张真人《金石灵砂论》外丹黄白考释

张真人《金石灵砂论》与外丹黄白之关系,学界迄今未有详论[1].作者考释认为,张真人生于唐神龙五年(707)而卒于唐贞元十六年(800),享年93岁.又今本《道藏》所题"蒙山张隐居撰",当为"雾山张隐居撰"之误;在丹药理论方面,该经实际包括了"阴阳相配原理"和"转化论"两个方面,它们贯穿于中国外丹黄白术的整个流变史中;在黄白的具体烧炼上,廓清了"铅"与"黑铅"的区别,使以往的诸多疑虑得以释然.事实说明,唐代道士在外丹黄白烧炼的温度控制和丹药性质的划分上,已形成一套有别于汉晋南北朝的方法和理论.

联合快速测定砂(石)含水(泥)量筒法

详细介绍了检测操作方法、计算原理和砂(石)含水率快速查表。此法操作简单。易于掌握、检测时不用加热烘干砂石,约5分钟即可得结果。它特别适合商品混凝土搅拌厂,或建筑工程施工现场,拌制混凝土或砌筑砂浆时,随时检测砂(石)含水(泥)使用。用测得的数据去科学调整施工配合比,确保混凝土工程和砌筑工程质量。

联合快速测定砂（石）含水（泥）量简法

文中较详细的介绍了检测操作方法，计算原理和砂（石）含水率，此法操作简单、易于掌握，不用加热烘干砂（石），约五分钟左右即可得到检测结果。它特别适宜建筑施工现场使用，可随时对进入施工现场的砂（石）做含水（泥）检测，用测得的数据科学指导调整混凝土或砌筑砂浆配合比，确保建筑工程质量。

用酒精烧干法快速测定现场砂（石）含水率

现场搅拌砼（砂浆）时，如何及时、快捷地测定砂（石）含水率和提出施工配合比，是一个经常遇到的问题。推荐一种酒精烧干砂（石）含水率快速测定法。

PERFORMANCE OF BRAZED DIAMOND CUP-TYPE WHEELS WITH DEFINED GRAIN PATTERN IN GRINDING CEMENTED CARBIDE

A new cup-type grinding wheel of the brazed monolayer diamond is developed with a defined grain pattern on the wheel surface. Grinding performance of the brazed wheel in the surface grinding of cemented carbide is studied. Experimental results show that when continuous dry grinding is employed, grits of the brazed diamond grinding wheel fail mainly in attritious wear and fracture modes and no pull-out ones are found in conventional electroplated and sintered diamond wheels. It indicates the strong retention of brazing alloy to diamond grits and the longer service life of the wheel. In addition, the ground surface has good roughness. The theoretical surface roughness agrees well with experimental results.

Analyzing the mid-low porosity sandstone dry frame in central Sichuan based on effective medium theory

Tight gas sandstone reservoirs in Guang＇an are characterized by wide distribution and low abundance. Sandstone samples from this area usually have low porosity and poor connectivity. We analyze the observed velocity data of tight sandstone samples with the Mori- Tanaka model, and give the sandstone framework physical model in this area based on theory and experiment analysis. The matrix modulus was obtained by an empirical relationship and then the experiment data were compared with the values predicted by the Mori-Tanaka model with different pore shapes. The results revealed that the experiment data were close to the model with low pore aspect ratio. Considering the matrix modulus and pore shape variation, we find that, under the condition of small mineral composition change, the effective pore aspect ratio of these samples increased with porosity evidently.

A novel model for assessing the pore structure of tight sands and its application

Pore-structure poses great influence on the permeability and electrical property of tight sand reservoirs and is critical to the petrophysical research of such reservoirs.The uncertainty of permeability for tight sands is very common and the relationship between pore- structure and electrical property is often unclear.We propose a new parameterδ,integrating porosity,maximum radius of connected pore-throats,and sorting degree,for investigating the permeability and electrical properties of tight sands.Core data and wireline log analyses show that this newδcan be used to accurately predict the tight sands permeability and has a close relation with electrical parameters,allowing the estimation of formation factor F and cementation exponent m.The normalization of the resistivity difference caused by the pore- structure is used to highlight the influence of fluid type on Rt,enhancing the coincidence rate in the Pickett crossplot significantly.

