A field study was performed at rivers in Gunung Jerai forest reserve(Kedah,Malaysia) to assess seasonal changes in mayfly community structure and abundance in relation to altitude and water physicochemistry.Rivers at ...A field study was performed at rivers in Gunung Jerai forest reserve(Kedah,Malaysia) to assess seasonal changes in mayfly community structure and abundance in relation to altitude and water physicochemistry.Rivers at lower(Batu Hampar River) and higher(Teroi River) elevations were visited through dry and wet seasons in September 2007 to August 2008.Monthly visits were made to 20 sites on each river,and water and aquatic insects were sampled using D-pond aquatic nets.Water was warmer,more acid,and more turbid in Teroi River during wet season.Ammonia was the only nutrient exhibiting significant seasonal variations(greater during wet season).Chemical oxygen demand content was higher in Teroi River where biochemical oxygen demand content was low during wet season.Species richness was higher in Batu Hampar River,but displayed seasonal variations only in Teroi River.Among the eight families encountered,Baetidae was the commonest.Baetid abundance was usually high during wet season,and those belonging to the dominant genus(Baetis) were more abundant in Teroi River.Heptageniidae was the second commonest family;its predominant genus,Thalerospyrus was more abundant in Teroi River during dry season.Caenidae,Leptophlebiidae and Oligoneuriidae were only found in Batu Hampar River where their abundances peaked during dry season,i.e.,Habrophlebiodes sp.and Isonychia sp.Ephemerellidae and Teloganodidae occurred only in Teroi River,with the first found only during dry season.Mayflies were recorded under very distinct physicochemical conditions,illustrating their potential usefulness for assessing water quality.Caenids,leptophlebids,oligoneurids ephemerellids and teloganodids seem to be particularly sensitive to temperature,acidity,turbidity,chemical oxygen demand and biochemical oxygen demand,parameters that varied with river altitude.展开更多
Friction exists wherever relative motion occurs and is the main source of energy consumption.Lubrication plays a significant role in improving fuel efficiency,reducing emissions,and prolonging the service life of mach...Friction exists wherever relative motion occurs and is the main source of energy consumption.Lubrication plays a significant role in improving fuel efficiency,reducing emissions,and prolonging the service life of machines.Surface interactions between two moving solid surfaces or the flow of a fluid (and/or environment) on a solid surface are the primary causes of friction.Apart from the mechanical design of moving parts,surface physicochemistry is of crucial importance to lubrication.This review deals with the frontier research on controlling friction and lubrication,highlights the importance of physicochemistry aspects,and enumerates the state-of-the-art chemistry solutions to tribological issues.It aims at inspiring talented young scientists from different fields to make significant contributions to the area.展开更多
In Morocco,hydrological and hydrobiological surveys of wadis,river and stream are rare.In this research,we plan to attempt to characterize the physico-chemistry of surface waters of sixteen stations sampled at the lev...In Morocco,hydrological and hydrobiological surveys of wadis,river and stream are rare.In this research,we plan to attempt to characterize the physico-chemistry of surface waters of sixteen stations sampled at the level of the Sebou basin during the period 2013-2023.The diagnosis showed that this natural watercourse is highly enriched in oce-anic salts.A large fluctuation in the chemical nature of the waters was recorded,as well as electrical conductivity(EC),which oscillates between 629 and 22,766μS/cm.Hydrogen Potential ranges from 8.01 to 8.79 while remaining basic.Nitrate(NO3-)concentrations range from a maximum of 886.9 mg/l to a minimum of 0.24 mg/l.Similarly,the am-monium concentration varies from 0.04 to 15.34 mg/l.It was also noted that the waters were very rich in chloride ions(860.27 to 145.55 mg/l),in sodium Na+ion(51 to 2,530 mg/l),in sulfate ions SO4--(441.4 to 37.62 mg/l),in calcium ions Ca2+(97.6 to 1,072.8 mg/l)and in magnesium ions Mg2+(631.2 to 17.28 mg/l)which explains the high hardness of these waters.The concentrations of potassium ions(K+)range from 2.54 to 17.55 mg/l.The high alkalinity is due to the high concentrations of bicarbonate ions(75.64 to 362.34 mg/l).Our study concludes that the waters of the Sebou re-main below the irrigation threshold authorized by Moroccan law when moving away from its Atlantic estuary.They are too degraded and we suggest that urban and industrial wastewater be pre-treated as a priority to reduce natural environment.展开更多
For around fifty years,the regression and degradation of wetlands were considered so worrying that they were the subject of an international Convention signed on 2 February 1971,in Iran(RAMSAR).This treaty aims to con...For around fifty years,the regression and degradation of wetlands were considered so worrying that they were the subject of an international Convention signed on 2 February 1971,in Iran(RAMSAR).This treaty aims to conserve wetlands meeting criteria of international importance through the notion of rational use of these spaces and their biodiversity.The national and even international value of Lake Sidi Boughaba(Kenitra,Morocco)lies in its biodiversity which allowed its inclusion on the Ramsar list in 1980.This importance motivated us to begin an ecological assessment of the level of its pollution through spatiotemporal monitoring and analysis of physicochemical tracers from surface waters at seven sampling stations between January and December 2023.The waters of Lake Sidi Boughaba are relatively basic(pH=8.63),cold(15.14℃),very hard(64 meq/L),quite turbid(7.65 NTU),very salty(1935.85μs/cm)and well saturated with Calcium ions=312;Magnesium=605;Chlorides=5892;Sulfates=944;Silicates=26(mg/l).Other elements including nitrates(1.29 mg/l),ammonium(1.56 mg/l),fluorides(410μg/l),iron(350μg/l)and manganese(35μg/l)are low.This study concludes that Lake Sidi Boughaba is classified in the category of oligomesotrophic lakes and that it is too threatened by the progressive transformation of its fresh water into brackish water and consequently the change in its benthic and planktonic fauna necessary for food of avian fauna.The study further concludes that this wetland is under significant threat,and to protect its biodiversity,innovative approaches to hydrological development are necessary.展开更多
