206results about How to "Realize the package" patented technology

The invention discloses a fiber with multiple core-shell structures. The fiber is provided with the multiple core-shell structures. The diameter of the fiber is 10 microns to 1*106 microns, and the length of the fiber is more than one 1 micron. The cross section of the fiber is in a circular shape or a hollow ring shape. The invention further provides a preparation method of the fiber. With the structure, the fiber with the multiple core-shell structures is controllable in morphology and structure, and the preparation method is convenient and fast to operate, and designability and piratical applicability of the fiber are strong. Packaging miscellaneous nano particles, medicines or living cells can be achieved. The fiber with the multiple core-shell structures can be applied in the fields of cell cultivation, medicine sustained release, tissue engineering and the like.

The invention discloses a branched polyethylene glycol iso-bifunctional derivative, as well as a preparation method and a two-component biological related substance conjugate thereof. The structure ofthe branched polyethylene glycol iso-bifunctional derivative is shown as a general formula (1) and contains i (more than or equal to 2) alkoxy-terminated PEG chains, U is a branched center of a valence state i+1, Ld does not exist or becomes a bivalent linking group, and the iso-bifunctional end is composed of a trivalent branched center G and two different functional ends F1 and F2 and respectively independently contains a plurality of functional end groups R01 and R02 of the same type. Two functional groups of the branched polyethylene glycol iso-bifunctional derivative are positioned on the same side of the branched polyethylene glycol component, a product of the conjugated biological related substance is a branched polyethylene glycol two-component biological related substance, the functional groups are conjugated with two different biological related substances and are uniformly distributed on the same side of the polyethylene glycol component, and the derivative is capable of improving properties of targeted drugs, optically marked drugs and the like and is expected to be applied to the field of drug combination. The structural formula is as shown in the description.

The invention belongs to the technical field of industrial winding machines, and particularly discloses a fish paper wrapping device, which comprises a support plate. The fish paper wrapping device is characterized in that: one side of the support plate is provided with a tape capturing mechanism, and the other side of the support plate is provided with a fish paper box supporting plate and a tape transmission device; a fish paper box is arranged on the fish paper box supporting plate; a cutting device is arranged on the middle part of the support plate; a rotating shaft is arranged above the support plate; and a coil skeleton is fixedly arranged on the rotating shaft. In the fish paper wrapping device, fish paper is adhered to a tape by utilizing the viscosity of the tape at the same time of wrapping of the tape on the coil skeleton, and is wrapped on a coil when the coil on the device is wrapped with the tape so as to realize the wrapping of the fish paper. The fish paper wrapping device has the advantages of high degree of automation, high efficiency, high reliability, high consistency and low labor cost.

The invention discloses a metal-organic framework-phenolic resin composite material and a method for preparing the same, and belongs to the field of material chemistry. The metal-organic framework-phenolic resin composite material comprises metal-organic frameworks, phenolic resin or phenolic resin precursors. A mass ratio of the metal-organic frameworks to the phenolic resin or the phenolic resin precursors is 1:(0.5-10). The metal-organic framework-phenolic resin composite material and the method have the advantages that the metal-organic frameworks are used as cores for the metal-organic framework-phenolic resin composite material, the phenolic resin is used as a shell for the metal-organic framework-phenolic resin composite material, accordingly, porous materials can completely wrap the metal-organic frameworks, and the problems that existing metal-organic frameworks grow on the outer surfaces of existing porous materials and phase separation appears on composite materials can be effectively solved; the wall thickness, namely, the thickness of the phenolic resin, of the metal-organic framework-phenolic resin composite material prepared by the aid of the method can be completely regulated and controlled according to the quantity of the added phenolic resin precursors, and accordingly the hydrothermal stability and the structural stability of the metal-organic frameworks can be effectively enhanced.

The invention provides a preparation method of a microcapsule for preparing a temperature-adjusting textile product. The preparation method comprises the following steps: mixing mixed liquid of sodium alginate and calcium carbonate, paraffin and a water-oil composite emulsifying agent, and performing emulsifying reaction to obtain oil-in-water emulsion; mixing the obtained oil-in-water emulsion, petroleum ether and an acidic solvent, and performing curing reaction to obtain a primary microcapsule; performing condensation reaction on the obtained primary microcapsule and a chitosan acidic solution to obtain the microcapsule for coating the surface of the textile product. Results of embodiments show that after the temperature-adjusting textile product, of which the surface is coated with the microcapsule prepared by the method, is washed with water for 1 to 5 times, the mass loss rate is lower than 5 percent, so that the firmness of a phase-change material and a base fabric is high.

