Application of Two-dimensional Viscous CE/SE Method in Calculation of Two-phase Detonation

The method of two-dimensional viscous space-time conservation element and solution element (CE/SE) can be used to calculate the gas-liquid two-phase interior flow field in pulse detonation engine (PDE). In this paper, the evolution of the detonation wave and the distribution of its physical parameters were analyzed. The numerical results show that the change of axial velocity of gas is the same as that of detonation pressure. The larger the liquid droplet radius is, the longer the time to get stable detonation wave is. The calculated results coincide with the experimented results better.

Periodic oscillation and fine structure of wedge-induced oblique detonation waves

An oblique detonation wave for a Mach 7 inlet flow over a long enough wedge of 30 turning angle is simulated numerically using Euler equation and one-step rection model.The fifth-order WENO scheme is adopted to capture the shock wave.The numerical results show that with the compression of the wedge wall the detonation wave front structure is divided into three sections：the ZND model-like strcuture,single-sided triple point structure and dual-headed triple point strucuture.The first structure is the smooth straight,and the second has the characteristic of the triple points propagating dowanstream only with the same velocity,while the dual-headed triple point structure is very complicated.The detonation waves facing upstream and downstream propagate with different velocities,in which the periodic collisions of the triple points cause the oscillation of the detonation wave front.This oscillation process has temporal and spatial periodicity.In addition,the triple point trace are recorded to obtain different cell structures in three sections.

Numerical study on three-dimensional flow field of continuously rotating detonation in a toroidal chamber

Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.

Effect of two-step solid solution on microstructure andδphase precipitation of Inconel 718 alloy

Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical properties.The effects of different two-step solid solution treatments on microstructure andδphase precipitation of Inconel 718 alloy were studied,and the transformation mechanism fromγ″metastable phase toδphase was clarified.The precipitates were statistically analyzed by X-ray diffractometry.The results show that theδphase content firstly increased,and then decreased with the temperature of the second-step solid solution.The changes in microstructure andδphase were studied by scanning electron microscopy and transmission electron microscopy.An intragranularδphase formed in Inconel 718 alloy at the second-[100]_(δ)[011]γ step solid solution temperature of 925℃,and its orientation relationship withγmatrix was determined as//and(010)_(δ)//(111)γ.Furthermore,the Vickers hardness of different heat treatment samples was measured,and the sample treated by second-step solid solution at 1010℃ reached the maximum hardness of HV 446.84.

IMPLICIT TVD SCHEMES APPLIED TO GAS-DROPLET DETONATION CALCULATION

In order to investigate parameters of FAE (fuel air explosive) explosion, the two-phase gas-droplet conservation equations with two-dimensional axial symmetry in the Euler coordinate were used. High-resolution implicit TVD ( total variation diminishing) schemes were applied to gas phase equations and MacCormack schemes to liquid equations. The formation and propagation of gas-droplet detonation wave were simulated numerically. The simulation results and the others are compared with a good agreement.

Phase evolution of plasma sprayed Al_2O_3-13%TiO_2 coatings derived from nanocrystalline powders

Commercial nanosized alumina and titania particles were selected as raw materials to prepare the blended slurry with composition of A1203-13%TiO2 （mass fraction）, which were reconstituted into micrometer-sized granules by spray drying, subsequently sintering at different temperatures to form nanostructured feedstock for thermal spraying, and then A1203-13%TiO2 nanocoatings were deposited by plasma spraying. The evolution of morphology, microstructure, and phase transformation of the agglomerated powder and as-sprayed coatings were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that A1203 retains the same a phase as the raw material during sintering, while TiO2 changes from anatase to futile. During plasma spraying, some a-A1203 phases solidify to form metastable y-A1203, and the volume fraction of a-A1203 decreases as CPSP increases. However, peaks of the TiO2 phase are not observed from the as-sprayed coatings except for the coatings sprayed at the lower CPSP. As the CPSP increases, nanostructured TiO2 is dissolved easily in y-A1203 or z-A1203＇TiO2 phase. After heat treatment, y-A1203 in the coatings transforms to a-A1203, and rutile is precipitated.

Synthesis and Solid Phase Extraction Performance Study of NNAL-specific Molecularly Imprinted Polymers Using Dummy Templates

Dummy molecularly imprinted polymers （DMIPs） for 4-（methylnitrosamino）-1-（3-pyridyl）-1-butanol （NNAL） were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-（acetymethylamino）-1-（3-pyridyl）-butanol, 4- （methylamino）-1-（3-pyridyl）-1-butanol, and 1-（3-pyridyl）-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy （XPS） and Fourier transform infrared spectroscopy （FT-IR）. Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-（acetymethylamino）-1-（3-pyridyl）-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction （DMISPE） was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%.

