霍州曹村矿下组煤底板高承压水突出条件剖析

本文分析了曹村井田下组煤矿井充水条件，进而从定性与定量两个方面论述了下组煤底板隔水性能。最后在综合考虑井田构造、岩溶陷落柱、奥陶纪灰岩（以下简称奥灰岩）水压、隔水层抗水能力以及采矿影响等的基础上，对全井田进行了突水条件分区预测．从而为解放奥灰岩水威胁下的煤炭储量和煤矿安全生产提供了依据。

Experimental validation of horizontal joints in an innovative totally precast shear wall system

To investigate the feasibility and seismic performance of the horizontal joints in an innovative precast shear wall system, two test walls were fabricated, and the monotonic and cyclic loading tests were performed on the two test walls, respectively. Then, the lateral load-top displacement curves, load beating capacity, ductility, lateral stiffness, strains of steel bars, strain distribution on the connecting steel frame （CSF）, and relative slippages between the CSF and embedded limbic steel frame （ELSF） were discussed in detail. The test results show that the load bearing capacity and ductility of the test wall are both favorable with a displacement ductility factor of more than 3.7. The normal and shear stresses in the CSF except for the compression end are far smaller than the yield stresses throughout the test procedure. Certain slippages of about 1.13 mm occurs between the CSF and ELSF on the compression side of the test wall, while almost no slippages occurs on the tension side. The seismic performance of the test wall is favorable and the new-type scheme of the horizontal joints is both feasible and reliable.

改性剂在氯氧镁胶凝材料中对硬化结晶相的影响及对游离氯离子减少的试验研究

改性剂可以改善氯氧镁胶凝材料制品的硬化结构,增强耐水性,减少成品中游离氯离子含量,解决氯氧镁制品易吸潮返卤的问题。文章通过两方面重点论述:①通过XRD射线衍射谱图与CEM扫描电子显微镜观察,改性剂具有改变硬化结晶相的结构形态,促进硬化结晶相生成,提高反应产物稳定性的作用;②改性后的氯氧镁胶凝材料试样比空白试样游离氯离子降低了30%～70%,空白试样浸泡6 h游离氯离子浸出量:7%,几乎全部被浸出,而改性后的试样6 h游离氯离子浸出量:2.5%,24 h游离氯离子浸出量:3.8%,改性剂显著地减少了游离氯离子的量,提高了氯氧镁胶凝材料的耐水性。

Simplified stiffness-based approach for seismic performance evaluation of moment-resisting frame

Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis （e. g. the pushover analysis）, and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.

Simultaneous Effects of Hydrostatic Pressure and Conduction Band Non-parabolicity on Binding Energies and Diamagnetic Susceptibility of a Hydrogenic Impurity in Spherical Quantum Dots

Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.

建筑防水材料使用性能的研究

通过对各类防水材料的抗开裂性能、抗窜水能力及耐高温性能的研究探讨,比较评价了各类防水材料的不同性能状态,为在施工过程中正确选择防水材料提供了客观依据。

Effect of Gastrointestinal Protease Digestion on Bioactivity of Marine Peptides

Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.

Investigation into the Total Phenols and Antioxidant Activity during Storage of Fruit Smoothies

In this study, the total phenols （TP） and antioxidant activity of three different fruit smoothies （Blackberries, Raspberry and Boysenberry （BRAB）, Mango and Passion fruits （MAP） and Blackcurrant, Acerola cherries and Rosehips （BACAR）） were determined during storage by Folin-Ciocalteu and ferric reducing antioxidant power （FRAP） assays respectively. TP ranged from 1,943 to 2,692 mg L-1 gallic acid equivalent whereas FRAP from 43,217 to 126,125 μmol L-1 Trolox equivalent for the three smoothies on opening. BACAR had the highest TP and antioxidant activity. The smoothies showed significant decrease （P 〈 0.05） in TP during storage. The decrease in antioxidant activity was significant （P 〈 0.05） for BRAB and MAP only. However, the study revealed that the smoothies had high antioxidant activity even during shelf-life at 4 ℃ which implies that consumption of smoothies may give considerable antioxidant benefits. Correlation between TP and antioxidant activity was strong and highly significant （r = 0.890, P 〈 0.0001）.

Design of a modern automatic control system for the activated sludge process in wastewater treatment

The Activated Sludge Process(ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times is a challenging matter. The proposed control method is an I-P modi fied controller automatic control system with state variable feedback and control canonical form simulation diagram for the process. A more stable response is achieved with this type of modern control. Settling times of 0.48 days are achieved for the concentration of microorganisms,(reference value step increase of 50 mg·L-1) and 0.01 days for the concentration of oxygen(reference value step increase of 0.1 mg·L-1). Fluctuations of concentrations of oxygen and microorganisms after an inlet disturbance of5 × 103m3·d-1are small. Changes in the reference values of oxygen and microorganisms(increases by 10%, 20% and 30%) show satisfactory response of the system in all cases. Changes in the value of inlet wastewater flow rate disturbance(increases by 10%, 25%, 50% and 100%) are stabilized by the control system in short time. Maximum percent overshoot is also taken in consideration in all cases and the largest value is 25% which is acceptable. The proposed method with I-P controller is better for disturbance rejection and process settling times compared to the same method using PI controller. This method can substitute optimal control systems in ASP.