The invention discloses a preservation solution of a time-resolved fluorescent microsphere labeled myoglobin antibody. The preservation solution is prepared from the following components in percentage by mass: 0.1 percent to 1.5 percent of 4-(2-hydroxyethyl)piperazine-1-erhanesulfonic acid, 1.0 percent to 3.0 percent of sodium chloride, 0.3 percent to 0.8 percent of potassium chloride, 0.08 percent to 0.9 percent of disodium ethylene diamine tetraacetate, 0.01 percent to 0.06 percent of sodium dodecyl sulfonate, 0.1 percent to 3.0 percent of bovine serum albumin, 0.05 percent to 0.5 percent of glucan, 0.02 percent to 0.2 percent of triton, 0.01 percent to 0.05 percent of Tween-20, 0.02 percent to 0.1 percent of a preservative and the balance of water; the pH (Potential of Hydrogen) is adjusted to be 8.0 to 9.0. The preservation solution has the advantages that the raw materials are low in cost and easy to obtain, and a relatively stable microenvironment is provided for preservation of fluorescent microspheres.

The invention discloses a preparation method of silicon dioxide coated crystal water-salt phase-change material microcapsules. The preparation method comprises the steps of regulating the pH of saturated crystal water and a salt solution to the range of 8-10, mixing the saturated crystal water and the salt solution with a surfactant and an organic solvent and stirring for 2-3 hours at a temperature within the range of 40-50 DEG C, thereby obtaining a W / O emulsion, next, dropwise adding a silicon dioxide precursor to the obtained emulsion and stirring for reacting at a room temperature for 20-30 hours, and finally, centrifuging, washing and drying the precipitate obtained through the reaction, thereby obtaining the finished product. The preparation method is simple in process and does no need high-temperature calcination; the preparation process is safe, and the obtained microcapsules are good in tightness and easy to adjust in particle size. The crystal water and the salt are taken as the core materials, and compared with other phase-change materials, the core materials are easily available and low in prices and have great latent heat of phase change.

The invention belongs to the field of fluorescent materials and particularly relates to an indium-based metal organic framework wrapped functional positive ion Ru(bpy)32+ fluorescent material. The indium-based metal organic framework wrapped functional positive ion Ru(bpy)32+ fluorescent material is characterized in that the molecular formula of the fluorescent material is In(BTB)(OA)1 / 2Ru1 / 2(bpy)3 / 2, wherein BTB is 1,3,5-tri(4-carboxyl phenyl) benzene, OA is oxalic acid and byp is 2,2'-bipyridine. The indium-based metal organic framework wrapped functional positive ion Ru(bpy)32+ fluorescent material provided by the invention not only retains excellent properties of an indium-based metal organic framework, but also can change the fluorescent service life of the fluorescent material in an organic ligand framework, so that a purpose of prolonging the fluorescent service life of Ru(bpy)32+ to [mu]s level is achieved. The preparation method is simple in process and easy to operate.

The invention discloses a patient wound anti-bleeding alarm device for the burn department. The device comprises an abdomen bandage, connecting cloth, a supporting pad, an anti-compression air cushion, fixed cloth, a fixing base, an alarm, a switch, a fixed cylinder, a connecting hose, a metal sliding block, a spring, a leakage hole and a metal sensor. By means of the patient wound anti-bleeding alarm device for the burn department, constraint and anti-compression protection can be conducted on the burnt limb of a patient, and the problems that the patient moves the arm unconsciously, accordingly the burn wound is torn, and the wound cracks and bleeds due to skin flap separation are solved; early warning and monitoring of the burnt limb of the patient can be achieved with the cooperation of a built-in detection and alarm mechanism, secondary damage, caused by external extrusion, to the burnt limb can be effectively prevented when the bedridden patient turns over. Therefore, the limb protection of the burnt patient after an operation is greatly improved, the workload of medical staff is reduced, and clinical application and popularization are facilitated.

