Influence of pre-stretching on quench sensitive effect of high-strength Al-Zn-Mg-Cu-Zr alloy sheet

The influence of pre-stretching on quench sensitive effect of high strength Al-Zn-Mg-Cu-Zr alloy AA 7085 sheet was investigated by tensile testing at room temperature,transmission electron microscopy(TEM)and differential scanning calorimetry(DSC).The water-cooled and aged alloy exhibits higher strength than the air-cooled and aged alloy;2.5%pre-stretching of tensile deformation exerts little effect on strength of water-cooled and aged alloy but increases that of air-cooled and aged one,and therefore the yield strength reduction rate due to slow quenching decreases from about 3.8%to about 1.0%,reducing quench sensitive effect.For the air-cooled alloy,pre-stretching increases the sizes ofη'strengthening precipitates but also increases their quantity and the ratio of diameter to thickness,resulting in enhanced strengthening and higher strength after aging.The reason has been discussed based on microstructure examination by TEM and DSC.

Study of ATP borate ester effects on cell sensitization to radiation emitted by a nuclear reactor

Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric acid.Next,ATP borate ester pretreatments were assessed to study their effects on cell sensitization from exposure to thermal neutron irradiation emitted by a nuclear reactor.Using cell viability assays(CCK8),survival rates of A549 cells pretreated with or without boroncontaining agents,including ATP borate ester and 4-dihydroxyborylphenylalanine(BPA),were measured.One week after feeding an ATP borate ester solution to tumorbearing nude mice,elemental B content values of tumor muscle and blood were measured using inductively coupled plasma mass spectrometry(ICP-MS).Meanwhile,other tumor tissue samples were placed in a culture medium,subjected to a 3-min neutron irradiation exposure,and then fixed in formalin 24 h later for the terminaldeoxynucleotidyl transferase(TDT)-mediated d UTP nick end labeling(TUNEL)immunohistochemical staining analysis.Results showed that A549 cell irradiation sensitization(irradiation dose of 0.33 Gy)varied with pretreatment.Sensitization values of the ATP borate ester pretreatment group were 1.3–14.1 with boron agent concentrations of 0.3–4.5 mM.Within 1.1–3.4 mM,ATP borate ester showed significantly higher sensitization values than BPA.Meanwhile,TUNEL results demonstrated that apoptosis rates of tumor tissue cells exposed to irradiation after ATP borate ester pretreatment significantly exceeded the corresponding rates for BPA-pretreated cells.In animal experiments,although the distribution ratio of ATP borate ester(tumor tissue/normal muscle,T/N)of 1.2 was not significantly different compared with that of BPA(1.3),the total ATP borate ester concentration in the tumor tissue(0.79±0.05μg/g)significantly exceeded that of BPA(0.58±0.05μg/g).Thus,compared with BPA,the greater enrichment of ATP borate ester in tumor tissues permits preferential targeting toward tumor cells for radiation sensitization.Therefore,ATP borate ester is superior to BPA for use in boron neutron capture therapy.

Theoretical Insight into the Influence of Molecular Ratio on the Stability, Mechanical Property, Solvent Effect and Cooperativity Effect of HMX/DMI Cocrystal Explosive

Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in different molecular molar ratios. The mechanical properties were estimated in different molar ratios. Solvent effects were evaluated and the cooperativity effects were discussed in the HMX···HF···DMI ternary by using the M06-2x/6-311＋G（2df,2p） and MP2（full）/6-311＋G（2df,2p） methods. The results indicate that the substituted patterns（020） and（100） own the highest binding energies. The stabilities of cocrystals in the 1：1 and 2：1 ratios are the greatest, and thus the HMX/DMI cocrystals prefer cocrystallizing in the 1：1 and 2：1 molar ratios, which have good mechanical properties. The sensitivity change of cocrystal originates from not only the formation of intermolecular interaction but also the increment of bond dissociation energy of the N–NO2 bond. The cooperativity effect appears in the linear complex while the anti-cooperativity effect is found in the cyclic system. DMI binding to HMX is not energetically and structurally favored in the presence of HF. This is perhaps the reason that the solvent with large dielectric constant weakens the stability of the HMX/DMI cocrystals. Therefore, the solvents with low dielectric constants should be chosen in the preparation of HMX/DMI cocrystals.