旋转爆轰发动机内煤粉-氢气两相爆轰流场数值研究

旋转爆轰发动机因其较高的热循环效率在航空航天领域备受关注。为了研究气固混合燃料在空气氛围中的旋转爆轰特性,在圆柱坐标系中建立了气固混合相燃料爆轰理论模型,并基于三维守恒元与求解元方法,对圆盘形燃烧室内的爆轰过程进行三维数值模拟。计算获得了气固混合相旋转爆轰波稳定传播时的流场结构,分析了爆轰流场的热力学参数分布特征、化学反应区分布以及旋转爆轰波后的波系分布特点。研究结果表明,微米级煤粉在氢气辅助作用下可快速反应并支持旋转爆轰波的稳定传播,但因盘形燃烧室的扁平结构特征和非预混喷注方式,导致爆轰波波阵面呈现为不规则的曲面。煤粉和氢气射流穿透空气层的能力差异导致气固混合燃料的化学反应区发生分离,最终以双反应区的爆轰组织形式支持旋转爆轰波稳定传播。旋转爆轰波不规则的曲面结构使其在扁平的燃烧室中发生多次反射,进而在爆轰波后有规律地出现多道反射激波。

乙烯对煤粉-氧气爆轰波起爆特性影响机制的实验研究

为实现煤粉连续旋转爆轰发动机的可靠点火,开展乙烯对煤粉-氧气起爆特性的影响机制研究。在初始压力p 0=100 kPa下,采用高能电点火对有无0.5当量比乙烯氛围下的煤粉-氧气混合物开展直接起爆实验研究。点火能量通过测定在空气中高能电火花产生的爆炸波压强进行计算。计算后发现:采用6.3 J的有效点火能量,煤粉-氧气在不含乙烯的氛围下无法起爆;在此能量下,煤粉-氧气在0.5当量比的乙烯氛围条件下可实现直接起爆;将能量降低为3.6 J,使其低于乙烯-氧气(0.5当量比)混合物的临界起爆能量,虽然乙烯-氧气无法直接起爆,但是在加入煤粉后却可以形成稳定的自持爆轰波。研究结果表明:若要实现煤粉-氧气的直接起爆,则需要添加一定量的助爆气体(如乙烯);煤粉的加入还可以拓宽乙烯-氧气混合物的起爆极限。所得结果可以为煤粉连续旋转爆轰发动机的点火起爆提供理论依据并提供技术支撑。

Modification and refinement mechanism of Mg_2Si phase in Sr-containing AZ61-0.7Si magnesium alloy

The effect of Sr on modification and refinement of the Mg 2 Si phase in an AZ61-0.7Si magnesium alloy has been investigated and analyzed.The results indicate that Sr can effectively modify and refine the Chinese-script shaped Mg2Si phase in the AZ61-0.7Si alloy.By adding 0.06wt.%-0.12wt.%Sr to AZ61-0.7Si alloy,the Mg2Si phase in the alloy can be changed from the initial coarse Chinese-script shape to fine granule and/or irregular polygonal shapes.Accordingly,the Sr-containing AZ61-0.7Si alloy exhibits higher tensile and creep properties than the AZ61-0.7Si alloy without Sr modification.The mechanism on modification and refinement of the Mg2Si phase in Sr-containing AZ61-0.7Si alloy is possibly related to the following two aspects:(1)adding Sr may form the Al4Sr phase which can serve as the heterogeneous nucleus for the Mg2Si particles and/or(2)adding Sr may lower the onset crystallizing temperature and increase the undercooling level.

