In China, there is a great variety of integrated fish farms which are involved in lake, reservoir and pond fish culture. This chapter mainly deals with the design and construction of an integrated fish farm which combines pond fish culture with crop, livestock, poultry farming and sideline occupations.
1. Site selection and preparation
An integrated fish farm is a production base. The design and quality of its construction would directly affect the investment and the deployment of labour force in construction and, more important, fish, livestock and poultry production.
In constructing a farm, the following requirements should be emphasized in calculation and design. All the information should be gathered in detail for analysis and comparison and thus, it can provide the reliable scientific basis for site selection.
1) Water source
(1) Plentiful water supply of desirable quality:
The most important requirement in fish culture is water supply. Water, irrespective of its origin, can be used providing it is of desirable quality and available in quantity. However, if the water source is near some factory or mine sewage, water quality must be examined to see if its contents are harmful to fish. For example, the effluent from metallurgical factory contains lead; the one from instrument plant and table salt-electrolysing plant contains mercury; the one from coking plant; petroleum and gas industry contains phenol. All these toxic materials can either kill fish directly or accumulate in fish body which smells and brings harm to people's health. In such a case, other water sources should be considered.
The waste water from some food processing mills such as slaughterhouse, brewery, beancurd works is rich in organic materials, which are beneficial to fish farming through fermentation, or sedimentation or controlled introduction to fish ponds.
Underground water often contains excessive
The acidity or alualinity (pH value) of water represents the hydro chemical quality. In general, the optimum pH value for pond fish culture is between 6.5 and 8.5. The value beyond this range would affect the fish yield and even cause fish to die in high mortality.
many cultured fish spp. are of eurysalinity, such as Tilapia, mullet,
redeye mullet, milkfish and Common carp that have a strong tolerance
When you make an investigation of water quality, one thing must be taken into account, that is, in flooding season the water may be of less toxicity; but in dry season, due to evaporation, the concentration of poisonous elements in it will go up and the water will become harmful to fish. If you are forced to use it as a water source, the reserved water supply should be prepared. Generally speacing, only the water you want to use is not toxic and is toxic and is suitelic for the farming, can other problems on farm construction be considered, or they should be put aside for the time being.
(2) Water amount
Water should be abundant with a stable level to meet the
This is the principal consideration to design the area for fish ponds. Water amount will influence the production potentials, so the relevant information as hydrology, meterology, topographical feature, edaphic quality, etc. should be collected and then, the calculation could be conducted in conjunction with water depth needed by per unit area fish pond based on the flowing amount of different seasons so as to ensure adequate water supply for fish ponds and fields as well. If a farm is constructed along a lake, river or reservoir, be sure to get the information of the highest and lowest water levels in the years passed and to select the areas with stable water levels to establish a farm, thus, avoiding the draught through leakage in the dry season and the overflow in flooding seasons. Flooding prevention measures should be taken the same as the small-scale irrigation works which is not offended by the water within 25 years. The farm should be kept safe above the safety line. The water-logged area and depressions with too much rainfall can not afford site selection for the time being.
2) Soil quality
Different soil characters deeply affect the quality of the pond construction and influence the future fish yield to some extent and even the crop yield. Therefore, soil quality should be carefully differenciated and chosen. The soil for pond construction should ensure non-leakage and no collapse for dykes. This is the most important thing for manured pond.
Loam is characterized by conservation of water and fertilizer with proper ventilation. Therefore, it is the best soil for the dyke construction. Sandy loam is also good for water conservation; however, it has a weak coagulation so it is poor for dyke construction. Clay is good for water conservation. It can be used as soil materials for pond bottom, but not good for dyke, because it cracks when dry. If these latter two soils are used for dykes, the dyke crown should be widened and the gradient of slope decreased. Grit soil, sand soil and silty soil are greatly porous, poor in water and fertilizer retention.
They are not good materials for pond constructions. The sand, however, could replace part of clay for dyke construction.
Apart from the consideration given to the soil quality which effects the construction, attention should also be paid to the soil contents, which influence the fish growth. If the iron contents is too much, ferric hydroxide will form colloid in water and will deposit on the pond bottom. This rosty sediment is often attached to fish hills hindering fish respiration especially, fish egg hatching, fry rearing. This type of soil appcars russet brown or green and is relatively easy to identify.
The soils with excessive decaying matter have lower water and fertilizer retention power. It is easy to collapse down if used as the material of pond dyke.
