“提沉”在中国古典舞身韵训练中的作用及运用

中国古典舞继承了传统戏曲和武术文化的精粹,提炼了东方神韵的审美特质,而双人舞正是古典舞的一种舞台表现方式。中国古典舞的身韵是中国古典舞的根本,是中国古典舞传承之灵魂。"提沉"是中国古典舞身韵训练的基础,是呼吸与肢体完美配合的体现。"提沉"是一种呼吸的艺术,它在古典舞的传承中占有举重若轻的地位。本文将对"提沉"这一舞蹈基本元素进行解读,研究其作用和运用方式。

交叉学科视角下的中国古典舞“提沉”训练

呼吸是人生命中必不可少的动作,呼吸方法在各个舞种中都是至关重要的。"气"的流转顺畅是中国古典舞表演非常关键的因素。"气"是个抽象概念,与呼吸近似又不完全等同。本文尝试将人体解剖学介入中国古典舞身韵教学,通过对学生学习体会的反馈调查,揭示这种多学科教学法有益于学生更形象更有效地理解并掌握古典舞的呼吸方法,佐证了舞蹈在高等教育中具备拓展学生感知力与表达力的重要作用。

A Rapid Metagenomic DNA Extraction from Sediments: Potassium Dichromate SDS Method

[Objective] The objective of this study was to report an improved method for rapid DNA extraction from black-order sediments, without any purification step. [Methods] Sediments in eutrophic lake are complex ecosystems and soil microbes involved in anthropogenic nutrient cycling are very important. DNA-based molecular methods offer new tools for characterization of these mixed communities of mi- croorganisms. However, it is very difficult to remove humic substances, heavy met- als that co-existed with genome DNA representing the microbial community directly from these complex systems and can interfere with subsequent genetic analysis. The potassium dichromate solution was firstly used to remove humic substances. [Results] The steps of removing humic substances and DNA extraction were per- formed simultaneously that improved the speed of extraction to approximately 1 hour and the nucleic acids that were obtained with this method did not need to be washed with 70% ethanol and dissolved directly in sterile water for total bacterial 16S rDNA, nosZ gene of denitrifying bacteria, pmoA of methanotrophs, nifH of nitro- gen-fixing bacteria, amoA of ammonia-oxidizing bacteria and ammonia-oxidizing ar- chaea molecular ecology analyses. [Conclusion] This method could provide a plat- form for preparing a fast sediments DNA extraction.

A Comparative Study on Three Methods for the Extraction of Total RNA from Pinus bungeana

[Objective] The aim of this study was to compare three RNA extraction methods and thus find out the suitable one for isolating intact and high quality total RNA from Pinus bungeana.[Method] Employing three extraction methods of Trizol,RNeasy Mini Kit,LiCl precipitation,total RNAs of P.bungeana were extracted from pine leaf samples,and their integrity and purity were detected via agarose gel electrophoresis and spectrophotometry for a comparative study.[Result] Among the three extraction methods,LiCl precipitation method demonstrated higher yield and better integrity of total extracted RNA,with OD260/OD280 ratio between 1.8-2.0 and clear 28 S and 18 S bands in electrophoresis pattern.[Conclusion] LiCl precipitation method could be used to extract highly pure and intact total RNA from P.bungeana.

Calculation Method for Effect of Silt Sediment on Lifting Force of Hydraulic Gate

In this paper, silt sediment is considered to be Bingham body, which is made up of coarse and fine particles in front of a hydraulic gate. The coarse and fine particles provide friction and shear stress in the course of opening the gate. They constitute together the adhesion force of the sediment. Based on this viewpoint, this paper puts forward a formula for the effect of silt sediment on the lifting force. The formula includes gate weight, down-suction force, sealing rubber friction, plus-weight, water-column pressure, plus-silted-sediment weight and rolling(or sliding)-bearing friction. Finally, the verification results show that the formula has certain reliability and the calculation accuracy can meet the need of practical engineering.