With the gradual reduction in high-quality iron ore resources,the global steel industry faces long-term challenges.For example,the continuous increase in the Al_(2)O_(3) content of iron ore has led to a decrease in th...With the gradual reduction in high-quality iron ore resources,the global steel industry faces long-term challenges.For example,the continuous increase in the Al_(2)O_(3) content of iron ore has led to a decrease in the metallurgical performance of sinter and fluctuations in slag properties.Considering calcium ferrite(CF)and composite CF(silico-ferrite of calcium and aluminum,SFCA)play a crucial role as a binding phase in high-alkalinity sinter and exhibit excellent physical strength and metallurgical performance,we propose incorporating excess Al_(2)O_(3) into SFCA to form a new binding phase with excellent properties for high-quality sinter preparation.In the synthesis of high-Al_(2)O_(3) SFCA,two high-Al_(2)O_(3) phases were identified as types A(Al_(1.2)Ca_(2.8)Fe_(8.7)O_(2)0Si_(0.8))and B(Ca_(4)Al_(4.18)Fe_(1.82)Si_(6)O_(26)).Results show that type A SFCA sample had a higher cell density(4.13 g/cm^(3))and longer Fe-O bond length(2.2193Å)than type B(3.46 g/cm^(3) and 1.9415Å),with a significantly greater lattice oxygen concentration(7.86%vs.1.85%),which demonstrates advantages in strength and reducibility.Type A SFCA sample contained a lower proportion of silicates,was predominantly composed of SFCA,and exhibited minimal porosity.Melting point and viscosity simulation tests indicate that type A SFCA sample formed a liquid phase at 880°C with a viscosity range of 0-0.35 Pa·s,which is notably lower than that of type B SFCA sample(1220°C and 0-20 Pa·s).This finding suggests that type A SFCA sample has a low initial melting temperature and viscosity,which facilitates increasing liquid-phase generation and improving flow properties.Such a condition enhances the adhesion to surrounding ore particles.Compressive strength tests reveal that type A SFCA sample(36.83-42.48 MPa)considerably outperformed type B SFCA sample(5.98-12.79 MPa)and traditional sinter(5.02-13.68 MPa).In addition,at 900°C,type A SFCA sample achieved a final reducibility of 0.89,which surpassed that of type B SFCA sample(0.83).In summary,type A SFCA sample demonstrates superior structural,thermophysical,and metallurgical properties,which highlights its promising potential for industrial applications.展开更多
The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derive...The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derived mainly from the gravity of its overlying rocks. In this paper, the stress state of any point in the crust is suggested to have been caused by both the gravity and the tectonic force. The author proposes that the hydrostatic pressure is a combination or superposition of two isotropic stresses in the tectonic force and gravity stress fields. The results obtained with a finite element simulation indicate that the additional hydrostatic pressure borne by rocks decreases gradually from the compression zone ( p s c), the shear zone ( p s sh ) to the tensile zone ( p s t), and that the difference in the additional tectonic hydrostatic pressure between these deformed zones tends to increase, following the increase in the absolute value and/or the difference in external forces between different directions. This paper presents the foundation for the research into the tectonic physicochemistry.展开更多
L-（＋）-α-（positive butyl）-leucine ethyl ester bromide chiral ionic liquid was synthesized by using microwave-assisted synthesis method and L-（＋）-α-（positive butyl）-leucine ethyl ester terafluoroborate and h...L-（＋）-α-（positive butyl）-leucine ethyl ester bromide chiral ionic liquid was synthesized by using microwave-assisted synthesis method and L-（＋）-α-（positive butyl）-leucine ethyl ester terafluoroborate and hexafluorophosphate chiral ionic liquids were synthesized by the anion exchange reaction. The structures were characterized by IR, ~1HNMR and structure optimization calculation. The results of studies on physicochemical properties show that they possess better thermal stability, solubility, bio-solubility and high conductivity. They can serve as effective reaction media as well as chiral catalysts. They are presently being investigated as dispersion agents in molecular imprinting ployer.展开更多
The Gounti Yéna valley, the subject of this study, is a tributary of the Niger River, it is the main watercourse that divides the left bank of the city of Niamey into two unequal parts. The surface area of its wa...The Gounti Yéna valley, the subject of this study, is a tributary of the Niger River, it is the main watercourse that divides the left bank of the city of Niamey into two unequal parts. The surface area of its watershed is estimated at about 62 Km2. The objective of the present study is on the one hand to evaluate the current state of the physico-chemical and bacteriological quality of the water of Gounti Yéna basin, and on the other hand to define the risks of water pollution and its origin in the face of the phenomenon of rising water table of this basin. In order to carry out this work, we proceeded to a study of the evolution of the physicochemical and bacteriological parameters of the water of the basin of Gounti Yéna during the period going from November 2020 to October 2021, at the level of four points of sampling chosen from the upstream to the downstream of the basin. The results obtained showed that the physico-chemical quality of the water in Gounti Yéna basin is influenced by the lithology of the watershed, climatic factors (rainfall and temperature) and anthropic actions. This study also highlighted the presence of fecal contamination in the water of the Gounti Yéna basin, with a greater degree of emphasis during the rainy season. This contamination remains a concern and may constitute a health risk.展开更多