Brittleness index and seismic rock physics model for anisotropic tight-oil sandstone reservoirs

Brittleness analysis becomes important when looking for sweet spots in tightoil sandstone reservoirs. Hence, appropriate indices are required as accurate brittleness evaluation criteria. We construct a seismic rock physics model for tight-oil sandstone reservoirs with vertical fractures. Because of the complexities in lithology and pore structure and the anisotropic characteristics of tight-oil sandstone reservoirs, the proposed model is based on the solid components, pore connectivity, pore type, and fractures to better describe the sandstone reservoir microstructure. Using the model, we analyze the brittleness sensitivity of the elastic parameters in an anisotropic medium and establish a new brittleness index. We show the applicability of the proposed brittleness index for tight-oil sandstone reservoirs by considering the brittleness sensitivity, the rock physics response characteristics, and cross-plots. Compared with conventional brittleness indexes, the new brittleness index has high brittleness sensitivity and it is the highest in oil-bearing brittle zones with relatively high porosity. The results also suggest that the new brittleness index is much more sensitive to elastic properties variations, and thus can presumably better predict the brittleness characteristics of sweet spots in tight-oil sandstone reservoirs.

Effect of graphene on mechanical properties of cement mortars

Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious material were then investigated. The results indicate that the addition of FGN decreases the fluidity slightly and improves mechanical properties of cement-based composites significantly. The highest strength is obtained with FGN content of 0.02% where the flexural strength and compressive strength at 28 days are 12.917 MPa and 52.42 MPa, respectively. Besides, scanning electron micrographs show that FGN can regulate formation of massive compact cross-linking structures and thermo gravimetric analysis indicates that FGN can accelerate the hydration reaction to increase the function of the composite effectively.

Effects of temperature and age on physico-mechanical properties of cemented gravel sand backfills

Cemented backfill used in deep mines would inevitably be exposed to the ambient temperature of 20−60℃in the next few decades.In this paper,two types of cemented gravel sand backfills,cemented rod-mill sand backfill(CRB)and cemented gobi sand backfill(CGB),were prepared and cured at various temperatures(20,40,60℃)and ages(3,7,28 d),and the effects of temperature and age on the physico-mechanical properties of CRB and CGB were investigated based on laboratory tests.Results show that:1)the effects of temperature and age on the physico-mechanical properties of backfills mainly depend on the amount of hydration products and the refinement of cementation structures.The temperature has a more significant effect on thermal expansibility and ultrasonic performance at early ages.2)The facilitating effect of temperature and age on the compressive strength of CGB is higher than that on CRB.With the increase of temperature,the compressive failure modes changed from X-conjugate shear failure to tensile failure,and the integrity of specimens was significantly improved.3)Similarly,the shear performance of CGB is generally better than that of CRB.The temperature has a weaker effect on shear strength than age,but the shear deformation and shear plane morphology are closely related to temperature.

Channel Response to Gravel Mining Activities in Mountain Rivers

s: The removal of bed material from active river channels usually affects the bed profile of the streambed, causing progressive degradation upstream and downstream of the extraction site. These effects can extend for kilometers affecting hydraulic structures located in the vicinity of the river reach. In this paper, the geomorphic effects of gravel mining are reviewed and summarized. Some cases in Venezuelan streams are presented to illustrate the problem. To describe the processes of erosion and sedimentation in a gravel extraction pit, a recent developed mathematical model for the simulation of flow and sediment transport in gravel-cobble bed streams is applied to a hypothetical case of gravel mining in a river channel. A simple rectangular dredge pit is imposed as initial condition in the channel bed, and changes in bed elevations and grain size distribution of bed material are calculated by using the numerical model. The process of deposition within the pit, and the downstream and upstream migration of the erosion wave are well simulated by the model and closely resemble the phenomena observed in laboratory experiments. The response of the friction coefficient to the changes in flow and bed elevations shows the importance in modeling adequately flow resistance and sediment transport in gravel-cobble bed streams.

Effects of Roughness Elements Distribution on Overland Flow Resistance

Roughness elements are various in a mountain area; they include gravel and ground surface vegetation that often result in surface friction drag to resist overland flows. The variation and characteristics of flow resistance strongly impact the overland flow process and watershed floods. In view of the universal existence of natural vegetation, such as Chlorophytum malayense(CM) or Ophiopogon bodinieri(OB), and the sand-gravel bed of the river channel, it is important to understand the role of different types of roughness elements in flow resistance. This study was performed to investigate and compare through flume experiments the behaviors of overland flow resistance by the reaction of multi-scale configuration of different roughness elements. The result showed that the resistance coefficient gradually reduced versus the increase of flow rate in unit width and tended to be a constant when q = 3.0 l/s.m, Fr = 1.0, and Re = 4000 for slopes of 6 to 10 degrees. The gap of the vegetated rough bed and the gravel rough bed is limited to the same as the gap of the two types of vegetation, CM and OB. It was noted that the vegetation contributed to the increase in form resistance negatively and may lead to the mean resistance on decrease. To classify the flow pattern, the laminar flows were described by DarcyWeisbach's equation. In the study the f-Re equation of vegetated bed was developed with f ?5000 Re.The friction coefficient for laminar flows can be regarded as the critical value for identifying the transformation point of the flow pattern.