Assessment of heavy metal pollution in sediments from Xiangjiang River(China) using sequential extraction and lead isotope analysis

The heavy metal(such as Cr,Ni,Cu,Cd,Pb,and Zn)concentration,speciation,and pollution source in 43 sediment samples from the Xiangjiang River were investigated using sequential extraction combined with Pb isotope analysis.Cu,Cd,Pb,and Zn concentrations are higher than their background values,while Cr and Ni concentrations are close to those.Sequential extraction demonstrates that heavy metals have different fractions,showing different bioavailabilities.The w(206Pb)/w(207Pb)ratio increases with decreasing bioavailability in the order of exchangeable<carbonate≈Fe-Mn oxides≈organic<residual(p<0.05).Wastewater,dust,and slag from mining and smelting areas,and the residual Pb are assumed to be the primary anthropogenic and natural sources of Pb,respectively.The percentages of anthropogenic Pb in the exchangeable,carbonate,Fe-Mn oxides,and organic fractions are(91.5±16.7)%,(61.1±13.9)%,(57.4±11.1)%,and(55.5±11.2)%,respectively,suggesting a significant input of anthropogenic Pb in these four fractions.

Field trial on use of soybean crude extract for carbonate precipitation and wind erosion control of sandy soil

Wind erosion is a major cause of land desertification and sandstorm formation in arid and semi-arid areas.The objective of this study was to evaluate the potential of soybeans crude extract induced calcium carbonate precipitation(SICP)on reducing wind erosion risk of sandy soil.Field tests were carried out in Ulan Buh Desert,Ningxia Hui Autonomous Region,China.Results showed that the SICP method could significantly enhance the surface strength and wind erosion resistance of the topsoil.The optimal cementation solution(urea-CaCl2)concentration and spraying volume,according to experiments conducted on sandy land,were 0.2 mol/L and 4 L/m^2,respectively.Under this condition,the CaCO3 content was approximately 0.45%,the surface strength of sandy soil could reach 306.2 kPa,and the depth of wind erosion was approximately zero,after 30 d completion of SICP treatment.Soil surface strength declined with the increase of time,and long-term sand fixation effects of SICP treatment varied depending on topography.Whereas wind erosion in the top area of the windward slope was remarkable,sandy soils on the bottom area of the windward slope still maintained a relatively high level of surface strength and a low degree of wind erosion 12 month after SICP treatment.Scanning electron microscopy(SEM)tests with energy dispersive X-ray(EDX)confirmed the precipitation of CaCO3 and its bridge effect.These findings suggested that the SICP method is a promising candidate to protect sandy soil from wind erosion in desert areas.

Comparison of Different Extraction Approaches for Heavy Metal Partitioning in Sediment Samples

Three extraction methods, ultrasonic assisted extraction (USE), microwave assisted extraction (MSE), and conventional single extraction (CSE), in conjunction with the modified three-stage BCR sequential extraction procedure (SEP) were applied to examine the contents of Cd, Cu, Cr, Ni, Pb and Zn from lake sediment samples, to know whether these techniques can reduce extraction time and improve reproducibility. The SEP and developed alternative single extrac- tion methods were validated by the analysis of certified reference material BCR 601. By the use of optimized sonication and microwave conditions, steps 1, 2 and 3 of the BCR sequential extraction methods (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication and microwave) could be completed in 15-30 min and 60- 150 s, respectively. The recoveries of total extractable metal contents in BCR 601, obtained by three single extractions ranged from 93.3%-102%, 88.9%-104% and 81.2%-96.2% for CSE, USE and MSE, respectively. The precision of the single extraction methods was found in the range of 3.7%-9.4% for all metals (n = 6).

Optimization of Ultrasonic Extraction and Clean-up Protocol for the Determination of Polycyclic Aromatic Hydrocarbons in Marine Sediments by High-performance Liquid Chroma-tography Coupled with Fluorescence Detection

The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.