The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong...The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three dimensional tectonic principal stresses and additional tectonic stress induced hydrostatic pressure [ p s=( σ 1+ σ 2+ σ 3)/3] are reconstructed according to the differential stress and the strain ratio ( α ) of the garnet in the minor coesite bearing eclogite of the Yingshan County. Then the gravity induced hydrostatic pressure ( p g) is calculated following the equation p minus p s, where p is estimated to be 2.8 GPa based on the quartz coesite geobarmeter. Therefore, the thickness of the rock column overlying the coesite bearing eclogite in the Ying shan County is determined ≥32 km. This estimation, significantly different from ≥100 km, the previous one obtained solely based on the weight/specific weight ratio (W/SW), offers a proper explanation for the puzzle that no tracer of the addition of mantle derived material has been found in the Dabie UHPM zone during the process of UHPM, although a number of researchers claim that this process took place at the depth of the mantle (≥100 km). It is concluded that attention should be paid to the additional tectonic stress induced hydrostatic pressure in the study of UHPM zones.展开更多
The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana...The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana;">the physicochemical properties and microbial quality of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> produced in the Borana zone</span></span><span style="font-family:Verdana;">. </span><span><span style="font-family:Verdana;">A total number of 35 <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> samples, 30 traditionally made plus 5 laboratories made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>,</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">were analyzed for their physicochemical properties and microbiological quality</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The overall average (±SD) values for pH, titratable acidity, total protein, fat, total solids, and ash were </span><span style="font-family:Verdana;">3.59</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> ±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.04</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">2.86</span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.18%</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> 7.26</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.41%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">9.85</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.73</span><span style="font-family:Verdana;">%, </span><span style="font-family:Verdana;">21.23</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 1.48</span><span style="font-family:Verdana;">%, and </span><span style="font-family:Verdana;">0.84</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.11</span><span><span style="font-family:Verdana;">%, respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The result of all physicochemical parameters of traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> was not significantly) different (P</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> (control sample).The average (±SD) total bacteria count (TBC), coliform count (CC), yeast and mould count (YMC), Staphylococcus aureus count and Listeria monocytogenes count were </span></span><span style="font-family:""><span style="font-family:Verdana;">8.36 ± 1.29</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.47 ± 0.51</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">8.06 ± 1.28</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.79 ± 0.91</span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">3.15</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.17</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml, respectively for traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. Whereas, the </span><span style="font-family:Verdana;">corresponding values for the laboratory-made </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> were </span></span><span style="font-family:""><span style="font-family:Verdana;">4.17 ± 0.55</span><span><span style="font-family:Verdana;"> log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml,</span></span></span><span style="font-family:Verdana;"> 0, </span><span style="font-family:""><span style="font-family:Verdana;">5.76 ± 0.57</span><span style="font-family:Verdana;"> log<sub>10</sub>cfu/ml, 0 and 0, respectively. Significant (P</span></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) differences were observed between traditional and laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> for coliform, S. aureus and L. monocytogenes count. The Prevalence of pathogenic microorganisms for S. aureus and L. monocytogenes were </span></span><span style="font-family:""><span style="font-family:Verdana;">33.33% and 6.67%, </span><span><span style="font-family:Verdana;">respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span></span></span><i><span style="font-family:""> </span></i><span style="font-family:""><span style="font-family:Verdana;">while not detected for laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The results indicated that the quality of traditional </span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"> was substandard and not safe for consumption. This in general, the production of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> in the study area requires intervention such as awareness creation of keeping good hygienic quality and pasteurization (heating up to boiling) of milk to be used for</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> making in order to make it safe from the public health point of view.展开更多
