Characterization of chemical composition of high viscosity heavy oils:Macroscopic properties, and semi-quantitative analysis of molecular composition using high-resolution mass spectrometry

Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy oil is crucial for revealing its viscosity-inducing mechanism and solving practical exploitation issues. In this study, the techniques of high-temperature gas chromatography and high-resolution mass spectrometry equipped with an electrospray ionization source were applied to reveal the chemical composition of typical heavy oils from western, central, and eastern China. The results indicate that these heavy oils display significant variations in their bulk properties, with initial boiling points all above 200℃. Utilizing pre-treatment and ESI high-resolution mass spectrometry, an analysis of the molecular composition of saturated hydrocarbons, aromatic hydrocarbons, acidic oxygen compounds, sulfur compounds, basic nitrogen compounds, and neutral nitrogen compounds within the heavy oil was conducted. Ultimately, a semi-quantitative analysis of the molecular composition of the heavy oil was achieved by integrating the elemental content. The semi-quantitative analysis results of Shengli-J8 heavy oil and a conventional Shengli crude oil show that Shengli-J8 heavy oil lacks alkanes and low molecular weight aromatic hydrocarbons, which contributes to its high viscosity. Additionally,characteristic molecular sets for different heavy oils were identified based on the semi-quantitative analysis of molecular composition. The semi-quantitative analysis of molecular composition in heavy oils may provide valuable reference data for establishing theoretical models on the viscosity-inducing mechanism in heavy oils and designing viscosity-reducing agents for heavy oil exploitation.

A Semi-Quantitative Analysis of Essential Micronutrient in Folium Lycii Using Laser-Induced Breakdown Spectroscopy Technique

Abstract In this paper, the capabilities of laser-induced breakdown spectroscopy （LIBS） for rapid analysis to multi-component plant are illustrated using a 1064 nm laser focused onto the surface of folium lycii. Based on homogeneous plasma assumption, nine of essential micronutrients in folium lycii are identified. Using Saha equation and Boltzmann plot method electron density and plasma temperature are obtained, and their relative concentration （Ca, Mg, A1, Si, Ti, Na, K, Li, and Sr） are obtained employing a semi-quantitative method.

Semi-quantitative analysis on the content of berberine hydrochloride in compound berberine tablets with the fluorescence spectral imaging method

The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging method was used to study the relative content of BH from a physics perspective.By comparing the relative fluorescence intensity of self-made CBTs with di®erent mass percentages of BH,a linear positive relationship was observed between the BH content and the relative fluorescence intensity,and accordingly the quality of CBTs of different brands was evaluated.The results indicate that the fluorescence spectral imaging method can be a simple,fast and nondestructive semi-quantitative analysis method to determine the content of BH in CBTs,and this method has great potential in the quality control of CBTs.

A semi-quantitative coal burst risk classification system

Safety is the highest priority in the mining industry as underground mining in particular poses high safety risks to its workers. In underground coal mines, coal bursts are one of the most catastrophic hazards, which involves sudden and violent dynamic coal mass failure with rapid ejection of the broken material into the mine workings. Despite decades of research, the contributing mechanisms of coal bursts are still not completely understood. Hence, it remains challenging to forecast coal bursts and quantify their likelihood of occurrence. However, a range of geological and geotechnical factors are associated with coal bursts and can increase the coal burst proneness. This paper introduces a semi-quantitative coal burst risk classification system, namely, BurstRisk. Based on back-analysis of case histories from Australia, China and the United States, BurstRisk classifies the coal burst risk into three categories:low, medium and high risk. In addition, it allows mining engineers to modify the weighting of the selected factors based on specific conditions. The risk classification charts introduced are for both longwall retreat and development sections of long-wall mining operations. This paper also provides a set of risk management strategies and control measures for effective coal burst mitigation.

A Semi-quantitative Serological Method to Assess the Potency of Inactivated Rabies Vaccine for Veterinary Use

Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.

Can semi-quantitative evaluation of uncertain (type II) time-intensity curves improve diagnosis in breast DCE-MRI?