Field analysis of metallogenic information and its application

Focusing on the issue to deal with inadequate extraction of metallogenic information especially geological information,a new method of extracting metallogenic information based on field model,i.e.the field analysis method of metallogenic information,was proposed.In addition,a case study by using the method of the extraction of metallogenic information from the west Guangxi and southeast Yunnan district as an example was performed.The representation method for the field models of metallogenic information,including the metallogenic influence field model and the metallogenic distance field model,was discussed by introducing the concept of the field theory,based on the characteristic analysis of the distance gradualness and the influence superposition of metallogenic information.According to the field theory superposition principle and the spatial distance analysis method,the mathematical models for the metallogenic influence field and the metallogenic distance field of point,line and area geological bodies were derived out by using parameter equation and calculus.Based on the metallogenic background analysis,the metallogenic information field models of synsedimentary faults and manganese sedimentary basins were built.The relationship between the metallogenic information fields and the manganese mineralization distribution was also investigated by using the method of metallogenic information field analysis.The instance study indicates that the proposed method of metallogenic information field analysis is valid and useful for extracting the ore-controlling information of synsedimentary faults and manganese sedimentary basins in the study area,with which the extraction results are significant both statistically and geologically.

Geochemistry of sedimentary rocks from Permian–Triassic boundary sections of Tethys Himalaya: implications for paleo-weathering, provenance, and tectonic setting

The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—have been studied in the context of provenance, paleo-weathering, and plate tectonic setting.These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions primarily consists of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values between 65 and 74; such values reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of present studied siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O/Na_2 O tectonic setting diagram.

Acid volatile sulfide and simultaneously extracted metals in superficial sediments from Baihua Lake, China

The bioavailability of five divalent cationic heavy metals （Pb, Cd, Cu, Zn and Ni） in 10 superficial sediment samples from Baihua Lake was assessed based on the molar ratio of simultaneously extracted metals （SEMs） to acid volatile sulfide （AVS）. Atomic absorption spectrometry （AAS） and X-ray powder diffraction （XRD） were used to determine the heavy metal concentrations and examine the mineralogy of the crystalline phases, respectively. The AVS loadings in sediments from Baihua Lake ranged from 64.30 to 350.08 ~rnol/g （dry weight）. The corresponding SEM levels for the sampling sites varied from 1.770 to 14.660 vrnol/g. The molar ratio of SEMs to AVS ranged from 0.014 to 0.084 with a mean value of 0.034. The XRD analysis also confirmed the presence of some metal sulfides in sediments from Baihua Lake. The SEMs/AVS ratios for all sampling sites were significantly lower than 1.0, indicating that AVS in the sediments was sufficient to bind the five heavy metals; thus, these heavy metals are currently not significantly bioavailable to benthic organisms. Comparing the SEMs results to published guideline values for metal toxicity to benthic organisms in sediments, however, suggests that Zn and Ni pose a risk at some sampling locations in Baihua Lake.

Modeling for tungstic precipitation and extraction based on Pitzer equation

This work presented the results of tungstic precipitation from Na2WO4-Na2SO4-H20 system at 293.15 K, with which the Pitzer parameters of β（0）Na2wo4 and β（1）Na2wo4 were determined from Pitzer equation by regression. Thus the mean ionic activity coeffi- cients of sodium tungstate were calculated. The obtained β（0）Na2wo4 and β（1）Na2wo4 were substituted as fixed values in extraction modeling from Na2WO4-H2SO4-H20 system by primary amine （N1923） in toluene as diluent. Meanwhile the activity coeffi- cient expressions in organic phase were varied based on Pitzer theory that the interaction term for the solvent should not be in- cluded. The Pitzer parameters for organic phase were re-regressed in order to make the model more accurate. The average ab- solute relative deviation （AARD） for calculated and experimental molality of WO42 in aqueous phase was 5.24%. The results showed that the model can not only correlate but also predict the liquid-liquid equilibrium （LLE） data.

Application of orthogonal design to the extraction and HPLC analysis of sedimentary pigments from lakes of the Tibetan Plateau

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.