Sensitizing Effect of Mixed Surfactants on the Colouration of Scandium(Ⅲ)with Phenylfluorone or Its Derivatives

In the presence of mixed micelle of a cationic and a nonionic surfactants,the reaction of scandium(Ⅲ) with phenylfluorone or its derivatives results in a very sensitive colouration:furthermore this chromophoric system tolerates the existence of a considerable amount of masking agents,so that many interfering ions can be masked and its selectivity would be further improved.After studying the optimum conditions and main charac- ters of some similar systems,the system of Sc(Ⅲ)—Orthonitrophenyuorone—Cetyltrimethylammonium Bromide(CTMAB)—Triton X-200 is chosen for the spectrophotometric determination of microamount of scandium.The proposed method shows not only high sensitivity(with a molar absorptivity of 2.12×1~sL mol^(-1)·cm^(-1))and selectivity,but also high tolerance of chromophoric conditions.Beer's law is obeyed over a range of 0～6.0 μg Sc/25ml.If the dual-wavelength method is applied,a much higher molar absorptivity o|' 3.04×10~5L·mol^(-1)·cm^(-1)than those of other systems ever reported in the literatures can be attained:more- over.its linear range is extended to 0～8.0 μg Sc/25ml and its reproducibility is also improved.

Effect of desensitization treatment for highly sensitized uremic patients before kidney transplantation

Objective To explore the feasibility and efficacy of desensitization protocol for highly sensitized renal transplant patients ( HSP ) . Methods Thirty - five HSPs ( HLA class - I panel reactive antibody 2〉50 % ) , including 27 patients with a positive T and/or B cell cy-

Preparation and properties of RE^(3+) doped luminescent co-polymer by solution copolymerization

Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200-400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene co-polymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the 'sensitization effect' for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by increasing the rigidity of main and side chain.

Controls of Acid-sensitive Minerals on Reservoir Sensitivity Testing： An Example from the Silurian Kepingtage Formation in Tazhong Area, Tarim Basin

The Silurian Kepingtage Formation in Tazhong area is regarded as an acid-sensitive hydrocarbon reservoir. However, formation mechanism of acid-sensitive of the reservoir cannot be interpreted by the existing acid-sensitive evaluation criterion based on damage rate. The contents of acid-sensitive minerals illustrated by bulk-rock XRD, scanning electron microscopy and clay mineral composition analysis exert the dominant control on acid-sensitive flow testing of the reservoir. The ironbearing minerals（including pyrite cements and chlorite cements） mainly deteriorate reservoir quality, while the iron-free minerals（including calcite cements and dolomite cements） mainly improve permeability. The permeability variation of the tested samples is controlled by the relative content of two acid-sensitive minerals. On the basis of newly established sensitivity mechanism and its influence on permeability, the corresponding ion（Fe^（2＋）） stabilizer was added to the acidizing fluids during the acidification reconstruction, which inhibited the negative factors of acid-sensitive minerals and improved the target layer quality effectively.

A design and application of compound multi-functional sensor in wood-based panel processing

A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments.

MODEL ANALYSIS AND PARAMETER EXTRACTION FOR MOS CAPACITOR INCLUDING QUANTUM MECHANICAL EFFECTS

The high frequency CV curves of MOS capacitor have been studied. It is shown that semiclassical model is a good approximation to quantum model and approaches to classical model when the oxide layer is thick. This conclusion provides us an efficient （semiclassical） model including quantum mechanical effects to do parameter extraction for ultrathin oxide device. Here the effective extracting strategy is designed and numerical experiments demonstrate the validity of the strategy.

Gefitinib plus Fuzheng Kang'ai Formula(扶正抗癌方) in Patients with Advanced Non-Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation:A Randomized Controlled Trial