A Phase II Study of Antineoplastons A10 and AS2-1 in Children with High-Grade Glioma. Final Report (Protocol BT-06), and Review of Recent Trials

Standard treatment for high-grade glioma involves surgical resection followed by radiation therapy and temozolomide. Unfortunately, there are no standard treatment recommendations after recurrence and new therapies are needed for patients whose tumor recurs after first-line treatment. This single-arm, two-stage, interventional Phase II study evaluated the efficacy and safety of a combination of antineoplastons A10 and AS2-1. Nineteen patients were enrolled in the study (safety population), but fifteen patients with a median age of 9.4 years who met eligibility criteria were evaluated. The majority of subjects (12/15) were Caucasian and 8/15 (53%) were female. More than half (53%) of patients were diagnosed with glioblastoma and 33% with anaplastic astrocytoma. All patients had failed standard therapy including surgery, radiation, and chemotherapy. Antineoplastons were administered intravenously every four hours (median dose of A10 6.9 g/kg/d and AS2-1 0.30 g/kg/d) until objective response was documented and thereafter for a further 8 months. Clinical evaluations were performed every 8 weeks. All patients enrolled in the study were included in the safety analysis but only patients fulfilling the inclusion criteria were included in the efficacy evaluation. The duration of treatment with antineoplastons ranged from 2 weeks to 120 weeks. A complete response was documented in 2/15 (13%), partial response in 2/15 (13%), stable disease in 3/15 (20%). Progression-free survival at six months was 47% and overall survival (OS) at one year was 33.3%. One patient (6.7%) survived 10 years from treatment start. A small group of patients suffered reversible Grade 3 and 4 toxicities including hypernatremia 2/19 (11%) and decrease of neutrophils 1/19 (5%). There were no chronic toxicities. There was improvement of quality of life in patients who had objective response. It is concluded that antineoplastons show efficacy with an acceptable profile in this cohort of patients with recurrent high-grade glioma.

A Phase II Study of Antineoplastons A10 and AS2-1 in Adult Patients with Recurrent Glioblastoma Multiforme: Final Report (Protocol BT-21)

Treatment of recurrent glioblastoma multiforme (RGBM) creates one of the most difficult challenges to neuro-oncology. The purpose of this study is to evaluate the outcome of adults with high-grade glioma with special attention to RGBM patients treated with Antineoplastons (ANP) A10 and AS2-1 injections. The study was conducted according to Protocol BT-21, which accrued patients who failed standard radiation therapy (RT) and chemotherapy. There were 40 candidates registered in the study. Among the intent-to-treat (ITT) population, there were 30 cases of RGBM that progressed during and after prior treatment, 4 patients with anaplastic astrocytoma (AA), 1 with anaplastic mixed glioma (AMG), and 5 with persistent GBM. The aim of this paper is to evaluate the responses, survival and toxicity of all 40 patients, the efficacy in 30 patients with RGBM, and in 24 patients with RGBM who received at least 28 days of ANP (ERGBM). All RGBM patients were treated before with RT and chemotherapy, except one patient who only had surgery (patient refused radiation). In this group, 63% had one recurrence, 30% had two recurrences, and 7% had three recurrences. The median duration of ANP and ITT was 12 weeks and the median dosage of ANP A10 was 6.52 g/kg/d and ANP AS2-1 was 0.23 g/kg/d. Responses were assessed by gadolinium-enhanced magnetic resonance imaging (MRI) repeated every eight weeks. In the ITT population, objective responses (ORs) were determined in 10% of cases (complete response—CR, and partial response—PR in 5% each). Progression-free survival (PFS) in ITT at six months was 17.5%. Overall survival (OS) was 28.3% at one year, 2.6% at two years, five and ten years. In the RGBM population, objective responses (ORs) were determined in 13.3% of cases (CR and PR in 6.7% each). PFS in RGBM at six months was 16.7%. OS was 34.7% at one year, 3.47% at two years, five?and ten years. In the ERGBM population, ORs were determined in 16.7% of cases (CR and PR in?8.3% each). PFS in ERGBM at six months was 20.8%, OS was 39.3% at one year, 4.4% at two years, five and ten years. The treatment was well-tolerated with reversible Grades 3 and 4 toxicity in 17.5% of patients (7 patients who experienced multiple toxicities) and no chronic toxicity. In conclusion, the study reached efficacy endpoint. ANP is well-tolerated and compares favorably to the current treatment for RGBM.

Thermodynamic modeling and phase diagram prediction of salt lake brine systemsⅡ.Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems

It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high concentration.The essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model.Liquid parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,i.e.the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization method.The solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities.The modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary systems.The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.

