Damage assessment and preservation of suspending system of Yongle-Big-Bell

The Yongle-Big-Bell is an exquisite heritage of ancient China and has more than 600 years history. The long history renders the suspending wooden rack serious damage. Therefore, the security is of our great concern. In order to know if the wooden rack is safe or not for the conventional striking in the festival service, a systemic research work has been done. At first the existing deformation and response to the strike of the beetle were measured, and then calculations using method of material mechanics and finite element analysis were conducted. Based on the results of our research, some concluding remarks and suggestion were given: The Yongle-Big-Bell can be struck regularly without urgent danger of collapse. In view of the existence of serious rotten damage, the repair and protection of wooden rack are pressing.

Determination of SARS-coronavirus by a microfluidic chip system

We have developed a new experimental system based on a microfluidic chip to determine severe acute respiratory syndrome coronavirus (SARS-Cov). The system includes a laser-induced fluorescence microfluidic chip analyzer, a glass microchip for both polymerase chain reaction (PCR) and capillary electrophoresis, a chip thermal cycler based on dual Peltier thermoelectric elements, a reverse transcription-polymerase chain reaction (RT-PCR) SARS diagnostic kit, and a DNA electrophoretic sizing kit. The system allows efficient cDNA amplification of SARS-CoV followed by electrophoretic sizing and detection on the same chip. To enhance the reliability of RT-PCR on SARS-CoV detection, duplex PCR was developed on the microchip. The assay was carried out on a home-made microfluidic chip system. The positive and the negative control were cDNA fragments of SARS-CoV and parainfluenza virus, respectively. The test results showed that 17 positive samples were obtained among 18 samples of nasopharyngeal swabs from clinically diagnosed SARS patients. However, 12 positive results from the same 18 samples were obtained by the conventional RT-PCR with agarose gel electrophoresis detection. The SARS virus species can be analyzed with high positive rate and rapidity on the microfluidic chip system.

Demulsification of emulsions exploited by enhanced oil recovery system

Experimental data are presented to show the influence of the enhanced oil recovery system's components, alkali, surfactant, and polymer, on the demulsification and light transmittance of the water separated from the emulsions. Among which, the effects of surfactants, polyoxyethylene (10) alkylphenol ether (OP-10) and sodium petroleum sulfonate (CY-1) on emulsion stability, are the strongest of any component, the effects of polymer, hydrolytic polyacrylamide (HPAM) 3530S, on emulsion stability are the weakest. This research also suggests a possible emulsion minimization approach, which could be implemented in refineries utilizing microwave radiation. Compared with conventional heating, microwave radiation can effectively enhance the demulsification rate by an order of magnitude and increase the light transmittance of the water separated from the emulsions. The demulsification efficiency may reach 100% in a very short. time under microwave radiation.

Emergy Assessment of a Wheat-Maize Rotation System with Different Water Assignments in the North China Plain

Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240-330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability.

Electrochemiluminescence in the S2O82- system: Pt-Cd electrodes

The electrochemiluminescence (ECL) in the S2O82- system occurs under conventional cyclic voltammetry, when the Pt working electrode was coated with Cd elementary substance. The ECL mechanism was proposed, due to the reaction between the strongly oxidizing intermediate SO4 center dot- and the transitory production, CdO, generated by oxidation of Cd with SO4 center dot-. Moreover the ECL behavior was studied in different pHs and concentrations of S2O82- solution. It was showed that the ECL signal was strongest at pH 8.0, and its intensity increased with S2O82-. The experimental results verified well with the proposed ECL mechanism.

Study of ionizable drugs transfer across the water/1,2-dichloroethane interface with phase volume ratio equal to unity using a three-electrode system

The electrochemical behavior of ionizable drugs (Amitriptyline, Diphenhydramine and Trihexyphenedyl) at the water/1,2-dichloroethane interface with the phase volume ratio (r = V-o/V-w) equal to 1 are investigated by cyclic voltammetry. The system is composed of an aqueous droplet supported at an Ag/AgCl disk electrode and it was covered with an organic solution. In this manner, a conventional three-electrode potentiostat can be used to study the ionizable drugs transfer process at a liquid/liquid interface. Physicochemical parameters such as the formal transfer potential, the Gibbs energy of transfer and the standard partition coefficients of the ionized forms of these drugs can be evaluated from cyclic voltammograms obtained. The obtained results have been summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer mechanisms of ionizable drugs at the liquid/liquid interfaces and biological membranes.

Evaluation and application of micro-sampling system for inductively coupled plasma mass spectrometry

Two Meinhard microconcentric nebulizers, model AR30-07-FM02 and AR 30-07-FM005, were employed as a self-installed micro-sampling system for inductively coupled plasma-mass spectrometry (ICP-MS). The FM02 nebulizer at 22 muL/min of solution uptake rate gave the relative standard deviations of 7.6%, 3.0%, 2.7%, 1.8% for determinations (n = 10) of 20 mug/L Be, Co, In and Bi, respectively, and the detection limits (3s) of 0.14, 0.10, 0.02 and 0.01 mug/L for Be, Co In and Bi, respectively. The mass intensity of In-115 obtained by this micro-sampling system was 60% of that by conventional pneumatic nebulizer system at 1.3 mL/min. The analytical results for La, Ce, Pr and Nd in 20 muL Wistar rat amniotic fluid obtained by the present micro-sampling system were precisely in good agreement with those obtained using conventional pneumatic nebulization system.

An application of the analytic hierarchy process and fuzzy logic inference in a decision support system for forage selection

Forage selection plays a prominent role in the process of returning cultivated lands back into grasslands. The conventional method of selecting forage species can only provide attempts for problem-solving without considering the relationships among the decision factors globally. Therefore, this study is dedicated to developing a decision support system to help farmers correctly select suitable forage species for the target sites. After collecting data through a field study, we developed this decision support system. It consists of three steps: (1) the analytic hierarchy process (AHP), (2) weights determination, and (3) decision making. In the first step, six factors influencing forage growth were selected by reviewing the related references and by interviewing experts. Then a fuzzy matrix was devised to determine the weight of each factor in the second step. Finally, a gradual alternative decision support system was created to help farmers choose suitable forage species for their lands in the third step. The results showed that the AHP and fuzzy logic are useful for forage selection decision making, and the proposed system can provide accurate results in a certain area (Gansu Province) of China.

A homogeneous DNA hybridization system by using a new luminescence terbium chelate

Homogeneous DNA hybridization assay based on the luminescence resonance energy transfer (LRET) from a new luminescence terbium chelate, N,N,N-1,N-1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA)-Tb3+ (lambda(ex) = 325 nm and lambda(em) = 545 nm) to an organic dye, Cy3 (A,. = 548 nm and A,. = 565 nm), has been developed. In the system, two DNA probes whose sequences are complementary to the two different consecutive sequences of a target DNA are used; one of the probes is labeled with the Tb3+ chelate at the T-end, and the other is with Cy3 at the 5'-end. Labeling of the Tb3+ chelate is accomplished via the linkage of a biotin-labeled DNA probe with the Tb3+ chelate-labeled streptavidin. Strong sensitized emission of Cy3 was observed upon excitation of the Tb3+ chelate at 325 run, when the two probe DNAs were hybridized with the target DNA. The sensitivity of the assay was very high compared with those of the previous homogeneous-format assays using the conventional organic dyes; the detection limit of the present assay is about 30 pM of the target DNA strand.