Constitutive Laws for Visco-plastic Porous Medium Shaped by Regularly Distributed Circular Particles

A numerical study is presented,using a homogenization technique to consider the plain strain problem of visco-plastic porous medium shaped by regularly distributed circular particles. Based on a rigid plastic material,the paper derives the macroscopic constitutive laws for homogenous equivalent medium. By changing the shape parameter of circular particles,the effect of pore shape on macroscopic constitutive laws is explored. Yield surfaces with different pore shapes are obtained. About voids,a two-scale conception is introduced,which regards main void as macroscopic scale and secondary cavities as microscopic scale. The macroscopic potential involving main and secondary voids is achieved. The proposed macroscopic constitutive law taking microscopic features as influence factors is helpful for exploring the macroscopic mechanical properties of porous medium when numerical simulation is required.

Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA

To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits.

Non-stationary Buffeting Response Analysis of Long Span Suspension Bridge Under Strong Wind Loading

The non-stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non-stationary fluctuating winds with probabilistic model for non-stationary strong wind fields is first presented. Non-stationary wind forces induced by strong winds on bridge deck and tower are then given a brief introduction. Finally,Non-stationary buffeting response of Pulite Bridge in China,a long span suspension bridge,is computed by using ANSYS software under four working conditions with different combination of time-varying mean wind and time-varying variance. The case study further confirms that it is necessity of considering non-stationary buffeting response for long span suspension bridge under strong wind loading,rather than only stationary buffeting response.

Prediction of Restriction Width of Carcass by Belts for Radial Tires :Theory, Experiment and Simulation

The restriction width of carcass by the belts( RWCB) as an important parameter of radial tire design has been neglected for a long time. In order to improve the accuracy and efficiency of tire profile design,the calculating method of RWCB is proposed. The equilibrium profile is calculated by geometric model and variational approach,based on it,the predicted model of RWCB is developed for tire design. Finally,four different designs of 12R22.5 tires are investigated by experiment and finite element method,which is used to validate the accuracy of the theoretical method. Results indicate that experimental and finite element analysis results are found to be in good agreement with theoretical results; linear relationships are existed between the cord length and RWCB,and also existed between the position of belt and RWCB; tires designed by the methods have smaller and more uniform displacement,so the method can be used for tire optimized design.

内毒素休克大鼠肝线粒体H^+-ATP酶活性变化的研究

目的：研究内毒素休克时线粒体呼吸功能的变化及其与 Ｈ＋ Ａ Ｔ Ｐ酶活性变化的关系。方法：测定内毒素休克大鼠肝线粒体呼吸控制率（ Ｒ Ｃ Ｒ）、磷氧比（ Ｐ／ Ｏ）和 Ｈ＋ Ａ Ｔ Ｐ酶活性的变化；并通过体外孵育实验研究离体情况下不同浓度梯度细菌内毒素（ Ｌ Ｐ Ｓ）对线粒体 Ｒ Ｃ Ｒ、 Ｐ／ Ｏ 和 Ｈ＋ Ａ Ｔ Ｐ酶活性的影响。结果：内毒素休克早期，大鼠肝线粒体 Ｒ Ｃ Ｒ、 Ｐ／ Ｏ 及 Ｈ＋ Ａ Ｔ Ｐ酶活性显著增强，晚期则显著减弱。而 Ｌ Ｐ Ｓ与线粒体共同孵育导致线粒体 Ｒ Ｃ Ｒ、 Ｐ／ Ｏ 和 Ｈ＋ Ａ Ｔ Ｐ酶活性下降。线粒体 Ｈ＋ Ａ Ｔ Ｐ酶活性的变化和 Ｒ Ｃ Ｒ、 Ｐ／ Ｏ 的变化有较好的一致性。结论： Ｈ＋ Ａ Ｔ Ｐ酶活性的变化可能是内毒素休克线粒体功能变化的重要原因之一；提出了内毒素休克时线粒体功能早期增强晚期减弱的观点。

