Ultra-Wideband Electromagnetic Radiation from GaAs Photoconductive Switches

The experiment results of ultrawide band electromagnetic radiation with DC biased GaAs photoconductive semiconductor switch combining double ridge horn antenna triggered by high repeat frequency femto-second laser pulse are reported.The GaAs switches are insulated by solid multi-layer transparent dielectrics and the distance of two electrodes is 3mm.The electrode material of the switch is ohmic contact through alloy technics with definite proportion of Au/Ge/Ni.This switch and double ridge horn antenna are integrated and the receive antenna is connected with the test instrument.From receiving antenna,ultra fast electrical pulse of 200ps rise time and 500ps pulse width is obtained,the repetition rate of the pulse is about 82MHz and the frequency spectrum is in the range of 4.7MHz～14GHz.The radiation characteristic of the ultrafast electrical pulse is analyzed.

TaChord: a Chord system using topology-aware routing and super peers

Due to minimum consideration of an actual network topology, the existing peer-to-peer (P2P) overlay networks, such as CAN, Chord, Pastry and Tapestry, will lead to high latency and low efficiency. In TaChord, a topology-aware routing approach in P2P overlays and an improved design in Chord are presented. TaChord and other algorithms are evaluated by physical hops, interdomain-adjusted latency, and aggregate bandwidth used per message. Experimental results demonstrate that TaChord has the drastic improvement in routing performance where average physical hop is half that of chord, and the impact of cache management strategies in the TaChord overlay cannot be neglected.

刘峁塬区长8油藏增注技术研究与试验

通过对刘峁塬区三叠系长8油藏地层物性、岩性等微观性质进行分析、评价,统计分析该区三叠系长8油藏正常注水井与欠注井在宏观与微观上的差别,进而分析出欠注原因。通过对目前成熟应用的注水井增注技术原理进行再分析与评价,在2011年地面增压注水、减阻剂系统降压技术的基础上,2012年主要试验和应用了注水井酸化、氧化剂增注、水力钻孔增注技术等。通过研究,认为刘峁塬区域物性差,基质渗透率低,闭合应力高,天然裂缝不发育或不易开启导致注水门槛压力高,是导致欠注的主要原因。

Vegetative Storage Proteins in Meliaceae

采用光学和电子显微镜技术及SDS_PAGE研究了营养贮藏蛋白质 (VSPs)在楝科树木中的分布和超微结构 ;并采用免疫印迹技术 ,以大叶桃花心木 (SwieteniamacrophyllaKing)的 2 1kDVSP的抗血清检测楝科树木VSPs的免疫相关性。结果表明 ,在桃花心木亚科 (Swietenioideae)的树木中普遍存在VSPs ,但楝亚科 (Melioidae)仅部分属的树木有VSPs而椿亚科 (Cedreloideae)树木没有VSPs。VSPs在同一属树木中的分布是一致的。桃花心木亚科和楝亚科树木之间的VSPs几乎没有免疫相关性 ,但是在桃花心木亚科中 ,VSPs具有相对高的同源性。楝科树木VSPs的超微结构存在一定程度的差异 ,这可能与VSPs的种类不同有关。VSPs的分布。

Design considerations for the improved current-doubler-rectifier ZVS PWM full-bridge converter

The improved current-doubler-rectifier zero-voltage-switching PWM full-bridge converter (CDR ZVS PWM FB converter) achieves ZVS for the switches in a wide load range with the use of the energy stored in the output filter inductances, and the rectifier diodes commute naturally, therefore no oscillation and voltage spike occurs. The transformer needs no special manufacture method to limit the leakage inductance. The ZVS achievement and the design considerations for the output filter inductances and the blocking capacitor are discussed for the improved CDR ZVS PWM FB converter. A 540 W prototype converter is built in the lab to verify the operational principle and design considerations for the improved converter, the experimental results are also included.

Use of piezocone tests to predict consolidation yield stress and overconsolidation ratio of lagoonal deposit soil

Existing empirical methods for interpreting the consolidation yield stress and the overconsolidation ratio （OCR） in clays from piezocone tests are briefly reviewed. It can be seen that no universal correlation exists for all worldwide sites. However, for a given clay deposit, there does exist a most appropriate method to reflect the consolidation yield stress and the OCR based on piezocone test data. Three empirical methods are compared based on the piezocone test data collected on Lixia River lagoonal deposit soil sites in the north of Jiangsu province. The objective of this study is to evaluate the validity of the existing relationships linking the consolidation yield stress to piezocone test data and identify the appropriate method for Lixia River lagoonal deposit soil. It is shown that the correlation based on the net tip resistance has much higher accuracy for estimating the consolidation yield stress of lagoonal deposit soil than other methods.

