37 results about "Light Cycle" patented technology

A process for hydroprocessing hydrocarbons in a combined targeted pretreatment and selective ring-opening unit wherein the targeted pretreatment comprises at least two stages in a single liquid recycle loop. The process operates as a liquid-full process, wherein all of the hydrogen dissolves in the liquid phase. Heavy hydrocarbons and light cycle oils can be converted in the process to provide a liquid product having over 50% in the diesel boiling range, with properties to meet use in low sulfur diesel.

A method is provided for raising poultry, such as chickens, for food production. In a first preferred embodiment, the method includes the steps of: providing a facility for housing the poultry, providing at least one light-absorbing ventilation fan associated with the facility for ventilating the facility, exposing an interior of the facility to natural light cycles of an outside environment for a first period and regulating light cycles of the interior for a second period, thereby mimicking daylight duration variation representative of seasonal changes for stimulating sexual development of the poultry. In a second preferred embodiment, the method includes the steps of: providing a facility for housing the poultry, providing at least one light-absorbing ventilation fan associated with the facility for ventilating the facility, limiting exposure of an interior of the facility to light to produce a brown-out effect therein for enhancing physical development of the poultry.

The invention discloses a roxburghanoectochilus factory cultivation method and cultivation module. The roxburghanoectochilus factory cultivation method comprises following steps: 1) After being washed and sterilized, the roxburghanoectochilus bud is transplanted on a cultivation board; the cultivation board is arranged in a cultivation tank; a nutrient solution flowing in the cultivation tank is provided; the nutrient solution adopts a nutrient liquid membrane technique and the liquid membrane is 0.7 centimeter-1.3 centimeter; only new root of the roxburghanoectochilus bud is immersed in nutrient solution. 2) The roxburghanoectochilus terminal bud is transplanted to the cultivation board for 2 days of dark adaptation. 3)After the dark adaptation, the roxburghanoectochilus terminal bud is irradiated by shot photoperiod for 3 days. 4) Then regular light cycle exposure for the roxburghanoectochilus bud which has been irradiated by shot photoperiodis performed.

The present invention provides an industrial aquaculture illumination system of promoting the epinephelus fry growth and improving a survival rate and an application thereof. The illumination system comprises a composite LED lamp set composed of the cold white, green and blue monochromatic LED light emitting chips, a light source control system and a waterproof shell, wherein the light source control system comprises a power supply module and a circuit control module and can control the illumination intensity and illumination time of the composite LED lamp set, and the waterproof shell uses an anticorrosion material and carries out the waterproof processing by a sealant. The system and application of the present invention are developed and set according to the hobbies of the epinephelus juvenile fishes to the specific spectrum, the light intensity and the illumination cycle, can satisfy the demands of the industrial aquaculture epinephelus juvenile fishes on the light colors, the light intensity and the light cycle, promote the healthy growth of the epinephelus juvenile fishes and improve the survival rate, and further enable the economic benefits of the epinephelus industrial aquaculture to be improved.

The invention provides an intersection signal lamp control method based on bus dwell time, including the following steps: establishing a bus stop dwell time estimation model; acquiring the number of passengers getting off and the number of passengers getting on at next stop for each bus, and substituting the number of passengers getting off and the number of passengers getting on into the bus stopdwell time estimation model to estimate the dwell time of each bus at next stop; calculating the number of buses queuing at an intersection and a queuing sequence of the buses, and estimating the time needed for all the buses at the intersection to enter the stop; and obtaining the signal timing scheme of the intersection, querying for the green time of next traffic light cycle at the intersection, and making a judgment: if the time needed for all the buses at the intersection to enter the stop is longer than the green time of next traffic light cycle, taking the time needed for all the busesat the intersection to enter the stop as the green time of next traffic light cycle; otherwise, continuing to execute the original timing scheme of the intersection.

The invention relates to a method for cultivating anoectochilus roxburghii in an artificial light type plant factory and belongs to the technical field of precious plant cultivation and planting. Light sources are reasonably arranged according to growth requirements of anoectochilus roxburghii in different growth stages, light quality, light intensity, light cycle and other conditions of the light sources are strictly controlled, and accordingly growth requirements of anoectochilus roxburghii in different growth stages are right met. Meanwhile, temperature, humidity, fertilizer application and other conditions are synergistically controlled in different growth stages of anoectochilus roxburghii, and the vegetative period of anoectochilus roxburghii is prolonged. Growth habits of anoectochilus roxburghii are fully used, fresh weight, stem diameter and leaf area of anoectochilus roxburghii plants are increased by controlling the growth environment of anoectochilus roxburghii through the artificial light type plant factory, the content of anoectochilus roxburghii polysaccharides, flavone and alkaloid in anoectochilus roxburghii is increased, limitation of seasons and climate conditions to anoectochilus roxburghii cultivation is eliminated, and the method plays an important role in large-scale medicinal anoectochilus roxburghii indoor cultivation.

