1104 results about "Alkali metal oxide" patented technology

A method of making an optical fiber precursor includes generating vapors from an alkali metal source comprising compound containing oxygen and one or more alkali metals and applying the vapors to a surface of a glass article comprising silica at a temperature that promotes diffusion of the alkali metal into the surface of the glass article. An optical fiber has a core comprising silica and an alkali metal oxide of the form X₂O, where X is selected from the group consisting of K, Na, Li, Cs, and Rb, wherein a concentration of the alkali metal oxide along a length of the core is uniform.

Disclosed is an optical fiber having a core with an alkali metal oxide dopant in an peak amount greater than about 0.002 wt. % and less than about 0.1 wt. %. The alkali metal oxide concentration varies with a radius of the optical fiber. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low loss optical fiber may be obtained. Also disclosed are several methods of making the optical fiber including the steps of forming an alkali metal oxide-doped rod, and adding additional glass to form a draw perform. Preferably, the draw preform has a final outer dimension (d2), wherein an outer dimension (d1) of the rod is less than or equal to 0.06 times the final outer dimension (d2). In a preferred embodiment, the alkali metal oxide-doped rod is inserted into the centerline hole of a preform to form an assembly.

Alkaline earth alumino-silicate glass compositions with improved chemical and mechanical durability and pharmaceutical packages comprising the same are disclosed herein. In one embodiment a glass composition may include from about 65 mol. % to about 75 mol. % SiO₂; from about 6 mol. % to about 12.5 mol. % Al₂O₃; and from about 5 mol. % to about 12 mol. % alkali oxide. The alkali oxide may include Na₂O and K₂O. The K₂O may be present in an amount less than or equal to 0.5 mol. %. The glass composition may also include from about 8.0 mol. % to about 15 mol. % of at least one alkaline earth oxide. The glass composition is susceptible to strengthening by ion-exchange thereby facilitating chemically strengthening the glass to improve the mechanical durability.

A glass article may formed from a glass composition that may include from about 70 mol. % to about 78 mol. % SiO₂, from about 3 mol. % to about 13 mol. % alkaline earth oxide, X mol. % Al₂O₃, and Y mol. % alkali oxide. The alkali oxide may include Na₂O in an amount greater than or equal to about 9 mol. % and less than or equal to about 15 mol. %. The ratio of Y:X may be greater than 1. The glass article may be free of boron and compounds of boron. The glass article may have a compressive stress layer with a compressive stress greater than or equal to about 250 MPa and depth of layer greater than or equal to about 25 μm. The glass article may have at least a type HGA2 hydrolytic resistance according to the ISO 720 standard.

Disclosed is an optical fiber having a silica-based core comprising an alkali metal oxide a silica-based core, said core comprising an alkali metal oxide selected from the group consisting of K₂O, Na₂O, LiO₂, Rb₂O, Cs₂O and mixtures thereof in an average concentration in said core between about 10 and 10000 ppm by weight, and a silica-based cladding surrounding and directly adjacent the core, the cladding including a region having a lower index of refraction than the remainder of such cladding. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low loss optical fiber may be obtained which exhibits a cable cutoff less than 1400 nm chromatic dispersion at 1550 nm between about 13 and 19 ps/nm/km, and a zero dispersion wavelength less than about 1324 nm.

The invention relates to a method for synthesizing IM-5 molecular sieve, which comprises the following steps: 1) dissolving inorganic base, aluminum source and a template in deionized water, uniformly mixing; 2) adding silicon source in a mixture obtained in the step 1), adding an additive or not to prepare colloid or a solid-liquid mixture, uniformly mixing; 3) moving the colloid or the solid-liquid mixture obtained in the step 2) to a crystallization kettle, carrying out hydrothermal dynamic crystallization at the temperature of 120-200 DEG C for 1-10 days, cooling after finishing the crystallization, washing the obtained mixed liquor, filtering and drying to obtain the IM-5 molecular sieve raw powder; wherein the mole ratio of the reactant is SiO2: Al2O3:M2O: R: H2O with 60: (0.3-6): (6-20): (0.6-18): (300-1800), M2O is alkali metal oxide and R is the template. The method of the invention has the advantages that IM-5 molecular sieve crystallization time is shortened, the raw material ratio range is wide, the single kettle yield is enhanced and the industrial amplification can be achieved.

The invention relates to a jade-type glass-ceramic and a preparation method thereof. The jade-type glass-ceramic contains a main crystal phase and can also contain a secondary crystal phase, wherein the maximum crystallite dimension of the secondary crystal phase is equal to or smaller than visible wavelength, the jade-type glass-ceramic contains the following components in percentage by weight: 45.0-75.0% of SiO2, 1.0-25.0% of Al2O3, 0-20.0% of alkaline earth metal oxide, 3.0-15.0% of alkali metal oxide, 0-4.0% of TiO2, 0-2.5% of ZrO2, 0-8.0% of F and the balance of flux and clarifier. The preparation method of the jade-type glass-ceramic comprises the steps that the main raw materials and the auxiliary materials are mixed uniformly and then are melted at high temperature to form molten glass, then the molten glass is thermally treated after being cooled and molded so as to form an organization structure beneficial to the penetration of the visible light part in molten glass, and after thermal treatment, the glass-ceramic is in a semitransparent neftdegil shape and becomes a jade-type glass-ceramic. The jade-type glass-ceramic has delicate texture, is translucent, can be widely used as a decorative plate, and can also be carved into handicrafts and prepared into tableware and sanitary ware.