Measurement of spatiotemporal characteristics of femtosecond laser pulses by a modified single-shot autocorrelation

To overcome the shortcomings of the single-shot autocorrelation SSA where only one pulse width is obtained when the SSA is applied to measure the pulse width of ultrashort laser pulses a modified SSA for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions is proposed. The spatiotemporal characteristics of femtosecond laser pulses output from the Ti sapphire regenerative amplifier system are experimentally measured by the proposed method. It was found that the complex spatial characteristics are measured accurately.The pulse widths at different spatial positions are various which obey the Gaussian distribution.The pulse width at the same spatial position becomes narrow with the increase in input average power when femtosecond laser pulses pass through a carbon disulfide CS2 nonlinear medium.The experimental results verify that the proposed method is valid for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions.

Molecular dynamics study on temperature and strain rate dependences of mechanical tensile properties of ultrathin nickel nanowires

Based on the EAM potential, a molecular dynamics study on the tensile properties of ultrathin nickel nanowires in the （100〉 orientation with diameters of 3.94, 4.95 and 5.99 nm was presented at different temperatures and strain rates. The temperature and strain rate dependences of tensile properties were investigated. The simulation results show that the elastic modulus and the yield strength are gradually decreasing with the increase of temperature, while with the increase of the strain rate, the stress--strain curves fluctuate more intensely and the ultrathin nickel nanowires rupture at one smaller and smaller strain. At an ideal temperature of 0.01 K, the yield strength of the nanowires drops rapidly with the increase of strain rate, and at other temperatures the strain rate has a little influence on the elastic modulus and the yield strength. Finally, the effects of size on the tensile properties of ultrathin nickel nanowires were briefly discussed.

Positioning planning of high-intensity-focused ultrasound surgery platform using Bezier curve

A positioning volume ellipsoid method is proposed to represent tumor volume in the workspace of a high-intensity-focused ultrasound (HIFU) surgery platform during the platform's positioning motion. To this simplified tumor model, a nearest neighbor search method is used to determine intermediate configuration and goal configuration, which the treatment head and ultrasound focus must pass in their localization to target volume. Based on the decided configurations, the continuity condition of combined Bezier curve in Euclidean space and De Casteljau algorithm on Lie group SO(3) are integrated to construct a combined Bezier positioning path of C2 continuity at junctional configuration, and an illustration of different positioning path planning is analyzed based on a liver tumor case.

Minimally Invasive Perventricular Device Closure of Ventricular Septal Defect: a Comparative Study in 80 Patients

Objective To evaluate the efficacy of minimally invasive perventricular device closure of ventricular septal defect(VSD). Methods Between September 2011 and February 2013, we collected 40 patients who underwent perventricular closure via a small lower sternal incision(minimally invasive group), aged 15.5±3.5 years(12 months to 32 years) with a body weight of 24.2±7.5 kg(10.8-58.0 kg). The mean size of VSD was 5.6±0.5 mm(2-14 mm). Another 40 patients were included as the surgical group, receiving the conventional surgical repair of VSD. The device of the minimally invasive group was released under the guidance of transesophageal echocardiography. Success rate, cardiac indicators, and clinical outcomes of the 2 groups were compared. Results The patients in the surgical group and those in the minimally invasive group showed similar results in success rate(both 97.5%). The procedure time, intensive care unit stay, hospital stay, and postoperative recovery time in the minimally invasive group were significantly shorter than those in the surgical group(58±21 minutes versus 145±26 minutes, 2±1 days versus 8±3 days, 5±1 days versus 16±6 days, 3±1 days versus 90±20 days, all P<0.05). The minimally invasive group had a higher incidence of conduction anomalies(17.5% versus 2.5%, P<0.05). In the follow-up period of 3-12 months, there was no new residual shunt, noticeable aortic regurgitation, significant arrhythmias, or device failure except for new complications in the surgical group. Conclusions The success rate of minimally invasive perventricular device closure of VSD under transesophageal echocardiography guidance is similar to that of conventional surgical repair, but the short-term outcomes of the minimally invasive approach is much better. Long-term follow-up is necessary to confirm the effectiveness of this technique.