The invention relates to a quantum dot / polymer microsphere composite material. The material is characterized by comprising quantum dots and polymer microspheres, the polymer microspheres physically encapsulate the quantum dots, and the quantum dots are dispersed inside balls of the polymer microspheres. The invention also provides a preparation method and application of the quantum dot / polymer microsphere composite material. The material achieves the physical encapsulation protection of the quantum dots by the polymer microspheres, ensures the stability of the long-term use of the quantum dotsand the stability of the optical performance of a quantum dot backlight diaphragm as a whole, avoids the reduction or structural damage of the performance of the quantum dots caused by chemical changes, and ensures that the quantum dot luminescence efficiency and fluorescence efficiency of the quantum dot / polymer microsphere composite material are not affected.

The invention relates to an underactuated finger combination mechanism for changing enveloping space by radially adjusting swing rod fulcrums. The underactuated finger combination mechanism mainly comprises three finger grabbing assemblies and an enveloping space adjusting assembly, wherein each finger grasping assembly comprises a driving push rod and three knuckles, the three knuckles can be sequentially attached to the upper part, the middle part and the lower part of an object under the driving of the driving push rod, and the three finger grasping assemblies work at the same time to graspthe object in the enveloping space. The grabbing assembly of an underactuated structure can grab objects of different shapes and sizes in a self-adaptive mode, the underactuated structure is simple and compact in structure, light in weight and low in cost, a lead screw of the enveloping space adjusting assembly can drive a lifting adjusting plate to move up and down, a second connecting rod hinged to the first knuckle pulls a first connecting rod to move in a guide hole in the radial direction to change the radial position of the fulcrum at the lower end of the first knuckle, and therefore the size of the enveloping space among the three finger grabbing assemblies is changed, and the underactuated finger mechanism has self-adaptability and flexibility when grabbing an object.

The present invention relates to the field of living furniture, in particular to a massage chair, comprising a base, and a seat body movably arranged on the base; the seat body is connected to the base through a swing device, which is a non-electric swing device; the swing The device includes a lower base, an upper base, an elastic assembly for adjusting the hinge angle between the upper base and the lower base, and a first limiting part, and the elastic assembly and the first limiting part are respectively located on both sides of the rotating shaft. Compared with the prior art, the massage chair proposed by the present invention realizes the tilting and rocking function of the chair body due to the non-electric rocking device installed under the seat body, improves the comfort, flexibility and fun of the massage chair, and overcomes the It overcomes the defect of single function of the traditional massage chair, and adopts the non-electric swing device with simple accessories. First, it is convenient for maintenance and lowers costs. Second, it is convenient for users to operate. Therefore, it can be used for more consumer groups and can be used for home and office use. , with a better market prospect.

The invention belongs to the technical field of catalytic material, and discloses a core-shell structure nanometer copper cerium composite oxide catalyst, and a preparation method and applications thereof. The core-shell structure nanometer copper cerium composite oxide catalyst can be used for ammonia selective catalytic oxidation reaction. Catalyst synthetic conditions are adjusted, so that control on copper oxide particle surface local hydrolysis reaction is realized, regulation and control on cerium oxide outer wall generation and copper oxide particle etching degree are realized, and at last, the CuO@CeO2 core-shell structure composite material taking mesoporous structure CeO2 as the shell is obtained. The catalyst possesses excellent ammoxidation activity and N2 selectivity, and highreaction stability; the preparation method is simple, reliable, and high in efficiency; the raw materials are easily available; and the preparation method is convenient for large scale preparation.

The invention relates to a ceramic modified PTFE composite dielectric material with low dielectric constant and low thermal expansion. The PTFE composite material comprises PTFE and non-solid ceramicparticles, wherein the use amount of the non-solid ceramic particles is 1-60% of the overall volume fraction of the composite material, the dielectric constant of the modified PTFE composite dielectric material is 2.0-2.5, and the thermal expansion coefficient is 40-120 ppm / DEG C. The modified PTFE composite dielectric material has a low dielectric constant and a low thermal expansion coefficient.