In the tidal areas and swamps, the pond construction is more difficult to be carried out, because the ground water level is high. The operating cost may be much higher. These areas are too low to allow complete drainage as required for propoer management. The temperature adjustment may be affected after being put into operation too.
In termining soil quality, it si not enough to just examine the top soil. Enough samples have to be taken from various representative sports. The sampling depth should exceed the depth of the pond by one meter. There must be certain thickness of soil which has good water retention power to avoid serious leakage.
Owing to the variety of integrated different product of land can be fully utilized. It is most design too continue from a flat and wide. Watt generaly but generaly there is no problem a farm in tilly district. The slopes are good places for afforestation and fedder cultivation and livesock production indesinging fish pond gravitational flow canbe fully utilized to deduc by soil concervation and energy as much as possible use intertide pond or lake bay areas for pond construction. Probably, this kind of topography for a farm needs greater investment and is time-consuming. However, it doesn't occupy fertile crop land and the development and utilization of waste land is of great economic significance.
4) Transportation and Energy
There is a large amount of fresh produce and processed food being sent to the market and fishery necessities and livestock, etc. purchased from the market; therefore, the farm site should be a place easy of access. For example, Helei Fish Farm is located in the suburbs of Wuxi. Either water borne traffic or land transportation facilitates the development of the farm.
A fish farm, if it is possible, should be selected near the place where it is rich in natural food such as snails, Corbicula spp., aquatic grass, etc. to provide sufficient food for fish all the year round apart from self-supplied feeds and fertilizers.
Electricity is the principal energy of a fish farm. It is better to select a site where it is easy to get in connection with power plant. Water, road and electricity must be within reach of a farm site before starting capital construction.
2. Overall Layout of an Integrated Fish Farm
In order to work out an overall programme for a farm, land area elevation measurements should be carried out. Draw up an ichnography with a scale of 1:1000 - 1:500 before the earthwork calculation and the pond construction. The engagement items and their scale are determined by the natural conditions of a site, investment and consumers' preference. Then, the production departments can be determined. The overall layout of a farm means to make rational arrangement of each department and their affiliated equipment. It will not only involve the construction and investment but also the future operation. The reasonableness of the layout must be shown on the following:
The facilitates management and increases production and economic returns;
Every measure should be taken for easy operation, lessening labour intensity, heightening efficiency and protecting worker's health;
It economizes of capital construction investment and reduces material consumption and manpower.
The layout of integrated fish farm is not only for the present being but also for the future development and there should be room enough to realize a practical long-run programme in stages according to the funds and labour force avaliable.
Other types of occupations in integrated fish farm serve fish production. The scale of crop and animal production depends upon the needs of aquaculture. Therefore, the locations and areas of various ponds should be considered first and then the location and areas of livestock pens, crop farming, processing insustry and finally, the ones of other facilities.
1) Aquaculture facility arrangements
Fish ponds are main buildings on the farm. Fish ponds in China are generally outdoor earthern ones. Fish seeds, if it is possible, should be produced within the farm. Thus, it can reduce operating cost and can get desirable sized fingerlings so as to bring out the full potentials of various fish ponds and to avoid infectious fish diseases from outside. The farm with food-feeders as major cultivated species needs large-sized fingerlings. The nursery ponds generally account for 25– 30%, growout ponds for 70–75%; if plankton-feeders as dominant spp. the nursery ponds should account for 15% while growout ponds 85%. If the production scale is rather large and the farm intands to breed fry and fingerlings by itself, it has to build the spawning ponds and hatcheries. The rate of the areas of brooders, fry and fingerling ponds depends on the quantity of fry and fingerlings needed. In general, the ratio is about 5:10:85. The ratio between the water surface and total farm area is dependent on soil quality and integrated management requirements. Generally, water area occupies about 60–70. In Wuxi area it holds 68%; pond dykes 21%; inlet and outlet channels 11%. Various fish ponds are arranged on the basis of water demands and operational convenience for the purpose of raising the survival rate of fish. The brooder ponds, spawning ponds and hatcheries, etc. should be placed at the nearest area of water inlet. Spawning ponds should be close to the hatching facilities. Both of them should be built in the vicinity of brooder ponds to facilitate brooder transportation. Fingerlings' ponds ought to be next to fry nurturing ponds and food fish ponds. Thus, fish ponds will be arranged in such a rational way that the various cultural operations such as fry stocking and fingerling transference can be carried out in the shortest possible time with the minimum amount of labour.
