34 results about "Low gradient" patented technology

A low pressure gradient prosthetic heart valve for implant in a human. The valve includes a support frame with undulating inflow cusps and outflow commissure posts to which flexible leaflets attach and coapt in a flow area. The commissure posts angle outward in a neutral state to widen the outflow orifice area. Also, the leaflets are designed to fit within the support frame and expand outward in a valve open state without creating a shelf or belly that would restrict flow.

The invention discloses a processing method for correcting error of a low-gradient optical mirror surface, which comprises the following steps: firstly acquiring a removal function through experiment, then using a wave surface interferometer to acquire a surface shape error function of an element, dispersing the surface shape error function, programming a processing path at the same time, extending the surface shape error function, establishing a model and solving processing residence time, carrying out numerical control processing by using the solved residence time, identifying error and controlling accuracy for the processed result, so as to finish processing. The processing method has the advantages of high process efficiency, low processing cost and good error correction effect, and can effectively correct the surface shape error of the low-gradient optical mirror surface.

A normal temperature low-ammonia-nitrogen nitrosation starting method belongs to the field of urban sewage treatment and reclamation. Researches show that nitrosation starting can be achieved in short time by controlling condition of low dissolved oxygen (DO=0.30mg/L) and inoculating sludge with certain nitrosation effect. If whole course nitration sludge is inoculated, no accumulation of nitrite occurs within 30 days in a water distribution test, no accumulation of nitrite occurs in 30 days in a reactor which utilizes the A/O dephosphorization process processing water as a research object, and the nitrosation starting fails accordingly. Nitrite accumulation can occur by adopting the mode of high-low gradient oxygen limit culture, domesticating the sludge for 10 days under the condition that DO=0.70-0.80mg/L, then controlling condition of low dissolved oxygen (0.30-0.40mg/L) to enable the reactor to discharge water if the whole course nitration sludge is inoculated. Over 90% of nitrosation rate can be achieved within 38 days by continuously domesticating the sludge under the condition of the dissolved oxygen, so that nitrosation can be successfully started.

The invention discloses a forest fire smoke detection method based on image segmentation, and belongs to the field. Most traditional forest fire hazard smoke detection algorithms only consider fire hazard detection under an ideal background, analyze images on a pixel level, and are not necessarily suitable for smoke identification under complex environments such as forests. A forest fire smoke detection method based on image segmentation sequentially comprises the following steps of initializing a color image in a CIELAB space a clustering center; moving the clustering center to the lowest gradient of a 3 * 3 neighborhood; performing distribution; updating; when each pixel is classified to the nearest cluster center, updating the cluster center by using the average value of vectors of allpixels in the region; merging the isolated pixel points into the nearest super pixel; combining the superpixels; segmenting the sky and the ground; performing smoke recognition. The limitation that acamera needs to be fixed in a traditional forest fire smoke detection algorithm is broken through, and the method is suitable for dynamic panoramic sampling of the camera on a forest.

The invention relates to a light trap adopted epitaxial material structure of an ultrafine divergent angle high-power semiconductor laser, which comprises a substrate, a buffer layer, an N-type lower limiting layer, a lower gradient light trap layer, an upper gradient light trap layer, an N-type upper limiting layer, an N-type gradient waveguide layer, a quantum well active area, a P-type gradient waveguide layer, a P-type limiting layer and an electrode contact layer, wherein the substrate is used for carrying out the epitaxial growth of all layers of materials of a laser; the buffer layer is prepared on the GaAs substrate; the N-type lower limiting layer is prepared on the buffer layer; the lower gradient light trap layer is prepared on the N-type lower limiting layer; the upper gradient light trap layer is prepared on the lower gradient light trap layer; the N-type upper limiting layer is prepared on the lower gradient light trap layer; the N-type gradient waveguide layer is prepared on the N-type lower limiting layer; the quantum well active area is prepared on the N-type gradient waveguide layer; the P-type gradient waveguide layer is prepared on the quantum well active area; the P-type limiting layer is prepared on the P-type gradient waveguide layer; and the electrode contact layer is prepared on the P-type limiting layer.

