base fertilizer. Basal fertilizers are dominated by organic fertilizers, which are usually soil-fertilizers, manure, compost, green manure, river mud and grass pond mud. Their nutrient content and the absorption and utilization rate of cotton plants in the same year were not the same. The absorption and utilization rate of the same year accounted for about 30% of the total nutrient content of the base fertilizer. Therefore, the amount of basal fertilizer used must be greater. There are many types of farmyard manure used as basic fertilizers in cotton fields, and the fertilizer efficiency varies. The cotton fields in the cotton fields of the Yellow River Basin are often used as base fertilizers for compost or mixed crops. Due to the lower fertilizer efficiency of basic fertilizers, generally more than 30,000 kilograms of fertilizer is applied per hectare in cotton fields. Before the winter plowing in the cotton fields in the cotton fields of the Yellow River Basin, the fertilizer is applied to the ground, or the ditch is concentratedly applied, and then the soil is ploughed to facilitate decomposition of fertilizers. . If the fertilizer is not sufficient and it is not applied in winter tillage, early ploughing should be applied early in the spring. Cotton and cotton are used to interplant cotton fields to better apply basal before the jointing of wheat, because the wheat seedlings are still small, and the ploughs can be used to deepen furrows between rows, which can ensure the quality of fertilization without damaging wheat seedlings and wheat roots. .
Some phosphorus deficiency and potassium deficiency in cotton fields can increase the use of phosphorus and potassium fertilizers as base fertilizers, which is beneficial to the absorption and utilization of deep root systems. Summarizing the experiences of various regions, the general soil fertility cotton fields are treated with nitrogen fertilizer as the base fertilizer, and the amount can account for 50% to 60% of the total amount. The shortage of organic fertilizer sources in northern dryland cotton areas has been promoted in recent years with ammonium bicarbonate as a base fertilizer application, which has greatly improved the utilization rate of ammonium bicarbonate, and has significantly increased production. The use of cake fat as a base fertilizer in cotton fields, especially in areas where the source of organic fertilizer is lacking, should be strongly promoted. The basal fertilizer is returned to the field with cake fertilizer. Generally, 750 kg per hectare is used. Basal application of phosphate fertilizer, the application of superphosphate generally 300 to 350 kg per hectare is appropriate; base application of potassium fertilizer, potassium sulfate or potassium chloride, the general amount of 150 to 225 kg per hectare. The advantage of fertilizer as base fertilizer is that the basic fertilizer in cotton field is developed from a single organic fertilizer into a combination of organic fertilizer and inorganic fertilizer, combined with delayed fertilizer and quick-acting fertilizer, which can make up for the soil supply capacity at the seedling stage and continue to supply cotton. Fertility needs. Kishi fertilizer can also serve as a substitute for fertilizer, and it is safer and more effective than applying fertilizer.
top dressing. After the combination of base fertilizer and topdressing in cotton fields, in order to meet the demand of nutrients for each growth period of cotton, it is also necessary to carry out fertilizer by stages. Nitrogen fertilizers are generally topdressing, and the amount of topdressing nitrogen fertilizers accounts for about 40% to 50% of the total application amount. The principle of “lightness, stability, weight, and complement†should be mastered in the application of different growth periods. That is, the seedling and bud stage of cotton should be light and stable. The flowering and flowering period should be “heavy and complementaryâ€. . Medium or middle and upper fertility cotton fields, the number of top dressing is usually 2 to 3 times, which is mainly used in the bud period and flowering period. It is necessary to change the practice of top-dressing high-yield cotton fields and adopting blindly increasing the frequency of top-dressing in order to avoid wasting fertilizer and increasing input. It is also easy to cause the growth of cotton.
Ventilator block diagram
One. Main mechanical ventilation modes
(1) Intermittent Positive Pressure Ventilation (IPPV): positive pressure in the inspiratory phase and zero pressure in the expiratory phase. 1. Working principle: The ventilator generates positive pressure in the inspiratory phase and presses the gas into the lungs. After the pressure rises to a certain level or the inhaled volume reaches a certain level, the ventilator stops supplying air, the exhalation valve opens, and the patient's thorax Passive collapse of the lungs and exhalation. 2. Clinical application: Various patients with respiratory failure mainly based on ventilation function, such as COPD.