Objective/Background: Qualitative assessment of uncertain (type II) time-intensity curves (TICs) in breast DCE-MRI is problematic and operator dependent. The aim of this work is to evaluate if a semi-quantitative assessment of uncertain TICs could improve overall diagnostic performance. Methods: In this study 49 lesions from 44 patients were retrospectively analysed. Per each lesion one region-of-interest (ROI)- averaged TIC was qualitatively evaluated by two radiologists in consensus: all the ROIs resulted in type II (uncertain) TIC. The same TICs were semi-quantitatively re-classified on the basis of the difference between the signal intensities of the last-time-point and of the peak: this difference was classified according to two different cut-off ranges (±5% and ±3%). All patients were cytological or histological biopsy proven. Fisher test and McNemar test were performed to evaluate if results were statistically significant (p < 0.05). Results: Using ±5% cut-off 16 TICs were reclassified as type III and 12 as type I while 21 were reclassified again as type II. Using ±3% 22 TICs were reclassified as type III and 16 as type I while 11 were reclassified again as type II. The semi-quantitative classification was compared to the histological-cytological results: the sensitivity, specificity, positive and negative predictive values obtained with ±3% were 77%, 91%, 91% and 78% respectively while using ±5% were 58%, 96%, 94% and 68% respectively. Using the ±5% cut-off 26/28 (93%) TICs were correctly reclassified while using the ±3% cut-off 34/38 (90%) TICs were correctly reclassified (p < 0.05). Conclusions: Semi-quantitative methods in kinetic curve assessment on DCE-MRI could improve classification of qualitatively uncertain TICs, leading to a more accurate classification of suspicious breast lesions.

Research on Fast Semi-Quantitative Risk Assessment Method for High Temperature and High Pressure Gas Wells

Aiming at the problem that the existing risk assessment methods in China cannot simply and accurately assess the safety risk of gas wells, a rapid semi-quantitative risk assessment method for gas wells under high temperature and pressure is studied. Based on the rapid risk assessment method of annulus well with pressure in Chevron Company and the existing risk assessment methods, the well barrier and annulus pressure of high temperature and high pressure gas wells are fully considered. A rapid semi-quantitative risk assessment method for high temperature and high pressure gas wells is established, which takes the annulus pressure value, well service life, annulus pressure recovery after pressure relief, reservoir conditions (formation pressure, production) and well CO2 and H2S content as the key risk indexes. The method is applied in a gas field, and the risk value and risk grade of a practical well are semi-quantitatively evaluated. The overall risk situation of the well is obtained. The research results provide important technical guidance for the safe production of gas well.

Fault diagnosis of AMT gear shifting process based on semi-quantitative SDG model

In order to diagnose gear shifting process in automated manual transmission（AMT）,a semi-quantitative signed directed graph（SDG）model is applied.Mathematical models are built by analysis of the power train dynamic and the gear shifting control process.The SDG model is built based on related priori knowledge.By calculating the fuzzy membership degree of each compatible passway and its possible fault source,we get the possibilities of failure for each possible fault source.We begin with the nodes with the maximum possibility of failure in order to find the failed part.The diagnosis example shows that it is feasible to use the semi-quantitative SDG model for fault diagnosis of the gear shifting process in AMT.

Standardized Semi-Quantitative Evaluation of [123I]FP-CIT SPECT in a Multicenter Study

