is uncommon, however it is a serious condition which frequently leads to catastrophic complications during or after invasive procedures resulting in significant morbidity and mortality. For a successful re- suscitation of patients with intracardiac air embolism, hy- perbaric oxygen therapy is critical.~~2~ Still, due to a hyper- baric chamber＇s unavailability at many hospitals and con- cerns about patient movement resulting in further embolism during transport, such treatment method is gradually dimin- ishing.

Applying machine learning approaches to improving the accuracy of breast-tumour diagnosis via fine needle aspiration

Diagnosis and treatment of breast cancer have been improved during the last decade; however, breast cancer is still a leading cause of death among women in the whole world. Early detection and accurate diagnosis of this disease has been demonstrated an approach to long survival of the patients. As an attempt to develop a reliable diagnosing method for breast cancer, we integrated support vector machine (SVM), k-nearest neighbor and probabilistic neural network into a complex machine learning approach to detect malignant breast tumour through a set of indicators consisting of age and ten cellular features of fine-needle aspiration of breast which were ranked according to signal-to-noise ratio to identify determinants distinguishing benign breast tumours from malignant ones. The method turned out to significantly improve the diagnosis, with a sensitivity of 94.04%, a specificity of 97.37%, and an overall accuracy up to 96.24% when SVM was adopted with the sigmoid kernel function under 5-fold cross validation. The results suggest that SVM is a promising methodology to be further developed into a practical adjunct implement to help discerning benign and malignant breast tumours and thus reduce the incidence of misdiagnosis.

Fine needle aspiration cytology of Wilms' tumor:a case report

Wilms' tumor is extremely rare.In this article,we reported one case diagnosed by fine needle aspiration cytology(FNAC) and pathology.A three and a half-year-old boy was admitted to hospital with abdominal pain for two days.CT scan showed a large mass in the region of the left kidney of the boy.FNAC was performed on the mass,and the cytologic specimen showed malignant cells suggestive of a Wilms' tumor.Histologic examination of the operative specimen after the left nephrectomy also revealed Wilms' tumor.

A research on an energy-saving software for pumping units based on FNN intelligent control

An energy-saving scheme for pumping units via intermission start-stop performance is proposed. Because of the complexity of the oil extraction process, Fuzzy Neural Network (FNN) intelligent control is adopted. The structure of the Takagi-Sugeno (T-S) fuzzy neural network model is introduced and modified. FNNs are trained with sample information from oil fields and expert knowledge. Finally, pumping unit energy-saving FNN software, which cuts down power costs substantially, is presented.