In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both...In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both the physical and social health of all people. Water samples were obtained during the dry and wet seasons from a borehole and a man-made lake constructed through self-help effort in Obazuwa community in Ovia North East Local Government Area of Edo State, Nigeria. They were analyzed for physicochemical parameters and subjected to cyto-genotoxic evaluation using the Allium cepa assay. Results of the physicochemical analysis showed that most of the parameters (pH, chromium, copper, chlorides, nickel, iron, zinc, cadmium, lead and manganese) of the lake water in both seasons exceeded World Health Organisation (WHO) permissible limits. Total heterotrophic bacteria and E. coli were present with dry season water samples having higher amounts. Compared to the control, the mitotic index decreased significantly (p < 0.05) in the water samples and were characterized by a number of chromosomal aberrations notably bridges, fragments, sticky chromosomes, disoriented chromosomes, and micronuclei in significant amounts and these were more pronounced in water samples obtained during the dry season. The findings in this study are of public health relevance as access to safe water is a fundamental human need and therefore, a basic human right.展开更多
Dallol Maouri is one of the fossil valleys on the left bank of the Niger River. Its watershed drains water from valleys in the Tahoua and Dosso regions of Niger. The watercourse is not continuous and has areas of surf...Dallol Maouri is one of the fossil valleys on the left bank of the Niger River. Its watershed drains water from valleys in the Tahoua and Dosso regions of Niger. The watercourse is not continuous and has areas of surface water accumulation (ponds) and areas of spreading and infiltration. The surface water potential in this area is limited, with most of the ponds having a temporary to the semi-permanent regime. Groundwater resources are, therefore, the main sources of withdrawal for human food, agriculture, and livestock. Climate change through the variation in rainfall, the often-anarchic multiplication of catchment works (wells and boreholes) and agricultural activities can have impacts on the qualitative and quantitative evolution of surface and groundwater. The objective of this study is to characterize the surface and underground water of the upper dallol Maouri through the physicochemical parameters of the water and the use of the isotopes of the water molecule (<sup>18</sup>O, <sup>2</sup>H and <sup>3</sup>H). A total of 53 water samples were analyzed at the laboratory of the Regional Directorate of Hydraulics and Sanitation of Tillabéri (Niger) for chemical parameters and 73 samples were analyzed at the Radio Analysis and Environment Laboratory (LRAE) of the National School of Engineers of Sfax (ENIS) of Tunis for isotopy. The water of the ponds is characterized by three types of facies: calcium bicarbonate, calcium and magnesium bicarbonate, and calcium nitrate chloride. The groundwater is 75% of the chloride-nitrate-calcium facies and the CT3/CT2 groundwater is calcium and magnesium bicarbonate. The results of the stable isotopes made it possible to highlight the presence of four distinct water groups: ponds characterized by highly evaporated water, the sheets of Continental Terminal 1 and 2 (CT1 and CT2) with an isotopic cachet of old water, the water table consisting of a two-layer system in the southwestern part of the area. The water is not very mineralized (40 μS to 600 μS) and is slightly acidic (pH = 6.4). The analysis of the radioactive isotope (<sup>3</sup>H) content of the water from the water table has made it possible to identify the areas of recharge of the water table. These results also highlight: the presence of an upward drainage zone, and the contribution of lowland ponds to the recharge of alluvial aquifers ranging from 24% to 84%. No structure in this zone reaches the Continental Intercalaire and the Continental Hamadien, the depth of which is estimated at an average of 600 m. The relationship between the <sup>18</sup>O and <sup>3</sup>H contents of groundwater water shows two types of water with tritium contents higher than 2 TU for alluvial aquifers and tritium contents lower than 2 TU for groundwater (CT3). The analysis of the radioactive isotope (<sup>3</sup>H) contents of the groundwater has made it possible to identify recent recharges at the level of the alluvial aquifers and in the outcrop zone of CT3. There is no hydraulic continuity between the plateau ponds and groundwater.展开更多
The present work aims to study the influence of some physicochemical parameters (light, temperature, ethanol, bile salts, potassium hydroxide, hydrogen peroxide) on the content of Metronidazole (MTZ) contained in the ...The present work aims to study the influence of some physicochemical parameters (light, temperature, ethanol, bile salts, potassium hydroxide, hydrogen peroxide) on the content of Metronidazole (MTZ) contained in the reference substance (SR) and in a pharmaceutical specialty Flagyl<sup>®</sup> 250 mg tablet (FLG). The method developed was linear and accurate in accordance with USP 38 and the MTZ contents were obtained by UV-visible spectrophotometry at 278 nm. These contents ranged from 225 mg to 275 mg and were thus consistent with the concentration present in the proprietary medicines (250 mg). The study of the influence of physicochemical parameters on the MTZ content in SR and FLG showed that MTZ contents are unstable in the presence of Ethanol at 96˚, KOH at 0.1N and bile salts but also when the temperature is higher than 25˚C. However, they remain stable in the presence of light and H<sub>2</sub>O<sub>2</sub> and undergo degradation in an acidic environment.展开更多
TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis appl...TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis applications.In this presentation,we summarize some progress in surface constructions of nano TiO_2 and its characterizations of physicochemistry and properties. (1)Superhydrophobic nanostructure TiO_2 films Superhydrophobic nanotube,nanopore and sponge-like structure TiO_2 films are fabricated ...展开更多
The knowledge that hydrostatic pressure is equal to the gravity value of the overlying rocks in studying a dynamic state of certain underground site is argued. It is suggested that the stress field T in the crust is a...The knowledge that hydrostatic pressure is equal to the gravity value of the overlying rocks in studying a dynamic state of certain underground site is argued. It is suggested that the stress field T in the crust is a combination or superposition of total hydrostatic pressure P with differential stress σ,and the total hydrostatic pressure P at any point in the crust comprises two parts: one is spherical stress tensor P<sub>G</sub> caused by the gravity, and the other is spherical stress tensor P<sub>s</sub> caused by tectonic stress; therefore P could not be attributed to the gravity of overlying rocks only. The results obtained by a finite-element simulation indicate that the tectono-original additional hydrostatic pressures P<sub>s</sub> decrease gradually from the compressive zone （p<sub>c</sub><sup>S</sup>） to the shear zone (P<sub>SH</sub><sup>s</sup>)and to the tensile zone （P<sub>T</sub><sup>s</sup>）, i.e.P<sub>c</sub><sup>s</sup>】P<sub>sH</sub><sup>s</sup>】P<sub>T</sub><sup>s</sup> in the same depth. On the basis of the above-mentioned research, the method of measurement and calculation of metallogenetic depth corrected by P<sub>s</sub> is展开更多
基金supported by the Fundamental Research Grant Scheme (FRGS) from the Ministry of Science, Technology and Innovation (MOSTI)
文摘A field study was performed at rivers in Gunung Jerai forest reserve(Kedah,Malaysia) to assess seasonal changes in mayfly community structure and abundance in relation to altitude and water physicochemistry.Rivers at lower(Batu Hampar River) and higher(Teroi River) elevations were visited through dry and wet seasons in September 2007 to August 2008.Monthly visits were made to 20 sites on each river,and water and aquatic insects were sampled using D-pond aquatic nets.Water was warmer,more acid,and more turbid in Teroi River during wet season.Ammonia was the only nutrient exhibiting significant seasonal variations(greater during wet season).Chemical oxygen demand content was higher in Teroi River where biochemical oxygen demand content was low during wet season.Species richness was higher in Batu Hampar River,but displayed seasonal variations only in Teroi River.Among the eight families encountered,Baetidae was the commonest.Baetid abundance was usually high during wet season,and those belonging to the dominant genus(Baetis) were more abundant in Teroi River.Heptageniidae was the second commonest family;its predominant genus,Thalerospyrus was more abundant in Teroi River during dry season.Caenidae,Leptophlebiidae and Oligoneuriidae were only found in Batu Hampar River where their abundances peaked during dry season,i.e.,Habrophlebiodes sp.and Isonychia sp.Ephemerellidae and Teloganodidae occurred only in Teroi River,with the first found only during dry season.Mayflies were recorded under very distinct physicochemical conditions,illustrating their potential usefulness for assessing water quality.Caenids,leptophlebids,oligoneurids ephemerellids and teloganodids seem to be particularly sensitive to temperature,acidity,turbidity,chemical oxygen demand and biochemical oxygen demand,parameters that varied with river altitude.
基金The work is financially supported by the National Natural Science Foundation of China (NSFC)，the National Key Basic Research and Development (973) Program of China，Natural Science Foundation of Gansu Province
文摘Friction exists wherever relative motion occurs and is the main source of energy consumption.Lubrication plays a significant role in improving fuel efficiency,reducing emissions,and prolonging the service life of machines.Surface interactions between two moving solid surfaces or the flow of a fluid (and/or environment) on a solid surface are the primary causes of friction.Apart from the mechanical design of moving parts,surface physicochemistry is of crucial importance to lubrication.This review deals with the frontier research on controlling friction and lubrication,highlights the importance of physicochemistry aspects,and enumerates the state-of-the-art chemistry solutions to tribological issues.It aims at inspiring talented young scientists from different fields to make significant contributions to the area.
文摘In Morocco,hydrological and hydrobiological surveys of wadis,river and stream are rare.In this research,we plan to attempt to characterize the physico-chemistry of surface waters of sixteen stations sampled at the level of the Sebou basin during the period 2013-2023.The diagnosis showed that this natural watercourse is highly enriched in oce-anic salts.A large fluctuation in the chemical nature of the waters was recorded,as well as electrical conductivity(EC),which oscillates between 629 and 22,766μS/cm.Hydrogen Potential ranges from 8.01 to 8.79 while remaining basic.Nitrate(NO3-)concentrations range from a maximum of 886.9 mg/l to a minimum of 0.24 mg/l.Similarly,the am-monium concentration varies from 0.04 to 15.34 mg/l.It was also noted that the waters were very rich in chloride ions(860.27 to 145.55 mg/l),in sodium Na+ion(51 to 2,530 mg/l),in sulfate ions SO4--(441.4 to 37.62 mg/l),in calcium ions Ca2+(97.6 to 1,072.8 mg/l)and in magnesium ions Mg2+(631.2 to 17.28 mg/l)which explains the high hardness of these waters.The concentrations of potassium ions(K+)range from 2.54 to 17.55 mg/l.The high alkalinity is due to the high concentrations of bicarbonate ions(75.64 to 362.34 mg/l).Our study concludes that the waters of the Sebou re-main below the irrigation threshold authorized by Moroccan law when moving away from its Atlantic estuary.They are too degraded and we suggest that urban and industrial wastewater be pre-treated as a priority to reduce natural environment.