2) Other types of Occupations Arrangement in an Integrated Fish Farm
(1) Location of livestock houses: Presently, the animals raised in integrated fish farms are pigs, cows, ducks, chickens and geese. Their penthouse and shed are arranged as follows:
(i) Pigsty location
In order to lead the pig excreta into the fish ponds, the pigsties, generally built on the pond dykes or on the highlands nearby the fish pond. A limited-scale farm may centralize the pigsties in divisional areas. The pigsties constructed on pond dykes are easy of access through canals or roads. Pig excreta are ushered into the septic tanks for fermentation before being put into use; thus, it shortens the distance of transportation.
Cows need both cowshed and playground which occupy more areas than pigsties on pond dykes. Generally, intensive farming is practised. The cowshed is built in the place near the fish pond for easy transportation of the wastes, feeds and milk.
(iii) Location of duck and goose pens
They are just built separately along the pond dykes.
(iv) Location of chicken house
This type of house is open type with good ventilation. It is almost on the highlands with dry ground. In order to prevent the outbreak of chicken diseases, the chicken house should be located a bit far away from other domestic animal houses. But, for the sake of transportation, they should be near the roads.
(2) Fodder crop field
Aside from the pond dyke, slope for crop cultivation, an integrated fish farm should have special plots for fodder crop cultivation. The area of plots depends upon the requirements of fodder crops and lands available. If the fine feeds are provided mainly by the market the fodderland of a farm can be less; if conditions were otherwise, the fodderland should be more. The full use ought to be made of wasted plots, hilly place and even water surface. Some of the farms grow crop even in fingerling rearing pond in off-season and lake bay and river bends.
3) Farm administration building
The farm administration building is like a headquarters which is responsible for organization and leadership of its production. Therefore, the headquarters is located in the central area easy of access.
4) Industry and side-line occupations
Simple processing workshops for fish, duck eggs, milk, bean and slaughtery, brewery and fish gear repairing shop should be established for better sale, speedy transportation, comprehensive utilization of produce and enhancement of employment in a large-scale farm. These workshops should be arranged near the source of materials.
(See Fig. 10–1)
3. Fish Pond Design
After determining the location and the area of land for fish ponds, steps are taken in arranging the position of ponds and pond dykes and setting the directions, shapes, size of inflow and outflow channels.
1) Fish pond size
Pond size depends upon the environmental requirements of fish in different stages of growth and the requirements of operational management. The general practice size of growth pond ranges from 5 to 10 mu with depth 3–3.5 m (water depth 2.5–3 m); fingerling pond 2–5 mu with depth 2–2.5 m (water depth 1.5–2 m); nursery pond 1–2 mu with depth 1.5–2m (water depth 1–1.5 m). The brooder pond equals to the growout pond. Is it necessary to construct the storage, settlement filtering or sunexposure ponds? That depends.
A fish pond is often in a rectangular shape, broad from the east to the west. This kind of fish ponds get more solar irradiance which benefits photosynthesis of aquatic plants and enables them to produce more oxygen, which in turn, promotes the growth of fish and natural food organisms. The ratio of pond length and width should be 2:1 or 3:2. The length of a big pond ought to be enlarged. The width of same type of ponds should be uniform. In this case, it needs less fishing gears and spares much time in operations.
2) Pond structure
All the fish ponds have the same structure with a little differences in size and depth.
The embankment includes pond dyke, partitional dyke, marginal dyke, transportation dyke and cofferdam. Soil quality and the use of dyke are the main factors to decide the width of dyke crown and the gradient of slope. The width of pond dyke can be narrower if the soil quality is better or the food supply is sufficient or the area of land is not adequote. The common width of pond bank ranges from 2–5 meters. The big pond is with wider crown while small pond with narrower one. The width of the dyke between fish pond and inflow and outflow canals keeps between 3–5 m while the width of the dykes for pigsties, cow shed, etc. or piping and traffic roads 5 to 10 m. If the outflow canal is too small for boat traffic, the dyke should be wider at least on one side of a pond so as to enable vehicles to get to the fish pond.
The gradient of dyke slope of loam soil should be 1:1 to 1:1.5 while the one of poor soil or growout pond dyke should be greater, that is, 1:2.5 to 1:3 under the water surface and 1:1 to 1:1.5 above the water surface. In grow-out pond 0.5–1 m wide path along the inner slopes should be provided for the sake of pulling nets and avoiding erosion by waves. (See Fig. 10–3b)
A cofferdam is a sort of building to prevent a fish farm from flooding. It requires 0.5 m higher than the peak water level in the history. Crown width of the cofferdam is 4–6 m or even 10 m wide as required for the stretch against the wind and waves, the gradient should be larger. The leeward slope is about 1:1.5 to 1:2.5 while the windward slope 1:2.5 to 1:3.5. If the slopes are well protected with grass and stone pieces, the gradient of slopes may be reduced to 1:2. A slope of several meters wide out of dyke foot should be left as buffer zone where the aquatic plants can be planted to lessen wave attacks.