Extraction of cerium(Ⅳ) using tributyl phosphate impregnated resin from nitric acid medium

Tributyl phosphate （TBP） solvent was used for impregnation into Amberlite XAD-16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin （SIR）. Undiluted TBP in a ratio to the resin support （volume to mass） of 6.0 at room temperature （RT） in 24 h was impregnated the resin with a mass ratio of 1.944, while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88. Cerium（Ⅳ） oxide concentrate, prepared from crude Egyptian monazite sand, containing 37% cerium, 1.6% thorium and about 40% the other trivalent rare earth oxides, was used to prepare cerium（Ⅳ） nitrate solution for extraction using the prepared SIR. The impregnated resin was satisfactory for Ce（Ⅳ） extraction from nitric acid medium at room temperature. Cerium loading capacity of the impregnated resin reached 95.6% of the calculated theoretical capacity （173 g/kg （Ce/SIR）） under the conditions of 51.57 g/L cerium and 2.48 g/L thorium, 5.0 mol/L free nitric acid, solution to resin ratio of 10.0 and contacting the phases for 5.0 min. The loading capacity reached 98.75% when cerium concentration was increased to 91.43 g/L under the same conditions.

Potential Role of Feldspathic Sandstone as a Natural Water Retaining Agent in Mu Us Sandy Land,Northwest China

This paper analyzed the water-retention mechanism of feldspathic sandstone （fine-（〈 1 mm diam.） and gravel-sized （2-3 cm diam.） in Mu Us Sandy Land, Northwest China. The objective of this study is to study the effect of feldspathic sandstone amendment on water retention in sandy land. The results showed that as the proportion of fine feldspathic sandstone in the sandy land soil increased, the soil texture changed from sand to silt loam, the capillary po- rosity gradually increased from 26.3% to 44.9%, and the soil saturated hydraulic conductivity decreased from 7.10 ram/rain to 0.07 mm/min. Feldspathic sandstone gravel formed micro-reservoirs in the sandy land soil, playing the role of a ＇water absorbent＇ and ＇water retaining agent＇ in sandy land. Amendment with feldspathic sandstone can increase water retention in the arable layer of sandy land by 67%. This study provides a theoretical basis for the amelioration of sandy land on a large scale. It can be concluded that amendment with feldspathic sandstone can improve the physical properties of sandy land soil and increase soil water retention.

Behaviour of large post-liquefaction deformation in saturated sand-gravel composites

The laboratory tests on the post-liquefaction deformation of saturated sand-gravel composites were performed to investigate the characteristics of stress-strain relation and the dissipation of pore water pressure by the hollow cylinder apparatus. It is found that the stress-strain response and the dissipation process of pore water pressure are composed of three stages, including the low intensive strength stage, the superlinear strength recovery stage and the sublinear strength recovery stage, and the demarcation points of the curve of pore water pressure are lag behind those of the stress-strain response. The comparison results of the behaviour of large post-liquefaction deformation between saturated sand-gravel composites and Nanjing fine sand show that the low intensive strength stage and the superlinear strength recovery stage of saturated sand-gravel composites are shorter while the sublinear strength recovery stage is longer. A stress-strain model and a dissipation model of excess pore water pressure of liquefied sand-gravel composites are established, in which the initial confining pressure and the relative density can be considered synthetically. And it is found that the predicted results by the two models are in good agreement with experimental data.

Erosion and erosion-corrosion of Al-brass alloy: Effects of jet velocity, sand concentration and impingement angle on surface roughness

Effects of jet velocity,sand concentration and impingement angle on the surface roughness of Al-brass alloy were investigated after erosion and erosion?corrosion tests.The tests were performed using a jet impingement rig.The eroded surfaces were characterized using2-D and3-D surface profilometery and scanning electron microscopy(SEM).The results showed that there was an increase in the surface roughness of the erosion?corrosion samples as sand concentration was increased to1,5and10g/L at jet velocities of9,6and3m/s,respectively.However,the surface roughness decreased with a further increase in sand concentration.This decrease in the surface roughness was attributed to the higher work hardening of the surface,rebounding or blanketing effect and very high frequency of the impacts at the higher sand concentrations.The surface roughness increased as the jet velocity increased.The results also showed that the change in the surface roughness with impingement angle was not significant at two jet velocities of3and6m/s.However,at a higher jet velocity of9m/s,formation of ripples on the erosion surfaces at oblique angles resulted in a higher surface roughness as compared with the normal impingement angle.

