两种离子型铱配合物的合成、光物理性质及对OH^(-)的检测

以两种2,2’-联吡啶衍生物为中性配体,2-(3-氟苯基)吡啶为环金属配体,合成了两种新型的离子型Ir(Ⅲ)配合物Ir1和Ir2。利用核磁、质谱和晶体结构分析确认了配合物Ir1和Ir2的结构。配合物Ir1和Ir2在CH_(2)Cl_(2)溶液中的最大发射波长分别为570和528 nm,为橙红光和黄光。两种配合物在无氧CH_(2)Cl_(2)溶液中的量子产率分别为0.88和0.57,磷光寿命分别为2.43和2.40μs。通过理论计算详细讨论了中性配体的取代基种类对其光谱性质的影响。在配合物Ir1的DMSO/H_(2)O溶液中加入OH^(-)后,其发射峰强度提高了近100倍,溶液的发光颜色由红色变为明亮的绿色,检出限为8.47×10^(-6)mol/L。机理研究表明,OH^(-)取代了Ir1的中性配体上的溴取代基,形成了新的含有羟基的配合物,从而改变了Ir1的光谱特性,实现对OH^(-)的高选择性和高灵敏度检测。

Diffusion bonded transition joint of TC4 to QAl10-3-1.5

Solid-state diffusion bonding has been done to produce transition joint between TC4 and QAl10-3-1.5 at the temperature 850℃ for 60 min. The produced diffusion bonded couples were evaluated by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. SEM revealed the presences of the different reaction regions in the diffusion zone and “kirkendall voids” were observed in the interface. This study indicated the existences of Cu3 Ti, Cu and Ti phases in the diffusion zone of the joint confirmed by XRD. The microhardness tests revealed that the microhardness of TC4 jointing affected zone （ JAZ） is higher than the TC4 base materials, and transition zone close to TC4 possesses the highest microhardness value.

Diffusion bonding of Ti-6Al-4V to ZQSn10-10 in vacuum

The experimental investigation of the direct diffusion bonding of Ti-6Al-4V to ZQSn10-10 was carried out in vacuum. The microstructure of bonded joint was studied by scanning electron microscopy （SEM）, energy dispersive spectroscopy （ EDS ） and the mechanical properties were detected by the tensile experiments. The microstructure and tensile strength of the joint mainly depend on the bonding temperature and bonding time. A satisfying diffusion bonded interface with a tensile strength of 73.9 MPa can be obtained under the condition of bonding temperature 850℃ for 30 rain. Three kinds of reaction products were observed in the bonded interface, namely β-Ti, CoaTi and CuSn3Ti5. And the brittle Cu3Ti and CuSn3 Ti5 are mainly responsible for lowering the strength of the bonded joint. The diffusion distances of Sn , Cu and Ti and square root of bonding time are approximately linear relationship. And diffusion velocity of Sn, Cu and Ti in the diffusion reaction layer are 0. 013 9,0. 069 7 and 0. 056 4 mm^2/s.

A Numerical Algorithm Based on Quadratic Finite Element for Two-Dimensional Nonlinear Time Fractional Thermal Diffusion Model

In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+
t2)is obtained,which is verified by the numerical results.

Superplastic Forming and Diffusion Bonding for Sandwich Structure of Ti-6Al-4V Alloy

Superplastic forming and diffusion bonding (SPF/DB) is a well-established process for the manufacture of components almost exclusively from Ti-6AI-4V sheet material. The sandwich structure of Ti-6AI-4V alloy is investigated. The effects of the microstructure on the SPF/DB process were discussed. The microstructure at the interfaces and the distribution of thickness were researched.

Diffusion bonding behaviour of β-γTiAl alloys containing high niobium with Ti interlayer by spark plasma sintering

High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The joint included three diffusion zones. The β/B2 phase formed in the Zone Ⅰ, α_(2)phase in the Zone Ⅱ, and β-Ti and α-Ti phases in the Zone Ⅲ. The thickness of β/B2 phase, the average grain size of α_(2)phase and the amount of β-Ti phase increased with the increase of bonding temperature or bonding time. The growth activation energies of β/B2 and α_(2)phases were 582 and 253 kJ/mol, respectively. The joint acquired at 1000 °C, 10 min and 10 MPa showed the maximum shear strength of 308 MPa. Fracture mainly occurred along the interfaces between Zone Ⅰ and HNBG alloy, and between Zone I and Zone Ⅱ. Fracture mechanism of the joint was characterized by brittleness rupture along the phase boundary.