The invention relates to a slow-release patch used for external application and prepared from natural tobacco extracts (nicotine as the main component). The slow-release patch is prepared from the natural tobacco extracts and proper auxiliary materials and is used for achieving the aim of slowly releasing nicotine according to a particle slow-release principle. The nicotine slow-release patch provided by the invention comprises a back lining layer, a medicine-contained paste body and a cover lining layer, wherein the medicine-contained paste body is prepared from auxiliary materials such as nicotine micelle, an adhesive, a filling agent, a transdermal enhancer, a humectant and the like according to a certain ratio; each patch contains 20-40mg of nicotine. The nicotine slow-release patch has the characteristics of slow release, rapidness in taking effects, good moisture retention and air permeability, comfort in use and the like.

The invention provides a method for preparing an arsenic-cadmium passivator, the arsenic-cadmium passivator prepared through the method and an application. The preparation method comprises the following steps that an aluminosilicate material is mixed with an activating agent and a fluxing agent, and then undergoes high-temperature roasting treatment; the roasted material, ferric salt and manganesesalt are added into water, and the system pH value is adjusted for reaction; and solid-liquid separation is performed, the obtained solid is dried to obtain the passivator. The passivator is a novelpassivator which is efficient, environment-friendly, low in cost and capable of being used for treating soil (such as a farmland and a field), waste residues or water bodies with arsenic and cadmium contents exceeding the standard, the technological difficulty that arsenic (trivalent arsenic / pentavalent arsenic) and cadmium cannot be efficiently passivated at the same time is solved, and the passivator and the method have very good popularization and application values.

The invention relates to preparation of an inorganic nano material and discloses a sodium yttrium tetrafluoride / ferroferric oxide / carbon multifunctional nano material and a preparation method thereof. A chemical expression of the nano material is as follows: NaYF4:Yb, Er / Tm@Fe3O4@C. The preparation method of the sodium yttrium tetrafluoride / ferroferric oxide / carbon multifunctional nano material comprises the following steps: A, uniformly dispersing up-conversion fluorescent nanoparticles into cyclohexane; B, mixing dispersion liquid with acetone; C, adding dicyclopentadienyl iron into mixed liquid, and sufficiently stirring; D, carrying out ultrasonic action onto the mixed liquid after the dicyclopentadienyl iron is dissolved; E, slowly adding hydrogen peroxide into the mixed liquid, and stirring uniformly; F, transferring the mixed liquid into a high-pressure reaction kettle which takes tetrafluoroethylene as a substrate, and carrying out solvothermal reaction; and G, after the solvothermal reaction is ended, naturally cooling, centrifuging and cleaning. According to the preparation method disclosed by the invention, package of Fe3O4 on the surface of an up-conversion material is realized by one step, and a carbon layer is formed on the surface of the up-conversion material, so that the material has hydrophilicity and high biocompatibility.

The invention discloses a treatment system for cooperatively treating garbage incineration fly ash and garbage leachate. The treatment system for cooperatively treating the garbage incineration fly ash and the garbage leachate comprises a fly ash collection bin connected with flue gas purification equipment, a leachate collection pool located at the bottom of a garbage dump, as well as a washing pool, a drying box, a reaction kettle, a microwave treatment device, a solid-liquid separator, a melting furnace and a cooling pool which are sequentially connected with the fly ash collection bin, wherein a heat exchanger is connected to the leachate collection pool, and connected with the drying box through a pipeline; a filter material tower is connected to the bottom of the leachate collectionpool, and a compressor is connected to the reaction kettle; and the melting furnace is connected with the drying box through a pipeline, and flue gas generated due to melting is capable of drying thedrying box; and an adjuvant bin is connected to the melting furnace. The treatment system has the advantages of being capable of cooperatively treating the garbage incineration fly ash and the garbageleachate, good in treatment effect, and low in cost.

The invention discloses a multi-dimensional stacked-hanging-type mushroom planting, human-hand-simulated atomization support picking, dehumidifying and recycling vehicle, and belongs to the technicalfield of mushroom picking machinery. The vehicle comprises a multi-dimensional annular stacked-hanging-type mushroom planting device, a human-hand-simulated multi-directional liquid bag covered atomization flow support-type lossless picking mechanism, a multi-dimensional stacked hanging adaptive stable mushroom stick grasping device, a Z-shaped lossless conveying device, a mild cyclone circulationdehumidifying mechanism, a progressive packaging freshness preservation mechanism, an oblique self-rolling-type anti-squeezing transmission device, a portable moving device and a mushroom stick recycling containing box. Particularly, the multi-dimensional stacked-hanging-type mushroom planting, human-hand-simulated atomization support picking, dehumidifying and recycling vehicle truly achieves complete coverage and lossless picking of mushrooms through the combination of principles of air pressure, hydraulic pressure and atomization and human-hand-simulated picking, removes water on the surfaces of the mushrooms by utilizing the internal circulation of dry warm air, conducts bagging freshness preservation on the mushrooms and can achieve single-adaptability and high-efficiency recycling of the mushroom sticks.