The invention discloses a method utilizing a light cycle control technique to cultivate chrysanthemum morifolium, and relates to the technical field of cultivating of out-of-season chrysanthemum morifolium. The long sunlight time is provided in the vegetative growth phase, namely that the sunlight time is longer than 13 hours each day. If the natural sunlight time is not enough, the light is manually supplemented at night, and then the vegetative growth period of the chrysanthemum morifolium is prolonged. After the height of the chrysanthemum morifolium reaches 500nm, the short sunlight time is provided, namely that the sunlight time is shorter than 11 hours, and then the chrysanthemum morifolium enters the reproductive growth period. By matching with the techniques of sprout picking, bud picking and the like, the growth height of single chrysanthemum morifolium can reach 900mm to 1000mm, so the height of the chrysanthemum morifolium can meet the requirement of a customer, the flower period can be adjusted, and the sustained supply of the chrysanthemum morifolium on market can be ensured by the out-of-season cultivating of chrysanthemum morifolium.

The invention discloses a red illumination method for prompting the mating and oviposition of artificially bred dichocrocis punctiferalis. The method specifically includes the following steps that: temperature in an insectary is controlled in a range of 24 to 26 DEC C, and relative humidity in the insectary is controlled in a range of 40 to 60%, and a common fluorescent lamp is adopted to provide a light source, so that the alternation of day and light can be controlled, and the ratio of the illumination duration of the day to the illumination duration of the light is 15:9; 15% sucrose water is provided for supplementing nutrition for the adults, an apple wrapped with medical gauze is suspended at the top of a cage so as to provide a place for the oviposition of the females; the gauze can be taken off regularly, so that ovums can be obtained; the interior of the insectary is regularly disinfected and is kept ventilating; and in the dark period of a light cycle, a red fluorescent lamp is adopted as a light source, and the fluorescent lamp is suspended right above the cage by 10cm, and the illumination intensity of the four corners of the bottom of the cage is not lower than 2lux assuredly, and illumination time lasts for 9 hours assuredly, namely, red illumination is always provided in the dark period. According to the method, red illumination is provided in the breading period of the adults so as to simulate the natural spectrum at dusk and dawn, and therefore, the dichocrocis punctiferalis can be promoted to mate and oviposit, and breeding effects can be improved. The method is worthy of promotion and use.

A method is provided for raising poultry, such as chickens, for food production. In a first preferred embodiment, the method includes the steps of: providing a facility for housing the poultry, providing at least one light-absorbing ventilation fan associated with the facility for ventilating the facility, exposing an interior of the facility to natural light cycles of an outside environment for a first period and regulating light cycles of the interior for a second period, thereby mimicking daylight duration variation representative of seasonal changes for stimulating sexual development of the poultry. In a second preferred embodiment, the method includes the steps of: providing a facility for housing the poultry, providing at least one light-absorbing ventilation fan associated with the facility for ventilating the facility, limiting exposure of an interior of the facility to light to produce a brown-out effect therein for enhancing physical development of the poultry.

The invention discloses an annual culturing method for marine medaka in a lab. Culturing conditions include: culture seawater is 28-30 in salinity and 4-8mg / L in dissolved oxygen level after subjected to five-stage filtering via a nylon film, biological adsorbent, activated carbon, biochemical filter and ultraviolet sterilization system; the culture water is at 26-30 DEG C; the culture density reaches 0.2-0.5L per fish in the growth period and reaches 0.5-1L per fish in the breeding period; a light cycle includes 14 hours of illumination and 10 hours of no illumination, and illumination is performed from 5:00 to 19:00; the culture male-to-female ratio is 2:3; in terms of feeding frequency and feeding time, the fishes are fed with marine tropical fish feed three times a day, from 7:30 to 8:30, from 11:30 to 12:30 and from 15:30 to 16:30, and are fed with Artemia larvae twice a day, from 9:45 to 10:15 and from 13:45 to 14:15. By the annual culturing method, the defects that breeding conditions are difficult to control, cost is high, continuous egg laying fails, egg laying amount is low, breeding conditions are limited, and the like are overcome.