If the soil is poor in quality, an edaphic core made of soil with good coagulation should be built. (See Fig. 10–2)
(2) Pond bottom
The bottom is flat. It should be slanting from the inlet to the outlet. There is a slope of about 3‰ for big pond while about 5‰ for small one; a slight slope from dyke foot to the central area and so it is good for drainage and harvest operation. (See Fig. 10–3a)
3) Water intake and drainage system of fish ponds
This system of the fish pond functions to maintain the water level and to adjust pond water quality, to prevent draught and flood and the dissemination of fish diseases. Its construction is extremely important. No neglect could be allowed even if one thinks of economizing on the investment and land use, otherwise, the potential danger will occur in the future operation. Therefore, an independent water intake and drainage system should be prepared.
This system includes inlet and outlet canals and its bypass channels such as aqueducts, culvert, stilling basins and slnice gates etc.
(1) Inlet canal
Inlet canal can be as general canal, branch canal and by-pass chennal. The flowing amount of water should suffice the demand of water supply in a given time. The bottom of inflow canal ought to be higher than the peak water level in fish ponds. It should be kept dry when no irrigation. Sectional size of the canal is dependent upon the flowing amount of water. The section of earth dyke is trapezium-shaped with the gradient of 1:1 to 1:1.5 on both sides. If protected with bricks and stones, it often appears rectangular. The slope of the canal will influence the flowing speed of water. In a field construction, it should be adjusted based on the slope of land. Thus, it is economical and simplified. If it is too steep on topographical features, several stilling basins in certain places should be built. In constructing the canals, the following slanting ratio is adopted:
The distance of conveyance should not be too long. Otherwise, it wastes land and it has bad effects on water supply to fish ponds. It is suitable for a general canal to supply 150–200 mu of fish ponds.
Inlet water locks generally adopt culvert type using underground pipes constructed with bricks, stones and cement. The size of head gate depends on the pond size so as to ensure the ponds with sufficient water supply in a given time. The place between the gate and the pond bottom had better be cemented with stones so as to prevent bank erosion. (Fig. 10–4)
(2) Outflow canal
The design of outflow canal is almost the same as the inflow canal, but the bottom of the canal is 0.3 m lower than the pond bottom. If it is used as flooding drainage canal in flooding season, it should be large enough to get the water drained in a limited time. Mostly, outlet waterlocks often adopt trough type; however, it is difficult to close the gate tightly because of strong water pressure. It's not convenient to lift it up too; hence, the terraced type of outflow sluice is used with the advantages of easy operation. The size of sluice gate should be big enough for draining the water in a given time. (See Fig. 10–5)
The inflow and outflow canals should be arrayed alternately one side for irrigation and the other for drainage. It can not only prevent the dissemination of fish diseases but also can benefit the rearing of brooders and flood control. (See Fig. 10–6)
(3) Open ditch and hidden culvert or subdrainage
Inflow and outflow canals employ not only open ditch as mentioned above but also hidden culvert or a combination. Open ditch has many advantages - simple construction, less labour and material, easy maintenance or otherwise - occupying large area of land, obstructing the traffic, losing large amount of water. The hidden culvert has many advantagesoccupying small area of land, obstructing no traffic, losing small amount of water but it has some disadvantages too, such as big financial investment. For the sake of convenience, several maintenance wells should be built at intervals along the channel to avoid being silt up.
4) Earthwork calculation
Based on the level measurement, the area of fish ponds and the depth of excavation, the earthwork quantity can be figured out. The amount of excavation ought to be equal to the one of filling of by and large. The excavated soil should be piled up as near as possible for shortening the transport and saving labour and time. Therefore, either the excavation work or the filling work should be wellplanned to avoid no where to pile the soil for excavating and nowhere to get the soil for filling.
In balancing the earthwork, if the soil excavated is more than the soil filled, more small fish ponds can solve this problem e.g. reducing the depth of fish ponds, enlarging the area of stacking section or broadening or heightening the weir, etc.