Theoretical derivation of risk-ratios for assessing wind damage in a coastal forest

Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii trees and stands were de-duced from stem bending theory and coefficients characterizing wind profile, distribution of branches and optical stratification po-rosity. The results showed that if the value of constant b in the branch distribution-model equals the attenuation coefficient s in the wind profile model for a single tree crown, then the parameter H/D1.33 (height over stem diameter cubed) can be used to compare and evaluate the risk-ratio of wind damage for individual trees. The same method can be applied to stands using the coefficient of wind profile in a stand, i.e. attenuation coefficient , the coefficient from distributions of optical stratification porosity, i.e. extinction coefficient , and the parameter D1.33. The application of parameter H/D1.33 and the process of determining risk ra-tios of wind damage for stands were also given in the paper.

Effect of Sr and Ce on Synthesis of Nanometer Perovskite LaMnO_(3+λ)

Nanometer perovskite LaMnO 3+λ, La 0.6Ce 0.4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were prepared by citric acid-aid ed sol-gel method. The effects of Ce, Sr on the structure and properties of nan ometer perovskite were studied through DT-TGA, XRD, TEM and BET analyses. The r esults show that, by sol-gel method, LaMnO 3+λ, La 0.6Ce 0. 4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were made with average particle size of about 60, 100 and 30 nm, respectively. After partially substituting Sr on La positions in LaMnO 3+λ, it is found that Sr is l ocated at the perovskite lattice so as to reduce the formation temperature of th e perovskite. As a result, the perovskite has a smaller particle size and larger specific surface area. On the contrary, it is difficult for Ce to enter the per ovskite lattice. Ce exists mostly in the form of CeO 2 as partially substitutin g La in LaMnO 3+λ. The formation temperature of the perovskite increas es, and the catalyst containing CeO 2 presents a larger particle size and less specific surface area.

Analysis Method of Transient Temperature Field for Fuel Tank ofHigh-Altitude Large UAV

Based on the analysis of factors affecting transient temperature field of aircraft fuel tank and coupled heat transfer mechanism, a mathematical model of transient coupled heat transfer, including the dynamic- change of fuel quality, the internal heat transfer, the external aerodynamic convection and the radiation heat transfer, is established. Taking the aerodynamic convection and radiation heat transfer outside the tank as the third kinds of thermal boundary conditions for the thermal analysis of the fuel tank, calculation of internal and external coupling heat of fuel tank is decoupled. Ther^nal network method combined with hierarchical dynamic- grid is used to deal with the fuel consumption, and carry on the heat transfer analysis of the fuel tank. The numerical method for the transient temperature field of aircraft fuel tank is established. Through the simulation calculation, the transient temperature distribution of the fuel tank under different flight conditions is obtained, and the influence of the fuel mass and the external thermal environment on the temperature field is analyzed.

浅谈FRACAS管理方法在提高产品可靠性中的应用

FRACAS管理方法,是有效提高产品可靠性的最佳途径之一。该文介绍了FRACAS与产品可靠性的关系、FRACAS闭环管理工作流程,并以某型舰船产品可靠性提高为例展示FRACAS在提高产品的可靠性中的作用,同时通过创建信息化管理平台,实现信息共享。

Ecological Characteristics of Plants of Harboi Rangeland, Kalat, Pakistan

The floristic composition, ecological characteristics and ethnoecology of plants of Harboi rangeland (Kalat, Pakistan) were done during 1997 to 1999. There were 202 species that belonged to 45 plant families. Asteraceae, Papilionaceae, Poaceae, Brassicaceae and Lamiaceae were the leading families. Juniperus macropoda was the only tree species while Artemesia maritima, Sophora griffithii, Hertia intermedia, Nepeta juncea, Perovskia abrotanoides, Convolvulus leiocalycinus and Astragalus spp. were the most common shrubs. The dominant life forms were therophyte and hemicryptophyte while nanophylls, microphylls and leptophylls were dominant leaf sizes. The growing season lasts from March to November with two flowering periods. Most, i.e. 83.6% plants flowered during April to June while 63.3% plants bloomed during July to September. Some 145 species had various local uses. They included 129 fodder species, 50 medicinal species, 12 vegetable/fruits species, 7 fuel wood species, 3 species each were used for roof thatching and making herbal tea. Deforestation, over grazing and over collection of medicinal and fuel wood species have led to the degradation of this rangeland. There is need to conserve these resources with the participation of local communities.