For each of the traveling directions (traveling direction 1 to traveling direction 4) at an intersection, a traffic-light cycle length estimation device acquires a time at which a vehicle in the stopped state starts moving, calculates the time difference between neighboring start times, which have been acquired, as a start interval, and generates a histogram based on the number of samplings of start intervals. The device combines the generated histograms into a histogram for all direction to generate one histogram that represents the relation between the start intervals and the number of samplings and, based on this histogram, estimates the cycle length of the traffic light. If a particular value, one of the start intervals, corresponds to the maximum number of samplings, that particular value is estimated as the cycle length.

The invention discloses a stably expressed reference gene group of harmonia axyridis with different factors and application of the reference gene group. Specifically, a scheme of a stably expressed reference gene group of harmonia axyridis with different factors is that a stably expressed reference gene group under different temperature conditions comprises 18S, 28S and GAPDH (Reduced Glyceraldehyde-Phosphate Dehydrogenase), comprises 18S, 28S and HSP90 under different light cycle conditions, comprises 18S, 28S and HSP70 at different age stages, and comprises 18S, 28S and RP49 at different tissue combinations. By adopting the reference gene group, a most stable reference gene group of harmonia axyridis under four factors is confirmed for a first time, reference gene selection bases are made for study on gene expression levels of different tissues of different ages of harmonia axyridis under different temperature conditions and different light cycle conditions, and a solid base is madefor studying gene functions of the harmonia axyridis, RNAi (Ribonucleic Acid Interfere) transgenic crop environment risk estimation, and the like.

The invention belongs to the technical field of aquaculture, and relates to a catadromous migration salmon breeding method for migratory salmon. The method specifically comprises the following steps:(1) selection of juvenile salmons, wherein the average sampling weight is at least 25g, and the proportion of individuals smaller than 25g is not higher than 10%; (2) during the catadromous migrationperiod, adding an underwater light source at the bottom of the culture pond to ensure that the illumination intensity in the water body at the bottom of the pond is not lower than 20Lux; (3) cultivation in a catadromous migration stage, wherein a light control strategy is as follows: firstly, a light cycle strategy (LD12: 12) of 12 hours of illumination every day and 12 hours of darkness is adopted for 6 weeks, and then the light cycle strategy is converted into 24 hours of illumination every day (LD24: 0) and lasts for 6 weeks as well; and (4) completing the catadromous migration stage. According to the method, the weight of the catadromous migration juvenile salmon is controlled, light rays are controlled, and the form and physiological indexes of the catadromous migration stage are monitored. The catadromous migration rate can be increased by at least 4.9%, the survival rate after s catadromous migration is increased by at least 6.3%, and large-scale cultivation of catadromous migration salmons under the industrialized condition can be achieved.

The invention belongs to the technical field of biological control, and discloses a breeding method for increasing the percentage of females in neoseiulus californicus offsprings. The breeding methodincludes the following steps that firstly, spider mites are fed, then, neoseiulus californicus is fed with the spider mites as a mite source, and the conditions of feeding neoseiulus californicus include that illumination time is 10-14 h during a light cycle, the highest temperature is 23-32 DEG C, the lowest temperature is 13-25 DEG C, and the difference between the highest temperature and the lowest temperature is 8-13 DEG C; spawn laid by female neoseiulus californicus is collected and placed under the same condition to be fed into adult mites. The breeding method for increasing the percentage of the females in the neoseiulus californicus offsprings has the advantages that the percentage of the females in the artificially fed neoseiulus californicus offsprings is significantly increased, the population quantity is increased rapidly, the population breeding quantity in a unit interval is greatly increased, commercial production is promoted, and important bases are provided for areasand seasons of producing and releasing neoseiulus californicus. Neoseiulus californicus offspring breeding is rapid so that an ideal quantity can be reached within a short time without later rejuvenation or periodical putting or other operation, and economic value of neoseiulus californicus natural enemy commodities can be improved.

