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赤纬

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赤道座標 赤纬 (英文 Declination ;縮寫為 Dec ;符號為 δ )是天文学中赤道座標系統中的两个坐标数据之一,另一个坐标数据是赤经。赤纬与地球上的纬度相似,是纬度在天球上的投影。赤纬的单位是度,更小的单位是“角分”和“角秒”,天赤道为0度,天北半球的赤纬度数为正数,天南半球的赤纬的度数为负数。天北极为+90°,天南极为-90°。值得注意的是正号也必须标明。 例如,织女星的确切赤纬(曆元2000.0)为+38°47'01"。 在观测者天顶的赤纬与該觀測地的纬度相同。 目录 1 赤纬的变化 1.1 太阳 1.2 月球 1.3 恒星 2 参见 赤纬的变化 随著时间的变化,由于天体运动和地轴变化,天体的赤纬不是固定的數值,而是不断变化的。极星的赤纬为+90°或-90°。假如观测者的纬度为 l{displaystyle l} 的话,则赤纬高于 90{displaystyle 90} ° − l{displaystyle -l} 的天体终日不落于地平线下。这样的天体称为拱极星座。终日不落的太阳称为午夜太阳。 太阳 太阳的赤纬等于太阳入射光与地球赤道之间的角度,由于地球自转轴与公转平面之间的角度基本不变,因此太阳的赤纬随季节不同而有周期性变化,变化的周期等于地球的公转周期,即一年。 太阳赤纬的最高度数为23°26',夏至时太阳的赤纬为+23°26',冬至时太阳的赤纬为-23°26'。春分和秋分时太阳的赤纬为0°。 由于地球公转轨道的偏心率非常低,可以看作是一个圆圈,太阳赤纬可用下面两个公式来计算: δ =− 23.44∘ ⋅ cos⁡ (360365⋅ (N+10)){displaystyle delta =-23.44^{circ }cdot cos left({frac {360}{365}}cdot left(N+10right)right)} 余弦中的角度的单位是角度 δ =− 23.44∘ ⋅ cos⁡ (2π 365⋅ (N+10)){displaystyle delta =-23.44^{circ }cdot cos left({frac {2pi }{365}}cdot left(N+1...

Mission San Buenaventura

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Mission San Buenaventura An exterior view of the restored chapel at Mission San Buenaventura in July, 2005. Location of Mission San Buenaventura in California Location 211 East Main Street Ventura, CA 93001 Coordinates 34°16′52″N 119°17′53″W  /  34.28111°N 119.29806°W  / 34.28111; -119.29806 Coordinates: 34°16′52″N 119°17′53″W  /  34.28111°N 119.29806°W  / 34.28111; -119.29806 Name as founded La Misión San Buenaventura [1] English translation The Mission of Saint Bonaventure Patron Saint Bonaventure [2] Nickname(s) "Mission by the Sea" [ citation needed ] Founding date March 31, 1782 [3] Founding priest(s) Junípero Serra [4] Founding Order Ninth [2] Military district Second [5] Native tribe(s) Spanish name(s) Chumash Ventureño Native place name(s) Mitsqanaqa'n [6] Baptisms 3,875 [7] Marriages 1,097 [7] Burials 3,150 [8] Secularized 1836 [2] Returned to the Church ...

How to implement search on encrypted database fields

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up vote 1 down vote favorite Iam Using PHP & MySql for my web application. I have a requirement where I need to encrypt user specific information, say name & email_id. $name = "Kevin John"; $encryptionMethod = "AES-256-CBC"; $secretHash = "25c6c7ff35b8879b151f2136cd13574"; $enc_name = openssl_encrypt($textToEncrypt, $encryptionMethod, $secretHash); Iam storing this encrypted name in my database. But the real problem is that I need to search the users based on their name.For example:- $qry = "select * from users where name like %john%"; Any suggestion appreciated php mysql search encryption share | improve this question ...