A comprehensive health education plus monitoring support program for older adults with knee osteoarthritis coexisting with overweight and type 2 diabetes

Objectives:To examine the patient outcomes of a comprehensive health education plus village health volunteer monitoring support program on older adults with knee osteoarthritis who are overweight and have type 2 diabetes.Methods:Quasi-experimental,two-group,pretest-posttest design was applied.Using random geographic cluster sampling,older adults who met the inclusion criteria were assigned to two groups,62 in the intervention group and 71 in the control group.The intervention group received the comprehensive health education plus village health volunteer monitoring support program.The control group received only the comprehensive health education program.Study outcomes,including blood glucose level,knee pain and range of motion,body weight,physical ability(Timed Up and Go Test),fatigue,depressive symptoms,quality of sleep,and quality of life,were assessed at baseline,3 months,and 6 months after enrollment and analyzed using descriptive statistics and multivariate analysis of variance.Results:One hundred and ten participants completed the study(55 participants in each group).Most patient outcomes in the two groups showed general improvement with statistical significance(P<0.001):pain decreased,physical ability improved,less depressive symptoms and fatigue,quality of life and sleep improved.The interaction effect(the group and time)demonstrated statistically significant differences between the intervention and control groups on pain,knee range of motion,and fatigue according to each time follow-up(P<0.001).Conclusions:The comprehensive health education plus village health volunteer monitoring support program promotes good patient outcomes in this population.The integrated health education resource and support for older adults with knee osteoarthritis and type 2 diabetes is an effective,non-surgical treatment that highlights professional nursing roles and non-professional rolesdvillage health volunteers.Nurses should consider implementing a health education plus monitoring support program to mitigate the effects of chronic diseases and improve patients’quality of life.

Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum

When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a ＂main key stratum＂, will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway （we can also drill them in the drilling field located high in an air gateway）. Given the practice in the Haizi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.

RELATIONS OF ENDOTHELIAL FUNCTION AND BLOOD FLOW IN BRACHIAL ARTERY AND CORONARY ARTERY

Objective:To determine the relations between endothelium-dependent vasodilator function and blood flow in the brachial and coronary arteries in patients with suspected coronary artery disease.Methods:Twenty-eight patients with suspected coronary artery disease underwent brachial artery endothelial function test by using high-resolution B-mode ultrasound before coronary angiography(CAG)and coronary flow reserve(CFR)test by using intracoronary Doppler technique.The correlation of coronary artery dilatation induced by an increase in blood flow after intracoronary adenosine infusion and brachial artery flow-mediated dilatation(FMD) following reactive hyperemia was evaluated.The relation between the change of brachial artery blood flow and CFR was also studied.Results:There was a positive correlation between brachial FMD and percent change of coronary diameter after adenosine infusion(12.50%±9.35% vs 11.38%±7.55%,r=0.425,P=0.02).There was also a weak negative relation between brachial flow change following reactive hy-peremia and CFR(r=-0.397,P=0.04).Conclusion:There is a correlation between the coronary endo-thelial function and the CFR by ultrasonic determination of brachial flow changes following reactive hyperemia.

Long-term effects of di-octyl phthalate on the expression of immune-related genes in Tegillarca granosa

Di-octyl phthalate(DOP) is widely used as a plasticizer in the plastics industry.As a result,DOP is often found in marine water ecosystems where many species are exposed to it.Our objective was to evaluate the effect of long-term(14 d) DOP exposure(2.6,7.8,or 31.2 mg/L) on the expression of immunerelated genes in Tegillarca granosa.The expression of small heat shock protein(sHSPs) and tissue inhibitor of metalloproteinase(TIMP) were highest in clams exposed to 31.2 mg/L DOP on days 7 and 14.The relative expression of Tg-ferritin,superoxide dismutase(SOD),and metallothionein(MT) increased initially then decreased as the concentration of DOP increased.The hemoglobin of T.granosa(Tg-Hb I) exhibited two distinct expression patterns at two time points.Our results suggest that the immune response of T.granosa against DOP pollution varies depending on the dose.Additionally,we identified some immune-related genes that are promising candidates for biomarkers of DOP.

Stiffness of individual quadriceps muscle assessed using ultrasound shear wave elastography during passive stretching

Background: Until recently it has not been possible to isolate the mechanical behavior of individual muscles during passive stretching. Muscle shear modulus(an index of muscle stiffness) measured using ultrasound shear wave elastography can be used to estimate changes in stiffness of an individual muscle. The aims of the present study were(1) to determine the shear modulus—knee angle relationship and the slack angle of the vastus medialis oblique(VMO), rectus femoris(RF), and vastus lateralis(VL) muscles;(2) to determine whether this differs between the muscles.Methods: Nine male rowers took part in the study. The shear modulus of VMO, RF, and VL muscles was measured while the quadriceps was passively stretched at 3°/s. The relationship between the muscle shear modulus and knee angle was plotted as shear modulus—knee angle curve through which the slack angle of each muscle was determined.Results: The shear modulus of RF was higher than that of VMO and VL when the muscles were stretched over 54°(all p < 0.01). No significant difference was found between the VMO and VL(all p > 0.05). The slack angle was similar among the muscles: 41.3°± 10.6°, 44.3°± 9.1°, and 44.3°± 5.6° of knee flexion for VMO, RF, and VL, respectively(p = 0.626).Conclusion: This is the first study to experimentally determine the muscle mechanical behavior of individual heads of the quadriceps during passive stretching. Different pattern of passive tension was observed between mono-and bi-articular muscles. Further research is needed to determine whether changes in muscle stiffness are muscle-specific in pathological conditions or after interventions such as stretching protocols.

