摘要：Using a suitable solvent for extracting pigments from sediment for high performance liquid chromatography（HPLC） analysis is critical for obtaining qualitative and quantitative estimates of phytoplanktonic and benthic algal biomass,as well as community composition. Five methodological factors（sample dehydration,extraction solvent,extraction duration,number of extractions,and ratio of solvent volume：sample weight） were studied using an L 9（3 4 ） orthogonal design in a sedimentary pigment extraction experiment on samples collected from the Changjiang large-river delta-front estuary（LDE）,using HPLC analysis. The results show that the optimal extraction method for sedimentary pigments should include freeze-drying samples prior to extraction. The effects of different factors on sedimentary pigment extraction were separated by the L 9（3 4 ） orthogonal design experiments and showed that the extraction solvent was the most important,with extraction duration the second most important,and numbers of extraction and ratio of solvent volume：sample weight was the least important. The mixed solvent treatment comprised of acetone,methanol and water（80：15：5,by volume） was best for polar pigment extraction,with 100% acetone better for apolar pigments. For most pigments employed in this study（i.e.,peridinin,fucoxanthin,alloxanthin,diatoxanthin,zeaxanthin,pheophytin-a and β-carotene） ,3 h was found to be enough time for extraction from these deltaic sediments. However,for chlorophyll-a,the most important pigment used for estimating algal biomass,12 h was needed. A small amount of solvent（3 ml） with duplicate extractions obtained the greatest amount and diversity of pigments. Unfortunately,no extraction method was found to be suitable for all pigments in sediments. The choice of extraction procedure should be made in accordance with the objective of each study,taking into consideration the properties of sediments and pigments in question.

摘要：Sedimentary pigments are useful proxy indicators of phytoplankton biomass, community structure, primary productivity and human influence in lacustrine and oceanic ecosystems. Pigments are relatively labile due to their complex chemical structures, which makes the extraction and analysis of sedimentary pigments challenging. In addition, it is important to select appropriate methods to study sedimentary pigments in regions which lack previous investigations. In this study, we adopted the L9（34） orthogonal design to develop methods of extraction and HPLC （high performance liquid chromatography） analysis of sedimentary pigments at two lakes on the Tibetan Plateau： meromictic lake-Dagze Co and dimictic lake-Jiang Co. The orthogonal design comprises 9 combinations of various parameters for extraction and HPLC analysis. The results show that the type and volume of solvent are the most important factors for pigment extraction, and the mobile phase and column selection are the most important for HPLC analysis. For the study sites, we found that the best methods to extract sedimentary pigments are as follows： the use of a mixture of acetone：methanol：water （80： 15：5, v：v：v） as the extraction solvent; sol- vent/sample ratio of 10 mL/g; sonication for 30 s and standing extraction for 6 h. The best methods for HPLC analysis are as follows： Zorbax Eclipse plus C8 column with mobile phase A, methanol：acetonitrile：0.25 M aqueous pyridine （50： 25：25, v ： v ： v） and mobile phase B, methanol： acetonitrile： acetone （20： 60： 20, v： v： v）; pH of mobile phase A adjusted to 6 with acetic acid; and HPLC column temperature maintained at 40~C. The study provides an experimental basis for future investigations of past changes in primary productivity and the response of lake ecosystems to climate change and human activities on the Tibetan Plateau.

摘要：Differential modulation was widely used for wireless networks in which channel estimation was *** on orthogonal design,a novel distributed differential space-time coding/decoding scheme forM-PSK modulations was proposed,which had a high code rate of 2/3 and second-order diversity for thetwo-user cooperative *** performance of decode-and-forward (DF) protocols was *** show that the differential space-time modulation scheme in this paper has better bit error rate(BER) performance or higher code rate than the schemes proposed by Tarasak and Wang when interuserchannel states are good *** impacts of transmission error between two users for the whole systemBER performance were also investigated.

摘要：The individual difference and non-repeatability in acupuncture have not only restricted the devel- opment of acupuncture, but have also affected the specificity of acupoints. The present study used instruments to control needle depth, lifting and thrusting frequency, and the duration of acupuncture. Effects of the quantified acupuncture were observed at Neiguan （PC6） with different stimulation parameters. A frequency of 1, 2, or 3 Hz and duration of 5, 60, or 180 seconds were used to observe cerebral blood flow and ratio of infarct volume recovery. Results showed that stimulation at Neiguan with a frequency of 1 Hz and long duration of 180 seconds or 2/3 Hz and long duration of 5/60 seconds significantly increased cerebral blood flow and decreased the ratio of infarct volume. In- teractions between frequency and duration play a critical role in quantified acupuncture therapy.