Flavonoid Content and Antioxidant Properties in Different Extracts of Calluna vulgaris （L,） Flowers

This study evaluated the effect of four different solvent, i.e., water, ethanol, water-ethanol mixture and ethyl acetate, on the antioxidant activities of wild and cultivated heather （Calluna vulgaris （L.） Hull） plant. The highest values for total flavonoid content were obtained for samples extracted using ethanol-water mixture and ethyl acetate. Cupric reducing antioxidant capacity （CUPRAC） method, scavenging ability on 1,1-diphenyl-2-pirylhydrazyl radicals （DPPH） radicals and chelating activity on Fe2~ ions have been used for evaluation of antioxidant activity of the extracts. Ethanolic fraction exhibited the lowest reducing capacity, despite a heather sample used. The extracts of cultivated heather exhibited significant scavenging effect on DPPH radicals, and ethanol and ethanol-water fractions were found to be the most effective. The metal-chelating effect of the extracts increased in the order： ethanol 〈 ethyl acetate 〈 ethanol-water 〈 water. The results may be helpful for better utilization of heather flowers extracts as potential pharmaceutical and nutraceutical ingredient.

Bee Pollen in Transylvania （Romania）： Palynological Characterization and ORACFL Values of Lipophilic and Hydrophilic Extracts of Monofloral Pollen Pellets

A melissopalynological study carried out on 35 bee pollen samples from Romania （Transylvania） shows predominant species as Taraxacum officinale, Tilia sp., Ferbascum sp., Zea mays L., Onobrychis viciifolia Scop., Geranium sanguineum L., Filipendula ulmaria L., Cydonia oblonga L., Calluna vulgaris L. and Brassica sp.. This is the first time for the contribution of total phenolic （TP） and total carotenoid （TC） content to the modified oxygen radical absorbance capacity （ORACFL） values in 29 monofloral samples. Hydrophilic ORACFL （H-ORACFL） values ranged between 7.13-10.12 μmol TE/g and 6.94-22.46 μmol TE/g, whereas lipophilic ORACFL （L-ORACFL）values were between 2.19-7.79 μmol TE/g and 1.65-9.96 μmol TE/g, in multifloral and monofloral samples, respectively. It has proved the complex involvement of botanical origins on the antioxidant features with a specific occurrence. Some monofloral samples presented particular high antioxidant potential, such as Salix sp., Taraxacum officinale, Matricaria chamomilla, Cichorium intybus and the poorly studied Cirsium arvense （L.） Scop. and Scilla bifolia L.. New variables, such as soil characteristics, climates together with botanical origins, were introduced in a multivariate analysis of antioxidant data matrix, given a possible important involvement of all of them in affecting, not only the phytochemical composition, but thereafter the antioxidant capacity. All these data could be crucial to a new way of gathering, by beekeepers, depending on the market demand and the purposes for the product that has a potential for further therapeutic bioactivities investigations, and added value in the enrichment of certain products.

Shear Behavior of Novel Prestressed Concrete Beam Subjected to Monotonic and Cyclic Loading

Prestressed steel ultrahigh-strength reinforced concrete(PSURC) beam is a new type of prestressed concrete beam, which not only has a considerable compressive strength attributed to the ultrahigh strength concrete, but also ensures a certain degree of ductility at failure due to the existence of structural steel. Five of these beams were monotonically tested until shear failure to investigate the static shear performance including the failure pattern, loaddeflection behavior, shear capacity, shear crack width and shear ductility. The experimental results show that these beams have superior shear capacity, crack control ability and shear ductility. To study the shear performance under repeated overloading, seven PSURC beams were loaded in cyclic test simultaneously. The overall shear performance of cycled beams is similar to that of uncycled beams at low load level but different at high load level. The shear capacity and crack control ability of cycled beams at high load level are reduced, whereas the shear ductility is improved. In addition, the influences of variables including the degree of prestress, stirrup ratio and load level on the shear performance of both uncycled and cycled beams were also discussed and compared, respectively.

Biocompatibility and bone regeneration of PEO/Mg-Al LDH-coated pure Mg:an in vitro and in vivo study

Forming a stable anti-corrosion surface layer on magnesium(Mg)and its alloys has become a major challenge in developing a desirable degradable medical implant in bone.In this study,a porous MgO layer was first formed on Mg by plasma electrolytic oxidation(PEO),and then a Mg-Al layered double hydroxide(LDH)layer was prepared to seal the porous structure of the PEO layer(LDH-2h and LDH-12h)via hydrothermal treatment.The bilayer structure composite coating,which can effectively resist the penetration of surrounding media,is similar to plain Chinese tiles.The in vitro results revealed that compared with other coatings,the LDH-12h composite coating can reduce the release of Mg ions and induce a milder change in pH when immersed in phosphate-buffered saline(PBS).In vitro rat bone marrow stem cell(rBMSC)culture suggested that the LDH-12h composite coating is favorable for cell activity,proliferation and could improve the osteogenic activity of rBMSCs.A subcutaneous implantation test revealed that the as-prepared sample showed enhanced corrosion resistance and histocompatibility in vivo,especially in the LDH-12h group.Moreover,LDH-12h had the lowest rate of degradation and the closest combination with the new bone after being inserted into a rat femur for 12 weeks with no major organ dysfunction.In summary,the asprepared PEO/Mg-Al LDH composite coating is able to improve the corrosion resistance and biocompatibility of Mg and to enhance osteogenic activity in vivo,suggesting its promising prospects for orthopedic applications.