The Properties of the Hyper Relation R_i

In this paper we discuss the basic properti es of hyper relationR i, which is upgraded from the base re lation R. The relationship between R i and R is con sidered.

Development and Static Mode Characterization of a New Low-Loss AC Switch Based on Super-gain BJT

This paper deals with an innovative low-loss AC switch, named as TBBS （transistor based bidirectional switch）, based on the association of super-gain BJTs developed by the GREMAN laboratory. The main characterization results of the super-gain BJT are reminded to identify the key parameters that are essential to build the TBBS. A complete characterization database in static mode of this new AC switch is discussed. In particular, its forward and reverse-biased features have been measured to see the evolution of the DC current gain as a function of the current density. The TBBS makes sense when using the super-gain BJT （bipolar junction transistor） in reverse mode. It means that the reverse DC current gain has to be sufficient （at least higher than l compared with the conventional BJT one）. This new AC switch is bidirectional in current and voltage, totally controllable （turn-on and turn-off） and the most attractive solution in terms of on-state power losses. Further, its manufacturing process is as easier as existing device such as triac.

OBSERVATION ON THE THERAPEUTIC EFFECT OF ACPUNCTURE COMBINED WITH MASSAGE FOR CERVICAL SPONDYLOSIS OF VERTEBRAL ARTERIAL TYPE BY USING TRANCRANIAL DOPPLYER ULTRASONOGRAPHY

To observe the effect of acupuncture combined with massage on blood flow velocity of the vertebro-basilar artery in cervical spondylosis of vertebral arterial type （CSVAT） patients. Methods： In the present study, methods of evidence-based medicine, triple-centers, single-blindness, randomization and control were used. A total of 100 cases of CSVAT patients were randomized into acupuncture plus massage （acu-massage） group （n = 38）, acupuncture group （n = 32） and massage group （n = 30）. Acupoints used were Fengchi （风池, GB 20）, cervical Jiaji （颈夹脊 EX-B 2）, Baihui （百会 GV 20）, and the methods of massage used were kneading-rolling, adhesion-separating and acupoint-digital pressing, topical digital pressing and rubbing, traction-extending and mild palm-rubbing. The treatment was conducted once daily, with 7 sessions being a therapeutic course and continuously for 2 courses. Changes of peak velocity （Vp）, end-diastolic velocity （Vd）, mean velocity （Vm） of blood flow of the vertebral artery （VA） and basilar artery （BA）, etc were detected before and after the treatment by using transcranial Doppler （TCD） ultrasonography. Resuits： After the treatment, the abnormally low Vp of both VA and BA in acu-massage, acupuncture and massage groups, Vm of VA in acu-massage and acupuncture groups, Vm of BA in acu-massage and massage groups, and Vd of VA and BA in the 3 groups all increased significantly in comparison with their own pretreatment（ P 〈 0.05, 0.01）, and the therapeutic effects of acu-massage group in the 3 indexes were significantly superior to those of acupuncture group and/or massage group （P 〈0.05, 0.01 ）. The abnormally increased Vp of VA in acu-massage and acupuncture groups, Vm of VA in the 3 groups, and Vd of VA in acu-massage and massage groups decreased obviously after the treatment in comparison with their own pretreatment （P 〈 0.05, 0.01）, and the therapeutic effects of acu-massage group were significantly superior to those of acupuncture and/or massage group in the 3 indexes of VA （P〈0.05, 0.01）. In addition, the abnormally increased Vp, Vm and Vd of BA in the 3 groups showed a similar tendency. No significant differences between acupuncture and massage groups in 3 indexes （ P 〉0.05）. Conclusion： The therapeutic effects of acupuncture plus massage is significantly superior to those of simple acupuncture and simple massage therapies in improving abnormal blood dynamics of vertebral and basilar arteries in CSVAT patients.

Study of front bumper process on the basis of hot stamping

The fitting method is used for obtaining the constitutive relation of ultra-high strength steel in this paper. At the same time, the forming limit of material is researched under different de/brmation conditions. Through experiments, the paper obtains stress-strain curve under different deformation temperatures and strain rates. On the basis of experimental data, the constitutive relation model is established which can reflect the de- fomlation capacity of ultra-high strength steel during process of hot stamping. Combining with finite element simulation results of hot stamping by the commercial software AUTOFORM, transfer path of load and matching law of strength, the paper determines the design criteria and forming process requirements of parts manufactured by hot stamping. Through setting different process parameters, such as punch velocity and friction coefficient, and blank shape, the paper finds that process parameters and blank shape have an essential effect on the quality of parts.