To the best of our knowledge no multicenter studies have been published using standardized semi-quantitative evaluation of [123I]FP-CIT scan (DAT-SPECT). The aims of this study were: 1) to cross-compare semi-quantitative software-assisted evaluations of DAT-SPECTs performed in three centers with different equipments;2) to assess the accuracy of semi-quantitative evaluations of DAT-SPECT and 3) to identify the threshold with the best accuracy, sensitivity and specificity in a patient population with suspected parkinsonian syndrome. Materials and Methods: Two hundred twenty patients (mean age at the time of SPECT acquisition, 67.4 ± 9.5 yy) acquired in three centers (Ospedale San Luigi Gonzaga;Ospedale San Giovanni Battista Molinette;Ospedale Mauriziano Umberto I) were included. All of them underwent DAT-SPECT from January 2006 to July 2010. All exams were analyzed with the freely available software BASGAN and semi-quantitative data were used to predict disease. In particular, analyses were based on the values from the most deteriorated putamen and caudate, normalized for age and corrected for equipment. ROC analysis was performed and area under the curve (AUC) was estimated. Results: Analysis showed high AUCs (0.898, 0.864, 0.900 and 0.891 for each center and for the multicenter setting, respectively) confirming the very good accuracies reached. The best cut-off were 0.72 and 0.82 for putamen and caudate respectively. These thresholds allowed sensitivities and specificities in each center and in the multicenter setting of 76% and 96%, 91% and 82%, 93% and 90%, 86% and 89% respectively. No significant differences were observed between sensibility and specificity in each center. Conclusion: A unique threshold useful for all centers with high and similar sensitivities and specificities is possible after correction for age and equipments. The high accuracy reached in this multicenter trial by the semi-quantitative analysis seems similar to accuracies from qualitative analysis in other multicenter studies.

Hematization of Quartz Grains: Study of the Surface of Quartz Grains (M.E.B) and Semi-Quantitative Mineralization

Interest in the Côte d’Ivoire sedimentary basin has led to numerous investigations. All these investigations are aimed at understanding the functioning of the basin and a paleogeographic approach including sediment transport dynamics. However, the use of exoscopy and semi-quantitative mineralogy has been little developed. This study was carried out to compensate for this lack of interest in these methods. Its aim is to understand the transformation of quartz into hematite using exoscopy and semi-quantitative mineralogy in the Adiaké locality, in the eastern onshore basin of Côte d’Ivoire. Two methods were applied to 250 μm-diameter quartz grains from the 40 m coasts. Exoscopy provides information on microscopic texture, surface and corrosion, as well as determining the transport mechanism and deposition phases of quartz grains. Semi-quantitative mineralogy provides an estimate of the weight percentages of major element oxides and the ultrastructure of quartz grains. Exoscopy showed that these grains had been subjected to torrential fluvial transport. They were marked by mechanical and chemical traces during this transport and evolved in different environments. Semi-quantitative mineralogy shows the existence of negative and positive correlations between oxides. Negative correlations indicate a substitution, in order of importance, of silicon by iron, phosphorus and aluminum in these quartz. Positive correlations show that there is no substitution between the oxides concerned in these quartz grains. Divo’s quartz grains have recorded several mechanical and chemical microstructures of their sedimentary episodes, with the appearance of iron nodules in the ports left by silica.

Semi-Quantitative Estimation of Ce³⁺/Ce⁴⁺Ratio in YAG:Ce³⁺Phosphor under Different Sintering Atmosphere

In order to confirm the relationship between the luminescence and the ratio of Ce3+/Ce4+ more clearly, a series of YAG:Ce3+ (Yttrium Aluminum Garnet, Y2.94Al5O12:0.06Ce3+) phosphors were pre- pared under different sintering atmosphere. A semi-quantitative analysis based on X-ray photoe-lectron spectroscopy (XPS) was introduced to study the mole ratio of Ce3+/Ce4+ in the as-synthesized YAG:Ce3+ phosphors. The results indicated that the percentage of Ce3+/(Ce3+ + Ce4+) reached 88.46% under the reduction atmosphere. The emission intensity of YAG:Ce3+ phosphors was in-creased significantly with the increasing of Ce3+ concentration.