The invention relates to a differential trajectory jet energy dissipater in an absorption basin, belonging to the field of engineering hydraulics. The differential trajectory jet energy dissipater comprises the absorption basin and a differential triangular flip bucket energy dissipater arranged in the absorption basin, wherein the differential triangular flip bucket divides the absorption basin into a front basin and a rear basin; and the flip position thereof can be changed in the range of one fourth to two thirds of the length of the absorption basin. The up gradient of the upstream face of the differential triangular flip bucket is incontinuous, the part with higher gradient is a main flip bucket, the part with lower gradient is a trajectory jet groove, and the downstream gradient of the differential triangular flip bucket is continuous. The differential trajectory jet energy dissipater in the absorption basin not only shortens the length of the absorption basin and contributes to the saving of construction cost, but also increases the efficiency of energy dissipation, and has the extremely high ability of anti-cavitation. The differential trajectory jet energy dissipater can be used singly in any normal absorption basin and can also be combined with other assistant energy dissipaters in the normal absorption basin.

A golf ball having an inner core layer having an outer surface and a geometric center and being formed from a rubber composition. An outer core layer surrounds the inner core to form a dual core. An inner cover layer surrounds the dual core, and includes a high-acid ionomer having a hardness of about 66 to 75 Shore D and an acid content of 16 wt. % or greater. An outer cover layer surrounds the inner cover layer, and includes a polyurethane and having a material hardness of about 38 to 56 Shore D. The inner core layer surface hardness is from 0 Shore C to 10 Shore C lower than the geometric center hardness to define a negative hardness gradient and the outer core layer has a surface hardness at least 10 Shore C greater than the geometric center hardness to define a dual core positive hardness gradient.

The invention discloses a river discharge comprehensive measuring and calculating method and system in the technical field of hydrologic survey and aims at solving the technical problems that a discharge online measurement method is high in cost and low in measurement accuracy in the prior art. The river discharge comprehensive measuring and calculating method comprises the following steps: setting up a water level master station, a representative flow velocity station and a water level auxiliary station, acquiring actually measured water level of a cross section, an elevation of the lowest point of a river bottom of the cross section, rate of rise and fall of the water level of the cross section, actually measured flow velocity of a water surface at a representative point as well as waterlevel difference of upper and lower gradient cross sections, substituting the acquired data into a river discharge comprehensive measuring and calculating model, and calculating and obtaining river cross-section discharge.

The invention discloses a tap-hole filling material, main raw materials of which are quartz sand, sintered magnesia clinker and waste and old magnesia-chromite bricks and auxiliary materials of which are a carburant and a sintering aid. The raw materials contain, by weight, 25-45% of quartz sand, 30-60% of sintered magnesia clinker, 10-35% of waste and old magnesia-chromite bricks, 0-2% of the carburant and 0-11% of the sintering aid. A filling method of the tap-hole filling material comprises the following step: more than one tap-hole filling material with different ratios undergoes layered filling according to contents of the carburant and the sintering aid from low gradient to high gradient, and the contents of the carburant and the sintering aid at the bottom layer are the lowest. Through compounding of the main raw materials and the auxiliary materials and layered gradient filling, fluidity, sintering property and pouring rate of the filling materials are raised, limitations such as poor fluidity, low free-opening rate and the like of existing tap-hole filling materials are overcome, and technological requirements of converter tapping are met. In addition, cost is low.

A photovoltaic waterproof system used for a low-gradient roof comprises a supporting structure, sealing strips and flow guide strips. The supporting structure is composed of multiple section bars. Each section bar comprises a section bar body and clamping hooks on the section bar body. Each sealing strip is arranged between the two corresponding section bar bodies. Each sealing strip comprises a plunger and a first umbrella sheet kept being connected with the two corresponding section bar bodies in an abutting manner. A second umbrella sheet of a V-shaped structure is further arranged on eachplunger. The edge of each second umbrella sheet is connected with the corresponding section bar bodies in an abutting manner, and a first flow guide groove is formed among each plunger, the corresponding second umbrella sheet and the corresponding section bar body. Each flow guide strip is arranged on the end portion of the corresponding sealing strip. When rainwater seeps in the photovoltaic waterproof system, because the second umbrella sheets are connected with the section bar bodies in the abutting manner, water seeping into every two corresponding section bar bodies is guided through thecorresponding first flow guide grooves to flow into the corresponding flow guide strips, the first flow guide grooves formed through the sealing strips are more convenient to implement, and the construction quantity of supporting structure laying is decreased. The flow guide strips arranged on the end portions of the sealing strips can converge the water flowing out of the sealing strips togetherand guide the water to be discharged out of the roof.