Investigation of Intrachain Exciton Diffusion of MEH-PPV in Solution with Different Polarity

Femtosecond time-resolved transient grating technique was adopted to insight into the intra-chain exciton diffusion of MEH-PPV in solution with different polarity. Broadband white-light continuum was introduced as the probe to observe the transient absorption and the femtosecond time-resolved transient grating information simultaneously. The vibrational dephasing behaviors, single exciton relaxation, and population relaxation dynamics of MEH-PPV were systematically investigated. The result shows that the relaxation processes of the sample solution will be accelerated in the solvent with larger polarity.

Diffusion coefficients of natural gas in foamy oil systems under high pressures

The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.

8-hydroxy-2-(di-n-propylamino)tetralin intervenes with neural cell apoptosis following diffuse axonal injury

Previous studies have reported a neuroprotective effect of 8-hydroxy-2-（di-n-propylamino）tetralin （8-OH-DPAT） against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal injury were established. 8-OH-DPAT was intraperitoneally injected into model rats. 8-OH-DPAT treated rats maintained at constant temperature served as normal temperature controls TUNEL results revealed that neural cell swelling, brain tissue necrosis and cell apoptosis occurred around the injured tissue. Moreover, the number of Bax-, Bcl-2- and caspase-3-positive cells increased at 6 hours after diffuse axonal injury, and peaked at 24 hours. However, brain injury was attenuated, the number of apoptotic cells reduced, Bax and caspase-3 expression decreased, and Bcl-2 expression increased at 6, 12, 24, 72 and 168 hours after diffuse axonal injury in normal temperature control and in 8-OH-DPAT-intervention rats. The difference was most significant at 24 hours. All indices in 8-OH-DPAT-intervention rats were better than those in the constant temperature group. These results suggest that 8-OH-DPAT inhibits Bax and caspase-3 expression, increases Bcl-2 expression, and reduces neural cell apoptosis, resulting in neuroprotection against diffuse axonal injury. This effect is associated with a decrease in brain temperature.

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.

Inhibition of Notch 1 signaling in the subacute stage after stroke promotes striatal astrocyte-derived neurogenesis

Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis.

Evaluation of Fast Flood Diffusion through a Drainage Channel: A Flood Disaster Case Study of Japan’s Kinugawa River, September 10, 2015

On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for help despite supposedly having sufficient time to evacuate. Some said that small initial flood before main severe flood arrived made them make a mistake in deciding whether to evacuate or stay there, despite having to actually evacuate in reality. This study focused on flood behaviour in this area, in particular, the effect of a small drainage channel lying on the flood plain which caused fast flood diffusion in case of occurring huge overflowing. Field investigations starting on time of the disaster with high-resolution positioning system were conducted to obtain spatial maps of flood depth and height. For appropriate modelling of the effect of small channel, we applied simulation model coupling 1-dimensional (1D) and 2-dimensional (2D) hydraulic scheme on the field and compared results from the 1D/2D coupled model and model without 1D scheme. The models provided information that the flood could reach 4 hours earlier to the city central of Joso city comparing in case of model without 1D scheme. The water depth rose irregularly and it was more confusing and difficult for the victims to make appropriate evacuation act.

促进CaCO_(3)在溶液中成核的高效电化学水软化器

为解决电化学法除垢存在的电极频繁清理及效率低下的问题,开发了电极水平排列的新型电化学水软化反应器,设置从阴极区进水,从阳极区出水,利用水流和气泡运动推动OH-扩散,强化CaCO_(3)在溶液中成核。通过优化电流密度、流速和进水硬度强化电化学水软化反应器内CaCO_(3)在溶液中的成核,在流速为2.7 L/h、电流密度为80 A/m^(2)、进水硬度(以CaCO_(3)计)为400 mg/L时,软化效率可达到155 g/(h·m^(2)),硬度去除量可达到150 mg/L,电流效率可达到50%,去除单位质量CaCO_(3)能耗为15 kW·h/g,有效地降低了阴极清理频率。

受控扩散凝固制备过共晶Al-Si合金及其热力学分析

采用液-液混合受控扩散凝固技术(CDS)制备过共晶Al-20%Si合金,研究高硅合金温度对目标合金组织中初生硅的影响及混合过程中初生硅细化的热力学条件。结果表明:采用液-液混合制备过共晶铝硅合金,可以细化初生硅,初生硅平均尺寸可达到37μm;但随着高硅合金温度的升高,初生硅的平均尺寸增加,板条状和五瓣星状初生硅也增多,当高硅温度超过790℃时,初生硅细化效果丧失。分析得出,只有当混合前两种合金吉布斯自由能的加权平均值小于混合后目标合金在液相线的吉布斯自由能(liquidusfinal,m G=-39.336 6 kJ)时,初生硅才能得到明显的细化。