An Improved Chromosome-Level Genome Assembly and Annotation of Belted Beard Grunt(Hapalogenys analis)

Hapalogenys analis(order Lobotiformes)is an economically and ecologically significant fish species.It is a typical sedentary rocky reef fish and is primarily found in the northern Pacific Ocean.Here,we used Hi-C and PacBio sequencing technique to assemble a high-quality,chromosome-level genome for this species.The 539 Mb genome had a contig N50 with a size of 3.43 Mb,while 755 contigs clustered into 24 chromosomal groups with an anchoring rate of 99.02%.Of the total genomic sequence,132.74Mb(24.39%)were annotated as repeat elements.A total of 21360 protein-coding genes were identified,of which 20787 genes(97.32%)were successfully annotated to public databases.The BUSCO evaluation indicated that 96.90%of the total orthologous genes were matched.The phylogenetic tree representing H.analis and 14 other bony fish species indicated that the H.analis genome contained 364 expanded gene families related to olfactory receptor activity,compared with the common ancestor of H.analis and Sciaenidae.Comparative genomic analysis further identified 3584 contracted gene families.Branch-site modeling identified 277 genes experiencing positive selection,which may facilitate the adaptation to rocky reef environments.The genome reported here is helpful for ecological and evolutionary studies of H.analis.

Cloning and Analysis of ISA1 from Oryza sativa

[Objective] The aim was to clone ISA1 from Oryza sativa and analyze its expression situation in different tissues and different endosperm filling stage.[Method] With japonica rice cultivar nipponbare as test material,the expression patterns of ISA1 in different tissues and different endosperm filling stage was analyzed by using semi-quantitative RT-PCR technique.[Result]The full length open reading fragments of ISA1 encoded 811 amino acid residues.The homologous alignment and phylogenetic analysis showed th...

Analysis of the Impact of Off-farm Employment of Agricultural Labor on Grain Production in Shandong Province and Henan Province

[Objective] This study aimed to investigate the impact of off-farm employment of agricultural labor on grain production. [Method] Impact of off-farm employment of agricultural labor on grain production was investigated based on path analysis by using data from 200 counties and cities in Shandong Province and Henan Province in 2000 and 2008. [Result] Off-farm employment of agricultural labor affects grain production through agricultural land use patterns, off-farm employment of agricultural labor has negative impacts on grain production through multiple cropping index and positive impacts through the proportion of grain planting area. The positive impacts were greater in 2008. [Conclusion] Prerequisite of the positive impacts of off-farm employment on grain production is the substitution of agricultural mechanization development and agricultural technology advancement for agricultural labor. Orderly land circulation and scale land use should be promoted to avoid the lack of agricultural labor due to off-farm employment.

A Contrastive Genre Analysis of Chinese and American University Admission Brochures

This study mainly uses the move and step analysis to conduct a contrastive genre analysis on the selected 20 Chinese ad-mission brochures(CABs) and 20 American admission brochures(AABs).Differences in moves,move sequences and step arrange-ments have revealed themselves in this comparison.Firstly,Chinese university admission brochures cast more focus on basic infor-mation about the university,the application procedure and admission criteria,while American universities,besides offering such in-formation,also emphasize the promotional function of the admission brochures.They use appealing and creative moves to commer-cially‘sell'advantages of the university to the potential applicants.Secondly,based on Kress & van Leeuwen's visual grammarsymbolic meaning,images and colors in admission brochures are also explored and analyzed as language.For one thing,after count-ing the frequency of the four categories of images,namely portrait,campus scenery,campus life pictures and graphs,it is foundthat,compared with CABs,AABs have a highly more obvious tendency in using images.The images are used as an effective tool toincrease the sense of credibility,identity-recognition,attract reader's attention,and help understanding,making the facts and in-formation more intuitive.For another thing,the main colors used in the brochures are yet another noticeable feature.Especially inAmerican brochures,universities tend to use their‘traditional colors' in the brochure to achieve a sense of consistency.Some Chi-nese brochures also follow this promotional strategy,yet a large percentage of them do not use any recognizable colors other thanthe printed black and white.Based on these differences,suggestions are put forward from perspectives including choice of movesand steps to improve the quality of CABs,hopefully raising their acceptance in the international level.