A Phase II Study of Antineoplastons A10 and AS2-1 in Children with Recurrent, Refractory or Progressive Primary Brain Tumors—Final Report (Protocol BT-22)

Primary malignant brain tumors are a leading cause of cancer-related death in children. This Phase II study evaluated the efficacy and safety of Antineoplastons A10 and AS2-1 (ANP) in children who developed progression during standard treatment. A total of 43 children were recruited to the study, but only 41 met eligibility criteria. There were twelve cases of glioblastoma multiforme (GBM), eight anaplastic astrocytomas (AA), twelve diffuse intrinsic pontine gliomas (DIPG), three supertentorial primitive neuroectodermal tumors (sPNET), three cases of medulloblastoma and one case each of anaplastic ependymoma (AE), atypical teratoid rhabdoid tumor (AT/RT), and disseminated pilocytic astrocytoma (PAD). ANP was administered intravenously daily every four hours (median dose of A10 8.74 g/kg/d and AS2-1 0.35 g/kg/d), until objective response (OR) was documented, and then a further eight months. All enrolled patients were included in safety, but only eligible patients in the efficacy evaluation. A total of 12.2% of patients obtained OR;2.4% complete response (CR) and 9.8% partial response (PR). Stable disease (SD) was determined in 17.1% and progressive disease (PD) in 43.9% of cases. There were 26.8% of nonevaluable (NE) cases due to premature discontinuation. Out of five OR cases, four patients were diagnosed with recurrent DIPG and one with recurrent AA. Median progression-free survival (PFS) was 2.5 months. Median overall survival was 4.8 months. OS at 6 months was 46.3%, one year was 12.2%, and 4.8% at two, five, and ten years. The longest survivor is a patient diagnosed with DIPG and gliosarcoma who remains alive more than 15 years. A group of eleven patients reported grade 3 and 4 toxicity including hypernatremia in eight cases, somnolence in two cases, and hypokalemia in one case. There were no chronic toxicities, and the quality of life was very good. The largest group of patients were represented by DIPG, GBM, and AA. The best results were obtained in the DIPG and AA groups. In the DIPG group, CR was in 8.3%, PR was 25%, median PFS was 4.8 months, median OS was 6.1 months, and OS at 6 months was 58.3%, at one year 25%, and 8.3% at two, five, and ten years. In the AA group, PR was 12.5%, median PFS was 3.7 months, median OS was 4.7 months, and OS at 6 months was 37.5%, and 12.5%, at one, two, five, and ten years. In conclusion, antineoplastons showed efficacy and acceptable toxicity in patients with recurrent, refractory or progressive primary brain tumors.

A Phase II Study of Antineoplastons A10 and AS2-1 in Patients with Brainstem Gliomas. The Report on Non-Diffuse Intrinsic Pontine Glioma (Protocol BT-11)

Inoperable brainstem gliomas (BSG) are among the most difficult to treat malignancies. In the intent-to-treat (ITT) population of the BT-11 study for BSG, forty patients (median age 11.2 years old) were enrolled. Antineoplastons A10 and AS2-1 (ANP) were administered intravenously daily. The median daily dose of A10 was 8.70 g/kg/day and AS2-1 was 0.32 g/kg/day. Efficacy analyses were conducted in two subgroups: recurrent pediatric diffuse intrinsic pontine glioma (RPDIPG, N?= 17) and non-diffuse intrinsic pontine glioma (NDIPG, N?= 11). This paper reports the results of the study of the efficacy and safety of ANP in patients with NDIPG. The results in the RPDIPG group were reported before;complete response (CR) was 6%, partial response (PR) 23.5%, and stable disease (SD) 17.6%. One year overall survival (OS) was 29.4%, 2 years 11.8%, and 5, 10, and 15 years 6%. In the NDIPG group, there were 36% CR and 27.5% SD. OS at 1, 5, 10, and 15 years was 82%, 73%, 62%, and 50% correspondingly. There was only one serious adverse event (9%) reported in NDIPG represented by hypokalemia, Grade 4. The results suggest that ANP shows efficacy and an acceptable tolerability profile in patients with RPDIPG and NDIPG.

Synergistic Effect in Mixed Capillary Gas Chromatographic Stationap Phases Containing Heptakis(2,3,6-tri-o-pentyl)-β-cyclodextrin and Dibenzo-18-crown-6

used－silical capillary columns containing heptakis（2、3、6－tri－o－pentyl）-β-cyclodextrinand dibenzo-18-crown-6 were prepared．By studying the selectivity of mixed stationary phases forsome solute pairs.as well as comparing with the heptakis（2．3、6-tri-O-pentyl）-β-cyclodextrin and thedibenzo-18-crown-6 used as individual stationary phase、the synergistic effects were observed.These effects were affected by the column temperature．mixed ratio and linear velocity of carrier gas．