The invention relates to a method for preparing a chromium curing / stabilizing material, the chromium curing / stabilizing material prepared thereby and an application thereof. The method comprises the following steps of: uniformly mixing a silicon-aluminium mineral, calcium-magnesium mineral and an additive, and after high-temperature calcination at the temperature of 800-1600 DEG C, obtaining a calcinated material; then uniformly mixing the calcinated material, a stabilizer, a chromium precipitating agent and a viscosifier to obtain the chromium curing / stabilizing material. The chromium curing / stabilizing material can be used for curing / stabilizing chromium and controlling chromium pollution, and is especially used for remediation of soil polluted by the chromium.

The invention discloses a packaging method for cigarettes in carton. The packaging method comprises a step of twining and coating the to-be-packaged cigarettes in carton with a wrapping film, whereinthe twining film is stretchable and adhesive. According to the packaging method, the film needs no thermal shrinkage, so the problems about peculiar smell, power consumption and high cost generated ina thermal shrinkage process when a thermal sealing film is used for packaging the cigarettes in carton in the prior art can be avoided, and the packaging method has the advantages of being low in cost and friendly to working environment.

The invention relates to a method for evaluating efficacy of a sunscreen product. The method comprises the following steps: obtaining a culture solution, adding the to-be-tested sunscreen product withan active ingredient of alligator oil and a biological surfactant into the culture solution to obtain a sample solution; culturing zebrafish juveniles in the sample solution for culture time of T, and during the time of T, exposing the zebrafish juveniles to ultraviolet radiation; transferring the zebrafish juveniles exposed to the ultraviolet radiation to the culture solution for culture, and recording the degree of damage of pelvic fins, caudal fins, and dorsal fins of the zebrafish juveniles. According to the method for evaluating the efficacy of the sunscreen product, zebrafish is used asa model organism to evaluate the efficacy of the sunscreen product with the active ingredient of the alligator oil, and damage to the human health caused by the ultraviolet radiation dose of testingmethods separated from biological organisms and human bodies can be avoided.

The invention discloses a cable material for new energy vehicles, and belongs to the technical field of cable material preparation. The cable material is prepared from polyvinyl chloride resin, SEBS rubber resin, styrene-butadiene rubber, PVC resin, ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide, a silicon-containing hydrogen base, cellulose ether, carbon black N330, glass fiber,sodium silicate, chlorinated paraffin, dimethyl silicone oil, expanded vermiculite, a modified heat-resistant agent, vinyl triethoxysilane, an accelerant TMDT, zinc oxide, stearic acid, an antiager RD, a silane coupling agent A187 and tetrabromobisphenol A; the cable material for the new energy vehicles is obtained by preparing the base materials, preparing the modified materials and then mixing the main materials and the modified materials. The prepared cable material has the excellent heat resistance.

The invention provides a composite cooling water disc. The problem that an existing cooling water disc is low in heat transfer coefficient is solved by arranging the aluminum shell and the copper layer wrapped in the aluminum shell, copper is completely wrapped in the aluminum shell, it can be guaranteed that copper metal cannot leak out. The composite cooling water disc is applied to the field ofsemiconductors, and the stability of chip manufacturing can be guaranteed. The invention further provides a manufacturing method of the cooling water disc. Firstly, a copper layer is welded in an aluminum shell through hot isostatic pressing to obtain a welded assembly. After the assembly is machined out of the water tank, the assembly and the upper aluminum layer are combined and subjected to vacuum diffusion welding to obtain the cooling water disc, the copper layer is completely wrapped in the aluminum shell, the water tank cannot be blocked, and the manufactured cooling water disc is highin cooling efficiency and has high industrial application value.