电化学法处理循环冷却水的研究进展

循环冷却水系统已广泛应用于工业生产的冷却过程,其显著提高水资源的利用效率。然而,结垢问题直接影响循环冷却系统的稳定性。电化学法可以有效缓解结垢带来的负面问题。因此,本文从两个方面(调控阴极面积,高效分离氢离子和氢氧根)详细阐述电化学法处理循环冷却水的最新研究进展,以更好地利用电化学法处理循环冷却水。

Cu75Ni25合金平衡固-液界面的微观结构

采用NPH系综分子动力学(molecular dynamics,MD)方法模拟了Cu75Ni25合金的平衡固-液界面,并对其界面结构及属性进行了深入探究。根据相图计算,取Cu75Ni25合金成分点,求得不同晶向的熔点,Tm,[100]=1508.31 K,Tm,[110]=1514.92 K,Tm,[111]=1523.35 K,熔点存在各向异性。在界面区,统计了平衡构型的数密度、序参数、Ni原子浓度以及质量密度的分布曲线,展示了固-液界面的diffuse nature;所有参数在由固相向液相衰减的过程中呈现出很好的双曲正切的连续变化规律,其中采用Ni原子浓度计算得到的界面宽度明显小于采用其他属性计算得到的界面宽度。此外,按照“10%~90%”规则,以序参数为标准计算得到的界面宽度同样存在非常一致的各向异性;采用序参数aq 6计算得到的界面宽度始终大于序参数ξ的界面宽度。

Highly Heat-Resistant Materials for Microelectronics:Hydrodynamic,Optical,and Conformational Properties of Fluorine Containing Poly(Amido-ortho-Hydroxy Amide)

The polycondensation of the mixture of diamines 5,5-methylene bis(2-aminophenol) and 4,4-(hexafluoroisopropylidene)dianiline(molar ratio 0.8:0.2) with isophthaloyl dichloride was used to synthesize poly(amido-o-hydroxy amide)(POA-F)-new heat resistant binder of the composites for microelectronics. The copolymer was fractionated, its hydrodynamic, optical, and conformational properties were researched, and molecular masses(ММ) of the fractions were defined. The polydispersity index was estimated. Based on experimental data, calculation of the size of a segment of Kuhn characterizing degree of an intramolecular orientation order and value of coefficients of the equation of Mark-Kuhn-Hauvink for viscometric and diffusion data were performed. It was demonstrated that introducing 20 mol % of the monomer with-CF3-groups does not lead to any changes in conformational properties of the macromolecules and does not change the degree of intramolecular orientational order(the Kuhn segment length). Optical characteristics of POA-F solutions are virtually similar to the corresponding values for POA prepared with the use of single amine-containing component-5,5-methylene bis(2-aminophenol). The received MM distribution for POA-F(prepolymer) provided the solubility of its films in alkaline solutions. The heat resistance(τ5 and τ10-temperatures corresponding to 5% and of 10% PBO-F mass loss of a polymer) of the powders and the films of PBO, PBO-F were determined. The electrophysical parameters-dielectric permittivity(ε) and dielectric loss tangent(tan δ) of the PBO-F films decreased down to 3.30 and 0.017, in comparison 3.40 and 0.025 for PBO respectively.

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.

Dynamic changes in cerebral microcirculation and hypoxia in the early stages of diffuse axonal injury

This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.

Numerical Study on Plume Interaction Above An AlternatingDiffuser in Stagnant Water

The plume interaction above an alternating diffuser in stagnant water is studied with 3D Reynolds-averaged NavierStokes equations （RANS） combined with a buoyancy-extended κ-ε model. The steady three-dimensional turbulent flow and temperature fields are computed by use of the finite volume method on a non-uniform high resolution orthogonal grid. The numerical predictions demonstrate a generic flow pattern for different turbulent heated jet discharges： the buoyant jets on each side of the diffuser first merge to form an essentially two-dimensional plume which bends back toward the diffuser centerline due to a low pressure cavity. In general, an under-pressure exists in the cavity until the plumes merge; the pressure increases to slightly positive afterwards. Two-dimensionality of the scalar and flow field is attained much later than the point of zero pressure. The position of merging point is governed by mainly four parameters - the discharge densimetfic Froude number, the port diameter and space, and the horizontal distance between alternating jet nozzles. A formula from numerical simulations is obtained through regression analysis and it is used to predict the position of plume merging point. The predicted temperature fields are comparable to previous experiments.