A maternal-fetal blood group incompatibility immunosorbent therapy apparatus used in the medical field is characterized in that a blood separator and a plasma adsorber are connected through a circulation line to form a cardiopulmonary bypass adsorption device, wherein the blood separator is used for separating blood cells and plasma, as the separated plasma flows through and filters through the plasma adsorber, wherein the pathogenic antibody is adsorbed, the filtered plasma is combined with the separated blood cells and then re-enters a cardiopulmonary bypass adsorption device for circulatingadsorption to achieve the purpose of cleaning the pathogenic antibody, and the plasma adsorber is filled with a solid-phase carrier coated with blood group antigen or anti-blood group antibody with high to low gradient titer from an inlet to an outlet in a layered manner.

In a method and magnetic resonance (MR) apparatus for generating scan data of an examination object, radiation of RF pulses, activation of gradients, and reading out of MR signals generated by the radiated RF pulses and the activated gradients occur according to a pulse sequence. The signals that are stored as scan data. Repetition of the pulse sequence activating respective other gradients takes place until all the desired scan data are stored, wherein for determined repetitions, no gradients are activated. By the performance of repetitions in which no gradients are switched, a minimum repetition time, which is restricted by the utilized gradient unit due to hardware limitations thereof, can be further reduced. Thus repetition times can be selected more freely, e.g. according to a desired contrast, including on magnetic resonance systems with a low gradient output.

The present invention relates to a high performance aqueous phase polymer fluid, which is a seawater-based drilling fluid for well drilling in low gradient formations. It is formulated based on liquid state polymer chemical products, easy to aggregate, and quickly mixed; a preparation and homogenization that reduces preparation times, designed to drill hydrocarbon-producing deposits, focusing on minimizing damages to the producing formations, with a high rate of circulation loss in naturally-fractured deposits. The system is environmentally-friendly, it complies with the required main functions of the drilling fluids while also providing a high inhibition control by swelling and dispersion of clay zones, due to the polymeric nature of the materials with which it is formulated. It is a fluid that does not contain solids in its formulation and provides an excellent transport and cleaning of the drilling shears in the well.

The invention relates to a fuel tank with a gradient meter. The fuel tank with the gradient meter comprises a fuel tank body and a gradient meter. The gradient meter is fixed on the oil tank body; theslope meter comprises an accelerometer, a gyroscope and a display device; the accelerometer is used for detecting the inclination angle of the tank body; the gyroscope detects the change of the angular acceleration, and gives the display device a matching gear and a gradient according to the change of the angular acceleration. The invention has the advantages that the fuel tank with the gradientmeter can provide a matching gear when driving on the high and low gradient road surface, thus ensuring the safe driving of the new rider, so that the new rider can master the driving technology morequickly.

The invention discloses a method for reducing and controlling bamboo forest nitrogen runoff loss by utilizing charcoal and buffer zone coupling and belongs to the field of agroecological environment protection. The method comprises a step (1) of applying charcoal: applying the charcoal in a runoff producing area of a bamboo forest, wherein the application quantity of the charcoal is 0.5-3 kg/m2; a step (2) of arranging a buffer zone: lining out the buffer zone at the low-gradient water discharging end of a bamboo forest runoff area, wherein the specification design of the buffer zone is that the length is consistent with the length of the runoff area and the width is 0.5-3.5 m, and planting lolium perenne, cynodon dactylon or zoysia japonica in the buffer zone. Based on a charcoal and buffer zone coupling technology, the effect of applying the method to an intensively managed bamboo forest to reduce and control the soil nitrogen runoff loss is monitored, mechanism analysis is performed, so that the bamboo forest soil nitrogen runoff loss is reduced from two links which are source decrement and process blockage more effectively, and the goal of improving utilization efficiency of nitrogen fertilizer input into the bamboo forest and protecting the water environment is achieved.