(2) Intermittent positive and negative pressure ventilation (IPNPV): the inspiratory phase is positive pressure and the expiratory phase is negative pressure. 1. How it works: The ventilator works both in the inspiratory and exhaled phases. 2. Clinical application: Expiratory negative pressure can cause alveolar collapse and cause iatrogenic atelectasis.
(3) Continuous positive pressure airway ventilation (CPAP): Refers to the patient's spontaneous breathing and artificial positive airway pressure during the entire respiratory cycle. 1. Working principle: Inspiratory phase gives continuous positive pressure air flow, and exhalation phase also gives a certain resistance, so that the airway pressure of inhalation and exhalation phases are higher than atmospheric pressure. 2. Advantages: The continuous positive pressure airflow during inhalation is greater than the inspiratory airflow, which saves the patient's inhalation effort, increases FRC, and prevents the collapse of the airway and alveoli. Can be used for exercise before going offline. 3. Disadvantages: great interference to circulation, large pressure injury of lung tissue.
(4) Intermittent command ventilation and synchronized intermittent command ventilation (IMV / SIMV) IMV: There is no synchronization device, the ventilator air supply does not require the patient's spontaneous breathing trigger, and the time of each air supply in the breathing cycle is not constant. 2. SIMV: There is a synchronization device. The ventilator gives the patient a commanded breath according to the pre-designed breathing parameters every minute. The patient can breathe spontaneously without being affected by the ventilator. 3. Advantages: It exerts its ability to regulate breathing while offline; it has less influence on circulation and lungs than IPPV; it reduces the use of shock medicine to a certain extent. 4. Application: It is generally considered to be used when off-line. When R <5 times / min, it still maintains a good oxygenation state. You can consider off-line. Generally, PSV is added to avoid respiratory muscle fatigue.
(5) Mandatory ventilation per minute (MMV) When spontaneous breathing> preset minute ventilation, the ventilator does not command ventilation, but only provides a continuous positive pressure. 2. When spontaneous breathing is less than the preset minute ventilation volume, the ventilator performs command ventilation to increase the minute ventilation volume to reach the preset level.
(6) Pressure Support Ventilation (PSV) Definition: Under the prerequisite of spontaneous breathing, each inhalation receives a certain level of pressure support, increasing the patient's inhalation depth and inhalation volume. 2. How it works: The inspiratory pressure begins with the patient's inspiratory action, and ends when the inspiratory flow rate decreases to a certain level or the patient attempts to exhale hard. Compared with IPPV, the pressure it supports is constant, and it is adjusted by the feedback of the inspiratory flow rate. Compared with SIMV, it can get pressure support for each inhalation, but the level of support can be set according to different needs. 3. Application: SIMV + PSV: used for preparation before off-line, can reduce breathing work and oxygen consumption Indications: Exercise the ventilator; prepare before going offline; the ventilator is weak due to various reasons; severe flail chest causes abnormal breathing. 5. Note: Generally not used alone, it will produce insufficient or excessive ventilation.
(7) Volume Supported Ventilation (VSV): Each breath is triggered by the patient's spontaneous breathing. The patient can also breathe without any support and can reach the expected TV and MV levels. The ventilator will allow the patient to be truly autonomous Breathing also applies to preparations before going offline.
(8) Capacity control of pressure regulation
(IX) Biphasic or bilevel positive pressure ventilation How it works: P1 is equivalent to inspiratory pressure, P2 is equivalent to breathing pressure, T1 is equivalent to inspiratory time, and T2 is equivalent to exhalation time. 2. Clinical application: (1) When P1 = inspiratory pressure, T1 = inspiratory time, P2 = 0 or PEEP, T2 = expiratory time, which is equivalent to IPPV. (2) When P1 = PEEP, T1 = infinity, P2 = 0, T2 = O, which is equivalent to CPAP. (3) When P1 = inspiratory pressure, T1 = inspiratory time, P2-0 or PEEP, T2 = desired controlled inhalation cycle, equivalent to SIMV.
Medical Positive Pressure Breathing Machine
Positive Pressure Breathing Machine,Continuous Positive Pressure Ventilation,Intermittent Positive Pressure Ventilation,Intermittent Positive Pressure Breathing Machine
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