文摘For around fifty years,the regression and degradation of wetlands were considered so worrying that they were the subject of an international Convention signed on 2 February 1971,in Iran(RAMSAR).This treaty aims to conserve wetlands meeting criteria of international importance through the notion of rational use of these spaces and their biodiversity.The national and even international value of Lake Sidi Boughaba(Kenitra,Morocco)lies in its biodiversity which allowed its inclusion on the Ramsar list in 1980.This importance motivated us to begin an ecological assessment of the level of its pollution through spatiotemporal monitoring and analysis of physicochemical tracers from surface waters at seven sampling stations between January and December 2023.The waters of Lake Sidi Boughaba are relatively basic(pH=8.63),cold(15.14℃),very hard(64 meq/L),quite turbid(7.65 NTU),very salty(1935.85μs/cm)and well saturated with Calcium ions=312;Magnesium=605;Chlorides=5892;Sulfates=944;Silicates=26(mg/l).Other elements including nitrates(1.29 mg/l),ammonium(1.56 mg/l),fluorides(410μg/l),iron(350μg/l)and manganese(35μg/l)are low.This study concludes that Lake Sidi Boughaba is classified in the category of oligomesotrophic lakes and that it is too threatened by the progressive transformation of its fresh water into brackish water and consequently the change in its benthic and planktonic fauna necessary for food of avian fauna.The study further concludes that this wetland is under significant threat,and to protect its biodiversity,innovative approaches to hydrological development are necessary.
基金financially supported by the National Natural Science Foundation of China(Nos.52204331 and 52374315)the Major Industrial Innovation Plan of the Anhui Provincial Development and Reform Commission,China(No.AHZDCYCX-LSDT2023-01).
文摘With the gradual reduction in high-quality iron ore resources,the global steel industry faces long-term challenges.For example,the continuous increase in the Al_(2)O_(3) content of iron ore has led to a decrease in the metallurgical performance of sinter and fluctuations in slag properties.Considering calcium ferrite(CF)and composite CF(silico-ferrite of calcium and aluminum,SFCA)play a crucial role as a binding phase in high-alkalinity sinter and exhibit excellent physical strength and metallurgical performance,we propose incorporating excess Al_(2)O_(3) into SFCA to form a new binding phase with excellent properties for high-quality sinter preparation.In the synthesis of high-Al_(2)O_(3) SFCA,two high-Al_(2)O_(3) phases were identified as types A(Al_(1.2)Ca_(2.8)Fe_(8.7)O_(2)0Si_(0.8))and B(Ca_(4)Al_(4.18)Fe_(1.82)Si_(6)O_(26)).Results show that type A SFCA sample had a higher cell density(4.13 g/cm^(3))and longer Fe-O bond length(2.2193Å)than type B(3.46 g/cm^(3) and 1.9415Å),with a significantly greater lattice oxygen concentration(7.86%vs.1.85%),which demonstrates advantages in strength and reducibility.Type A SFCA sample contained a lower proportion of silicates,was predominantly composed of SFCA,and exhibited minimal porosity.Melting point and viscosity simulation tests indicate that type A SFCA sample formed a liquid phase at 880°C with a viscosity range of 0-0.35 Pa·s,which is notably lower than that of type B SFCA sample(1220°C and 0-20 Pa·s).This finding suggests that type A SFCA sample has a low initial melting temperature and viscosity,which facilitates increasing liquid-phase generation and improving flow properties.Such a condition enhances the adhesion to surrounding ore particles.Compressive strength tests reveal that type A SFCA sample(36.83-42.48 MPa)considerably outperformed type B SFCA sample(5.98-12.79 MPa)and traditional sinter(5.02-13.68 MPa).In addition,at 900°C,type A SFCA sample achieved a final reducibility of 0.89,which surpassed that of type B SFCA sample(0.83).In summary,type A SFCA sample demonstrates superior structural,thermophysical,and metallurgical properties,which highlights its promising potential for industrial applications.
文摘The research into the hydrostatic pressure in the crust has been previously conducted from the viewpoint that the hydrostatic pressure is equal to the gravity, based on the fact that the hydrostatic pressure is derived mainly from the gravity of its overlying rocks. In this paper, the stress state of any point in the crust is suggested to have been caused by both the gravity and the tectonic force. The author proposes that the hydrostatic pressure is a combination or superposition of two isotropic stresses in the tectonic force and gravity stress fields. The results obtained with a finite element simulation indicate that the additional hydrostatic pressure borne by rocks decreases gradually from the compression zone ( p s c), the shear zone ( p s sh ) to the tensile zone ( p s t), and that the difference in the additional tectonic hydrostatic pressure between these deformed zones tends to increase, following the increase in the absolute value and/or the difference in external forces between different directions. This paper presents the foundation for the research into the tectonic physicochemistry.
基金Funded by the National Natural Science Foundation of China(No.51433008)the Project of Scientific Research of Shaanxi(No.2017GY-182)the Science and Technology Fund Project
文摘L-（＋）-α-（positive butyl）-leucine ethyl ester bromide chiral ionic liquid was synthesized by using microwave-assisted synthesis method and L-（＋）-α-（positive butyl）-leucine ethyl ester terafluoroborate and hexafluorophosphate chiral ionic liquids were synthesized by the anion exchange reaction. The structures were characterized by IR, ~1HNMR and structure optimization calculation. The results of studies on physicochemical properties show that they possess better thermal stability, solubility, bio-solubility and high conductivity. They can serve as effective reaction media as well as chiral catalysts. They are presently being investigated as dispersion agents in molecular imprinting ployer.