国内外乡村景观研究进展与热点可视化分析

随着乡村振兴和美丽乡村政策的推动,乡村景观成为研究热点。文章借助CiteSpace软件对CNKI数据库与WoS数据库中2001—2023年乡村景观研究文献进行可视化分析。结果表明,国内研究者主要聚焦政策、策略、举措、评价、规划等五方向,研究主题为乡村景观、乡村旅游、乡村振兴、美丽乡村、景观规划等;国外研究聚焦于旅游、发展、分析,研究主题为可持续发展、乡村发展、乡村旅游、乡村振兴等。国外目前研究热点是乡村振兴、土地利用变化、动机。文章研究结果有助于了解当今乡村景观热点与趋势,为乡村振兴等领域提供参照基础与方向。

端口视角下的电力系统振荡分析方法综述

在众多电力系统振荡分析方法中,阻抗分析法和转矩分析法受到广泛关注。两种方法均从端口角度描述系统特性,因此振荡问题的端口分析方法具有重要研究价值。从端口角度分析,阻抗分析法和转矩分析法分别使用阻抗端口和转矩系数端口描述系统,因此重点对两种端口的研究现状做出综述。首先研究了变流器并网常用的阻抗端口,分析了不同类型阻抗端口的特点,总结阻抗端口在变流器系统稳定性分析中的优点;其次研究同步电机并网常用的转矩系数端口,重点从物理意义上阐释转矩系数端口的特点,指出了其在工程应用上的优越性;最后介绍了两种端口统一性相关理论,指出端口在不同场景下表现出不同的特点,为端口分析方法的选择提供一定参考。

基于基因组survey的横带髭鲷(Hapalogenys analis)微卫星位点筛选与特征分析

探究横带髭鲷(Hapalogenys analis)的种质资源情况以及群体的遗传多样性和遗传结构,对于其增养殖实践尤为重要。微卫星分子标记在研究物种种质情况及遗传信息方面有很大优势。采用基因组survey测序方法开发横带髭鲷微卫星位点,结果表明,横带髭鲷基因组大小为543Mb;微卫星位点丰富,共检测到280378个完美型微卫星位点,相对丰度为415.17个/Mb。二核苷酸重复是最丰富的微卫星类型(56.05%),其次为单核苷酸(29.20%)、三核苷酸(10.28%)、四核苷酸(2.99%)、五核苷酸(1.03%)、六核苷酸(0.45%)重复,短序列重复类型占95.53%。重复单元中A/T,TG/CA为优势重复单元,分别占总微卫星位点数的22.37%和21.98%;10次重复和6次重复的微卫星位点数量最多,占横带髭鲷基因组微卫星总数的14.60%和12.46%。利用筛选出的20对多态性微卫星位点扩增一个供试群体进行群体遗传学检测。结果表明,各位点等位基因数从5到13不等,均值为8.75个;平均观测杂合度(Ho)和期望杂合度(He)分别为0.808和0.863;多态信息含量(PIC)均值为0.826,且均大于0.5。经Bonferroni校正后有5个位点显著偏离哈迪–温伯格平衡(P<0.001);有4个位点存在无效等位基因。研究结果中的微卫星位点可用于今后横带髭鲷遗传育种和群体遗传学的研究。

Application of Integration of Spatial Statistical Analysis with GIS to Regional Economic Analysis

This paper summarizes a few spatial statistical analysis methods for to measuring spatial autocorrelation and spatial association, discusses the criteria for the identification of spatial association by the use of global Moran Coefficient, Local Moran and Local Geary. Furthermore, a user-friendly statistical module, combining spatial statistical analysis methods with GIS visual techniques, is developed in Arcview using Avenue. An example is also given to show the usefulness of this module in identifying and quantifying the underlying spatial association patterns between economic units.

Propensity score analysis demonstrated the prognostic advantage of anatomical liver resection in hepatocellular carcinoma

AIM: To compare the prognoses of hepatocellular carcinoma (HCC) patients that underwent anatomic liver resection (AR) or non-anatomic liver resection (NAR) using propensity score-matched populations.