The design and selection of indicators of agricultural comprehensive development project performance evaluation system

Integrated Agricultural Development Project is an important part of China＇ s fiscal expenditure. Make a reasonable assessment to Integrated projects for agricultural development, not only can to protect the quality of the project has been implemented, but also has important practical significance for enhancing China＇ s comprehensive agricultural production capacity. In this paper, combined with the present situation of China＇ s comprehensive agricultural development project performance evaluation, proposed the design process of comprehensive agricultural development project performance evaluation system, and analysis of the performance evaluation method selected.

The Performance Analysis for Distributed Collaborative Beamforming Transmission of Clustered Mobile Sensor Network

Sensor nodes cannot directly communicate with the distant unmanned aerial vehicle( UAV) for their low transmission power. Distributed collaborative beamforming from sensor nodes within a cluster is proposed to provide high speed data transmission to the distant UAV. The bit error ratio( BER) closed-form expression of distributed collaborative beamforming transmission with mobile sensor nodes has been derived. Furthermore,based on the theoretical BER analysis and the numerical results,we have analyzed the impacts of nodes 'mobility,number of sensor nodes,transmission power and the elevation angle of UAV on the BER performance of collaborative beamforming. And we come to the following conclusions: the mobility of sensor nodes largely decreases the BER performance; when the position deviation radius is large,incensement in power cannot improve BER anymore; the size of cluster should be bigger than 10 for the purpose of achieving good BER performance in Rayleigh fading channel.

Construct Protein-Protein Interaction Network by Mining Domain-Domain Interactions

Domain-domain interactions are important clues to inferring protein-protein interactions. Although about 8 000 domain-domain interactions are discovered so far,they are just the tip of the iceberg. Because domains are conservative and commonplace in proteins,domain-domain interactions are discovered based on pairs of domains which significantly co-exist in proteins. Meanwhile,it is realized that:( 1) domain-domain interactions may exist within the same proteins or across different proteins;( 2) only the domain-domain interactions across different proteins can mediate interactions between proteins;( 3) domains have biases to interact with other domains. And then,a novel method is put forward to construct protein-protein interaction network by using domain-domain interactions. The method is validated by experiments and compared with the state- of-art methods in the field. The experimental results suggest that the method is reasonable and effectiveness on constructing Protein-protein interactions network.

Hemostatic Drugs for Treating Severe Bleeding

Severe bleeding is a common problem and a main cause of death in a medical setting,including surgery,trauma,congenital and acquired abnormalities of hemostasis,fulminant hepatic failure,and gastrointestinal bleeding.It has been estimated that rxcessive blood loss may contribute to approximately 30% of trauma-related deaths.Bleeding in critical locations,especially intracerebral hemorrhage,pose also a major clinical challenge.Severe bleeding often needs blood transfusion.In many patients with abnormalities of hemostasis,bleeding can be effectively corrected by replacing the defective components of the hemostatic system,of which the most widely used are factor Ⅷ concentrations and recombinant factor Ⅷ products for hemophilia A treatment,prothrombin complex concentrates and recombinant factor Ⅸ for hemophilia B treatment,and fibrinogen or cryoprecipitate for afibrinogenemia.On the other hand,all the cases of excessive bleeding require pharmacologic strategies of hemostatic agents to minimize blood loss.