摘要：Due to the current trend towards lightweight design in automotive industry,hollow stepped gear shafts for automobile and its radial forging process are widely *** coupled finite element thermo-mechanical model,radial forging process of a hollow stepped gear shaft for automobile was *** optimal combination of three process parameters including initial temperature,rotation rate and radial reduction was also selected using orthogonal design *** examine the strain inhomogeneity of the forging workpiece,the strain inhomogeneity factor was *** results reveal that the maximum effective strain and the minimum effective strain appeared in the outermost and innermost zones of different cross sections for the hollow stepped gear shaft,*** forging parameters are determined as a combination of initial temperature of 780°C,rotation rate of 21°/stroke and radial reduction of 3 mm.

摘要：Wind barriers have attracted significant attention as an effective measure to ensure train safety under ***,in past decades,the influence of structural parameters such as the height and ventilation ratio of wind barriers on the difference of the average pressure coefficient between the train windward and leeward surface(ΔCp)has not been fully *** determine the influence of the interaction among the three factors,namely the wind barrier height(H),ventilation ratio(R),and distance to the train(D),twenty five numerical simulation cases with different structural parameters were considered based on an orthogonal *** shear stress transfer(SST)k-ωturbulent model was employed to calculate the wind pressure coefficients,and the calculation accuracy was validated by using wind tunnel *** results indicated that with an increase in R,ΔCp first decreased and then increased,andΔCp decreased while D ***,with the increase in H,ΔCp first increased and then ***,these three factors must be considered during the installation of wind ***,according to a range analysis(judging the relative importance of the three factors intuitively),the three factors were ranked in the following order:R>H>*** on a variance analysis,R was found to be of high significance toΔCp,followed by H,which was significant,whereas D had relatively insignificant ***,the optimal values of R and H were determined to be 20%and 110 mm,*** when R=40%,H=85 mm,the train was relatively unsafe under these such *** findings of this study provide significant guidance for the structural design of wind barriers.

摘要：An orthogonal design was used to optimize SSR-PCR amplification system using Panax ginseng genomic DNA as template. Four levels of five factors （DNA template, Taq DNA polymerase, Mg^2＋, primer, and dNTP） and annealing temperature have been tested separately in this system. The results demonstrated the reaction efficiency was affected by these factors. Based on the results, a stable, productive and reproducible PCR system and cycling program for amplifying a ginseng SSR locus were obtained： 20 μL system containing 1.0 U Taq DNA polymerase, 2.0 mmol·L^-1 Mg^2＋, 0.2 mmol·L^-1 dNTPs, 0.3 μmol·L^-1 SSR primer, 60 ng· μla^-1 DNA template, performed with a program of 94℃ for 5 min, 94℃ for 30 s, annealing at 56.3℃ for 30 s, 72℃ for 1 min, 37 cycles, finishing at 72℃ for 7 min, and storing at 4℃.

摘要：[Objective] The aim was to optimize the technical procedure of SRAP-PCR in Triticum aestivum L. [Method] The orthogonal design L16（45） was used to optimize SRAP-PCR amplification system of wheat Fengyou 68 on five factors （Taq polymerase,Mg2＋,DNA template,dNTPs and primer） at four levels. [Result] Effects of the five factors on SRAP-PCR reaction system were Mg2＋Taq polymerasedNTPsDNA templateprimer. Finally,an optimal SRAP-PCR system was established,that was the total 20 μl reaction system containing 2.0 μl 10×PCR Buffer,2.0 U Taq polymerase,2.0 mmol/L Mg2＋,0.2 mmol/L dNTPs,40 ng DNA template and 0.6 μmol/L primer. [Conclusion] The optimum SRAP-PCR system had provided some technical foundations to conduct SRAP genetic analysis for wheat varieties.

摘要：[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves by CTAB method as the template,PCR system was optimized by L16(45)orthogonal design.[Result] Clear bands were amplified from 16 different combinations,but the amplification effects and yields had *** most economic and applicable system was as follows:20 ng DNA template,150 μmol/L dNT...

摘要：[Objective] The aim was to protect wild resource of Atractylodes lances and to provide technical guidance for industrialization of Atractylodes lances. [Method] The test-tube seedlings were produced from seeds of Atractylodis Lances. At the same time, the effects of 6-BA, NAA and KT on the proliferation of aseptic seedling was studied through the orthogonal test. Effect of NAA concentration on the rooting of aseptic seedling was studied through nine types of light substrate groups, which consist of peat soil, fine sand and cotton seed hull, and their effects on Atractylodes lances growth were studied on with orthogonal design. [Result] The culture medium suitable for the proliferation of the Atractylodes lances tube seedling was MS＋6-BA 1.0 mg/L＋NAA 0.4 mg/L＋KT 0,4 mg/L. And the medium suitable for rooting was 1/2MS＋NAA 0.5 mg/L. The optimal ratio of soil, riversand and cotton seed hull was 3：3：2. [Conclusion] The research selected optimum culture medium, rooting medium and ratio of substrate, which provided technical guidance for laboratorial preservation of germplasm resource of Atractylodes lances and industrialization of its seedling production.