Inhibitory effect of α-cyclodextrin on α-amylase activity

Purpose: To explore the effect of α-cyclodextrin on the activity of α-amylase with a view to expanding its application range.Methods: The concentration of α-cyclodextrin, temperature, pH and interaction time were used as single factors to explore the influence of α-cyclodextrin on the activity of α-amylase and endogenous fluorescence in the enzyme system.Results: The results showed that the concentration, time, pH and temperature affect the interaction of them. The most obvious conditions for inhibition of α-amylase activity are as follows: 10 mmol/L concentration of α-cyclodextrin, pH 6.9, duration of 120 min and temperature at 55 oC. In addition, the fluorescence intensity of α-amylase changed as a result of the addition of α-cyclodextrin.Conclusion: The activity of α-amylase can be inhibited by α-cyclodextrin. At the same time, the addition of α-cyclodextrin will lead to the transfer of tryptophan group in α-amylase, which cause the change of microenvironment and changes the endogenous fluorescence intensity of α-amylase.Keywords: α-Cyclodextrin, α-Amylase, Fluorescence intensity, Inhibitio

PID Testing Method Suitable for Process Control of Solar Cells Mass Production

Voltage bias of several hundred volts which are applied between solar cells and module frames may lead to significant power losses, so-called potential-induced degradation (PID), in normal photovoltaic (PV) installations system. Modules and minimodules are used to conduct PID test of solar cells. The test procedure is time consuming and of high cost, which cannot be used as process monitoring method during solar cells fabrication. In this paper, three kinds of test including minimodule, Rsh, and V-Q test are conducted on solar cells or wafers with SiNx of different refractive index. All comparisons between test results of Rsh, V-Q, and minimodule tests have shown equal results. It is shown that Rsh test can be used as quality inspection of solar cells and V-Q test of coated wafer can be used as process control of solar cells

Effect of Photoconductive Properties of SiNx Passivation Film on Anti-PID Performance of Photovoltaic Cells and Modules

We investigated the impact of the photoconductive properties of crystalline silicon solar cells, having a SiNx passivation film, on potential induced degradation (PID) using voltage-corona (V-Q) and self-adjusting stead state (SASS) tests. The experimental results show that the conductivity of SiNx on the cell surface was gradually enhanced by the increase in refractive index, which effectively decreased the accumulated charge on the cell surface. Thus, changes in the conductivity of SiNx were found to be the cause of the different PID performance of the modules. The present work provides a theoretical basis for solving the PID problem of solar modules and power stations, and the exploration of the V-Q and SASS techniques provides a new, convenient method and corresponding basis for testing the PID performance of solar cells during industrial production. DOI: http://dx.doi.org/10.5755/j01.ms.24.2.17171</p

Effect of Surface Structure on Electrical Performance of Industrial Diamond Wire Sawing Multicrystalline Si Solar Cells

We report industrial fabrication of different kinds of nanostructured multicrystalline silicon solar cells via normal acid texturing, reactive ion etching (RIE), and metal-assisted chemical etching (MACE) processes on diamond wire sawing wafer. The effect of different surface structure on reflectivity, lifetime, and electrical performance was systematically studied in this paper. The difference between industrial acid, RIE, and MACE textured multicrystalline silicon solar cells to our knowledge has not been investigated previously. The resulting efficiency indicates that low reflectivity surface structure with the size of 0.2–0.8 μm via RIE and MACE process do not always lead to low lifetime compared with acid texturing process. Both RIE and MACE process is promising candidate for high efficiency processes for future industrial diamond wire sawing multicrystalline silicon solar cells

Application of Nano Texturing on Multi-Crystalline Silicon Solar Cells

Nano texturing has been confirmed as an effective structure to improve the efficiency of multi-crystalline silicon solar cells by reducing optical loss. In this study, nano textured solar cells are fabricated by the Reactive Ion Etching (RIE) method based on a conventional production line. Several characterization methods are employed to evaluate the morphology, minority carrier lifetime, quantum efficiency and electricity performance of both nano textured and micro textured solar cells. The results show that nano textured solar cells have a maxiumum efficiency of 19.21 % and an average efficiency that is 0.57 % higher than that of micro textured solar cells. Thus, the RIE method is an effective way to manufacture nano textured solar cells. It can demonstrably improve the photoelectric conversion efficiency of mass-produced solar cells and reduce the production cost, which is significant to the development of solar cell industy. DOI: http://dx.doi.org/10.5755/j01.ms.24.2.17398</p

The genome of the pear (<em>Pyrus bretschneideri</em> Rehd.)

The draft genome of the pear (Pyrus bretschneideri) using a combination of BAC-by-BAC and next-generation sequencing is reported. A 512.0-Mb sequence corresponding to 97.1% of the estimated genome size of this highly heterozygous species is assembled with 194× coverage. High-density genetic maps comprising 2005 SNP markers anchored 75.5% of the sequence to all 17 chromosomes. The pear genome encodes 42,812 protein-coding genes, and of these, ∼28.5% encode multiple isoforms. Repetitive sequences of 271.9 Mb in length, accounting for 53.1% of the pear genome, are identified. Simulation of eudicots to the ancestor of Rosaceae has reconstructed nine ancestral chromosomes. Pear and apple diverged from each other ∼5.4–21.5 million years ago, and a recent whole-genome duplication (WGD) event must have occurred 30–45 MYA prior to their divergence, but following divergence from strawberry. When compared with the apple genome sequence, size differences between the apple and pear genomes are confirmed mainly due to the presence of repetitive sequences predominantly contributed by transposable elements (TEs), while genic regions are similar in both species. Genes critical for self-incompatibility, lignified stone cells (a unique feature of pear fruit), sorbitol metabolism, and volatile compounds of fruit have also been identified. Multiple candidate SFB genes appear as tandem repeats in the S-locus region of pear; while lignin synthesis-related gene family expansion and highly expressed gene families of HCT, C3′H, and CCOMT contribute to high accumulation of both G-lignin and S-lignin. Moreover, alpha-linolenic acid metabolism is a key pathway for aroma in pear fruit