燃煤型氟中毒大鼠血清骨保护素的变化

目的观察燃煤型氟中毒骨病变早期血清骨保护素(OPG)的变化。方法以SD大鼠为实验对象,随机分6组(组内雌雄各半):对照、低氟、中氟加营养、中氟、高氟加营养、高氟组。各染毒组喂饲含不同比例的燃煤型氟中毒病区煤烘玉米的饲料复制燃煤型氟中毒动物模型。分两批以股动脉放血法处死动物,查看氟斑牙,测尿、骨、肾氟,骨密度(BMD),骨Ca、尿Ca,OPG。结果①建成氟中毒动物模型各染毒组均出现氟中毒,对照组正常。中毒严重程度随氟剂量增加而加重;氟剂量相同时,营养好中毒程度轻。②两批各染毒组大鼠血清OPG均升高(P<0.01),且随氟剂量升高而升高(P<0.05或0.01)。结论①血清OPG是反映燃煤型氟中毒骨病变的一个早期指标。②降低摄氟量及改善营养状况,可缓解氟中毒病情。

养血生化膏方制作工艺、包装及贮存的标准化研究

目的：测定本院养血生化膏水分含量，研究适合岭南养血生化膏方的包装及贮藏的标准。方法：采用碗装包装和新型单剂量小包装对养血生化膏膏方分别进行包装，考察不同包装材料对膏方质量的影响；选择常用的不同贮存方法【常温贮存；冰箱冷藏（2℃～8℃）；阴凉处贮存（≤20℃）]，分别进行O月、1月、2月、3月的微生物限度的考察。结果：碗装包装和新型包装材料均可以达到药典标准，碗装包装膏方在常温、阴凉、冷藏无显著性差异，单剂量包装冷藏效果优于常温和阴凉效果。结论：养血生化膏的挂旗标准含水量在（20．08±1．06）％范围内，达到药用标准。养血生化膏方的含水量在在选用新型小包装时，要防止新型包装材料引入细菌，碗装包装膏方在冬季可以常温保存．

全国单项体育协会的行政法律地位研究

在对全国单项体育协会法律性质分析的基础上,依据行政主体资格认定的法律标准,认为全国单项体育协会具备行政主体资格,属于行政主体的范畴;依据行政法理论,行政主体依法实施行政管理事务的活动才是行政行为,行政行为具有区别于非行政行为的法律特征,根据不同的标准行政行为又可以分为不同的类型,具备行政主体资格的全国单项体育协会依据《体育法》和《反兴奋剂条例》所行使的管理本项目的某些具体行为属于公共行政行为,在处理这些具体行政行为中全国单项体育协会当然地取得相应的行政法律地位,因此,当行政相对方对处罚不服而提起行政诉讼时,全国单项体育协会应当作为被告参与行政诉讼。

纳米银研究和应用新进展

包括化学还原法、光学还原法、电化学法、溶胶 凝胶法和真空蒸镀等。简述了纳米银在抗菌材料和催化剂等方面的应用,指出了纳米银的制备过程中存在的问题和发展方向。

从自然到仿生的超疏水纳米界面材料

浸润性是固体表面的重要特征之一,它是由表面的化学组成和微观几何结构决定的。日前我们关于荷叶和水稻叶的研究显示,一种具有较大接触角和较小滚动角的超疏水表面,需要微米和纳米级的结构有机结合形成复合结构,而且表面微观结构的排列方式会影响水滴的运动趋势。通过对水黾腿表面结构的详细研究,得到了超疏水性质与微、纳米结构取向之间的关系。据此,我们已成功制备出了超疏水和超双疏的纳米界面材料,并实现了热响应性和光响应的超疏水与超亲水可逆“开关”材料。

改进重铬酸钾法测定复方乳酸钠注射液中乳酸钠的含量

目的：测定复方乳酸钠注射液中乳酸钠含量。方法：以中国药典（１９９５版）离子交换法做对照，用改进重铬酸钾法测定复方乳酸钠注射液中乳酸钠含量。结果：改进方法与药典法平行测定样品含量，二者显示无显著性差异。结论：可作为复方乳酸钠注射液乳酸钠含量的快速检验。