The invention discloses a novel PLA. The PLA comprises the following raw materials: polylactic acid, lignosulfonate, epichlorohydrin, a modified antibacterial agent, linear low-density polyethylene, polyvinyl alcohol, polycarbonate, pentaerythritol, octanedioic acid, diphenyl methane diisocyanate, dioctyl phthalate, a silane coupling agent KH-570, bamboo fibers, potato starch, montmorillonite, konjac glucomannan, calcium carbonate, liquid paraffin, ethylene-ethyl acrylate, glycerol and fatty acyl diethanolamine. The invention also discloses a preparation method of the novel PLA. The prepared novel PLA has an excellent antibacterial property and high mechanical strength.

The invention relates to the technical field of plank periphery grinding, and discloses a wood board corner polishing device. The wood board corner polishing device comprises a workbench, four supporting columns are fixedly mounted at the top of the workbench, a top plate is fixedly mounted at the top ends of the four supporting columns, two groups of supports are fixedly mounted at the bottom of the top plate, each group of supports comprises two supports, a rotating roller is rotationally connected between the two supports in each group, the two rotating rollers are in transmission connection through a conveying belt, a plurality of pressing and conveying mechanisms are arranged on the outer circle face of the conveying belt, a rotating handle is fixed to the shaft end of one rotating roller, a fixing frame is fixedly installed at the top of the workbench, a plurality of conveying roller wheels are rotationally connected to the fixing frame, a scrap collecting mechanism is arranged on the top of the workbench, and a chipping pumping pipe and an air blowing pipe are arranged on the chipping collecting mechanism. According to the wood board corner polishing device,the problems that during polishing of an existing device for polishing the periphery of a wood board, chippings fly around, are very difficult to collect and inconvenient to collect, and follow-up machining is affected are solved.

The invention discloses an automatic coating device for insulation layers of wires and cables. The automatic coating device comprises a base, a control unit, a cooling device and a wire plasticizing device, wherein a second servo motor is arranged on one side of the upper surface of the base, a wire shaft is arranged on the front side of the second servo motor, a winder shaft is arranged on the other side of the upper surface of the base, a winding reel is arranged on the winder shaft, a first servo motor is arranged on one side of the winder shaft, the control unit is arranged on the lower surface inside the base, the wire plasticizing device is arranged on the upper side of the base, a liquid pump is arranged on the upper side in the base, a heating coil is arranged on the upper side ofthe liquid pump, a heater casing is arranged on the upper side of the base, and the cooling device is arranged on the upper side of the base. The automatic coating device has the following beneficialeffects: integration of coating and cooling of the insulation layers of the wires and cables can be realized, winding can be realized after coating of the insulation layers, working efficiency is high, and time and labor are saved.

The invention relates to a Mn < 2 + >-doped cesium lead halogen group perovskite quantum dot film and a preparation method thereof. The preparation method comprises the steps of firstly preparing a mixed solution of oleic acid, an amino / amino ligand, CsX, PbY2 and MnZ2, and obtaining a precursor solution; mixing the precursor solution with toluene to obtain a perovskite quantum dot solution; and finally, placing the film substrate in the perovskite quantum dot solution, carrying out centrifugal coating, and drying to obtain the perovskite quantum dot film. Compared with the prior art, the Mn < 2 + >-doped CsPbX3 (X = Cl, Br) perovskite quantum dot film material is successfully prepared by adopting a room-temperature one-step centrifugal coating film preparation technology. The method not only enables the film material to maintain the luminescent property of quantum dots to a great extent, but also has the characteristics of simple operation, low cost and the like, and the prepared perovskite quantum dot film material is high in crystallization quality and high in two-photon emission intensity, so that the material has great application potential in the fields of photoelectric devices such as illumination and display.

The embodiment of the invention discloses a message sending method, which is used for improving the express collecting efficiency of a deliveryman. The method of the embodiment of the invention comprises steps: an express delivering request sent by a first user terminal is received by a server, wherein the express delivering request contains first position information of the first user terminal, and the user corresponding to the first user terminal is an express sender; second position information of a second user terminal is acquired by the server, wherein the user corresponding to the second user terminal is the deliveryman; the server uses the first position information and the second position information to calculate the distance between the first user terminal and the second user terminal; and when the distance between the first user terminal and the second user terminal meets a first preset condition, the server sends a prompting message to the second user terminal, wherein the prompting message contains the position information and / or the contact information of the first user terminal. The embodiment of the invention also provides a server for improving the express collecting efficiency of the deliveryman.