4. Leakage control and acid soil improvement
1) Leakage control of fish ponds
First of all, investigation should be made to find the reason of pond leakage before taking any corresponding measures.
If the pond bottom or dyke contains much sand or grit soil which brings about pond leakage, spread clay soil on the pond bottom and it is evenly distributed by virtue of inlet water. The clay particles will enter into the cracks of the pond bottom during the process of leakage and then, it will stop the leakage. In certain countries, about 10 m3 of cow dung per-ha is spread on the pond bottom a few times; and it will greatly control the leakage blocking the soil pores.
If the leakage is due to poor construction of pond dyke, which should have been pressed by ramming, the remedy measure of compacting could be taken. If it still leaks, spread heavy clay soil or turn over the dyke for rebuilding till leakage stops.
2) Acid soil improvement
Acid soils are common in many parts of the world, e.g. lateritic soil in the tropics, humic soils in the temperate zone and acid sulphate soils in Southeast Asia, which the local people call coastal mangrove soil with pH value below 3. In the Philippines, there are about 100,000 ha of fish ponds of acid soil, which produce very low fish yields. This type of soil can be regulated with quicklime (Ca (OH)2) or limestone (CaCO3). However, the feasibility of this method depends on the local economic conditions. According to Swingle (1961), practical experience has shown that soils of pH5 require approximately 2 tons of limestone per ha and those with pH 4 require 4 to 6 tons/ha.
3) Newly-dug fish ponds often contain much heavy metals that harm fish growth and often cause body-curved disease of fry; therefore, in the first two years, it is better to farm two-year-old fingerlings and adult fish. If they are to be used to nurture fry, the water should be changed over before stocking fry so as to wash away the excessive elements which are harmful to fry.
Field Work Guide I -
Ichnographical drawing with a theodolite
Objectives: Within a given area designed for a fish farm, set several points where a theodolite is used for making measurements of horizontal angles and sight distances before drawing an ichnography and calculating the land area.
(1) Selected land area: 25–30 mu
(2) Based on the shape of the area, set several points as Point 1, 2,3,… n with the numbered stakes as indicators.
(3) Place the theodolite at Point No. 1, put the horizontal level at 6° or so and point the axis of the telescope towards true north, take down the readings and run the telescope clockwise towards Point number 2; take down the readings and calculate the magnetic bearing of Point No. 2.
(4) Set a leveling staff at Point No.2 and a theodolite at Point No.1. Write down readings of distance.
a'Fb' ~ AFB, a'b'= ab =p a constant, the distance between two scales
FO = f, AB = 1
|Use C instead of|
|FE = Cl,||D = FE +||+ f|
|c + f = q||D = Cl +q||q = O,||D = Cl|
(5) Turn the telescope clockwise toward Point n, write down the readings to calculate the azimuth of angle 1.
(6) The leveling staff is set at Point No. 2 up to Point n; use the same method as mentioned above to calculate the distance between Point No. 1 and Point No. 2; between Point No.2 and Point No.3....
(7) Move the theodolite to Point No.2. and level and centre it; repeat the same method as (4), (5), (6) and calculate the distance between Point No.2 and 3.
(8) An example of measurement
Measurement record form.
|point of origin||measured point||compass reading||horizonal azimuth||sight distance reading|
|1||2||00340||lower scale 2.044|
|n||179 34 50||179 31 10||upper scale 0.963|
|sight dist. 1.081|
|horiz dist. 108.1|
(9) Calculation and correction of angle deviation
In theory, the total amount of interior angles of a polygon should be as follows:
∑ β t = (n - 2) . 180°
n stands for the number of interior angle in a polygon or within a closed line.
β stands for the interior angle.
But in practice, the sum of the interior angles measured, Σ β m is often not equal to the sum ∑ β because of errors in measurement. The difference between the two is called the closed difference of the angles, that is,
fβ =∑ βm - ∑ βt
First of all, we must calculate whether it is within the range of allowable error, which is different in different instruments. If a theodolite is with 6" or 15" the allowable closed error of the angles is ±25" or 45. If the error is beyond the allowable range, the reason for that is to be found before it is redone. If f β is less than the allowable one, adjustment is made. The error with opposite symbol is to be distributed to each interior angle. The total corrected angles should be almost the same as ∑ β in theory.
(10) Land area calculation
On the ichonography that is drawn, a number of triangles, square or trapezoid can be divided as it is shown in Fig. 4 containing three triangles F1, F2, F3. The side parameters are measured with tape measure.