文摘The Gounti Yéna valley, the subject of this study, is a tributary of the Niger River, it is the main watercourse that divides the left bank of the city of Niamey into two unequal parts. The surface area of its watershed is estimated at about 62 Km2. The objective of the present study is on the one hand to evaluate the current state of the physico-chemical and bacteriological quality of the water of Gounti Yéna basin, and on the other hand to define the risks of water pollution and its origin in the face of the phenomenon of rising water table of this basin. In order to carry out this work, we proceeded to a study of the evolution of the physicochemical and bacteriological parameters of the water of the basin of Gounti Yéna during the period going from November 2020 to October 2021, at the level of four points of sampling chosen from the upstream to the downstream of the basin. The results obtained showed that the physico-chemical quality of the water in Gounti Yéna basin is influenced by the lithology of the watershed, climatic factors (rainfall and temperature) and anthropic actions. This study also highlighted the presence of fecal contamination in the water of the Gounti Yéna basin, with a greater degree of emphasis during the rainy season. This contamination remains a concern and may constitute a health risk.
文摘The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three dimensional tectonic principal stresses and additional tectonic stress induced hydrostatic pressure [ p s=( σ 1+ σ 2+ σ 3)/3] are reconstructed according to the differential stress and the strain ratio ( α ) of the garnet in the minor coesite bearing eclogite of the Yingshan County. Then the gravity induced hydrostatic pressure ( p g) is calculated following the equation p minus p s, where p is estimated to be 2.8 GPa based on the quartz coesite geobarmeter. Therefore, the thickness of the rock column overlying the coesite bearing eclogite in the Ying shan County is determined ≥32 km. This estimation, significantly different from ≥100 km, the previous one obtained solely based on the weight/specific weight ratio (W/SW), offers a proper explanation for the puzzle that no tracer of the addition of mantle derived material has been found in the Dabie UHPM zone during the process of UHPM, although a number of researchers claim that this process took place at the depth of the mantle (≥100 km). It is concluded that attention should be paid to the additional tectonic stress induced hydrostatic pressure in the study of UHPM zones.
文摘The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana;">the physicochemical properties and microbial quality of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> produced in the Borana zone</span></span><span style="font-family:Verdana;">. </span><span><span style="font-family:Verdana;">A total number of 35 <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> samples, 30 traditionally made plus 5 laboratories made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>,</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">were analyzed for their physicochemical properties and microbiological quality</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The overall average (±SD) values for pH, titratable acidity, total protein, fat, total solids, and ash were </span><span style="font-family:Verdana;">3.59</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> ±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.04</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">2.86</span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.18%</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> 7.26</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.41%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">9.85</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.73</span><span style="font-family:Verdana;">%, </span><span style="font-family:Verdana;">21.23</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 1.48</span><span style="font-family:Verdana;">%, and </span><span style="font-family:Verdana;">0.84</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.11</span><span><span style="font-family:Verdana;">%, respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The result of all physicochemical parameters of traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> was not significantly) different (P</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> (control sample).The average (±SD) total bacteria count (TBC), coliform count (CC), yeast and mould count (YMC), Staphylococcus aureus count and Listeria monocytogenes count were </span></span><span style="font-family:""><span style="font-family:Verdana;">8.36 ± 1.29</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.47 ± 0.51</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">8.06 ± 1.28</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.79 ± 0.91</span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">3.15</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.17</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml, respectively for traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. Whereas, the </span><span style="font-family:Verdana;">corresponding values for the laboratory-made </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> were </span></span><span style="font-family:""><span style="font-family:Verdana;">4.17 ± 0.55</span><span><span style="font-family:Verdana;"> log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml,</span></span></span><span style="font-family:Verdana;"> 0, </span><span style="font-family:""><span style="font-family:Verdana;">5.76 ± 0.57</span><span style="font-family:Verdana;"> log<sub>10</sub>cfu/ml, 0 and 0, respectively. Significant (P</span></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) differences were observed between traditional and laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> for coliform, S. aureus and L. monocytogenes count. The Prevalence of pathogenic microorganisms for S. aureus and L. monocytogenes were </span></span><span style="font-family:""><span style="font-family:Verdana;">33.33% and 6.67%, </span><span><span style="font-family:Verdana;">respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span></span></span><i><span style="font-family:""> </span></i><span style="font-family:""><span style="font-family:Verdana;">while not detected for laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The results indicated that the quality of traditional </span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"> was substandard and not safe for consumption. This in general, the production of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> in the study area requires intervention such as awareness creation of keeping good hygienic quality and pasteurization (heating up to boiling) of milk to be used for</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> making in order to make it safe from the public health point of view.
文摘In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both the physical and social health of all people. Water samples were obtained during the dry and wet seasons from a borehole and a man-made lake constructed through self-help effort in Obazuwa community in Ovia North East Local Government Area of Edo State, Nigeria. They were analyzed for physicochemical parameters and subjected to cyto-genotoxic evaluation using the Allium cepa assay. Results of the physicochemical analysis showed that most of the parameters (pH, chromium, copper, chlorides, nickel, iron, zinc, cadmium, lead and manganese) of the lake water in both seasons exceeded World Health Organisation (WHO) permissible limits. Total heterotrophic bacteria and E. coli were present with dry season water samples having higher amounts. Compared to the control, the mitotic index decreased significantly (p < 0.05) in the water samples and were characterized by a number of chromosomal aberrations notably bridges, fragments, sticky chromosomes, disoriented chromosomes, and micronuclei in significant amounts and these were more pronounced in water samples obtained during the dry season. The findings in this study are of public health relevance as access to safe water is a fundamental human need and therefore, a basic human right.