A sealing glass composition which has an alkali metal oxide content kept down as much as possible, and can stably join metal or ceramic members together in a temperature range of 600 to 900° C. The sealing glass composition is used to join together members each selected from the group consisting of metal members and ceramic members, and comprises, as essential components, 20 to 50 mol % of SiO₂, 1 to 9 mol % of Al₂O₃, 5 to 25 mol % of B₂O₃, 10 to 40 mol % of BaO, and 5 to 20 mol % of SrO. ZnO content is 0 to 10 mol %. An alkali metal oxide content is not more than 5 mol %. PbO is substantially not contained. The total content of MgO, CaO, SrO, BaO and ZnO is 30 to 50 mol %.

The invention relates to a propane dehydrogenation to propylene catalyst and preparation and applications thereof. The propane dehydrogenation to propylene catalyst is characterized by being a composition prepared from Gamma-Al2O3, a kind or many kinds of chromium oxides, a kind or many kinds of rare earth oxides and a kind or many kinds of alkali metal oxides, wherein the Gamma-Al2O3 accounts for 30-95%, the chromium oxides account for 1-50%, the rare earth oxides account for 0-30%, and the alkali metal oxides account for 0-10%. The preparation process comprises the following steps of: adding active components, such as chromium, rare earth, alkali metal and the like into aluminum oxide grout, regulating the pH value of 1-5 to form gelatum with concentrated nitric acid, and spraying and drying to form microballoons; then roasting for 0-5 hours at 250-750 DEG C in a nitrogen atmosphere; and roasting for 0.1-20 hours at 250-1000 DEG C in an air atmosphere. The obtained catalyst is in a fluid bed reactor, and reaction conditions comprise 400-700 DEG C of temperature, 0.01-3MPa of absolute pressure and 10-10000 h-1 of volume hourly space velocity.

A metal oxide nanoporous material comprises two or more kinds of first metal oxides selected from the group consisting of alumina, zirconia, titania, iron oxide, rare-earth oxides, alkali metal oxides and alkaline-earth metal oxides. The metal oxide nanoporous material has nanopores, each with a diameter of 10 nm or smaller, in which the metal oxides are dispersed homogeneously in the wall forming the nanopores.

Disclosed is a glass material essentially free of BaO and alkali oxide particularly suitable for the glass substrate of LCDs. The glass material consists essentially, expressed in mole percent on an oxide basis, of 70–80%, preferably 72–77% of SiO₂, 3–9%, preferably 4–7% of Al₂O₃, 8–18%, preferably 10–16% B₂O₃, 3–10%, preferably 3–8% of CaO, 0–4%, preferably 0–3% RO, 0–0.2%, preferably 0–0.1% SnO, 0–1%, preferably 0 to 0.5% of XO, where RO represents, collectively, MgO, SrO and ZnO, XO represents, collectively, TiO₂, ZrO₂, Y₂O₃ and La₂O₃. The glass has a strain point in the range of over about 600° C., a coefficient of thermal expansion (CTE) in the range of about 23–35×10⁻⁷/° C., a density lower than about 2.35 g/cm³, a liquidus temperature lower than or equal to about 1200° C. and a durability in BHF less than or equal to 0.5 mg/cm² weight loss.

The embodiments described herein relate to chemically and mechanically durable glass compositions and glass articles formed from the same. In another embodiment, a glass composition may include from about 70 mol. % to about 80 mol. % SiO₂; from about 3 mol. % to about 13 mol. % alkaline earth oxide; X mol. % Al₂O₃; and Y mol. % alkali oxide. The alkali oxide may include Na₂O in an amount greater than about 8 mol. %. A ratio of Y:X may be greater than 1 and the glass composition may be free of boron and compounds of boron. In some embodiments, the glass composition may also be free of phosphorous and compounds of phosphorous. Glass articles formed from the glass composition may have at least a class S3 acid resistance according to DIN 12116, at least a class A2 base resistance according to ISO 695, and a type HGA1 hydrolytic resistance according to ISO 720.