Objective： To evaluate the effect of Fuzheng Kang＇ai Formula （扶正抗癌方, FZKA） plus gefitinib in patients with advanced non-small cell lung cancer with epidermal growth factor receptor （EGFR） mutations. Methods： A randomized controlled trial was conducted from 2009 to 2012 in South China. Seventy chemotherapynaive patients diagnosed with stage ⅢB/Ⅳ non-small cell lung cancer with EGFR mutations were randomly assigned to GF group [gefitinib （250 mg/day orally） plus FZKA （250 mL, twice per day, orally）; 35 cases] or G group （gefitinib 250 mg/day orally; 35 cases） according to the random number table and received treatment until progression of the disease, or development of unacceptable toxicities. The primary endpoint [progression-free survival （PFS）] and secondary endpoints [median survival time （MST）, objective response rate （ORR）, disease control rate （DCR） and safety] were observed. Results： No patient was excluded after randomization. GF group had significantly longer PFS and MST compared with the G group, with median PFS of 12.5 months （95% CI 3.30-21.69） vs. 8.4 months （95% CI 6.30-10.50; log-rank P〈0.01）, MST of 21.5 months （95% CI 17.28-25.73） vs. 18.3 months （95% CI 17.97-18.63; log-rank P〈0.01）. ORR and DCR in GF group and G group were 65.7% vs. 57.1%, 94.3% vs. 80.0%, respectively （P〉0.05）. The most common toxic effects in the GF group and G group were rash or acne （42.8% vs. 57.1%, P〉0.05）, diarrhea （11.5% vs. 31.4%, P〈0.05）, and stomatitis （2.9% vs. 8.7%, P〉0.05）. Conclusion： Patients with advanced non-small cell lung cancer selected by EGFR mutations have longer PFS, MST with less toxicity treated with gefitinib plus FZKA than gefitinib alone.

Recent research progress of bimetallic phosphides-based nanomaterials as cocatalyst for photocatalytic hydrogen evolution

Hydrogen energy(H_(2)) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental pollution.Photocatalytic hydrogen evolution(PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H_(2)fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides(TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value.What is more, bimetallic phosphides have been also caused widespread concern in H_(2)evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides(BMPs) anchored on the photocatalyst. After that, the H;evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H_(2)evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.

Weakening sensitivity of global vegetation to long-term droughts

Droughts have dramatic direct and indirect impacts on vegetation and terrestrial ecosystem stability, including decreases in growth and subsequent decreases in CO_2 absorption. Although much research has been carried out on the response of vegetation to droughts, it remains unclear whether biomes are becoming more resistant or more vulnerable to drought. In this study, we used the Standardized Precipitation Evapotranspiration Index(SPEI, a multiscalar drought index) and the Normalized Difference Vegetation Index(NDVI, an indicator of vegetation growth) to detect the sensitivity of vegetation growth to droughts across 12–24 month timescales and to detect the change in this sensitivity over recent decades. We found that vegetation growth was most sensitive to 17–18 month droughts in water-limited regions, implying pronounce legacy effects from water conditions in previous years. In addition, we detected reduced coupling between drought and vegetation growth, probably caused by release moisture stress in water limited areas. Meanwhile, we observed a shortening of drought timescale to which vegetation most sensitively responded from an average of 18.1 to 17.2 months, suggesting the weakening of the drought legacy effect on vegetation growth. Results of this study contribute to the overall understanding of the resistance and resilience of ecosystems to drought conditions.

LIMK2 is required for membrane cytoskeleton reorganization of contracting airway smooth muscle

Airway smooth muscle(ASM)has developed a mechanical adaption mechanism by which it transduces force and responds to environmental forces,which is essential for periodic breathing.Cytoskeletal reorganization has been implicated in this process,but the regulatory mechanism remains to be determined.We here observe that ASM abundantly expresses cytoskeleton regulators Limk1 and Limk2,and their expression levels are further upregulated in chronic obstructive pulmonary disease(COPD)animals.By establishing mouse lines with deletions of Limk1 or Limk2,we analyse the length-sensitive contraction,F/Gactin dynamics,and F-actin pool of mutant ASM cells.As LIMK1 phosphorylation does not respond to the contractile stimulation,LIMK1-deficient ASM develops normal maximal force,while LIMK2 or LIMK1/LIMK2 deficient ASMs show approximately 30%inhibition.LIMK2 deletion causes a significant decrease in cofilin phosphorylation along with a reduced F/G-actin ratio.As LIMK2 functions independently of cross-bridge movement,this observation indicates that LIMK2 is necessary for F-actin dynamics and hence force transduction.Moreover,LIMK2-deficient ASMs display abolishes stretching-induced suppression of 5-hydroxytryptamine(5-HT)but not acetylcholine-evoks force,which is due to the differential contraction mechanisms adopted by the agonists.We propose that LIMK2-mediated cofilin phosphorylation is required for membrane cytoskeleton reorganization that is necessary for ASM mechanical adaption including the 5-HT-evoked length-sensitive effect.