Effect of nitrite intercalated Mg-Al layered double hydroxides on mortar durability under Cl−and SO_(4)^(2-) coexisting environment

The aim of this paper is to investigate the effect of nitrite intercalated Mg-Al layered double hydroxides(Mg-Al LDH-NO_(2))on mortar durability under the coexisting environment of Cl−and SO_(4)^(2-).Cl−and SO_(4)^(2-) binding properties of Mg-Al LDH-NO_(2) in simulated concrete pore solutions,Cl−and SO_(4)^(2-) diffusion properties of mortars with Mg-Al LDHNO 2 were examined.The steel corrosion and resistance of mortar against SO_(4)^(2-) attack were also evaluated.The results indicate that Mg-Al LDH-NO_(2) can effectively adsorb the Cl−and SO_(4)^(2-) in simulated concrete pore solution,and inhibit the diffusion of Cl−and SO_(4)^(2-) into cement mortars.The presence of SO_(4)^(2-) can greatly affect the uptake amount of Cl−,and there is a coupled effect of Cl−and SO_(4)^(2-) on their penetration into mortar specimens.In addition,Mg-Al LDH-NO_(2) can greatly upgrade the resistance of mortars against SO_(4)^(2-) attack and well prevent the steel from corrosion.However,Cl−will aggravate the SO_(4)^(2-) attack and SO_(4)^(2-) can initially decrease and then increase the steel corrosion.

Transitional geology and its effects on development and longwall mining in Pittsburgh Seam

This paper presents the geologic and ground control challenges that were encountered by Consol Energy＇s coal mining operations in southwestem Pennsylvania, USA. Geologic encounters, such as sandstone- to-limestone geology transition, massive sandstone channels, shale channels, pyritic rich green claystone, laminated roof, and soft floor, have significantly impacted the development and longwall mining in Consol＇s Pittsburgh Seam coal mines. Experience from different mines shows that, in the sandstone-to-limestone geology transition zone, 1.83 m high-tension, fully-grouted primary bolts employed along with 4.88 m cen- ter cable bolts at every other strap greatly improved beam building and ensured proper anchorage into the competent roof. Hydraulic fracturing of the massive sandstone was often necessary to enhance caving of the massive sandstone behind the shields to relieve pressure at the face. The presence of soft floor coupled with presence of thick floor coal and deep cover, induced excessive headgate convergence during retreat of the first right hand longwall panel. In all, it is important to explore the roof and in-seam geology in detail to delineate normal and anomalous geologic conditions prior to and during development. With diligent geologic reconnaissance, geotechnical monitoring, and assessment, site-specific geotechnical solutions have been provided to mine operations to improve safety and productivity.

Study on the cutting plane friction law of sandstone

The friction characteristics of rock damage plane have important impact on the stability of block structure formed after the stratum is broken. The mechanics properties of rock damage plane are described by parameters such as roughness coefficient, wall compress strength and basic friction angle. These three coefficients for fine grain sandstone and medium granular sandstone and grit sandstone are test. The friction stress is researched at the condition of different normal compressive stress acting on the tension damage plane. The friction law of tension damage plane of sandstone abided by is summed up. This law will provide scientific basis for block structure stability judging in basic roof stratum and roof pressure intensity calculating.

Diagenesis and reservoir quality of the fourth member sandstones of Shahejie formation in Huimin depression,eastern China

Petrographic analysis combined with various techniques, such as scanning electron microscopy and X-ray diffraction, was used to assess the timing of growth and original mineral cements, the controls on reservoir and reservoir quality of the fourth member sandstones of Shahejie formation (Es4). The Es4 sandstones are mostly arkose and lithic arkose, rarely feldspathic litharenite, with an average mass fraction of quartz 51.6%, feldspar 33.8% and rock fragments 14.6% (Q51.6F33.8R14.6). They have an average framework composition (mass fraction) of quartz 57.10%, K-feldspar 5.76%, sodium-calcium feldspar 13.00%, calcite 5.77%, dolomite 5.63%, siderite 0.95%, pyrite 0.30%, anhydrite 0.04%, and clay mineral 11.46%. The diagenentic minerals typically include kaolinite, illite-smectite (I/S), illite, chlorite, authigenetic quartz and feldspar, and carbonate and pyrite. Es4 sandstone has undergone stages A and B of eodiagenesis, and now, it is experiencing stage A of mesodiagenesis. Reservoir quality is predominantly controlled by the mechanical compaction, for example, 45.65% of the original porosity loss is related to compaction. The original porosity loss related with cementation is only 26.00%. The reservoir quality is improved as a result of dissolution of feldspar, rock fragment and so forth. The porosity evolved from dissolution varies from 3% to 4%.