The present invention relates to a pear tissue culture seedling rooting and domestication method. The method comprises the following steps: 1) rooting culture is conducted: 1.1) after 4 weeks of subculture, strong growing tissue culture seedlings are selected, callus and excess leaves of lower parts of plants are removed, upper half parts of the plants are retained for about 2-3 cm, and the plantsare transferred to a rooting culture medium; and 1.2) 2-3 plants are placed in each bottle, the bottles are placed in a culture room for 4-d dark culture at a culture temperature of 25 + / - 2 DEG C, then light culture is conducted, fluorescent lamps are used as light source, light intensity is 2,000 lx and light cycle is 16 h; 2) cap-opening domestication is conducted: the rooting-cultured tissueculture seedlings begin to take root in about a week and the rooting of the tissue culture seedlings is completed in about 40 d; and during the domestication, bottle caps are first unscrewed, one daylater, the bottle caps are opened for one third, and three days later, the bottle caps are opened two thirds; 3) hydroponic domestication is conducted: after the cap-opening domestication is conductedfor 7 d, the hydroponic domestication is conducted; and 4) substrate transplantation is conducted: when the seedlings grow to 5 cm or more, the seedlings are transplanted into substrates. The pear tissue culture seedling rooting and domestication method can improve rooting rate and is high in transplanting survival rate.

The invention relates to anartificial light type cultivation method for indoor saffron crocus cultivation and flowering in a plant factory. The physiological needs of saffron crocus can be exactly met by strictly controllingthe light quality, light intensity and light cycle and other conditionsof a light source. In a whole dormancy period, the light intensity is set as 10-40 micro-mol / m<2> / s, the temperature is set to be about 29 DEG C and is kept for 20 days, and the humidity is 75-80%. In an assimilating leaf differentiation period, the light intensity is set as 27-36 micro-mol / m<2> / s, the temperature is set to be about 25DEG C, and the humidity is 78-83%. In a flower bud differentiation period, the light intensity is set as 27-36 micro-mol / m<2> / s, the temperature is set as 23-27 DEG C, and the humidity is about 80%. In a flowering period, the light intensity is set as 40-60micro-mol / m<2> / s, the temperature is set as 15-18DEG C, and the humidity is 75%. The pH value requirements in the periods are basically same and is 5.5-6.5. The artificial light type cultivation method makes saffron crocus high in quality and yield, and the growing time is shortened.

The invention discloses a plant factory cultivation method of brassica junica var. The germination rate of the brassica juncea var. Can be significantly increased, the germination time can be shortened, regular germination of seedlings can be guaranteed through shallow sowing in a plant factory, full wetting of media in the early stage and germination under suitable environment, buds can be released within 1 day after seeding and pregermination, and the seedlings can be moved within 7-10 days; an automatic fluid filling device can effectively reduce the cost of artificial liquid supplement, prevent the growth of green algae, provide stable nutrient solutions and promote the growth of the seedlings; after the root system grows to absorb the nutrient solutions, the media are kept dry and breathable, browning and breaking of stem bases can be prevented, and multiple diseases and decay in the later stage are avoided; the light cycle is adjusted after the field planting, so that the harvesting can be facilitated in advance, and the yield is increased; the multiple planting and harvesting modes are beneficial to the safe, stable and annual production of the plant factory hydroponic planting method.

The invention discloses a rhododendron pulchrum callus induction method. The method includes the steps of firstly, cutting off a rhododendron pulchrum sterile seedling leaf to form a wound, and usingthe cut leaf as the explant; secondly, inoculating the explant into a culture medium to perform callus primary culture, wherein light intensity during the primary culture is 2000Lux, light cycle during the primary culture is 14 hours, temperature during the primary culture is 25 DEG C, and primary culture time is three weeks; By optimizing the culture medium and selecting culture conditions, the culture medium for inducing rhododendron pulchrum callus is provided, and the culture medium can evidently increasing callus inducing rate. The rhododendron pulchrum callus induction method which is high in inducing rate lays a foundation for the building of a rhododendron pulchrum tissue culture system and genetic transformation system.

For each of the traveling directions (traveling direction 1 to traveling direction 4) at an intersection, a traffic-light cycle length estimation device acquires a time at which a vehicle in the stopped state starts moving, calculates the time difference between neighboring start times, which have been acquired, as a start interval, and generates a histogram based on the number of samplings of start intervals. The device combines the generated histograms into a histogram for all direction to generate one histogram that represents the relation between the start intervals and the number of samplings and, based on this histogram, estimates the cycle length of the traffic light. If a particular value, one of the start intervals, corresponds to the maximum number of samplings, that particular value is estimated as the cycle length.

