Spatial statistics is an important methodology for geospatial data analysis. It has evolved to handle spatially autocorrelated and (locally) heterogeneous data, which aim capture the first second laws of geography, respectively. Examples stratified heterogeneity (SSH) include climatic zones land-use types. Methods such are relatively underdeveloped compared two properties. The presence SSH evidence that nature lawful structured rather than purely random. This induces another "layer"...

Photochemical catalytic CO2 reduction to formate and methanol has been demonstrated in an aqueous homogeneous system at pH 5.0 comprising ruthenium(II) trisphenanthroline as the chromophore, pyridine catalyst, KCl, ascorbic acid a sacrificial reductant, using visible light irradiation 470 ± 20 nm. Isotopic labeling with (13)CO2 yields six-electron-reduced product (13)CH3OH. After 1 h photolysis, two-electron-reduced are produced quantum of 0.025 1.1 × 10(–4), respectively. This represents 76...

Geminal dicationic ionic liquids (ILs) often display higher thermal stabilities, viscosities, and densities compared to traditional monocationic ILs. Also, ILs have advantages in terms of tuning their physicochemical properties by different structural modifications. They can be considered as a combination three moieties: (1) cationic head groups, (2) an alkane linker chain, (3) the associated anions. Two types each imidazolium, pyrrolidinium, phosphonium cations were joined linkages (C6, C9,...

Purpose To quantitatively assess the value of dual-energy CT (DECT) in differentiating malignancy and benignity solitary pulmonary nodules. Materials Methods Sixty-three patients with nodules detected by plain scan underwent contrast enhanced scans arterial phase (AP) venous (VP) spectral imaging mode for tumor type differentiation. The Gemstone Spectral Imaging (GSI) viewer was used image display data analysis. Region interest placed on relatively homogeneous area nodule to measure iodine...

Four ionic liquid (IL) columns, SLB-IL59, SLB-IL60, SLB-IL65, and SLB-IL111, were evaluated for more rapid analysis or improved resolution of long-chain methyl ethyl esters omega-3, omega-6, additional positional isomeric stereoisomeric blends fatty acids found in fish oil, flaxseed potentially complicated compositions. The three structurally distinct IL columns provided shorter retention times symmetric peak shapes the acid than a conventional polyethylene glycol column (PEG), resolving...

Paired ion electrospray ionization (PIESI) mass spectrometry was developed as a useful technique that provides sensitive detection for anions in the positive mode. The ion-pairing reagent (IPR) utilized plays an essential role affecting limits. This work describes design and synthesis of two novel dications with unsymmetrical structures their utilization anion mechanistic insights. performance evaluated seven selected both single monitoring (SIM) mode reaction (SRM) allowed these down to...

Phospholipids make up one of the more important classes biological molecules. Because their amphipathic nature and charge state (e.g., negatively charged or zwitterionic) detection trace levels these compounds can be problematic. Electrospray ionization mass spectrometry (ESI-MS) is used in this study to detect very small amounts analytes by using positive ion mode pairing them with fifteen different cationic reagents. The phospholipids analysis were phosphatidylethanolamine (PE),...

RATIONALE The detection of metal cations continues to be essential in many scientific and industrial areas interest. most common electrospray ionization mass spectrometry (ESI‐MS) approach involves chelating the ions detecting organometallic complex negative ion mode. However, it is well known that mode ESI‐MS generally less sensitive than positive To achieve greater sensitivity, necessary examine feasibility chelated ESI‐MS. METHODS Since highly solvated native have relatively low...

In contrast to the plethora of publications on separation fatty acids, analogous studies involving amines are scarce. A recently introduced ionic-liquid-based capillary column for GC was used separate trifluoroacetylated focusing analysis a commercial sample. Using ionic liquid (isothermal mode at 200 °C) it possible linear primary from C12 C22 chain length in less 25 min with MS identification. The log amine retention factors linearly related alkyl methylene selectivity 0.117 kcal/mol...

Metals play a very important role in many scientific and environmental fields, thus their detection analysis is of great necessity. A simple sensitive method has been developed herein for the metals positive ion mode ESI‐MS. Metal ions are positively charged, as such they can potentially be detected ESI‐MS; however, small mass‐to‐charge ( m/z ) ratio makes them fall low‐mass region mass spectrum, which largest background noise. Therefore, become extremely difficult. better well‐known way to...

A highly sensitive paired ion electrospray ionization mass spectrometry (PIESI-MS) approach was developed for the trace determination of sphingolipids.

At the current stage, service performance analysis of BeiDou satellite navigation system (BDS) can provide important references for BDS applications. Accuracy, integrity, availability, and continuity are indicators capability system. In this paper, relationships among them analyzed firstly. Secondly, describing accuracy, position dilution precision (PDOP) is selected quantitative calculation formulas its availability established. Then PDOP in Asia-Pacific region simulated analyzed, results...

Rationale The chromatographic analysis of topiramate and its degradation products is challenging due to the absence chromophoric moieties in their structures, wide polarity range compounds ionization differences. This work proposes two new mass spectrometry approaches for evaluating these analytes. Methods Based on calculated experimental limit detection (LOD), a highly sensitive high‐performance liquid chromatography (HPLC) paired‐ion electrospray (PIESI‐MS) method was developed...

With the considerable increase of visible satellites for positioning, fault detection and identification performance Range Consensus (RANCO) algorithm Receiver Autonomous Integrity Monitoring (RAIM) will significantly be improved. However, calculation amount RANCO exponentially sharp addition satellite subsets. This paper proposes a modified based on genetic (GA-RANCO) RAIM to inhibit expanded amount. To reduce in searching optimal minimal necessary subset (MNS), preselection step is...

Commonly, the code noise and multipath error is considered to fully obey Gaussian distribution. While in cases with different elevation angles orbit types, assumption may be inappropriate. Based on an empirical study, by considering both angle type, a new distribution model proposed describe more accurate this paper. Actual data from 10 observation stations during two months are researched, parameters range of determined. The verified than presented Global Navigation Satellite System...

The satellite signals are always blocked by obstructions in urban canyons, therefore multi-constellation global navigation system (GNSS) performs poor. Quantitative comparison of the performance different systems can provide a basis to analyze their advantages and disadvantages. This paper proposes fuzzy comprehensive evaluation (FCE) theory quantitatively evaluate GNSS, systematically puts forward how precision, availability, continuity integrity. A simulation was conducted emulate...