S = s (s-a)(s-b)(s-c)
a,b,c respectively stand for the parameters. The total area is the sum of F1 + F2 + F3.
Field work Guide II
Elevation measurement with levelling instrument
Based on the ichnographical measurement, typical points are selected for elevation measurement for design and calculation of fish ponds and earthwork.
At the practical site, several points are selected according to the topographical features. Elevation should be measured on the basis of the national standard sealevel point nearby. If there is none, a hypothetical one can be set as for a standard to establish an independent system. Then, from this point of origin onward, the elevation of each point can be measured.
Direction is set with a theodolite, and a tape measure for the length. Generally, every 20 m long there is a surveying point marked with numbered stakes which are called elevation control points, the number of which can be changeable in designing and construction of fish ponds based on the topographical features.
The leveling instrument is placed in a wide sighted view. The leveling staff will be set on the control points one after another and then, calculate out the elevation of each point.
Leveling measurement Table
|control pt.||staff No.||+||-|
Field Work Guide III
Design and layout of an integrated fish farm
Based on the practical work done with Guide I, II and the instructor's lecture, an integrated fish farm could be designed.
An integrated fish of fish-livestock-crop type with herbivorous fish as its major spp. (60% in fish yield)
An integrated fish farm with plankton-feeder as its dominant spp. (60% in fish yields)
(one of the two is chosen.)
Note: 1) Net yield is about 200 kg/mu.
2) The fine feeds needed by livestock are provided by the market.
3) Fry are provided by the market while the fingerlings are nurtured by the farm itself.
Figure out the area of fish ponds, the width of dyke crown, the position and structure of inflow and outflow canals, the amount of soil to be excavated and to be filled, the area of fodder crop land (including dyke crown and slopes); the positions of livestock and poultry houses and the number of them raised on the farm.
|Fig. 10–1 Plane figure of Xi Nan Fish Farm|
2. vegetable plots
3. green plots
4. yearling ponds
5. cow shed
6. experimental ponds
7. 2-year-old fingerling ponds
8. fodder grinder
9. grow-out ponds
10. fodder crop field
12 chicken house
13. office of livestockpoultry farming
15. overwintering ponds for Tilapia
16. brew house
17. office of aquaculture brigade
18. tool house
21. locks for flooding drainage
22. administration house
Fig. 10-2 Sectional view of flood control dykes
Fig. 10-3 Sketch map of pond structure
A. plane figure B. sectional view along line a - b
(after Science of the Culture of Freshwater Fish Spp. in China)
Fig. 10-4 Sectional view of inlet lock
(after Science of the Culture of Freshwater Fish Spp. in China)
Fig. 10-5 Sectional view of outlet lock
(after Science of the Culture of Freshwater Fish Spp. in China)
Fig. 10-6 Plane figure showing the inlet, outlet canals of the ponds
The English version of this teaching materials runs to nearly two hundred thousand words. Although the principles are not difficult to understand, it involves many disciplines such as biology (zoology or botany), ecology, physics, chemistry, economic and geodesy, etc. I have little talent and less learning while the editorial board laid a heavy burden on me to go all over the English Manuscripts. I do what I can to fulfil the revision task. Through days and nights of the 4 months, the materials are completely prepared now. The Centre put out the trial edition to solicit comments. The preliminary response from the participants of the 5th training course is good. I feel comfortable at this. Here, I want to express my gratitude to Ms. P. C. Spliethoff from Netherlands and other participants who gave us some suggestions and comments.
Because of less labour and limited time, this revision must have some errors and there is much room for improvement. I beseech a favour of comments from the compilers, translators and readers.
I am greatly indebted to Miss Ma Qian who typed most of the manuscripts, Mr. Qin Dong-zhu who assisted me in editing work especially on scientific aspect and my wife Li Pei-zhen who also assisted me in editing work esp. on English aspect. This teaching materials are compiled by the instructors concerned. I greatly appreciate their cooperation during the preparation. Also I' d like to thank the other translators who have made their efforts too. They are Mr. Yang Xian-guang (Chapter 1 & 3), Mr. Zhang Lai-fa (Chapter 2), Mr. Zhou En-hua (Chapter 4 & 5), Mr Chen Bao-hua (Chapter 6), Mr. Min Kuan-hong (Chapter 8 & 10). Chapter 7 was translated by myself and Chapter 9 was translated by unknown person but reviewed by Mr. Chen and Mr. Zhou.
I look forward to receiving further comments and suggestions.
Aug. 12, 1985