The invention discloses a method for detecting fungi carried by rice seeds by using an improved rose Bengal culture medium. The method comprises the steps of culturing and detecting the rice seeds by using the improved rose Bengal culture medium, wherein the culturing comprises the steps of putting culture dishes in an incubator, carrying out culturing for 1 day under the conditions of 25 DEG C, 9,000Lx illumination intensity, 12h illumination and 12h darkness, putting the culture dishes in a refrigerator with the temperature of -20 DEG C after the seeds are imbibed, keeping the temperature for 12 hours, taking out the culture dishes, carrying out culturing for 6 days under the conditions that the constant temperature is 28 DEG C, the illumination intensity is 9,000Lx and the light cycle is 12h light period and 12h dark period, picking the fungi, and microscopically observing and checking species of the fungi carried by the seeds. According to the improved rose Bengal culture medium, copper sulfate, zinc nitrate and cadaverine are added, and the consumption of magnesium sulfate is lowered. The method disclosed by the invention is beneficial to the growth of heterogeneous fungi, the species of the fungi can be detected and separated, the operation is not prone to bacterial contamination, the diameter of fungal colonies is relatively small, and thus, the separation and counting of the fungi are facilitated.

The invention discloses a method for detecting fungi carried by rice seeds by using an improved rose Bengal culture medium. The method comprises the steps of culturing and detecting the rice seeds by using the improved rose Bengal culture medium, wherein the culturing comprises the steps of putting culture dishes in an incubator, carrying out culturing for 1 day under the conditions of 25 DEG C, 9,000Lx illumination intensity, 12h illumination and 12h darkness, putting the culture dishes in a refrigerator with the temperature of -20 DEG C after the seeds are imbibed, keeping the temperature for 12 hours, taking out the culture dishes, carrying out culturing for 6 days under the conditions that the constant temperature is 28 DEG C, the illumination intensity is 9,000Lx and the light cycle is 12h light period and 12h dark period, picking the fungi, and microscopically observing and checking species of the fungi carried by the seeds. According to the improved rose Bengal culture medium, copper sulfate, zinc nitrate and cadaverine are added, and the consumption of magnesium sulfate is lowered. The method disclosed by the invention is beneficial to the growth of heterogeneous fungi, the species of the fungi can be detected and separated, the operation is not prone to bacterial contamination, the diameter of fungal colonies is relatively small, and thus, the separation and counting of the fungi are facilitated.

The invention relates to an asexual propagation method of gracilaria lemaneiformis. The method comprises the following steps: (1) healthy and immature gracilaria lemaneiformis is selected, washed for multiple times, and then flushed with disinfected seawater to remove parasitic protozoan and epiphytic hybrid algas on the surface of the algae body, and after the gracilaria lemaneiformis is cultured for one week by using the disinfected seawater, the cultured gracilaria lemaneiformis is repeatedly washed until the microscopic examination result shows that the surface of the algae body is free of hybrid algas, the washed gracilaria lemaneiformis is soaked in a 1.5% KI solution for 10 minutes, then the soaked gracilaria lemaneiformis is washed with the disinfected seawater for 3 times, the washed gracilaria lemaneiformis is soaked for 10 seconds by using 70% alcohol, and then the soaked gracilaria lemaneiform is washed with the disinfected seawater for 3 times; (2) the treated gracilaria lemaneiformis algae body is cut into cutting sections of 2-4 mm by using a scalpel blade, and the cut gracilaria lemaneiformis is cultured in a PES culture solution containing 0.25mg / mL 6-BA in dark for 7 days; and (3) the culture condition is changed as follows: the temperature is 17 DEG C, the illumination intensity is 10 + / -2 [mu]E.m<-2>.s<-1>, the light cycle is 16h: 8h (Light: Dark). The asexual propagation method is simple and easy to operate and short in induction period, provides a technical method for manual breeding and seedling culture of the gracilaria lemaneiformis, and provides a support for seed production and propagation expanding.

The invention relates to a method for promoting maturation of gonads of broodfish of barhead fish, belonging to the field of seawater culture. The water temperature of conventional culture is lowered by 0.5 ℃ to 17 ℃ every day. The light cycle starts from the conventional 12 hours of light and 12 hours of darkness every day. The light time is reduced by 20 minutes and the darkness is increased by 20 minutes. When the photoperiod of hourly light and 14 hour dark is maintained for 5-10 days; the temperature of the culture water is reduced by 0.5°C to 14°C every day, and the light time is reduced by 30 minutes and the darkness is increased by 30 minutes. When the daily light cycle becomes 8 hours of light 16 During the hourly dark photoperiod, maintain it for 5-10 days; reduce the culture water temperature by 1°C to 12°C every day, and maintain the culture water temperature at 12°C; reduce the light time by 60 minutes and increase the darkness by 60 minutes every day. During the 6-hour light and 18-hour dark photoperiod, it was maintained continuously.