Experimental study on detonation parameters and cellular structures of fuel cloud

In this paper, detonation parameters of fuel cloud, such as propylene oxide （PO）, isopropyl nitrate （IPN）, hex- ane, 90# oil and decane were measured in a self-designed and constructed vertical shock tube. Results show that the deto- nation pressure and velocity of PO increase to a peak value and then decrease smoothly with increasing equivalence ra- tio. Several nitrate sensitizers were added into PO to make fuel mixtures, and test results indicated that the additives can efficiently enhance detonation velocity and pressure of fuel cloud and one type of additive n-propyl nitrate （NPN） played the best in the improvement. The critical initiation energy that directly initiated detonation of all the test liquid fuel clouds showed a U-shape curve relationship with equiva- lence ratios. The optimum concentration lies on the rich-fuel side （;b 〉 1）. The critical initiation energy is closely related to molecular structure and volatility of fuels. IPN and PO have similar critical values while that of alkanes are larger. Detonation cell sizes of PO were respectively investigated at 25;C, 35;C and 50;C with smoked foil technique. The cell width shows a U-shape curve relationship with equivalence ratios at all temperatures. The minimal cell width also lies on the rich-fuel side （;b 〉 1）. The cell width of PO vapor is slightly larger than that of PO cloud. Therefore, the deto- nation reaction of PO at normal temperature is controlled by gas phase reaction.

A Phase II Study of Antineoplastons A10 and AS2-1 in Children with Low-Grade Astrocytomas—Final Report (Protocol BT-13)

Nonresectable Low-Grade Astrocytomas (LGA) can compromise function and threaten life. For the majority of patients, the most appropriate strategy is initial chemotherapy followed by Radiation Therapy (RT). Since curative treatment is not available for most of these patients, it is reasonable to conduct clinical studies to evaluate new agents. This Phase II study evaluates efficacy and safety of Antineoplastons A10 and AS2-1 (ANP) in LGA. Sixteen children diagnosed with LGA were treated. They included 12 males and 4 females, ages 1.6 - 17.4 years (median 10.6). Efficacy was evaluated in 16 patients. The majority of patients were previously treated, but 1 patient had stereotactic biopsy only. Out of the remaining 15 patients, 6 patients received chemotherapy, and 7 patients had surgery, and 2 patients received RT and chemotherapy after surgery. The patients received treatment with ANP administered daily every 4 hours (median dose of A10 was 7.71 g/kg/d and AS2-1 was 0.26 g/kg/d) until objective response or stable disease was documented and for 8 months thereafter. The duration of ANP IV ranged from 1.4 to 286 weeks with a median of 83 weeks. A complete response was documented in 25.0%, partial response in 12.5%, and stable disease in 37.5%. Overall survival was 67.7% at 5 years, and 54.2% at 10 and 15 years. Progression-free survival was 48.1%, 34.4% and 34.4% at 5, 10, and 15 years respectively. The treatment was associated with grade 3 or grade 4 Adverse Drug Experiences (ADE) in 6 patients. There were two hypernatremias of grade 4 (12%). Grade 3 ADE included urinary frequency (6%), fatigue (6%) and hypernatremia (6%). There were no chronic toxicities, and there was a high quality of survival. ANP shows efficacy with a very good toxicity profile in this cohort of children with low-grade astrocytoma.

Solid-phase Synthesis of-Haloaldehydes from Polymer-supported 4-(Phenylseleno)morpholine

Polystyrene-supported 4-(phenylseleno)morpholine was synthesized and could be used as an efficient ?selenenylating agent for saturated aldehydes. ?Haloaldehydes were prepared by reaction of polystyrene-supported ?selenoaldehydes with bromine or sulfuryl chloride in good yield and high purity.

X-ray diffraction study of effect of deposition conditions on α-β phase transition and stress evolution in sputter-deposited W coatings

Pure W and W-Cu-W trilayer coatings were deposited on an Fe substrate by d.c. magnetron sputtering. The α-β phase evolution, intragranular stress evolution in sputter-deposited W layer were investigated by x-ray diffraction. They are directly related to the film microstructure, density and adhesion. Therefore, control of the film stress and phase component transition is essential for its applications. The phase component transition from β-W to α-W and intragranular stress evolution from tensile to compressive strongly depend on the deposition parameters and can be induced by lowering Ar pressure and rising target power. The compressively stressed films with α-W phase have a dense microstructure and high adhesion to Fe substrate.