The invention provides a catalyst for alkane dehydrogenation as well as a continuous reaction regeneration device and method using the catalyst for catalytic dehydrogenation. The catalyst comprises four ingredients, the ingredient A is oxides of one kind of element or several kinds of elements from Ti, Nb, Ta, Mo, W, Re, In or Ga, the ingredient B is one kind or several kinds of materials in MgO, P2O5, ZrO2, Al2O3 or SiO2, the ingredient C is oxides of one kind of material or several kinds of materials from Zn, Cd and Sn, and the ingredient D is one kind of material or a mixture of several kinds of materials from alkali oxides or alkaline earth metal oxides. The catalyst does not contain noble metal such as Pt and the like, does not contain toxic ingredients such as Cr and the like and cannot pollute the environment. The activity of the catalyst is high, the selectivity of olefin generated by alkane dehydrogenation is high, the stability of the catalyst is good, the mechanical intensity is high, the continuous reaction regeneration device is used for alkane dehydrogenation, the reaction and the catalyst regeneration are continuously carried out, the efficiency is high, and the safety is high.

Disclosed is an optical fiber having a silica-based core comprising an alkali metal oxide selected from the group consisting of K₂O, Na₂O, LiO₂, Rb₂O, Cs₂O and mixtures thereof in an average concentration in said core between about 50 and 500 ppm by weight, said core further comprising chlorine and fluorine, wherein the average concentration of fluorine in said core is greater than the average concentration of alkali metal oxide in said core and the average concentration of chlorine in said core is greater than the average concentration of alkali metal oxide in said core; and a silica-based cladding surrounding and directly adjacent the core. By appropriately selecting the concentration of alkali metal oxide dopant in the core and the cladding, a low loss optical fiber may be obtained.

An IM-5 molecular sieve synthesis method comprises the following steps: 1, dissolving an inorganic alkali, an aluminum source and a template in deionized water, and uniformly mixing to prepare a mixed solution; 2, adding a solid silica gel to the mixed solution obtained in step 1, adding a template precursor, and uniformly mixing to prepare a colloid or a solid-liquid mixture; and 3, transferring the colloid or solid-liquid mixture obtained in step 2 to a crystallization kettle, carrying out hydrothermal crystallization for 1-10 days, cooling after the crystallization to obtain a mixed liquid, and washing, filtering and drying the mixed liquid to obtain raw IM-5 molecular sieve powder, wherein reactants comprise SiO2, Al2O3, M2O, R, A and H2O, a molar ratio of SiO2:Al2O3:M2O:R:A:H2O is 60:(0.3-6):(6-20):(4-15):(1.2-6):(300-1200), M2O is an alkali metal oxide, R is the template, and A is the template precursor. The IM-5 molecular sieve synthesis method has the advantages of good product repeatability, effective reduction of the water content, increase of the concentration of the template, crystallization time shortening and single kettle yield increase.

The invention relates to glasses and glass ceramics including a metal oxide concentration gradient. Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0t up to 0.3t and from greater than 0.7t, comprise a tangent that is less than about -0.1 MPa/micrometers or greater than about 0.1 MPa/micrometers, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0t to about 0.3t). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness. Methods for forming such glass-based articles are also disclosed.

The invention refers to a kind of catalyst in organic waster gas purification. It is made up of honeycomb pottery carrier and the paint layer on the carrier, and the precious metal active components. The layer has characters such as stable paint layer, excellent high temperature resistant performance, the efficiency is high. The paint layer is made up of Al2O3, SiO2 and a one kind of or more alkali metal oxide. The paint layer combines with the honeycomb pottery carrier stably.

The invention provides a technology device and method for preparing propylene by dehydrogenating propane or propane-enriching low carbon hydrocarbon. The device comprises a reacting/regenerating part and a product fractionating part. A reacting/regenerating system is divided into a parallel type arrangement scheme and a coaxial type arrangement scheme by a fluidized bed reacting/regenerating technology, wherein a raising pipe of the parallel type reacting/regenerating system is an internal or external raising pipe, and a raising pipe of the coaxial type reacting/regenerating system is an external raising pipe. The method comprises the steps: leading raw materials and reaction products to enter into a raising pipe reactor after heat exchange; performing a dehydrogenating conversion reaction under the conditions that the reaction temperature is 500-700 DEG C, the pressure is 0.1-0.4MPa, and the ratio of a microspherical catalyst to oil is 5-60, wherein the microspherical catalyst consists of chromium, rare earth oxides, alkali metal oxides and a gamma-Al2O3 carrier, preferably, the temperature is 550-670 DEG C, the pressure is 0.1-0.15MPa, and the ratio of the microspherical catalyst to oil is 6-14; leading the reaction products and the raw materials to enter into a gas-oil separator to separate a gas phase, a liquid phase from a water phase after heat exchange and cooling; leading the separated gas to enter into a gas compressor to be compressed and be transported to an absorbing/stabilizing part; pumping the liquid to an absorbing tower; transporting the liquefied gas from a return tank at the top of a stabilizing tower to a propylene/propane separating tower by a charging pump of a propylene tower; discharging the fine propylene separated from the top of the tower out of the device as a product; discharging the separated byproduct hydrogen out of the device; and returning products at bottom of the tower to the reacting/regenerating part to be recycled.