The invention discloses a method for inducing callus differentiation through peony stems. The method comprises the following steps: adding 3.0 mg / L of 6-BA, 0.2 mg / L of NAA, 30.0g / L of sucrose and 7.0g / L of agar into an MS culture medium, wherein the pH value is 5.6-5.8; transferring selectively proliferated stem callus having good growth into a differential medium for performing peony callus differentiation, wherein the temperature is 25 DEG C, the relative humidity is 70%, the light cycle is 12 hours, and the illumination intensity is 35-40 mol / m<2> / s; culturing for 30 days, and observing callus differentiation conditions. According to the method disclosed in the invention, the callus differentiation ratio of the peony stems can reach 24.44%, the callus differentiation is greatly promoted, and a good foundation is laid for establishing a peony regeneration system. The problem that the peony is difficult in differentiation during tissue culture is solved, and a technical support is provided for establishing the peony regeneration system.

The invention discloses a method capable of increasing forsythia seed germination rate. The method includes following steps: S1, selecting forsythia seeds with full grains and glossy seed skin, adopting a potassium permanganate water solution to soak the seeds for 1-3h, fishing out, and washing to obtain soaked seeds; S2, soaking the soaked seeds obtained in the S1 into a gibberellin solution of 50-200mg / L for 4-24h to obtain seeds waiting for germination; S3, putting the seeds waiting for germination obtained in the S2 onto a germination bed, and putting into a culture container for culture for 11-13d at temperature of 20-30 DEG C in an illumination condition and 15-25 DEG C in a dark condition, wherein a light cycle is 12h of illumination and 12h of darkness. The method can greatly increase forsythia seed germination vigor and germination rate, seed germination rate can reach 91.33%, and germination period is shortened; the method is simple in operation, low in cost, time-saving andlabor-saving.

The invention discloses an annual culturing method for marine medaka in a lab. Culturing conditions include: culture seawater is 28-30 in salinity and 4-8mg / L in dissolved oxygen level after subjected to five-stage filtering via a nylon film, biological adsorbent, activated carbon, biochemical filter and ultraviolet sterilization system; the culture water is at 26-30 DEG C; the culture density reaches 0.2-0.5L per fish in the growth period and reaches 0.5-1L per fish in the breeding period; a light cycle includes 14 hours of illumination and 10 hours of no illumination, and illumination is performed from 5:00 to 19:00; the culture male-to-female ratio is 2:3; in terms of feeding frequency and feeding time, the fishes are fed with marine tropical fish feed three times a day, from 7:30 to 8:30, from 11:30 to 12:30 and from 15:30 to 16:30, and are fed with Artemia larvae twice a day, from 9:45 to 10:15 and from 13:45 to 14:15. By the annual culturing method, the defects that breeding conditions are difficult to control, cost is high, continuous egg laying fails, egg laying amount is low, breeding conditions are limited, and the like are overcome.

The invention relates to a method for desulfuration by the selective hydrogenation of light cycle oil, mainly solving the problem that the loss of aromatic hydrocarbon is high during the existing hydrogenation desulfuration process. The method provided by the invention comprises the following steps: by taking the light cycle oil with the sulfur content of 2000 to 15000 ppm and the hydrogen as raw materials, contacting the raw materials with a catalyst under the conditions that the volume ratio of hydrogen to the light cycle oil is (300- 800):1, the temperature is 250 to 450 DEG C and the weight space velocity is 0.5 to 3.0 per hour and the pressure is 3.0 to 12.0 MPa, wherein after the reaction is finished, naphthalene series double-polycyclic aromatic hydrocarbon and polycyclic aromatic hydrocarbon in the oil product are partially saturated or opened, the conversion rate of the polycyclic aromatic hydrocarbon reaches more than 35.0%, the retention rate of the total aromatic hydrocarbon of a product is greater than 97.0%, the desulfuration rate is greater than 97.0%, and the denitrification rate is greater than 95.0%. Thus, according to the adopted technical scheme, the problem is solved well. The method provided by the invention can be applied to the industrial production of benzene and xylene by the selective hydrogenation of an inferior oil product.