文摘Dallol Maouri is one of the fossil valleys on the left bank of the Niger River. Its watershed drains water from valleys in the Tahoua and Dosso regions of Niger. The watercourse is not continuous and has areas of surface water accumulation (ponds) and areas of spreading and infiltration. The surface water potential in this area is limited, with most of the ponds having a temporary to the semi-permanent regime. Groundwater resources are, therefore, the main sources of withdrawal for human food, agriculture, and livestock. Climate change through the variation in rainfall, the often-anarchic multiplication of catchment works (wells and boreholes) and agricultural activities can have impacts on the qualitative and quantitative evolution of surface and groundwater. The objective of this study is to characterize the surface and underground water of the upper dallol Maouri through the physicochemical parameters of the water and the use of the isotopes of the water molecule (<sup>18</sup>O, <sup>2</sup>H and <sup>3</sup>H). A total of 53 water samples were analyzed at the laboratory of the Regional Directorate of Hydraulics and Sanitation of Tillabéri (Niger) for chemical parameters and 73 samples were analyzed at the Radio Analysis and Environment Laboratory (LRAE) of the National School of Engineers of Sfax (ENIS) of Tunis for isotopy. The water of the ponds is characterized by three types of facies: calcium bicarbonate, calcium and magnesium bicarbonate, and calcium nitrate chloride. The groundwater is 75% of the chloride-nitrate-calcium facies and the CT3/CT2 groundwater is calcium and magnesium bicarbonate. The results of the stable isotopes made it possible to highlight the presence of four distinct water groups: ponds characterized by highly evaporated water, the sheets of Continental Terminal 1 and 2 (CT1 and CT2) with an isotopic cachet of old water, the water table consisting of a two-layer system in the southwestern part of the area. The water is not very mineralized (40 μS to 600 μS) and is slightly acidic (pH = 6.4). The analysis of the radioactive isotope (<sup>3</sup>H) content of the water from the water table has made it possible to identify the areas of recharge of the water table. These results also highlight: the presence of an upward drainage zone, and the contribution of lowland ponds to the recharge of alluvial aquifers ranging from 24% to 84%. No structure in this zone reaches the Continental Intercalaire and the Continental Hamadien, the depth of which is estimated at an average of 600 m. The relationship between the <sup>18</sup>O and <sup>3</sup>H contents of groundwater water shows two types of water with tritium contents higher than 2 TU for alluvial aquifers and tritium contents lower than 2 TU for groundwater (CT3). The analysis of the radioactive isotope (<sup>3</sup>H) contents of the groundwater has made it possible to identify recent recharges at the level of the alluvial aquifers and in the outcrop zone of CT3. There is no hydraulic continuity between the plateau ponds and groundwater.
文摘The present work aims to study the influence of some physicochemical parameters (light, temperature, ethanol, bile salts, potassium hydroxide, hydrogen peroxide) on the content of Metronidazole (MTZ) contained in the reference substance (SR) and in a pharmaceutical specialty Flagyl<sup>®</sup> 250 mg tablet (FLG). The method developed was linear and accurate in accordance with USP 38 and the MTZ contents were obtained by UV-visible spectrophotometry at 278 nm. These contents ranged from 225 mg to 275 mg and were thus consistent with the concentration present in the proprietary medicines (250 mg). The study of the influence of physicochemical parameters on the MTZ content in SR and FLG showed that MTZ contents are unstable in the presence of Ethanol at 96˚, KOH at 0.1N and bile salts but also when the temperature is higher than 25˚C. However, they remain stable in the presence of light and H<sub>2</sub>O<sub>2</sub> and undergo degradation in an acidic environment.
文摘TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis applications.In this presentation,we summarize some progress in surface constructions of nano TiO_2 and its characterizations of physicochemistry and properties. (1)Superhydrophobic nanostructure TiO_2 films Superhydrophobic nanotube,nanopore and sponge-like structure TiO_2 films are fabricated ...
文摘The knowledge that hydrostatic pressure is equal to the gravity value of the overlying rocks in studying a dynamic state of certain underground site is argued. It is suggested that the stress field T in the crust is a combination or superposition of total hydrostatic pressure P with differential stress σ,and the total hydrostatic pressure P at any point in the crust comprises two parts: one is spherical stress tensor P<sub>G</sub> caused by the gravity, and the other is spherical stress tensor P<sub>s</sub> caused by tectonic stress; therefore P could not be attributed to the gravity of overlying rocks only. The results obtained by a finite-element simulation indicate that the tectono-original additional hydrostatic pressures P<sub>s</sub> decrease gradually from the compressive zone （p<sub>c</sub><sup>S</sup>） to the shear zone (P<sub>SH</sub><sup>s</sup>)and to the tensile zone （P<sub>T</sub><sup>s</sup>）, i.e.P<sub>c</sub><sup>s</sup>】P<sub>sH</sub><sup>s</sup>】P<sub>T</sub><sup>s</sup> in the same depth. On the basis of the above-mentioned research, the method of measurement and calculation of metallogenetic depth corrected by P<sub>s</sub> is
